Annual/Termination Reports:

[11/15/2007] [11/17/2008] [03/02/2011] [02/22/2022]

Report Information

Participants

Administrative Advisor Michael Harrington (Colorado), committee members George Bailey (Oregon State University), Len Bjeldanes (University of California, Berkeley), Roger Coulombe (Utah State University), Mike Denison (University of California, Davis) Mendel Friedman (USDA-WRRC Albany, CA), Bill Helferich (University of Illinois), Pratiba Nerurkar (University of Hawaii), Jim Pestka (Michigan State University), Ron Riley (USDA-ARS Athens, GA)

Brief Summary of Minutes

Annual meeting of the technical committee, October 4-5, 2007 Calistoga, CA

The annual meeting was called to order at 0800 Thursday morning, October 4th.

Advisor Michael Harrington provided a report on the current status of USDA funding and new initiatives within USDA for FY 2008. He reported that funding for food safety and the National Research Initiative were in good shape in the proposed 2008 budget. He also discussed possible funding for the W2122 group's collaborative research through the CSREES "National Integrated Food Safety Initiative" which will emphasize multidisciplinary teams from multiple states and/or institutions.

After these initial items, the annual reports were given.

The regular business portion of the meeting commenced Friday morning at 0830. Hawaii was selected as the site for the 2008 meeting and it was agreed that the 2008 meeting would meet Thursday and Friday the 2nd week in October. The agreed days were Thursday and Friday the 9th and 10th of October with arrival on Wednesday 8 October. For 2008, Pratiba Nerurkar (University of Hawaii) would serve as Secretary, Mike Denison (University of California, Davis as Chair-elect, and Bill Helferich (University of Illinois) as Chair. The responsibilities of the Secretary, Chair-elect and Chair were discussed and it was agreed that the Chair writes the report and chairs the meeting, the Chair-elect organizes the next years meeting working closely with the local host and also assists the Chair in writing the report, the Secretary writes the minutes. Submission of the Report and the minutes are the responsibility of the Chair and the Secretary. The meeting was adjourned at around 1200 on 7 October.

Accomplishments

<br /> OBJECTIVE 1. Consumption of food-borne bioactive compounds can protect against human diseases such as cancer, inflammation, birth defects, and microbial infection. We will determine the mechanisms by which selected compounds exert their protective action.<br /> <br /> <br /> A high affinity CYP1A5 was cloned from turkey liver with high AFBO formation activity. Subsequently a CYP3A4 homologue, CYP3A37 (Genbank DQ450083) was amplified and cloned with 76% sequence identity to human 3A4 and 97% identity to chicken CYP3A37. A truncated construct of the turkey CYP3A37 gene was expressed in Escherichia coli competent cells. The expressed protein metabolized AFB1 to form two metabolites. Comparing the kinetic parameters with those previously reported for CYP1A5, it appears that CYP3A37 has greater activity toward AFB1 epoxidation. Two GST enzymes were also cloned from turkeys. A study with dietary BHT showed that in turkeys fed BHT plus AFB1 that the BHT-fed turkeys had significantly less aflatoxin B1 in tissues and that the BHT levels in the tissues were substantially below U.S. FDA guidelines (Utah State University). <br /> <br /> <br /> Studies are ongoing to identify and characterize natural products or derivatives of natural products with therapeutic applications whose mechanisms of action are mediated via intracellular ligand-dependent nuclear receptor signaling systems (University of California, Davis). The emphasis has been on chemicals that specifically interact with and affect the function of the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR); specifically, analysis of natural and synthetic flavonoids for their ability to activate the AhR and ER signaling pathways using our recombinant cell lines. Several compounds were identified that appear to be relatively potent/efficacious activators of the ER, the bulk of the compounds were inactive. Interestingly, a large number of these chemicals could activate/inhibit the AhR signal tranduction pathway. We have also examined the ability of a number of these chemicals to inhibit proliferation of human liver (HepG2) cells or breast cancer (T47D) cells and have found that those chemicals that are agonists of the AhR could inhibit cell proliferation. Several of these chemicals will be examined for their functional chemotherapeutic activity in mice in vivo and in cancer cell systems in collaboration with Bill Helferich (University of IL) and Len Bjeldanes (University of California, Berkeley). We have begun a collaboration with Dr. Coulombe at UT to examine the functional activity of the AhR in turkey hepatic cytosolic samples we have obtained. <br /> <br /> <br /> Consumption of the n-3 polyunsaturated fat docosahexaenoic acid (DHA) was found to modulate the mucosal immune response to enteric infection with reovirus, a model intestinal pathogen. Mice were fed with either control diet or diet high in DHA-enriched fish oil for 4 wk and then gavaged with reovirus. Reovirus-specific IgA antibody was first detectable in the feces of mice fed control diet at 6 d post infection (PI) and was further elevated at 8 and 10 d. IgA responses in DHA-fed mice were similar at 6 and 8 d PI but greater at 10 d PI. Both reovirus-specific serum IgA and IgG2a were comparably induced in mice fed control or DHA diets. While both groups carried similar numbers of reovirus plaque-forming units (PFU) per intestine, DHA-fed mice shed nearly 10 times more viral RNA than control mice in feces at 2, 4, and 6 d PI. However, viral RNA was not detectable in either group at 8 and 10 d. Taken together, these data suggest that DHA consumption did not markedly alter mucosal or systemic immunoglobulin responses to reovirus and only slightly delayed clearance of the virus from the gastrointestinal tract (Michigan State University).<br /> <br /> <br /> Bitter melon (BM) is widely cultivated in Asia, East-Africa and South America and extensively used in folk medicines as a remedy for diabetes and its complications. We have recently demonstrated that BM juice (BMJ) reduces weight gain in mice fed a high-fat-diet (HFD) containing 58% fat. In our studies, BMJ also improved diabetes (fasting glucose and glucose and insulin tolerance) in these mice fed HFD as well as reduced triglycerides and the bad cholesterol (very low density lipoproteins, VLDL; low density lipoproteins, LDL) in the liver and blood of these HFD-fed mice. We further demonstrated that reduction in apolipoprotein B (apoB) was possibly due to BMs insulin-mimetic mechanisms through phosphorylation of insulin receptor and its down-stream targets (University of Hawaii).<br /> <br /> <br /> OBJECTIVE 2. Food-borne toxins and carcinogens are present per se or are induced by processing, preparation, and other post-harvest steps. We will identify mechanisms of action and develop biomarkers of natural and induced toxicants in food for human risk assessment and disease prevention. <br /> <br /> <br /> Little is known regarding the pharmacokinetics of AFB1 uptake, distribution, and elimination in humans. To examine chlorophyll chemopreventive mechanisms in humans, we have used IRB approved ultra-low dose 14C-AFB1 to assess these parameters in human volunteers. AFB1 was given on an empty stomach by capsule, and serum and urine samples were collected over 72 hours and sent to Lawrence Livermore for 14C determination by accelerator mass spectrometry. Although statistical analysis is not completed, the data provide convincing evidence that both CHL and Chl can significantly lower urinary excretion of aflatoxins in one or more volunteers, and alter plasma pharmacokinetic parameters for AFB1 uptake and disposition. These results provide the most complete pharmacokinetic analysis ever conducted for AFB1 in humans, and the first evidence that natural chlorophyll can reduce systemic uptake of AFB1 from the GI tract in humans (Oregon State University). <br /> <br /> <br /> Avlimil, a dietary supplement containing 11 different botanicals was shown to act as an estrogen or anti-estrogen depending on the dietary dosage. An extract of Avlimil was tested for its estrogenic and anti-estrogenic effects on the growth of MCF-7 cells in vitro. We observed in vitro that the DMSO extract of Avlimil (0.1-50 mg/mL media) increased MCF-7 cell proliferation, and Avlimil DMSO extract (at 100 mg/mL) inhibited proliferation in a dose-dependent manner. Avlimil and some constituents (black cohosh root and licorice root supplements) were fractionated by using sequential solvent extraction (hexane, ethyl acetate, and methanol) and the activity of the fractions were monitored by effects on the growth of MCF-7 cells. Depending on dosage (0.1  100 mg/mL media) both stimulatory and inhibitory effects of the extracts on the growth of MCF-7 cell were observed. The effect of dietary Avlimil at dosages approximating human intake was evaluated using a xenograft model, in which ovariectomized mice implanted with MCF-7 cells were fed diets containing 500 ppm or 1000 ppm Avlimil for 16 weeks. Dietary Avlimil at 500 ppm stimulated MCF-7 tumors, but Avlimil at 1000 ppm had no apparent effect on the growth of MCF-7 tumors, presumably because of combined estrogenic and anti-estrogenic effects. The observation of stimulated tumor growth in the absence of uterine wet weight gains suggest that estrogenic effect of Avlimil we observed may be dosage- and target tissue-specific, and that Avlimil may not be safe for women with estrogen-dependent breast cancer. The different biological effects of Avlimil extracts and different concentration dependencies warrant further dose-response studies, especially at lower dietary concentrations to determine dosages that have estrogenic effects (University of Illinois). <br /> <br /> <br /> The effects of deoxynivalenol (DON) on Bip (glucose-regulated protein [GRP]-78) and related signaling pathways were examined in the macrophage. Bip protein expression was markedly decreased in mouse peritoneal macrophages following incubation with DON (500 ng/ml) for 1 h and was almost completely undetectable from 6 to 24 h. Incubation with DON was found to markedly increase inositol-requiring enzyme -1, X-box-binding protein -1 and the unfolded protein response (UPR) sensor (ATF-6) protein expression within 1 h. Pretreatment of macrophages with an inhibitor of double-stranded RNA activated protein kinase (PKR) blocked expression of both IRE1 and IL-6. These data suggest that DON-induced IL-6 expression is PKR-dependent and might be mediated by Bip degradation and an ensuing UPR (Michigan State University).<br /> <br /> <br /> The capacities of ricin and DON to cleave 28S ribosomal RNA (rRNA) were compared. In a cell-free model, exposure to ricin at 320 ng/ml for 30 min depurinated yeast 28S rRNA. In contrast, DON at < 4000 ng/ml did not directly depurinate yeast 28S rRNA after 1 h incubation. Incubation of RAW 264.7 macrophages with either 20 to 320ng/ml of ricin or 250 to 5000 ng/ml of DON for 6 h generated 28S rRNA-specific products consistent with cleavage sites 1.2 and 1.5 kilonucleotide (knt) from the 3 terminal end of mouse 28S rRNA. When ricin-treated RAW 264.7 cells were analyzed by primer extension, two cleavage sites were identified, one (A4325) at the ricin/sarcin loop, and another (C4037) at the center of the peptidyl transferase. Although similar DON exposure did not damage the ricin/sarcin loop, the treatment caused cleavage of 28S rRNA at two sites (C4037 and A3560) in the peptidyl transferase center, where anisomycin is known to act, and at a third site (G3656). RNase activity as well as RNase 6 and RNase L mRNAs were increased in RAW 264.7 cells that were incubated with ricin (> 20 ng/ml) or DON (>125 ng/ml). These data suggest that ricin cleaves 28S rRNA directly and indirectly via RNase induction whereas DON induces 28S rRNA cleavage only by indirect induction of RNases (Michigan State University). <br /> <br /> <br /> A study in collaboration with Janee Gelineau van Waes (University of Nebraska) was undertaken to see if sphinganine 1-phosphate and its synthetic analog FTY 1-phosphate were elevated in blood, plasma and other tissues of SWV and LMBc mice treated with FB (ip injection) or FTY (gavage). The results show that in FB treated mice the levels of sphingoid bases and sphingoid base 1-phosphates are significantly elevated in blood, plasma and decidua. In the blood and plasma of FB treated mice the amount of Sa and Sa-1P were significantly greater in the LMBc mice as was the NTD incidence compared to the SWV mice. In the FTY treated animals FTY 1-P was significantly elevated in plasma and decidua in both strains although the levels in LMBc mice were greater than in the SWV as was the incidence of NTD. The results suggest that elevation in S1P receptor agonists may be risk factors for NTD (USDA-ARS, Athens).<br /> <br /> <br /> In collaboration with scientists in Guatemala and Duke University approximately 100 maize samples from local markets in highland and lowland Departments in Guatemala were analyzed for fumonisins. The results provide additional strong support for our hypothesis that lowland maize is the major source of exposure to fumonisins (an inhibitor of ceramide synthase and folate transport) in the highlands where NTD incidence is very high (USDA-ARS, Athens). <br /> <br /> <br /> In breast cancer MCF-7 cells the AhR-ligands B[a]P and TCDD stimulated transcription activity of a 3.9 Kb COX-2 promoter fragment and an AhR-responsive construct containing an enhancer element from the CYP1A1 promoter linked to an array of four XREs (pCYP1A1-4XRE). The TCDD-dependent induction of COX-2 transcription is mediated by two XRE sites (XRE-1 and XRE-2) which are targets for binding by the AhR. Both the stimulation by TCDD of COX-2 transcription activity and the binding of the AhR to the two XREs harbored in the 3.9kb COX-2 promoter fragment are repressed by cotreatment with a mixture of isomers of the dietary lipid conjugated linoleic acid (CLA) and selected isomers (t10,c12-CLA>c9,t11-CLA). The binding of the AhR to COX-2 and CYP1A1 oligonucleotides containing a consensus XRE was counteracted by synthetic (3-methoxy-4-naphthoflavone) and natural (resveratrol) AhR antagonists. Thes results show that the AhR directly participates in the trans-activation of the COX-2 promoter and that this mechanism is a potential target for dietary agents in the prophylactic management against stimulation of COX-2 expression by AhR agonists (University of Arizona).<br /> <br /> <br /> OBJECTIVE 3. Selected classes of bioactive compounds show potential for beneficial or adverse effects on human health. We will discover bioactive compounds that have beneficial or adverse effects on human health. <br /> <br /> <br /> The effects of 3,3-diindolymethane (DIM) on hypoxia signaling in cultured tumor cells was examined. It was found that DIM reduces levels of HIF-1a and HIF-1 activity in hypoxic cultured human cancer cells. DIM reduced the level of HIF-1a in hypoxic cells by increasing the rate of the prolyl hydroxylase- and proteosome-mediated degradation of HIF-1a, and by decreasing the rate of HIF-1a transcription. Using enzyme kinetics studies, we established that DIM binds to the oligomycin binding site on the F1 transmembrane component on mitochondrial F1F0-ATPase. The contributions of the resulting increases in levels of ROS and O2 in hypoxic cells to the inhibitory effects of DIM on HIF-1a expression are not fully clear. These studies are the first to show that DIM can decrease the accumulation and activity of the key angiogenesis regulatory factor, HIF-1a, in hypoxic tumor cells (University of California, Berkeley). <br /> <br /> <br /> N-Alkoxy derivatization of indole-3-carbinol (I3C) increases the efficacy of the G1 cell cycle arrest of human MCF-7 breast cancer cells. Structure-activity relationships of I3C that mediate this anti-proliferative response were investigated using synthetic and natural I3C derivatives that contain substitutions at the indole nitrogen. In indole-treated human MCF-7 breast cancer cells, dose response experiments examining the inhibition of DNA synthesis and G1 cell cycle arrest revealed a striking increase in efficacy of the N-alkoxy I3C derivatives that is significantly enhanced by the presence of increasing carbon lengths of the N-alkoxy substituents. Compared to I3C, the half maximal growth arrest responses occurred at 23-fold lower indole concentration for N-methoxy-I3C, 50-fold lower concentration for N-ethoxy-I3C, 217-fold lower concentration for N-propoxy-I3C, and 470-fold lower concentration for N-butoxy-I3C. At these lower concentrations, each of the N-alkoxy substituted compounds induced the characteristic I3C response in that CDK6 gene expression, CDK6 promoter activity, and CDK2 specific enzymatic activity for its retinoblastoma protein substrate were strongly down-regulated. In contrast to these effects, 3-methoxymethylindole and 3-ethoxymethylindole were approximately as active as I3C in the cell cycle arrest response. This study establishes the first I3C structure activity relationship for cytostatic activities, and implicates I3C-based N-alkoxy derivatives as a novel class of potentially more potent experimental therapeutics for breast cancer (University of California, Berkeley). <br /> <br /> <br /> Bitter melon juice was analyzed at the Agricultural Diagnostic Center (CTAHR, Honolulu, HI) for its physical properties and mineral contents. In our laboratory we have undertaken to identify the bioactive compounds in whole BM juice, using HPLC. We have so far identified various polyphenols and flavanoids in BMJ. We have also undertaken bioactivity guided fractionation of BMJ by fractionating BMJ using methanol, ethyl acetate, butanol and aqueous fractions (University of Hawaii). <br /> <br /> <br /> <br /> OBJECTIVE 4. Modifying foods is an increasingly important strategy to improve nutrition and safety. Therefore, we will improve food safety by developing approaches to increase beneficial or decrease adverse effects of bioactive food constituents and microbial contaminants. <br /> <br /> <br /> <br /> The control of Clostridium perfringens spores by green tea leaf extracts containing low (GTL) and high (GTE) catechin levels during abusive cooling of meats was investigated. The treatment protocol resulted in significant increases in germination and outgrowth of C. perfringens in the meats. At 2% GTE, significant (p < 0.05) inhibition of growth occurred at all chill rates for cooked ground beef, chicken or pork. These results suggest that widely consumed catechins from green tea can reduce the potential risk of C. perfringens spore germination and outgrowth during abusive cooling of ground beef, chicken, or pork (USDA-ARS, Albany). <br /> <br /> <br /> The bactericidal activity of several antimicrobial wine recipes was examined. The recipes consisting of red and white wine extracts of oregano leaves with added garlic juice and oregano oil were tested against the following foodborne pathogens: Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica. It was found that several combinations of the naturally occurring plant-derived ingredients rapidly inactivated the four pathogens. Polyphenolic compounds isolated by chromatography from red wine exhibited high antimicrobial activity at nanogram levels against two strains of Bacillus cereus. Wines appear to be useful solvents for plant-derived antimicrobial formulations to reduce pathogens in foods (USDA-ARS, Albany). <br /> <br /> <br /> HPLC and LC/MS methods were developed to be used in studies to measure the distribution of piperine isomers in four commercial ground black peppers, two from the United States and the other two from Korea after exposure to fluorescent light. The results establish the utility of the HPLC method for simultaneous analysis of the four isomers both in pure form and in black pepper extracts (USDA-ARS, Albany). <br /> <br /> <br /> A Southern analysis of banana strains of Fusarium verticillioides did not detect genes in the fumonisin biosynthetic gene (FUM) cluster but did detect genes flanking the cluster. The flanking genes included portions of FUM21 and FUM19, which are the terminal genes at each end of the FUM cluster. PCR analysis confirmed absence of the cluster in all banana strains examined. Cotransformation of a banana strain with two overlapping cosmids, which together contain the entire FUM cluster, yielded fumonisin-producing transformants that were pathogenic on maize seedlings. Together, the data indicate that fumonisin production may have been lost by deletion of the FUM cluster in the banana population of F. verticillioides but that fumonisin production could be restored by molecular genetic complementation. The results also indicate that fumonisin production by F. verticillioides is required for development of foliar disease symptoms on maize seedlings (USDA-ARS, Athens).<br /> <br /> <br /> Studies were conducted to determine the accumulation of fumonisins and sphingoid bases and their metabolites in leaf tissue of various maize cultivars. A simple and rapid method for analysis of fumonisins, sphingoid bases and sphingoid base-1-phosphates in maize leaf tissue was developed. In preliminary studies testing the method it was found that varieties of maize resistant to the mold Fusarium verticillioides- induced seedling disease did not accumulate high levels of fumonisins or sphingolipid metabolites in leaf tissue. This was not the case in the susceptible variety suggesting that both sphingolipid metabolism and fumonisin accumulation were critical for disease development in maize seedlings. Only one structural form of fumonisin (FB1) accumulated in leaf tissue (USDA-ARS, Athens). <br /> <br /> <br /> A study was done to determine how the presence of maize matrix during nixtamalization (cooking in alkaline water) affects fumonisin concentration and in vivo toxicity (rodent bioassay). Mechanism-based biomarkers of exposure were used to confirm the toxicity findings. The data from this model study indicate that the presence of maize matrix during nixtamalization reduces bioavailability and toxicity beyond that achieved by nixtamalization in the absence of the maize matrix. These results confirm that the nixtamalization process significantly reduces the risk of fumonisin exposure and that methods to optimize the nixtamalization process can be developed using mechanism-based toxicity assessment. <br />

Publications

Allred, C. A., Allred, K.F., Ju, Y.H., Doerge, D.R., and Helferich, W.G. (2004) Soy processing influences growth of estrogen-dependent breast cancer tumors. Carcinogenesis 25(9):1649-1657.<br /> <br /> <br /> Allred, C.A., Allred, K.F., Ju, Y.H., Doerge, D.R., Schantz, S., Korol, D., and Helferich, W.G. (2004) Dietary genistein results in larger MNU-induced, estrogen-dependent mammary tumors following ovariectomy of Sprague-Dawley rats. Carcinogenesis 25:211-218.<br /> <br /> <br /> Allred, C.D., Twaddle, N.C., Allred, K.F., Churchwell, M.I., Ju, Y.H., Helferich, W.G., and Doerge, D.R. (2005) Soy processing affects metabolism and disposition of dietary isoflavones in ovariectomized Balb/c mice. J. Agric. and Food Chem. 53(22):8542-8550.<br /> <br /> <br /> Carter, O., Wang, R., Dashwood, W.M., Orner, G.A., Fisher, K.A., Lohr, C.V., Pereira, C.B., Bailey, G.S., Williams, D.E. and Dashwood, R.H. (2007) Comparisons of white tea, green tea, epigallocatechin-3-gallate and caffeine as inhibitors of PhIP-induced colonic aberrant crypts. Nutr. Cancer 58(1), 1-6.<br /> <br /> <br /> Choi, S. P., Kang, M. Y., Koh, H. J., Nam, S. H., and Friedman, M. (2007) Anti-allergic activities of pigmented rice bran extracts in cell assays. J. Food Sci. 72 (9). S719-S727. <br /> <br /> <br /> Coulombe, R.A. and Yip, S.M.. (2007) Heterologous expression of a cytochrome P450 from turkey liver that activates aflatoxin B1. In Poisonous Plants: Global Research and Solutions (K. Panter, T. Wierenga, J. Phister, eds.) CAB International, London. pp. 82-88.<br /> <br /> DeAssis, S, Wang, M, Goel, S, Foxworth, A., Helferich, W.G. and Hilakivi-Clarke, L. (2006). Increased carcinogen-induced mammary tumorigenesis and activation of MAPK in obese (fa/fa) Zucker rats exposed to pregnancy hormonal environment. J. Nutr. 136(4):998-1004.<br /> <br /> <br /> Degner S.C., M.Q. Kemp, Bowden GT, and Romagnolo, D.F. (2006) Conjugated Linoleic Acid AttenuatesCyclooxygenase-2 Transcriptional Activity via an Anti-AP-1 Mechanism in MCF-7 Breast Cancer Cells. J. Nutr.136:421-427.<br /> <br /> <br /> Degner SC, Kemp MQ, Hockings JK, and Romagnolo,D.F. (2007) Cyclooxygenase-2 promoter activation by the aromatic hydrocarbon receptor in breast cancer MCF-7 cells: repressive effects of conjugated linoleic acid. Nutr Cancer. 59(2):248-57.<br /> <br /> <br /> Friedman, M. (2007) Overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas. Mol. Nutr. Food Res. 51 (1): 116-134.<br /> <br /> <br /> Friedman, M., Henika, P. R., Levin, C. E., and Mandrell, R. E. (2007) Recipes for antimicrobial wine marinades against Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica. J. Food Sci. 72 (6): M207-M213. <br /> <br /> <br /> Friedman, M., Mackey, B. E., Kim, H. J., Lee, I. S., Lee, K. R., Lee, S. U., Kozukue, E., and Kozukue, N. (2007) Structure-activity relationships of tea compounds against human cancer cells. J. Agric. Food Chem. 55 (2): 243-253.<br /> <br /> <br /> <br /> Friedman, M., McQuistan, T., Hendricks, J. D., Pereira, C., and Bailey, G. S. (2007) Protective effect of dietary tomatine against dibenzo[a,l]pyrene (DBP)-induced liver and stomach tumors in rainbow trout. Mol. Nutr. Food Res. 51 (12), 185-1491.<br /> <br /> <br /> Gray, J. S., and Pestka, J. J. (2007). Transcriptional regulation of deoxynivalenol-induced IL-8 expression in human monocytes. Toxicol. Sci. 99(2), 502-511.<br /> <br /> <br /> Guarisco, J.A., Hall, J.O., and R.A. Coulombe, Jr. (2007) Butylated hydroxytoluene reduces aflatoxin B1 bioavailability and hepatic adduct formation in turkeys. In Poisonous Plants: Global Research and Solutions (K. Panter, T. Wierenga, J. Phister, eds.) CAB International, London. pp. 197-202.<br /> <br /> <br /> Heemstra, J. M., Kerrigan, S. A., Doerge, D. R., Helferich, W. G. and Boulanger, W. A. (2006) Total synthesis of (S)-equol. Org. Lett.Vol. 8, No. 24, 5441-5443.<br /> <br /> <br /> Hill, N.S., Schwarz, L.S., Dahleen, L.S., Neate, S.M., Horsley, R., Glenn, A.E., and O'Donnell, K. (2006). ELISA analysis for Fusarium in barley: Development of methodology and field assessment. Crop Science 46: 2636-2642.<br /> <br /> <br /> Hockings J.K., Thorne P.A., Kemp M.Q., Morgan S.S., Selmin O. and Romagnolo D.F. (2006) The Ligand Status of the Aromatic Hydrocarbon Receptor Modulates Transcriptional Activation of BRCA-1 Promoter by Estrogen. Cancer Research, 66:1-9.<br /> <br /> <br /> Hsu JC, Dev A, Wing A, Brew CT, Bjeldanes LF and Firestone GL. (2006) Indole-3-carbinol mediated cell cycle arrest of LNCaP human prostate cancer cells requires the induced production of activated p53 tumor suppressor protein. Biochem Pharmacol. 72(12):1714-23.<br /> <br /> <br /> Islam, Z., Amuzie, C. J., Harkema, J. R., and Pestka, J. J. (2007). Neurotoxicity and inflammation in the nasal airways of mice exposed to the macrocyclic trichothecene mycotoxin roridin a: kinetics and potentiation by bacterial lipopolysaccharide coexposure. Toxicol. Sci. 98(2), 526-541.<br /> <br /> <br /> Islam, Z., Harkema, J. R., and Pestka, J. J. (2006). Satratoxin G from the black mold Stachybotrys chartarum evokes olfactory sensory neuron loss and inflammation in the murine nose and brain. Environ. Health Perspect. 114(7), 1099-1107.<br /> <br /> <br /> Ju, Y. H., Fultz J, Allred K.F., Doerge D.R., and Helferich, W.G. (2006) Effects Of Dietary Daidzein And Its Metabolite, Equol, At Physiological Concentrations On The Growth Of Estrogen-Dependent Human Breast Cancer (MCF-7) Tumor Implanted In Ovariectomized Athymic Mice. Carcinogenesis 27(4):856-63.<br /> <br /> <br /> Ju, Y.H., Allred, K.F., Allred, C.D., and Helferich, W.G., (2006) Genistein Stimulates Growth of Human Breast Cancer Cells in a Novel, Postmenopausal Animal Model, with Low Plasma Estradiol Concentrations. Carcinogenesis 27(6):1292-9<br /> <br /> <br /> Ju, Y.H., Clausen, L.M., Almada, A.L., and Helferich, W.G. (2004) Beta$-sitosterol, $Beta-sitosterol glucoside, and a mixture of $Beta- sitosterol and $-sitosterol glucoside modulate the growth of estrogen-responsive breast cancer cells in vitro and in ovariectomized athymic mice. J. Nutr. 134(5):1145-51.<br /> <br /> <br /> Juneja, V. K. and Friedman, M. (2007) Carvacrol, cinnamaldehyde, oregano oil, and thymol inhibit Clostridium perfringens spore germination and outgrowth in ground turkey during chilling. J. Food Protection. 70 (1): 218-222.<br /> <br /> <br /> Juneja, V. K., Bari, M. L., Inatsu, Y., Kawamoto, S., and Friedman, M. (2007) Control of Clostridium perfringens spores by green tea leaf extracts during cooling of cooked ground beef, chicken, and pork. J. Food Protection 70 (6): 1429-1433.<br /> <br /> <br /> Kemp, M.Q., Thorne, P.A., Liu, W., Kane, M.D., Selmin, O. and Romagnolo, D.F. (2006) Expression Profiles Induced by Polycyclic Aromatic Hydrocarbons: The Transferrin Receptor as an Aromatic Hydrocarbon Receptor-inducible Biomarker of Exposure. Environmental Molecular Mutagenesis 47:518-526.<br /> <br /> <br /> Kirui, G. K., Misra, A. K., Olanya, O. M., Friedman, M., El-Bedewy, R., and Ewell, P. T. (2007) Glycoalkaloid content of some superior potato (Solanum tuberosum L) clones and commercial cultivars. Archiv. Phytopathology and Plant Protection. Online (1): 1 - 11. 2007.<br /> <br /> <br /> Kozukue, N., Park, M.-S., Choi, S.-H., Lee, S.-U., Ohnishi-Kameyama, M., Levin, C. E., and Friedman, M. (2007) Kinetics of light-induced cis-trans isomerization of four piperines and their levels in ground black peppers as determined by HPLC and LC/MS. J. Agric. Food Chem. 55 (17): 7131-7139.<br /> <br /> <br /> Li, M., Harkema, J. R., Cuff, C. F., and Pestka, J. J. (2007). Deoxynivalenol exacerbates viral bronchopneumonia induced by respiratory reovirus infection. Toxicol. Sci. 95(2), 412-426.<br /> <br /> <br /> Li, M., Harkema, J. R., Islam, Z., Cuff, C. F., and Pestka, J. J. (2006). T-2 toxin impairs murine immune response to respiratory reovirus and exacerbates viral bronchiolitis. Toxicol. Appl. Pharmacol. 217(1), 76-85.<br /> <br /> <br /> Mbandi, E., and Pestka, J. J. (2006). Deoxynivalenol and satratoxin G potentiate proinflammatory cytokine and macrophage inhibitory protein 2 induction by Listeria and Salmonella in the macrophage. J. Food Prot. 69(6), 1334-1339.<br /> <br /> <br /> Morgavi, D.P. and Riley, R.T. (2007) Fusarium and their toxins: Mycology, occurrence, toxicity, control and economic impact. Animal Feed Science and Technology 137: 199-200.<br /> <br /> <br /> Morgavi, D.P. and Riley, R.T. (2007) An historical overview of field disease outbreaks known or suspected to be caused by consumption of feeds contaminated with Fusarium toxins. Animal Feed Science and Technology 137: 201-212.<br /> <br /> <br /> Muthyala, R.S., Ju, Y.H., Sheng, S., Williams, L.D., Doerge, D.R., Katzenellenbogen, B.S., Helferich, W.G., and Katzenellenbogen, J.A. (2004) Equol, a natural estrogenic metabolite from soy isoflavones: convenient synthesis and resolution of R- and S-equol and their biological activity through the estrogen receptors alpha and beta. Bioorganic & Medicinal Chemistry 12(6): 1559-567.<br /> <br /> <br /> <br /> Nerurkar, P.V., Pearson, L., Efird, J., Adeli, K., Theriault, A.. and Nerurkar, V.R. (2005) Inhibition of microsomal triglyceride transfer protein (MTP) gene expression and ApoB secretion by bitter melon in HepG2 Cells. J. Nutr. 135: 702-706.<br /> <br /> <br /> <br /> Nerurkar, P.V., Lee, Y.K., Linden, E.H., Lim, S., Pearson, L., Frank, J. and Nerurkar, V.R. (2006) Lipid lowering effects of Momordica charantia (bitter melon) on cellular lipids and apolipoproteins in protease inhibitor-treated human hepatoma cells. Br J Pharmacol. 148(8):1156-64.<br /> <br /> <br /> <br /> Putt, K.S., Chen, G.W., Pearson, J.M., Sandhorst, J.S., Hoagland, M.S., Kwon, J.T., Hwang, S.K., Jin, H., Churchwell, M.I., Cho, M.H., Doerge, D.R., Helferich, W.G. and Hergenrother, P.J. (2006) Small-molecule activation of procaspase-3 to caspase-3 as a personalized anticancer strategy. Nat Chem Biol. 2, 10, 543-550.<br /> <br /> <br /> Reed, K.M., Mendoza, K.M. and R. A. Coulombe, Jr. (2007). Structure and genetic mapping of the Cytochrome P4501A5 gene in the turkey (Meleagris gallopavo). Cytogenetics and Genome Research 116: 104-109<br /> <br /> <br /> Rojas-Graü, M. A., Olsen, C., Avena-Bustillos, R. J., Friedman, M., Henika, P. R., Martin-Belloso, O., and McHugh, T. H. (2007) Effects of plant essential oils and oil compounds on physicochemical and antimicrobial properties of alginate-apple puree edible film. J. Food Engineering 81 (3): 634-641.<br /> <br /> <br /> Romagnolo, D.F., S.C. Degner, M.Q. Kemp, J.K. Hockings, and O. Selmin. (2006) Role of dietary xenobiotics-gene interactions in carcinogenesis: protective effects of nutritional factors. Current Nutrition Review&Food Science. 2:205-214.<br /> <br /> <br /> Seiferlein, M., Humpf, H.-U., Voss, K. A., Cameron Sullards, M., Allegood, J. C., Wang, E. and Merrill, Jr., A. H. 2007. Hydrolyzed fumonisins HFB1 and HFB2 are acylated in vitro and in vivo by ceramide synthase for form cytotoxic N-acyl-metabolites. Molecular Nutrition and Food Research. 51: 1120-1130.<br /> <br /> <br /> Selvaraj V, Zakroczymski MA, Naaz A, Mukai M, Ju YH, Doerge DR, Katzenellenbogen JA, Helferich WG, Cooke PS (2004) Estrogenicity of the isoflavone metabolite equol on reproductive and non-reproductive organs in mice. Biology of Reproduction 71:966-972.<br /> <br /> <br /> Shi, Y., and Pestka, J. J. (2006). Attenuation of mycotoxin-induced IgA nephropathy by eicosapentaenoic acid in the mouse: dose response and relation to IL-6 expression. J. Nutr. Biochem. 17(10), 697-706.<br /> <br /> <br /> Sundar SN, Kerekatte V, Equinozio CN, Doan VB, Bjeldanes LF and Firestone GL. (2006) Indole-3-carbinol selectively uncouples expression and activity of estrogen receptor subtypes in human breast cancer cells. Mol Endocrinol. 20(12):3070-82.<br /> <br /> <br /> Suzuki, H., Riley, R.T. and Sharma, R.P. (2007) Inducible nitric oxide has protective effect on fumonisin B1 hepatotoxicity in mice via modulation of sphingosine kinase. Toxicology 229: 42-53.<br /> <br /> <br /> Tilton, S.C., Hendricks, J.D., Orner, G.A., Pereira, C.B., Bailey, G.S., and Williams, D.E. (2007) Gene expression analysis during tumor enhancement by the dietary phytochemical, 3,3-diindolylmethane, in rainbow trout. Carcinogenesis 28:1589-1598.<br /> <br /> <br /> Van Vleet, T.R., Watterson, T.L., Klein, P.J., and R.A. Coulombe, Jr. (2006) Aflatoxin B1 alters the expression of p53 in cytochrome P450-expressing human lung cells. Toxicological Sciences. 89 (2), 399-407.<br /> <br /> <br /> Voss, K.A., Riley, R.T., Gelineau van Waes, J. (2007) Toxicity of fumonisins, mycotoxins from Fusarium verticillioides. In: Wilson, C.L., Editor. Microbial Food Contamination, 2nd Edition. Boca Raton, FL: CRC Press LLC, pp. 107-126.<br /> <br /> <br /> Voss, K.A., Smith, G.W. and Haschek, W. M. (2007) Fumonisins: toxicokinetics, mechanism of action and toxicity. Animal Feed Science and Technology 137: 299-325.<br /> <br /> <br /> Watterson, T.L., Sorenson, J., Martin, R., and R.A. Coulombe, Jr. (2007) Effects of PM2.5 Collected from Cache Valley Utah on Genes Associated with the Inflammatory Response in Human Lung Cells. J. Toxicol. Environ. Health 70:1731-1734.<br /> <br /> <br /> Williams, L.D., Glenn, A.E., Bacon, C.W., Zimeri, A.M., Smith, M.A. and Riley, R.T. 2007. Fumonisin disruption of ceramide biosynthesis in maize roots and the effects on plant development and Fusarium verticillioides-induced seedling disease. J. Agric. Food Chem. 55:2937-2946.<br /> <br /> <br /> Xue L, Pestka JJ, Li M, Firestone GL and Bjeldanes LF. (2007) 3,3'-Diindolylmethane stimulates murine immune function in vitro and in vivo. J Nutr Biochem. 2007 Aug 16; [Epub ahead of print]<br /> <br /> <br /> Yip, S.S.M. and R.A. Coulombe, Jr. (2006) Molecular cloning and expression of a novel cytochrome P450 from turkey liver with aflatoxin B1 metabolizing activity. Chem. Res. Toxicol. 19:30-37. <br />

Impact Statements

1. Modern, ultra-sensitive detection technology was used to provide the best data set ever produced on aflatoxin B1 pharmacokinetics in humans, and to demonstrate that natural chlorophyll and its derivative chlorophyllin can substantially reduce AFB1 uptake and distribution. These data will be invaluable to researchers in assessing risk from AFB1 exposure. In particular, our findings have enormous implications for people in parts of Asia and Africa, where as many as 10% of adults may die of aflatoxin-related liver cancer. For additional information contact George Bailey (541/737-3164; george.bailey@oregonstate.edu)
2. 3,3-Diindolylmethane (DIM) DIM was shown to inhibit hypoxia signaling which accounts for its antiangiogenic activity and provides a specific molecular target for further studies of it chemotherapeutic effects. The results support the notion that DIM is useful in the control of some cancers and are used by commercial interests to justify the sale of DIM as a supplement, and with considerable success. For additional information contact Leonard F. Bjeldanes (510-642-1601, lfb@nature.berkeley.edu)
3. The discovery of the structural basis for the cytostatic activities of indole-3-carbinol will stimulate the development of potentially more potent experimental therapeutics for breast cancer. For additional information contact Leonard F. Bjeldanes (510-642-1601, lfb@nature.berkeley.edu)
4. Antioxidants such as BHT reduce bioavailability, increase excretion, and reduce residues of AFB1 in turkey meat products, and therefore is a potential strategy to improve food safety. Finding chemorevention strategies in domestic food animals such as poultry will help American agriculture produce a safer product for consumers. For additional information contact Roger Coulombe (435-797-1598 rogerc@cc.usu.edu)
5. The recently cloned CYP1A5 from poultry that has high activity toward AFB1 bioactivation bears substantial homology to to human CYP1A2 which bioactivates many dietary carcinogens, such as AFB1. Thus, the turkey homologue can be considered as a model for a human CYP gene associated with cancer risk, and studies here can shed light on the molecular basis of cancer susceptibility in people. For additional information contact Roger Coulombe (435-797-1598 rogerc@cc.usu.edu)
6. A novel chemical was identified that is a specific antagonist for toxic AhR ligands like dioxin, but has little effect on the binding and activation by flavonoids. This novel antagonist has significant potential as a therapeutic agent to block the toxic effects of some AhR ligands, while allowing activation of the AhR and production of beneficial effects by nontoxic naturally occurring and synthetic AhR ligands. For additional information contact Mike Denison (530 752-3879, msdenison@ucdavis.edu)
7. The pungent compound piperine possesses several properties that are beneficial to human health but are sensitive to light. Because light may influence the nature, amounts, and biological effects of piperine isomers present, labeling of peppers and pepper-containing foods for piperine content would undoubtedly benefit consumers. For additional information contact Milton Friedman (510 559-5615 ; mfried@pw.usda.gov)
8. Estrogenic Dietary supplements are consumed by older women for a variety of reasons and in most cases without their physicians knowledge. It is possible that the estrogen like compounds in these supplements can stimulate growth of estrogen-dependent breast cancer by individuals. The findings presented here indicate that dietary supplements have complex mixtures and can have varied responses depending on the dosage. For additional information contact Bill Helferich (217-244-5414, helferic@uiuc.edu)
9. At least 47-million American are afflicted with metabolic syndrome (hypertension, type 2 diabetes and cardiovascular diseases). Studies in mice fed high fat diets with bitter melon juice showed improved fasting glucose and glucose and insulin tolerance as well as reduced triglycerides and very low density lipoproteins, VLDL and low density lipoproteins, LDL. These findings could lead to new dietary strategies for treatment or prevention of obesity-associated type 2 diabetes. For additional information contact Pratibha V. Nerurkar (pratibha@hawaii.edu).
10. Studies on omega-3 fatty acids will yield important new safety information regarding potential deleterious affects of n-3 PUFAs in tissue and will inform medical workers on the applicability of n-3 PUFA supplementation for prophylaxis/treatment of diseases that involve inflammatory gene induction. Collectively, these outcomes will impact human health by providing a scientific basis for generating sound health recommendations for important class of supplements consumed by 12 percent of U.S. adults. For additional information contact James Pestka (517-353-1709 pestka@msu.edu).
11. Mechanism-based strategies can now be developed for preventing and/or treating toxic effects in persons exposed to trichothecenes and ribotoxic chemicals in foods via natural contamination or as a result of deliberate use in chemical terrorism or warfare. Collectively, these outcomes will positively impact human health by providing a scientific basis for generating sound public health recommendations relative to exposure to this important class of toxins and appropriate remedial actions should exposure happen. For additional information contact James Pestka (517-353-1709 pestka@msu.edu).
12. Understanding the underlying mechanistic basis for NTD development in response to fumonisin exposure in mice will assist in predicting the risk in humans. The specific finding that lysophospholipid receptors may play a role in the induction of NTDs and that an S1PR ligand (Sa 1-P) is elevated in tissues of mouse strains susceptible to fumonisin-induced NTDs provides a plausible basis for development of a biomarker for assessing NTD risk in humans. For additional information contact Ronald T. Riley (706 546-3377 ron.riley@.ars.usda.gov).
13. The discovery that fumonisin is a pathogenicity factor in maize seedling disease and that only fumonisin B1 is accumulated in leaf tissue suggests that perhaps only a very few fumonisin compounds are of toxicological significance in both plants and animals. If proven correct, this discovery could greatly simplify the fumonisin risk assessment saving millions of taxpayer dollars since monitoring for exposure could be focused on only the fumonisin compounds that are accumulated. For additional information contact Ronald T. Riley (706 546-3377 ron.riley@.ars.usda.gov).
14. The aryl hydrocarbon receptor was shown to directly participate in the trans-activation of the COX-2 promoter. This mechanism is a potential target for dietary agents in the prophylactic management against stimulation of COX-2 expression by AhR agonists. For additional information contact Donato F Romagnolo (520-626-9108, donato@email.arizona.edu).

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Report Information

Participants

Committee members: Len Bjeldanes (University of California, Berkeley), Roger Coulombe (Utah State University), Michael Denison (University of California, Davis), Bill Helferich (University of Illinois), Pratibha Nerurkar (University of Hawaii), Ron Riley (USDA-ARS Athens, GA) David Williams (Oregon State University)

Brief Summary of Minutes

BRIEF SUMMARY OF MINUTES OF ANNUAL MEETING

Annual meeting of the technical committee, October 9-10, 2008 Hilton Waikaloa, Hawaii.

The annual meeting was called to order at 0800 Thursday morning, October 9th.

After brief introduction and discussion of the meeting format and agenda, the annual reports were presented.

The regular business portion of the meeting commenced Thursday afternoon after the annual report presentations. Calistoga was selected as the site for the 2009 meeting and it was agreed that the 2009 meeting would meet Thursday the 8th and Friday the 9th of October. For 2009, David Williams, Oregon State University, would serve as Secretary, Pratibha Nerurkar (University of Hawaii) as Chair-elect, and Mike Denison (University of California, Davis) as Chair. The responsibilities of the Secretary, Chair-elect and Chair were discussed and it was agreed that the Chair writes the report and chairs the meeting, the Chair-elect organizes the next years meeting working closely with the local host and also assists the Chair in writing the report, the Secretary writes the minutes. Submission of the Report and the minutes are the responsibility of the Chair and the Secretary. The meeting was adjourned at around 5:00 pm on 9 October.

Accomplishments

ACCOMPLISHMENTS<br /> <br /> OBJECTIVE 1. Determine mechanisms of action by which food-borne bioactive compounds protect against human diseases such as cancer, inflammation, birth defects, and microbial infection.<br /> <br /> Poultry was developed as a model for sensitivity to dietary carcinogens, like aflatoxin B1 (AFB1), and responsiveness to chemopreventives such as phenolic antioxidants. Modern commercial turkeys are extremely sensitive to the toxic effects of AFB1, a condition associated with a combination of efficient cytochrome P450 (CYP)-mediated bioactivation of AFB1 to the reactive exo-AFB1-8,9-epoxide (AFBO), and a deficiency of AFBO detoxifying glutuathione S-transferases. Conversely, wild and heritage turkeys, which are relatively resistant to AFB1, possess hepatic GSTs that can detoxify AFBO. This profound difference in GST activities may be a result of the loss of allelic variation in commercial turkeys from intensive breeding. Thus, GSTs appear to play a central role in AFB1 susceptibility and resistance. Using 5-3 RACE, we cloned and sequenced four alpha-class GSTs from the livers of domestic turkeys. Single nucleotide polymorphisms (SNPs) have mapped the GST gene cluster to turkey chromosome MGA2. Based on the chicken sequence, we identified several transcription factors in the 5-regulatory elements of these GSTs, and their significance in GST regulation is under investigation. This genomic approach is aimed at identifying genetic markers related to AFB1 susceptibility and resistance in turkeys with the ultimate goal of re-introducing AFB1-protective alleles back into the genetic stock of commercial turkeys. <br /> <br /> In humans, hepatic cytochromes P450 (CYP) 1A2 and 3A4 bioactivate AFB1 to exo-AFB1-8,9-epoxide (AFBO) which is a requisite step in the toxic and carcinogenic action of this mycotoxin. In turkeys, AFB1 is bioactivated by human homologues CYP3A37 and CYP1A5. Heterologously expressed turkey CYP1A5 metabolizes AFB1 to AFBO and the detoxified metabolite aflatoxin M1 (AFM1) as human CYP1A2. Turkey CYP3A37 cloned from liver RNA was 76% identical to human CYP3A4, and the E. coli expressed protein CYP3A37 possessed metabolic similarities to human CYP3A4. Like CYP3A4, CYP3A37 efficiently metabolized AFB1 to exo-AFBO and the detoxified metabolite aflatoxin Q1 (AFQ1). Formation of exo-AFBO was inhibited by the specific CYP3A4 inhibitor 17b-ethynylestradiol (IC50 = 40.18 µM), while prototype inhibitors to other mammalian isoforms (1A2, 2D, 2E and 3A1) either slightly inhibited this activity, or not at all. Like its human homologue, CYP3A37 also had nifedipine oxidase activity. The gene, which is organized into 13 exons and 12 introns, has an ORF of 1512 bp, and the protein is predicted to be 504 amino acids with 97% homology to chicken CYP3A37. A single nucleotide polymorphism in the 11th intron was used to assign CYP3A37 to turkey linkage group 10. Because of the importance of P450s in the extreme sensitivity of turkeys to the toxic effects of AFB1, this study may be useful in identifying allelic variants of this gene in poultry. Polyclonal anti-CYP3A37 antibody directed against specific active-site peptides inhibited both AFBO formation and nifedpine oxidase activity. The comparative kinetic constants for exo-AFBO formation of expressed CYP3A37 and CYP1A5 lead us to believe that CYP3A37 may be the predominant AFB1 epoxidating enzyme in turkey liver. Ongoing immunoinhibition studies will examine this hypothesis. (Utah State University)<br /> <br /> The addition of the phytochemical, indole-3-carbinol (I3C), found in high concentrations in cruciferous vegetables, to the maternal diet of mice during pregnancy and lactation, markedly protected her offspring from transplacental carcinogenesis well into their adult lives. These studies were carried out in collaboration with Dr. Len Bjeldanes at the University of California, Berkeley. We found similar, although not as striking, results if green tea was utilized. Chlorophyllin, the derivative of the plant pigment chlorophyll, was very effective in inhibition of transplacental carcinogenesis due to administration of the polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP) to the pregnant mouse. (Oregon State University)<br /> <br /> <br /> Analysis of a variety of naturally occurring flavonoids and a large number of synthetic flavonoids and benzoflavones for their ability to affect nuclear receptor signaling pathways, particularly those of the Ah receptor (AhR). Utilizing recombinant cell lines that we have developed that express firefly luciferase in an AhR-dependent manner, our screening demonstrated that the majority of the naturally occurring flavonoids were weak agonists of the AhR, more than 20 synthetic flavonoids were identified as relatively potent AhR agonists, several with relative potencies in the nM range. The ability of these chemicals to inhibit the proliferation of human hepatocarcinoma and breast cancer cell lines, but not those of other AhR-containing cancer cell lines (A431) demonstrated their potential as chemotherapeutic activity in selected cancer cell types. The identification of a novel chemical that can act as an antagonist of the ability of the most potent ligand of the AhR, namely that of the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but not that of the flavonoids, provides strong support for differential ligand binding of chemicals to the AhR. Whether the differential interaction of flavonoids with the AhR contributes to the lack of toxic and biological effects by these chemicals, compared to those observed with TCDD and related chemicals, remains to be determined. (University of California, Davis).<br /> <br /> Breast cancer is the most commonly diagnosed cancer in women. Seventy five percent of breast cancers occur in postmenopausal women and the majority of these are estrogen dependent, which respond to antiestrogen like tamoxifen. It is observed that the dietary isoflavone supplements have been consumed by more American women, including the postmenopausal women with breast cancer by assuming that soy intake would be a safe alternative to hormone replacement therapy. Genistein, a predominant isoflavone in soy, acts as an estrogen agonist at physiologically relevant dosages and has shown to stimulate growth of estrogen-responsive breast cancer cells. If the breast cancer patients with tamoxifen treatment consume considerable isoflavone supplements, the potential combined effect of tamoxifen and genistein may result in significant undesirable outcome on mammary tumors. In this study, we investigated interaction of three dietary dosages of genistein with tamoxifen on the growth of estrogen-dependent breast cancer (MCF-7) cells implanted in ovariectomized athymic mice. We found that 250ppm and 500ppm genistein induced mammary tumor growth over the inhibitory effect of tamoxifen in a dose dependent manner. However at higher dosage, 1000ppm genistein did not negate the effect of tamoxifen. It is important to note that high incidence of tumor was observed in the 1000ppm treatment group. The high rate of apoptosis in this group may explain the small tumor size. Mice tumor characterization using primary culture indicates these tumors retain the estrogen dependent phenotype. These studies demonstrate that the interaction of genistein with tamoxifen is complex, involving multiple mechanisms that are dose-dependent. (University of Illinois) <br /> <br /> The consumption of the trichothecene mycotoxin deoxynivalenol (DON) induces interleukin-6 (IL-6)-dependent IgA nephropathy (IgAN) in mice and this effect can be prevented by feeding long chain n-3 polyunsaturated fatty acids (PUFAs) found in fish oil. Identificaiton of the signal transduction pathways by which DON upregulates IL-6 in the peritoneal macrophage and how consumption of fish oil enriched with the n-3 PUFA, docosahexaenoic acid (DHA), suppresses these processes is critical. Incubation with DON induced IL-6 expression in naïve macrophages maximally at 3 h. Knockdown of the transcription factor cAMP response element-binding protein (CREB) or pharmacologic inhibition of the CREB kinases, Akt1/2, MSK1 and RSK1, downregulated this expression. Inhibition of double-stranded RNA-activated protein kinase (PKR) suppressed not only IL-6 expression but also phosphorylation of CREB and its upstream kinases, Akt1, MSK1 and RSK1. Phosphorylations of PKR, CREB kinases and CREB were markedly impaired in peritoneal macrophages isolated from mice that consumed DHA-enriched fish oil for 6 to 8 wk. DHAs effects were not explainable by increased activity of protein phosphatase 1 and 2A since both were suppressed in mice consuming the DHA diet. Although cells cultured directly with DHA expressed less IL-6 compared to cells cultured with arachidonic acid (AA), neither fatty acid treatment affected DON-induced protein phosphorylation. Furthermore, DHA and AA similarly inhibited cell-free protein kinase activity. These data suggest that DON-induced IL-6 expression is CREB-mediated and PKR-dependent and that requisite kinase activities for these pathways were suppressed in macrophages from mice fed DHA for an extended period. (Michigan State University)<br /> <br /> Obesity-associated diabetes and hyperlipidemia are escalating worldwide. Changes in life style, such as dietary recommendations form the cornerstone of treatment. Our specific aim is to investigate the signaling mechanisms involved in the anti-obesity, anti-diabetic and hpolipidemic properties of Momordica charantia (bitter melon, BM). Traditionally, BM is used to treat diabetes and its complications. Our studies demonstrate that BM also reduces adiposity and plasma and hepatic lipids in mice fed high fat diet (HFD). We further demonstrated that BM lowers plasma apolipoprotein B (apoB) by improving hepatic insulin receptor phosphorylation and its downstream signaling molecules. (University of Hawaii)<br /> <br /> OBJECTIVE 2. Identify mechanisms of action and biomarkers of natural and induced toxicants in food for human risk assessment and disease prevention.<br /> <br /> Collaborative studies with scientists at the University of Nebraska Medical Center have focused on determination of the possible role of fumonisin-induced elevation of sphingoid base 1-phosphates, ligands for S1P Receptors (S1P1-5) as a risk factor for neural tube defects in mice. The results strongly suggest that the lysophospholipid receptors known as S1PR could play a key role in fumonisin-induced NTD in mice. This is an important discovery and provides a potential human risk factor which could be explored in Guatemala. In support of developing mechanism-based biomarkers for detecting fumonisin-induced effects in humans, we also found that human consumption of food products containing low levels of fumonisins (below the USFDA guidelines of 4 ppm) could cause easily detectable elevation of fumonisin B1 in human urine but at the levels consumed had no significant effect on sphingoid base 1-P levels in blood. In collaboration with researchers in Guatemala, a questionnaire was developed to identify heavy consumers of maize products in two areas of Guatemala. A study was initiated to determine if urinary FB could be used as an exposure marker. (USDA-ARS, Athens)<br /> A possible role for 1-dexoxysphingoid bases and 1-deoxydihydroceramides in FB hepatotoxicity has been examined. In cultured cells, inhibition of ceramide synthase (CerS) by FB1 increases sphinganine (Sa), Sa 1-phosphate and a previously unidentified metabolite, believed to be a novel sphingoid base. In this study, the metabolite was analyzed by mass spectrometry (MS) and assigned a m/z of 286.3123 in positive ionization mode, consistent with a 1- or 3-deoxysphinganine (deoxySa), C18H40NO. Mass spectrometry suggested that that the putative deoxySa was most likely formed from the utilization of alanine by serine palmitoyl transferase (SPT), the first and rate-limiting enzyme in sphingolipid biosynthesis. Inhibition of SPT with myriocin blocked the formation of both Sa and 1-deoxySa. Labeling studies using L-alanine-U-13C3 and L-serine-U-13C3 showed the preferential incorporation of alanine into 1-deoxySa, confirming that 1-deoxySa arises from condensation of alanine with palmitoyl-CoA via SPT. In LLC-PK1 cells, Vero cells, and other cell lines, 1-deoxySa accumulated to high levels after treatment with FB. 1-DeoxySa was also detected in liver and kidney of P53N5 mice and increased in mice fed FB diets. Cells treated with FB plus 10 µM 1-deoxySa showed a 25-fold elevation in 1-deoxySa compared to the FB-only treated cells and a 42-fold elevation compared to the cultures treated with only 10 µM 1-deoxySa. Conversely, in LLC-PK1 cells treated with 10 µM 1-deoxySa, the level of total N-acyl-1-deoxySa (i.e., 1-deoxydihydroceramides) went from 32.2 to 4,634 pmol/mg protein. Co-treatment with FB reduced the increase to 396 pmol/mg protein, indicating that the endogenous 1-deoxySa is acylated by CerS. 1-Deoxydihydroceramides were also easily detected in mouse liver. These findings implicate 1-deoxy sphingoid bases in diseases caused by FB, and they may play important roles in cell regulation. (USDA-ARS, Athens)<br /> PAHs are of increasing environmental concern. They are formed from the burning of organic materials, especially fossil fuels. With the large demand for energy production throughout the world, increasingly PAHs are being generated from the burning of coal, gasoline, diesel, etc. These PAHs get deposited on food and the majority of human exposures to PAHs are dietary. We have conducted studies employing Cyp1b1 knockout mice to demonstrate that transplacental cancer (primarily lymphoma) is DBP-dependent transplacental induction of lymphoma is dependent upon fetal expression of Cyp1b1. These results provide us with a new gene target for future cancer chemoprevention studies. In subsequent work, utilizing a cross-foster approach, where litters are switched after birth between control mothers and those exposed to DBP, that the majority of cancer in the offspring was from the short (2-3 day) in utero exposure rather than the 3 weeks of nursing. These studies have identified a critical window for prevention efficacy. (Oregon State University)<br /> <br /> The frequent presence of DON in cereal-based foods and the high intake of these foods by children raises particular concerns about the relative susceptibility of this subpopulation to adverse effects evoked by this mycotoxin. We tested the hypothesis that both toxicokinetics and proinflammatory cytokine gene expression following a oral DON exposure at 5 mg/kg bw differ between weanling (3-4 wk) and young adult (8-10 wk) female mice. DON was rapidly taken up with maximum plasma concentrations reaching 1.0 g/ml in adult mice at 15 min, whereas DON levels were approximately twice as much in weanling mice at these times. DON was rapidly cleared in both weanling and adult mice with concentrations being reduced by 78 and 81% of the peak levels, respectively, after 2 h. DON accumulation and clearance in spleen, liver, lung and kidney followed similar kinetics to that of plasma with tissue burdens also reaching twice that of adult mice. When TNF-, IL-1b and IL-6 mRNAs in spleens (a primary source of systemic proinflammatory cytokines) were used as biomarkers of the effects of DON, expression of these mRNAs was two to three times greater in weanling than adult mouse. However, differences in proinflammatory cytokine expression were less robust or not apparent in the liver or lung. Accordingly, these data suggest that young mice are modestly more susceptible than adult mice to the adverse effects of DON and that this might result from a greater toxin tissue burden. (Michigan State University)<br /> Translational inhibitors such as DON and ribosomal inhibitory proteins (RIPs) induce mitogen-activated protein kinase (MAPK)-driven chemokine and cytokine production by a mechanism known as the ribotoxic stress response (RSR). Double-stranded RNA-activated protein kinase (PKR) associates with the ribosome in close proximity to the peptidyl transferase center making it uniquely positioned to sense 28S rRNA damage and initiate the RSR. We have previously shown that PKR mediates DON-induced MAPK phosphorylation in macrophages and monocytes. The purpose of this study was to test the hypothesis that PKR is essential for induction of IL-8 expression in monocytes by DON and two prototypical RIPs, ricin and Shiga toxin 1 (Stx-1). Preincubation of human monocytic U937 cells with the PKR inhibitors C16 and 2-aminopurine (2-AP) blocked DON-induced expression of IL-8 protein and mRNA. Induction of IL-8 expression was similarly impaired in U937 cells stably transfected with a dominant negative PKR plasmid (UK9M) as compared to cells transfected with control plasmid (UK9C). NF-kB binding, which has been previously shown to be a requisite for DON-induced IL-8 transcription, was markedly reduced in UK9M cells as compared to UK9C cells. As observed for DON, ricin- and Stx-1-induced IL-8 expression was suppressed by the PKR inhibitors C16 and 2-aminopurine as well as impaired in UK9M cells. Taken together, these data indicate that PKR plays a common role in IL-8 induction by DON and the two RIPs, suggesting that this kinase might be a critical factor in RSR. (Michigan State University)<br /> <br /> OBJECTIVE 3. Discover bioactive compounds that have beneficial or adverse effects on human health.<br /> <br /> Perfluorinated compounds, typified by perfluorooctanoic acid (PFOA), are ubiquitous environmental pollutants. These compounds have a number of industrial uses, included the manufacture of Teflon and similar coatings. We have found that dietary exposure of trout to PFOA resulted in alterations in gene expression very similar to the pattern obtained with estrogens; hence, PFOA, at least in fish, is a xenoestrogens. As with other estrogens, PFOA is also a promoter of carcinogen-initiated liver cancer in this model. (Oregon State University)<br /> <br /> Liquiritigenin is a plant-derived highly selective estrogen receptor beta (ERb) agonist. After the Women's Health Initiative found that the risks of hormone therapy outweighed the benefits, a need for alternative drugs to treat menopausal symptoms has emerged. We explored the possibility that botanical agents used in Traditional Chinese Medicine for menopausal symptoms contain ERb-selective estrogens. We previously reported that an extract of 22 herbs, MF101, has ERb-selective properties. In this study we isolated liquiritigenin, the most active estrogenic compound from the root of Glycyrrhizae uralensis Fisch, which is one of the plants found in MF101. Liquiritigenin activated multiple ER regulatory elements and native target genes with ERb but not ERa. The ERb-selectivity of liquiritigenin was due to the selective recruitment of the coactivator steroid receptor coactivator-2 to target genes. In a mouse xenograph model, liquiritigenin did not stimulate uterine size or tumorigenesis of MCF-7 breast cancer cells. Our results demonstrate that some plants contain highly selective estrogens for ERb. (University of California, Berkeley)<br /> <br /> Novel estrogenic therapies are needed that have the bone-sparing effects of endogenous estrogens but do not promote breast or uterine cancer. Recent evidence suggests that selective activation of the ERb subtype inhibits breast cancer cell proliferation. We showed previously that DIM has estrogenic activity. We investigated whether the estrogenic activities of DIM are ERb-selective. DIM promoted ERb but not ERa activation of an estrogen response element upstream of the luciferase reporter gene. DIM also selectively activated multiple endogenous genes through ERb. The activation of ERb induced by DIM allows ERb to bind regulatory elements and recruit the GRIP1 coactivator leading to the activation of ER target genes. DIM did not bind to ERb, indicating that it activates genes by a ligand-independent mechanism. Our results demonstrate that DIM is an ERb-selective compound that might be an alternative to estrogens that are used in hormone therapy, which non-selectively activate both ER subtypes and are associated with increased breast cancer risk. (University of California, Berkeley)<br /> <br /> The AhR regulates the expression of a battery of genes in a wide range of species and tissues and is responsible for mediating the toxic and biological effects of TCDD and related halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). Differences in the toxic potency of HAHs and PAHs, the latter not producing AhR-dependent toxicity, suggested that these chemicals may differentially bind to and activate the AhR. We have demonstrated that the prototypical HAH (TCDD) and PAH (beta-naphthoflavone (BNF)) can differentially interact with the binding pocket of Ah receptor. This was accomplished by our identification of a novel chemical (MSD237) from high-throughput screening analysis that could inhibit the ability of TCDD, but not BNF, block to bind to AhR and activate AhR-dependent signal transduction pathway. Like that of other AhR ligands, the binding of MSD237 to the AhR ligand binding pocket was essentially irreversible. These results provide insights into the structural diversity of AhR ligands as these ligands may differentially interact with the ligand binding pocket and suggest that differential interactions of HAHs and PAHs with the AhR may contribute to differences in their ability to produce AhR-dependent toxicity. In addition, the use of MSD237 as a potential therapeutic agent to block the biological and toxicological effects of HAHs is being examined. (University of California, Davis)<br /> <br /> We have further developed our three-dimensional homology model of the mouse AhR (mAhR) PAS B ligand binding domain by extending this analysis using comparative structural modeling studies of the ligand binding domains of six additional high affinity mammalian AhRs. These results, coupled with site directed mutagenesis and AhR functional analysis, has allowed detection of the "TCDD-binding fingerprint" of conserved residues within the ligand binding cavity necessary for high affinity TCDD binding and TCDD-dependent DNA binding. The essential role of selected residues was further evaluated using molecular docking simulations of TCDD to both wild-type and mutant mAhRs. Further refinement of the docking simulation with TCDD and other known AhR ligands will facilitate the development of a model that can be used for screening purposes to identify new AhR ligands. Taken together, our results allow for a more complete understanding of the molecular determinants of TCDD binding and provides a basis for future studies directed toward rationalizing the observed species differences in AhR sensitivity to TCDD and understanding the mechanistic basis for the dramatic diversity in AhR ligand structure. (University of California, Davis)<br /> <br /> Anti-diabetic properties of BM, have been attributed to their high antioxidant properties due in part to phenols, flavonoids, isoflavones, terpenes, anthroquinones, and glucosinolates. Momordicosides and triterpenoids specifically demonstrated hypoglycemic effects in diabetic mice. Most of the studies, demonstrating an effect on body weights, and lipids were conducted using whole BM juice (BMJ) and the active ingredients remain unknown. We chemically fractionated BMJ and tested in mouse and human adipocyte cell cultures as well as human liver cell cultures to test the effect on lipid accumulation in the cells. Our results demonstrate that whole BMJ was more potent in lowering cellular lipids in mice adipocytes and human liver cells than any fraction alone. (University of Hawaii)<br /> <br /> OBJECTIVE 4. Develop strategies to increase beneficial or decrease adverse effects of bioactive food constituents and microbial contaminants.<br /> Fumonisin translocation and disruption of sphingolipid metabolism in maize seedling, developing strategies for resistance to Fusarium verticillioides maize seedling diseases. The ability of maize seedlings to translocate pure fumonisins from soil into aerial plant parts (leaves) was assessed. It was found that in maize seedlings watered with pure fumonisin B1, pure fumonisin B2 or the combination of B1 and B2, fumonisin B1 was preferentially accumulated in root tissue but was not significantly translocated into leaf tissue. Conversely, the fumonisin that entered roots caused significant elevation in sphingoid bases and sphingoid base 1-phosphates in roots and these were translocated into leaf tissues. This finding was different than what was seen when seedlings were grown from seeds inoculated with the fungus that produces fumonisins. In this case both fumonisin B1 and B2 accumulated in roots whereas only fumonisin B1 was appreciably translocated into leaf tissue. The results suggest that the fungal/plant/soil interaction contributes to the ability of fumonisins to enter the roots and be translocated into leaf tissues. This is important because plant debris can be a significant source of fumonisins and thus the factors which control fumonisin entry into plant parts could reduce the levels of fumonisins in field debris. (USDA-ARS, Athens)<br /> We have found that apple based edible antimicrobial films wrapped on contaminated ham and stored at 23 or 4°C for 72 hrs induced multi-log reductions in Listeria monocytogenes. In a collaborative study we also found that apple and tomato based edible films containing the plant essential oils from allspice, bay leaf, clove bud, thyme, and vanilla inactivated E. coli O157:H7 both in direct contact and in the vapor phase. These finding support the possible commercial use of the films and indicate that they may provide antimicrobial benefits, even when not in contact with the food. (USDA-ARS, Albany) <br /> <br /> The addition of a polyphenol-rich apple skin powder to contaminated ground beef reduced by up to two-thirds the time needed to heat-inactivate E. coli O157:H7. This finding suggests possible changes in culinary practice that may benefit consumers. (USDA-ARS, Albany)<br /> <br /> In a collaborative study, we found that cinnamaldehyde, cinnamon oil, carvacrol, oregano oils, 2,5-dihydroxybenzaldeyde, and 2-hydroxy-2-methoxyenzaldehyde inactivated Mycobacterium avium paratuberculosis that infects cattle causing Johns diseases and contaminates raw milk. Because there are no effective treatments for this organism, this finding offers new possibilities to protect cattle and milk against this virulent pathogen. (USDA-ARS, Albany)<br /> <br /> A collaborative modeling study has revealed that the number of hydrogen bonds formed by seven tea catechins with simulated cell membranes correlates with our published observations on relative antimicrobial and inhibitory effects of the same catechins against Bacillus cereus and human cancer cells, respectively. Computational modeling of catechin-cell membrane relationships contribute to understanding of molecular mechanisms of antimicrobial and anticancer activities of catechins. (USDA-ARS, Albany) <br /> <br /> We developed HPLC and LC/MS assays for flavonoids present in fresh, light exposed, and home-processed onions, and in commercial onion products. Improved HPLC and LC/MS assays for determining the content of flavonoids in onions, phenolic compounds in potatoes, and piperamides in peppercorns were also developed. Together, these studies facilitate ongoing efforts to relate content biologically active compounds in plant extracts to inhibitory activities against food-borne pathogens and bacterial toxins. (USDA-ARS, Albany)<br />

Publications

PUBLICATIONS<br /> <br /> Ahn, K.C., Zhao, B., Chen, J., Cherednichenko, G., Sanmarti, E., Denison, M.S., Lasley, B., Pessah, I.N., Kultz, D., Chang, D.P., Gee, S.J. and Hammock, B.D. (2008) In vitro biological activities of the antimicrobials triclocarban, its analogs, and triclosan in bioassay screens: receptor-based bioassay screens, Environ. Health Perspect. 116: 1203-1210.<br /> <br /> Amuzie, C. J., Harkema, J. R., and Pestka, J. J. (2008) Tissue distribution and proinflammatory cytokine induction by the trichothecene deoxynivalenol in the mouse: comparison of nasal vs. oral exposure. Toxicology 248: 39-44.<br /> <br /> Bae, H. K., and Pestka, J. J. (2008) Deoxynivalenol induces p38 interaction with the ribosome in monocytes and macrophages. Toxicol Sci 105: 59-66.<br /> <br /> Beli, E., Li, M., Cuff, C., and Pestka, J. J. (2008) Docosahexaenoic acid-enriched fish oil consumption modulates immunoglobulin responses to and clearance of enteric reovirus infection in mice. J Nutr. 138: 813-819.<br /> <br /> Bohonowych, J.E. and Denison, M.S. (2007) Persistent binding of ligands to the aryl hydrocarbon receptor, Toxicol. Sci. 98: 99-110.<br /> <br /> <br /> Brown, D. J., Orelien, J., Gordo, J. D., Chu, A. C., Chu, M. D., Murata, H. J., Kayama, F., Denison, M. S. and Clark, G. C. (2007) Mathematical model developed for environmental samples: prediction of GC/MS dioxin TEQ from XDS-CALUX bioassay data, Environ. Toxicol. Chem. 41: 4354-4360.<br /> <br /> Burns, T.D., Snook, M.E., Riley, R.T. and Voss, K.A. (2008) Fumonisin concentrations and in vivo toxicity of nixtamalized Fusarium verticillioides culture material: Evidence for fumonisin-matrix interactions. Food Chem Toxicol 46: 2841-2848.<br /> <br /> Carter, O., Dashwood, R.H., Wang, R., Dashwood, W.M., Orner, G.A., Fisher, K.A., Löhr, C.V., Pereira, C.B., Bailey, G.S. and Williams, D.E. (2007) Comparison of White Tea, Green Tea, Epigallocatechin-3-Gallate and Caffeine as Inhibitors of PhIP-Induced Colonic Aberrant Crypts. Nutr Cancer 58: 60-65.<br /> <br /> Castro, D.J., Löhr, C., Fischer, K., Waters, K., Webb-Robertson, B.-J., Dashwood, D.H., Bailey, G.S. and Williams, D.E. (2008) Identifying Efficacious Approaches to Chemoprevention with Chlorophyllin, Purified Chlorophylls and Freeze-Dried Spinach in a Mouse Model of Transplacental Carcinogenesis. Carcinogenesis 30: 315-320.<br /> <br /> Castro, D.J., Baird, W.M., Pereira, C., Giovanini, J., Löhr, C., Fischer, K., Yu, Z., Gonzalez, F.J., Krueger, S.K. and Williams, D.E. (2008) Fetal Cyp1b1 in Mice and Transplacental Carcinogenesis From Maternal Exposure to Dibenzo[a,l]pyrene. Cancer Prev Res 1: 128-134.<br /> <br /> Castro, D.J., Yu., Z., Löhr, C.V., Pereira, C.B., Giovanini, J., Fischer, K.A., Orner, G.A., Dashwood, R.H., and Williams, D.E. (2008) Chemoprevention of Dibenzo[a,l]pyrene Transplacental Carcinogenesis in Mice Born to Mothers Administered Green Tea: Primary Role of Caffeine. Carcinogenesis 29: 1581-1586.<br /> <br /> Castro, D.J., Yu, Z., Dashwood, R.H., Bailey, G.S., Baird, W.M. and Williams, D.E. (2008) A Model for the Study of Maternal Dietary Inhibition of Transplacental Carcinogenesis. In Recent Advances in Carcinogenesis, (R.M. Mohan, Ed.).<br /> <br /> Castro, D.J., Löhr, C.V., Fischer, K.A, Pereira, C. and Williams, D.E. (2008) Lymphoma and Lung Cancer in Offspring Born to Pregnant Mice Dosed with Dibenzo[a,l]pyrene: The Importance of In Utero Versus Lactational Exposure. Toxicol Appl Pharmacol 233: 454-458.<br /> <br /> Chang, E.C., Charn, T.H., Park, S.H., Helferich, W.G., Komm, B., Katzenellenbogen, J.A. and Katzenellenbogen, B.S. (2008). Estrogen Receptors alpha and beta as determinants of gene expression: influence of ligand, dose, and chromatin binding. Mol Endocrinol 22: 1032-1043.<br /> <br /> <br /> Coulombe, R.A. and Yip, S.M. (2007) Heterologous expression of a cytochrome P450 from turkey liver that activates aflatoxin B1. In Poisonous Plants: Global Research and Solutions (K. Panter, T. Wierenga, J. Phister, eds.) CAB International, London. pp. 82-88.<br /> <br /> Du, W.-X., Olsen, C.E., Avena-Bustillos, R.J., McHugh, T.H., Levin, C.E. and Friedman, M. (2008) Antibacterial activity against E. coli O157:H7, physical properties, and storage stability of novel carvacrol-containing edible tomato films. J Food Sci 73: M378-M383. <br /> <br /> <br /> Du, W.-X., Olsen, C.W., Avena-Bustillos, R.J., McHugh, T.H., Levin, C.E. and Friedman, M. (2008) Storage stability and antibacterial activity against Escherichia coli O157:H7 of carvacrol in edible apple films made by two different casting methods. J Agric Food Chem 56: 3082-3088.<br /> <br /> Dvorak, N., Riley, R.T., Harris M. and McGregor, J.A. (2008) Fumonisin mycotoxin contamination of corn-based foods consumed by potentially pregnant women in Southern California. Journal Reprod Mede 53: 672-676.<br /> <br /> Friedman, M. (2008) Dietary significance of processing-induced lysinoalanine in food. In "Process-Induced Food Toxicants: Occurrence, Formation, Mitigation, and Health Risks", Stadler, R.H. and Lineback, D.R., Eds., John Wiley & Sons, New York, Chpt. 6.1, pp. 477-510. 2009.<br /> <br /> Friedman, M. (2008) Dietary significance of processing-induced D-amino acids. In "Process-Induced Food Toxicants: Occurrence, Formation, Mitigation, and Health Risks", Stadler, R.H. and Lineback, D.R., Eds., John Wiley & Sons, New York, Chpt. 6.2, pp. 511-537. 2009.<br /> <br /> <br /> Friedman, M. and Levin, C.E. (2008) Review of methods for the reduction of dietary content and toxicity of acrylamide. J Agric Food Chem 56: 6113-6140.<br /> <br /> Friedman, M., C. E. Levin, C.E., Lee, S.-U., Lee, J.-S., Ohnisi-Kameyama, M. and Kozukue, N. (2008) Analysis by HPLC and LC/MS of pungent piperamides in commercial black, white, green, and red whole and ground peppercorns. J Agric Food Chem 56: 3028-3036.<br /> <br /> Glenn, A.E., Zitomer, N.C., Zimeri, A.M. , Williams, L.D., Riley, R.T. and Proctor, R.H. (2008) Transformation-mediated complementation of a FUM gene cluster deletion in Fusarium verticillioides restores both fumonisin production and pathogenicity on maize seedlings. Molec Plant-Microbe Interact 21: 87-97.<br /> <br /> Gray, J. S., Bae, H. K., Li, J. C., Lau, A. S., and Pestka, J. J. (2008) Double-stranded RNA-activated protein kinase mediates induction of interleukin-8 expression by deoxynivalenol, Shiga toxin 1, and ricin in monocytes. Toxicol.Sci 105, 322-330.<br /> <br /> Guarisco, J.A., Hall, J.O. and Coulombe, R.A., Jr. (2007) Butylated hydroxytoluene reduces aflatoxin B1 bioavailability and hepatic adduct formation in turkeys. In Poisonous Plants: Global Research and Solutions (K. Panter, T. Wierenga, J. Phister, eds.) CAB International, London. pp. 197-202.<br /> <br /> Guarisco, J.A., Hall, J.O. and Coulombe, R.A., Jr. (2008) Butylated hydroxytoluene chemoprevention of aflatoxicosis - effects on aflatoxin B1 bioavailability, hepatic DNA adduct formation, and biliary excretion. Food Chem Toxicol 46: 3727-3723.<br /> <br /> Guarisco, J.A., Hall, J.O. and Coulombe, R.A., Jr. (2008) Mechanisms of butylated hydroxytoluene chemoprevention of aflatoxicosis - inhibition of aflatoxin B1 metabolism. Toxicol Appl Pharmacol 227: 339-346.<br /> <br /> Heemstra, J. M., Kerrigan, S. A., Doerge, D. R., Helferich, W. G. and Boulanger, W. A. (2007). Total synthesis of (S)-equol. Org Lett 8:5441-5443.<br /> <br /> Helferich, W.G., Andrade, J.E. and Hoagland, M.S. (2008). Phytoestrogens and breast cancer: a complex story. Inflammopharmacology : 219-226.<br /> <br /> Higdon, J.V., Delage, B., Williams, D.E. and Dashwood, R.H. (2007) Cruciferous Vegetables and Human Cancer Risk: Epidemiologic Evidence and Mechanistic Basis. Pharmacol Res 55: 224-236.<br /> <br /> Hu, W., Sorrentino, C., Denison, M.S., Kolaja, K. and Fielden, M. (2007) Induction of Cyp1a1 is a Non-Specific Biomarker of Aryl Hydrocarbon Receptor Activation: Results of Large Scale Screening of Pharmaceuticals and Toxicants In Vivo and In Vitro, Molec. Pharmacol. 71: 1475-1486.<br /> <br /> Im, W.I., Suh, B.-S., Lee, S.-U., Kozukue, N., Ohnisi-Kameyama, M., Levin, C.E. and Friedman, M. (2008) Analysis of phenolic compounds by high-performance liquid chromatography and liquid chromatography/mass spectrometry in potato plant flowers, leaves, stems, and tubers and in processed potatoes. J Agric Food Chem 56:3341-3349.<br /> <br /> Islam, Z., Hegg, C. C., Bae, H. K., and Pestka, J. J. (2008) Satratoxin G-induced apoptosis in PC-12 neuronal cells is mediated by PKR and caspase independent. Toxicol.Sci 105, 142-152.<br /> <br /> Jiang, X., Patterson, N.M., Ling, Y., Xie, J. Helferich, W.G. and Shapiro, D.J. (2008). Low Concentrations of the Soy Phytoestrogen Genistein Induce Proteinase Inhibitor 9 and Block Killing of Breast Cancer Cells by Immune Cells. Endocrinology 149: 5366-5373.<br /> <br /> Ju, Y.H., Doerge, D. and Helferich, W.G. (2008). A dietary supplement for female sexual dysfunction, Avlimil, stimulates the growth of estrogen-dependent breast tumors (MCF-7) implanted in ovariectomized athymic nude mice. Food Chem Toxicol 46: 310-320.<br /> <br /> Ju, Y.H., Doerge, D.R., Woodling, K.A., Hartman, J.A., Kwak, J. and Helferich, W.G. (2008). Dietary Genistein Negates the Inhibitory Effect of Letrozole On The Growth Of Aromatase-expressing Estrogen-Dependent Human Breast Cancer Cells (MCF-7Ca) In vivo. Carcinogenesis 29: 2162-2168.<br /> <br /> Juneja, V.K. and Friedman, M. (2008) Carvacrol and cinnamaldehyde facilitate thermal destruction of Escherichia coli O157:H7 in raw ground beef. J Food Prot 71: 1604-1611.<br /> <br /> Lee, S.U., Lee, J.H., Choi, S.H., Lee, J.S., Ohnisi-Kameyama, M., Kozukue, N., Levin, C.E. and Friedman, M. (2008) Flavonoid content in fresh, home-processed, and light-exposed onions and in dehydrated commercial onion products. J Agric Food Chem 56: 8541-8548.<br /> <br /> Li, M., and Pestka, J. J. (2008). Comparative induction of 28S ribosomal RNA cleavage by ricin and the trichothecenes deoxynivalenol and T-2 toxin in the macrophage. Toxicol.Sci 105, 67-78.<br /> <br /> Lim, S., Dragull, K., Tang, C.S., Bittenbender, S. and Nerurkar, P.V. (2007) Effects of Kava Alkaloid, Pipermethystine (PM), and Kavalactones on Oxidative Stress and Hepatic Cytochrome P450 in F344 Rats. Toxicol Sci 97: 214-221.<br /> <br /> <br /> Loniewski, K., Shi, Y., Pestka, J., and Parameswaran, N. (2008) Toll-like receptors differentially regulate GPCR kinases and arrestins in primary macrophages. Mol Immunol. 45, 2312-2322.<br /> <br /> Mersereau, J.E., Levy, N., Staub, R.E., Baggett, S., Zogric, T., Chow, S., Ricke, W.A., Tagliaferri M., Cohen, I., Bjeldanes, L.F. and Leitman, D.C. (2008) Liquiritigenin is a plant-derived highly selective estrogen receptor beta agonist. Mol Cell Endocrinol 283: 49-57.<br /> <br /> <br /> Mottram, D.S. and Friedman, M. (2008) Preface - Symposium on the Chemistry and Toxicology of Acrylamide. J Agric Food Chem 56: 5983.<br /> <br /> Nerurkar, P.V., Lee, Y.-K., Motosue, M., Adeli, K. and Nerurkar, V.R. (2008) Momordica charantia (bitter melon) reduces plasma apolipoprotein B-100 and increases hepatic insulin receptor substrate and phosphoinositide-3 kinase interactions. British J Nutri 100: 751-759.<br /> <br /> <br /> Nerurkar, P.V. and Nerurkar, V.R. (2008) Is Sirt1 the magic target for diabetes? Cell Science Reviews, 2008; 4: 50-56.<br /> <br /> Nerurkar, P.V. (2008) Cancer and Sirt1 regulation Cell Science Reviews, 4: 82-96.<br /> <br /> Nording, M., Persson, Y., Spinnel, E., Baston, D., Denison, M.S. and Haglund, P. (2007) Analysis of dioxins in contaminated soils using CALUX and CAFLUX bioassays, an immunoassay and gas chromatography - high resolution mass spectrometry, Environ. Toxicol. Chem. 26: 1122-1129.<br /> <br /> Pestka, J. J., Yike, I., Dearborn, D. G., Ward, M. D., and Harkema, J. R. (2008). Stachybotrys chartarum, trichothecene mycotoxins, and damp building-related illness: new insights into a public health enigma. Toxicol.Sci 104, 4-26.<br /> <br /> Pestka, J. J., and Amuzie, C. J. (2008) Tissue distribution and proinflammatory cytokine gene expression following acute oral exposure to deoxynivalenol: comparison of weanling and adult mice. Food Chem Toxicol. 46, 2826-2831.<br /> <br /> Pestka, J. J. (2008) Mechanisms of deoxynivalenol-induced gene expression and apoptosis. Food Addit.Contam 1-13.<br /> <br /> Pestka, J. J., Islam, Z., and Amuzie, C. J. (2008) Immunochemical assessment of deoxynivalenol tissue distribution following oral exposure in the mouse. Toxicol.Lett 178: 83-87.<br /> <br /> Putt, K.S., Chen, G.W., Pearson, J.M., Sandhorst, J.S., Hoagland, M.S., Kwon, J.T., Hwang, S.K., Jin, H., Churchwell, M.I., Cho, M.H., Doerge, D.R., Helferich, W.G. and Hergenrother, P.J. (2007) Small-molecule activation of procaspase-3 to caspase-3 as a personalized anticancer strategy. Nat Chem Biol 10: 543-550.<br /> <br /> Ravishankar, S., Zhu, L.,Law, B., Joens, L. and Friedman, M. (2008) Plant-derived compounds inactivate antibiotic-resistant Campylobacter jejuni strains. J Food Prot 71: 1145-1149. <br /> <br /> Reed, K.M., Mendoza, K.M. and Coulombe, R.A., Jr. (2007). Structure and genetic mapping of the Cytochrome P4501A5 gene in the turkey (Meleagris gallopavo). Cytogenetics and Genome Research 116: 104-109. <br /> <br /> Riby, J.E., Firestone, G.L. and Bjeldanes, L.F. (2008) 3,3'-Diindolylmethane reduces levels of HIF-1alpha and HIF-1 activity in hypoxic cultured human cancer cells. Biochem Pharmacol 75: 1858-67. <br /> <br /> Rochester, J.R., Klasing, K.C., Stevenson, L., Denison, M.S., Berry, W. and Millam, J.r. (2008) Dietary red clover (Trifolium pratense) induces oviduct growth and decreases ovary and testes growth in Japanese quail chick, Reprod. Toxicol. 27: 63-71.<br /> <br /> Shi, Y., and Pestka, J. J. (2008). Mechanisms for suppression of interleukin-6 expression in peritoneal macrophages from docosahexaenoic acid-fed mice. J Nutr Biochem in press.<br /> <br /> Simonich, M.T., Egner, P.A., Robuck, B.D., Orner, O., Jubert, C., Pereira, C., Groopman, J.D., Kensler, T.W., Dashwood, R.H., Williams, D.E. and Bailey, G.S. (2007) Natural Chlorophyll Inhibits Aflatoxin B1 Induced Multi-Organ Carcinogenesis in the Rat. Carcinogenesis 28: 1294-1302.<br /> <br /> Simonich, M.T., McQuistan, T., Jubert, C., Pereira, C., Hendricks, J.D., Schimerlik, M., Zhu, B., Dashwood, R., Williams, D.E. and Bailey, G.S. (2008) Low-Dose Dietary Chlorophyll Inhibits Multi-Organ Carcinogenesis in the Rainbow Trout. Food Chem Toxicol 46: 1014-1024.<br /> <br /> Sirk, T.W., Brown, E.F., Sum, A.K. and Friedman, M. (2008) Molecular dynamics study on the biophysical interactions of seven green tea catechins with lipid bilayers of cell membranes. J. Agric. Food Chem 56: 7750-7758.<br /> <br /> Snee, L.S., Nerurkar, V.R., Dooley, D., Efird, J., Shovic, A., Nerurkar, P.V. (2008) Feasibility study to increase palatability and consumption of Momordica charantia (Bitter Melon). Appetite, submitted.<br /> <br /> Tilton, S.C., Hendricks, J.D., Orner, G.A., Pereira, C.B., Bailey, G.S. and Williams, D.E. (2007) Gene Expression Analysis During Tumor Enhancement by the Dietary Phytochemical and Supplement, 3,3-Diindolylmethane, in Rainbow Trout. Carcinogenesis, 28: 1589-1598.<br /> <br /> Tilton, S.C., Orner, G.A., Benninghoff, A.D., Carpenter, H.M., Hendricks, J.D., Pereira, C.B. and Williams, D.E. (2008) Genomic Profiling Reveals an Alternate Mechanism for Hepatic Tumor Promotion by Perfluorooctanoic Acid in Rainbow Trout. Environ Hlth Perspect 116: 1047-1055.<br /> <br /> Torres, O.A., Palencia, E., Lopez de Pratdesaba, L., Grajeda, R, Fuentes, M., Speer, M., Merrill, A.H., Jr., ODonnell, K., Bacon, C.W., Glenn, A.E. and Riley, R.T. (2007) Estimated fumonisin exposure in Guatemala is greatest in consumers of lowland maize. J Nutrition 137: 2723-2729.<br /> <br /> Voss, K.A., Riley, R.T. and Gelineau van-Waes, J.B. (2007) Fetotoxicity and neural tube defects in CD1 mice exposed to the mycotoxin fumonisin B1. Mycotoxins 57: 67-72.<br /> <br /> Wang, R., Dashwood, W.M., Löhr, C.V., Fisher, K.A., Pereira, C.B., Louderback, M., Nakagama, H., Bailey, G.S., Williams, D.E. and Dashwood, R.H. (2008) Protective Versus Promotional Effects of White Tea and Caffeine on PhIP-Induced Tumorigenesis and b catenin expression in the Rat. Carcinogenesis 29: 834-839.<br /> <br /> <br /> Wang, R., Dashwood, W.-M., Löhr, C.V., Fischer, K.A., Nakagama, H., Williams, D.E. and Dashwood, R.H. (2008) Beta-Catenin is Strongly Elevated in Rat Colonic Epithelium Following Short-Term Intermittent Treatment with 2-Amino-1-Methyl-6-Phenyimidazo[4,5-b]Pyridine (PhIP) and a High-Fat Diet. Cancer Sci 99: 1754-1759.<br /> <br /> Wang, V.C., Sable, H.J., Ju, Y.H., Allred, C.D., Helferich, W.G., Korol, D.L. and Schantz, S.L. (2008). Effects of chronic estradiol treatment on delayed spatial alternation and differential reinforcement of low rates of responding. Behav Neurosci 122: 794-804.<br /> <br /> Watterson, T.L., Sorenson, J., Martin, R., and Coulombe, R.A., Jr. (2007). Effects of PM2.5 Collected from Cache Valley Utah on Genes Associated with the Inflammatory Response in Human Lung Cells. J Toxicol Environ Health 70: 1731-1734.<br /> <br /> Wong, S.Y., Grant, I.R., Friedman, M., Elliott, C.T. and Situ, C. (2008) Antibacterial activities of naturally occurring compounds against Mycobacterium avium subsp. paratuberculosis. Appl Environ Microbiol 74: 5986-5990.<br /> <br /> Xue, L., Pestka, J. J., Li, M., Firestone, G. L., and Bjeldanes, L. F. (2008). 3,3'-Diindolylmethane stimulates murine immune function in vitro and in vivo. J Nutr.Biochem 19, 336-344.<br /> <br /> Zitomer, N. C., Glenn, A. E., Bacon, C.W. and Riley, R.T. (2008) A single extraction method for the analysis by liquid chromatography/tandem mass spectrometry of fumonisins and biomarkers of disrupted sphingolipid metabolism in tissues of maize seedlings. Anal Bioanal Chem 391: 2257-2263.<br />

Impact Statements

1. Turkey alpha-class GSTs have been expressed in E. coli and will facilitate studies to examine their catalytic activity. In addition, we are examining regulatory elements in the 5UTR of these genes using EMSA for the presence of regulatory proteins in nuclear extracts. For additional information contact Roger Coulombe (435-797-1598 rogerc@cc.usu.edu)
2. We are expressing turkey alpha-class GSTs in E. coli to examine their catalytic activity. In addition, we are examining regulatory elements in the 5UTR of these genes using EMSA for the presence of regulatory proteins in nuclear extracts. For additional information contact Roger Coulombe (435-797-1598 rogerc@cc.usu.edu)
3. Our studies provide the basis for further investigations of both the clinical usefulness of the selective ERb phytochemicals in hormone-related disorders ranging from cancer to hot-flashes, and of the development of more active analogues with fewer adverse side effects. For additional information contact Leonard F. Bjeldanes (510-642-1601, lfb@nature.berkeley.edu)
4. We plan to examine the primary molecular events that are responsible for the antimetastatic and the ERb activating activities of DIM in tumor cells. We also plan to further characterize the immune modulation effects of DIM. For additional information contact Leonard F. Bjeldanes (510-642-1601, lfb@nature.berkeley.edu)
5. Understanding the underlying mechanistic basis for NTD development in response to fumonisin exposure in mice will assist in predicting the risk in humans. Developing exposure and mechanistic markers will provide us with a tool to find high risk populations for future studies in humans. This will help identify populations with increased susceptibility to NTDs where maize consumption is high and deficient in folate. For additional information contact Ronald T. Riley (706 546-3377 ron.riley@ars.usda.gov).
6. The discovery that 1-deoxysphinganine accumulates in mouse liver to a greater extent than in kidney provides a possible explanation for the sensitivity of mouse liver to FB-induced hepatoxicity. In addition, 1-deoxydihydroceramides could play a role in other disease processes. For additional information contact Ronald T. Riley (706 546-3377 ron.riley@ars.usda.gov).
7. Understanding the mechanistic basis for fumonisin accumulation in maize tissues is important because plant debris can be a significant source of fumonisins and thus the factors which control fumonisin entry into plant parts could reduce the levels of fumonisins in field debris. In addition fumonisins in maize have been shown to accumulate in dried distillers grains with solubles (DDGS) and maize stalks and leaves will someday be useful for producing ethanol from cellulosic materials. Thus reducing the accumulation of fumonisins in plant parts could avert potential problems of fumonisins in DDGS using maize plant parts. For additional information contact Ronald T. Riley (706 546-3377 ron.riley@ars.usda.gov).
8. The results described in the paper by Du et al. listed below (J. Food Sci. 73:M378-383, 2008) were selected for inclusion in the Food Safety Network (FSNET). Our antimicrobial edible fruit and vegetable film studies were featured in the July 2008 issue of Agricultural Research. Thomsen Reuters Science WatchR featured our paper (Mol. Nutr. Food Res. 51:116-134, 2007) as a Fast Breaking Paper.
9. Our acrylamide review paper (J. Agric. Food Chem. 51, 4504-4526, 2003) has been cited 211 times. Expectations are that our current review on mitigation (see above reference), which also suggests numerous research needs, will also be widely read. For additional information contact Milton Friedman (510-559-5615; mfried@pw.usda.gov)
10. Our findings that supplementation of the maternal diet during pregnancy and nursing can have a marked effect on the risk of her offspring for developing cancer in later life has potential human health significance. Indole-3-carbinol is found in cabbage, Brussels sprouts, cauliflower, kale and other cruciferous vegetables and has shown to be effective against cancer in other models. For additional information contact David E. Williams (541-737-3277 David.Williams@orst.edu).
11. I3C is available as a dietary supplement. In addition to I3C, green tea and chlorophyllin (if given with the carcinogen) also provided significant protection against cancers developed in mice during what would correspond to young adulthood (lymphomas), but also well into middle age (lung and liver). Lymphoma and leukemias are the most prevalent cancer in young people and cancer is the 2nd (after accidents) most common cause of death in children. For additional information contact David E. Williams (541-737-3277 David.Williams@orst.edu).
12. Lung cancer is the number 1 cause of cancer mortality in the U.S. and liver cancer, though somewhat rarer, is the fastest increasing soft-tissue cancer in the U.S. and is the number 1 cause of death in other parts of the world such as China where aflatoxin B1 levels are high in the diet and the incidence of Hepatitis B and C infections are high. For additional information contact David E. Williams (541-737-3277 David.Williams@orst.edu)
13. Other studies characterizing the developmental stage of the fetus/infant that is most susceptible to carcinogens to which the mother is exposed can now help in designing the most effective chemoprevention protocols. Finally, our discovering that a class of very important environmental pollutants, the perfluorinated compounds, represents a threat due to their potential to function as endocrine disruptors and cancer promoters is important in the conduct of risk assessment of these compounds and is directly relevant to human health. For additional information contact David E. Williams (541-737-3277 David.Williams@orst.edu)
14. Estrogenic dietary supplements from soy are consumed by older women. It is possible that the estrogen like compounds in these supplements can negate the positive effects of tamoxifen and stimulate growth of estrogen-dependent breast cancer. The findings presented here indicate that dietary supplements have the potential to interfere with breast cancer therapies and reduce the effectiveness of these successful drugs. For additional information contact William Helferich (217-244-5414 helferic@uiuc.edu)
15. Our findings indicate that BM prevents obesity-associated metabolic disorders such as diabetes and hyperlipidemia. BM is available through out the year and is a staple among ethnic minorities such as Filipinos. Functional foods such as BM therefore will be readily acceptable among culturally sensitive population and will offer a cost-effective treatment or preventive strategy in developing nations. For additional information contact Pratibha V. Nerurkar (808-956-9195 pratibha@Hawaii.edu).
16. Novel synthetic flavonoids that can bind to and activate the AhR were identified and these chemicals can were shown to act as relative potent inhibitors of proliferation of several cancer cell lines. Interestingly, these chemicals interact with the ligand binding pocket of the AhR in a manner distinctly different from that of the AhR and may provide insights into the differential ability of AhR ligands to produce biological and toxicological effects. For additional information contact Michael Denison (530-752-3879 msdenison@ucdavis.edu).
17. We have identified and characterized a novel chemical (MSD237) that is a ligand-specific antagonist/inhibitor of the AhR. We found that MSD237 specifically inhibits the ability of TCDD and related toxic HAHs (2,3,7,8-tetrachlorodibenzofuran and 3,3,4,4,5-pentachlorobiphenyl) to bind to and activate the AhR, but that it was ineffective in inhibiting the ability of BNF or 10 other flavonoids to activate the AhR. Indirubin and PAHs which can activate the AhR signaling pathway were also similarly unaffected. MSD237 has potential utility as a therapeutic agent to block the biological and toxicological effects of HAHs. For additional information contact Michael Denison (530-752-3879 msdenison@ucdavis.edu).
18. We have further developed a three-dimensional structural homology model of the AhR ligand binding domain and extended this modelling to six additional high affinity mammalian AhRs. These analyses have allowed determination of the ligand (TCDD)-binding fingerprint of conserved residues within the ligand binding cavity necessary for high affinity ligand binding. Molecular docking simulations of TCDD to both wild-type and mutant mAhRs were also performed and refinement of these simulations will allow development of a model for use in silico high-throughput screening of chemicals and chemical libraries to identify new AhR ligands. For additional information contact Michael Denison (530-752-3879 msdenison@ucdavis.edu)
19. The n-3 fatty acid studies will generate several useful outcomes. The models developed will directly inform public health workers about the value of n-3 PUFA supplementation for prophylaxis/treatment of IgAN and other diseases that involve inflammatory gene induction. These outcomes will impact human health by providing a scientific basis for sound public health recommendations relative to nutritional supplements consumed by 12 percent of U.S. adults. For additional information contact James Pestka (517-353-1709, pestka@msu.edu)
20. Trichothecenes and ribotoxic chemicals can occur in foods via natural contamination or as a result of deliberate use in chemical terrorism or warfare. Outcomes of the mechanism studies here will enhance understanding of basis by which trichothecenes and other ribotoxic stressors disrupt immune function. These outcomes will positively impact human health by providing a science-based strategies for protecting or treating individuals at risk for exposure to this important class of toxins. For additional information contact James Pestka (517-353-1709, pestka@msu.edu)

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Report Information

Participants

Benninghoff, Abby, Abby.Benninghoff@usu.edu (Utah State University);
Bjeldanes, Len, lfb@nature.berkeley.edu (University of California, Berkeley);
Friedman, Mendel, mfried@pw.usda.gov (USDA, WRRL);
Harrington, Mike, wdal@lamar.colostate.edu (Colorado State University);
Helferich, Bill, helferic@illinois.edu (University of Illinois);
Kolluri, Siva, Siva.Kolluri@oregonstate.edu (Oregon State University);
Nerurkar, Pratibha, pratibha@hawaii.edu (University of Hawaii);
Pestka, Jim, pestka@pilot.msu.edu (Michigan State University);
Riley, Ron, rriley@saa.ars.usda.gov (USDA-ARS Athens, GA);
Saltos, Etta, ESALTOS@NIFA.USDA.GOV (USDA);
Weir, Tiffany, Tiffany.Weir@ColoState.edu (Colorado State University);
Williams, David, david.williams@oregonstate.edu (Oregon State University

Brief Summary of Minutes

The meeting was planned, arranged and conducted by the Vice President, David Williams, Oregon State University and was held at Casa Munras in Monterey, CA. Two guests participated in the meeting as well: Dr. Siva Kolluri who is a member of a programmatically related Mega-Project interested in collaboration and Dr. Tiffany Weir who is joining W2122 as a new representative of Colorado State University.The annual meeting was called to order at 08:00 am Thursday morning, October 21, 2010 at Casa Munras in Monterey, CA. The meeting was planned, arranged and conducted by the Vice President, David Williams, Oregon State University. The meeting commenced with a brief introduction and discussion of the meeting format and agenda. That was followed by a report from the NIFA liaison, Dr. Etta Saltos and a discussion of funding and organizational changes at NIFA. After the report the administrative advisor Dr. Michael Harrington provided information on Experiment Station Section Awards for Excellence in Research. This was followed by the annual report presentations from the attending committee members and guests. The regular business portion of the meeting commenced Friday morning after the annual report presentations. Calistoga, California was selected as the site for the 2011 meeting on Thursday and Friday the 13th and 14th of October 2011. For 2011, Jim Pestka (Michigan State University) would serve as Secretary, Roger Coulombe (Utah State University) as Vice President, and David Williams (Oregon State University) as President. The responsibilities of the Rewrite Committee (Bill Helfrich, Roger Coulombe and Ron Riley) for drafting the renewal proposal was discussed. It was suggested that the committee should meet the day before the 2011 meeting (12 October 2011) to discuss the rewrite. The meeting was adjourned at around 10:00 am on 22 October.

Accomplishments

OBJECTIVE 1. Determine mechanisms of action by which food-borne bioactive compounds protect against human diseases such as cancer, inflammation, birth defects, and microbial infection.<br /> <br /> Dr. Pratibha Nerurkar, University of Hawaii In Hawaii, Native Hawaiians and Pacific Islanders have the highest rates of obesity-associated diabetes, and Filipinos and Japanese in Hawaii have higher incidences of diabetes associated with abdominal fat accumulation. Current therapies for obesity are complicated due to factors including an inability to maintain long-term weight loss and drug-drug interactions. In addition, conventional therapies may not be affordable, suitable and/or acceptable for culturally sensitive minority populations.<br /> <br /> Momordica charantia, commonly known as bitter melon (BM) has been traditionally used in Chinese and Ayurvedic medicine, to treat diabetes and its complications. Similarly, Morinda citrifolia, commonly known as noni has been traditionally used in Hawaiian medicine, to treat diabetes and other chronic diseases. Our goal was to test the efficacy of BM and noni using cell culture and animal models.<br /> <br /> We have demonstrated earlier that BM can improve not only glucose and lipid metabolism, but also prevent weight gain in mice fed high-fat-diet (HFD) containing 58% fat. To extrapolate our studies to humans, we further tested the anti-obesity effects of BM in primary human adipocyte cell cultures. Our data indicates that BM reduced lipid accumulation and increases lipolysis in primary human adipocytes obetained commercially from overweight individuals.<br /> <br /> In a separate study we tested the anti-diabetic and anti-obesity effects of noni juice using male C57BL/6 mice fed high-fat-diet (HFD) containing 58% fat. Our data demonstrates that noni prevents weight gain and improves fasting glucose as well as glucose and insulin tolerance test in HFD-fed mice. Mechanistic studies further demonstrate that noni improves fasting glucose by inhibiting hepatic gluconeogenesis via transcription factor, forkhead box O (FoxO).<br /> <br /> Our studies help to demonstrate the efficacy of traditional medicine and identify molecular targets that can lead to drug discovery.<br /> <br /> James Pestka, Dr. Hui-ren Zhou, Brenna Flannery, Xiao Pan, Kaiyu He, Michigan State We will determine the mechanisms by which selected compounds exert their protective action. Food-borne toxins and carcinogens are present per se or are induced by processing, preparation, and other post-harvest steps. We will identify mechanisms of action and develop biomarkers of natural and induced toxicants in food for human risk assessment and disease prevention.<br /> <br /> Worldwide, obesity is a growing epidemic in need of prevention and intervention strategies. The effects of ingesting the common foodborne mycotoxin deoxynivalenol (DON) on body weight and composition were characterized in the high fat (HF) diet-induced obese mouse model. Female B6C3F1 mice were initially fed HF diets containing 45% kcal (HF45) or 60% kcal (HF60) as fat for 94 d to induce obesity. Half of each group was either continued on unamended HF diets or fed HF diets containing 10 mg/kg DON (DON-HF45 or DON-HF60) for another 54 d. Additional control mice were fed a low fat (LF) diet containing 10% kcal as fat for the entire 148 d period. DON induced rapid decreases in body weights and fat mass, which stabilized to those of the LF control within 11 d. These effects corresponded closely to a robust transient decrease in food consumption. While lean body mass did not decline in DON-fed groups, further increases were suppressed. DON exposure reduced plasma insulin, leptin, insulin-like growth factor 1 and insulin-like growth factor acid labile subunit as well as increased hypothalamic mRNA level of the orexigenic agouti-related protein. Overall, DON-mediated effects on body weight, fat mass, food intake and hormonal levels were consistent with a state of chronic energy restriction.<br /> <br /> Consumption of deoxynivalenol (DON), a trichothecene mycotoxin commonly detected in cereal-based foods, causes impaired growth in many animal species. While growth retardation is used as a basis for regulating DON levels in human food, the underlying mechanisms remain poorly understood. Consumption of deoxynivalenol (DON), a trichothecene mycotoxin commonly detected in cereal-based foods, causes impaired growth in many animal species. While growth retardation is used as a basis for regulating DON levels in human food, the underlying mechanisms remain poorly understood. Oral exposure of mice to DON rapidly induces multi-organ expression of proinflammatory cytokines and this is followed by upregulation of several suppressors of cytokine signaling (SOCS), some of which are capable of impairing growth hormone (GH) signaling. The purpose of this study was to test the hypothesis that impairment of the GH axis precedes DON-induced growth retardation in the mouse. Subchronic dietary exposure of young (4-wk old) mice to DON (20 ppm) over a period of 2 to 8 wk was found to: (1) impair weight gain, (2) result in a steady-state plasma DON concentration (40-60 ng/ml), (3) downregulate hepatic insulin-like growth factor acid labile subunit (IGFALS) mRNA expression and (4) reduce circulating insulin-like growth factor 1 (IGF1) and IGFALS levels. Acute oral exposure to DON at 0.5-12.5 mg/kg bw markedly suppressed hepatic IGFALS mRNA levels within 2 h in a dose-dependent fashion whereas 0.1 mg/kg bw was without effect. DON-induced IGFALS mRNA upregulation occurred both with and without exogenous GH treatment. These latter effects co-occurred with robust hepatic SOCS3 upregulation. Taken together, these data suggest that oral DON exposure perturbs GH axis by suppressing two clinically relevant growth-related proteins, IGFALS and IGF1. Both have potential to serve as biomarkers of effect in populations exposed to this common foodborne mycotoxin. The trichothecenes are a group of over 200 sequiterpenoid metabolites that can dysregulate cell signaling and modulate growth and immune function. Our results illustrate the dual nature of many natural chemicals in that they can promote both beneficial and adverse health effects depending on dose. Outcomes of the trichothecene mechanism studies here will include improved understanding of the molecular basis by which trichothecenes affect obesity and growth. This research will identify new targets for controlling the obesity pandemic. The data will also directly inform regulators involve in human risk assessment thus enabling better management of the risks from DON to the U.S. public.<br /> <br /> OBJECTIVE 2. Identify mechanisms of action and biomarkers of natural and induced toxicants in food for human risk assessment and disease prevention.<br /> <br /> Leonard F. Bjeldanes, Principal Investigator, Gary Firestone, Co-Investigator, UCB In our continued studies of the modes of action and potential efficacy of phytochemicals as cancer preventive and therapeutic agents, we examined the mechanism of action of Brassica indoles (I3C and derivatives) as inhibitors of cell proliferation and as modulators of estrogen receptor signaling. A. Direct Inhibition of elastase activity by indole-3-carbinol triggers a CD40-TRAF regulatory cascade that disrupts NF-ºB transcriptional activity in human breast cancer cells. Treatment of highly tumorigenic MDA-MB-231 human breast cancer cells with indole-3-carbinol (I3C) directly inhibited the extracellular elastase-dependent cleavage of membrane-associated CD40, a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 signaling has been implicated in regulating cell survival, apoptosis, and proliferation, as well as in sensitizing breast cancer cells to chemotherapy, and is therefore an important potential target of novel breast cancer treatments. The I3C-dependent accumulation of full-length unprocessed CD40 protein caused a shift in CD40 signaling through TNF receptorassociated factors (TRAF), including the TRAF1/TRAF2 positive regulators and TRAF3 negative regulator of NF-ºB transcription factor activity. Because TRAF1 is a transcriptional target gene of NF-ºB, I3C disrupted a positive feedback loop involving these critical cell survival components. siRNA ablation of elastase expression mimicked the I3C inhibition of CD40 protein processing and G1 cell cycle arrest, whereas siRNA knockdown of TRAF3 and the NF-ºB inhibitor IºB prevented the I3C-induced cell cycle arrest. In contrast, siRNA knockdown of PTEN had no effect on the I3C control of NF-ºB activity, showing the importance of CD40 signaling in regulating this transcription factor. Our study provides the first direct in vitro evidence that I3C directly inhibits the elastase-mediated proteolytic processing of CD40, which alters downstream signaling to disrupt NF-ºBinduced cell survival and proliferative responses.<br /> <br /> B. Indole-3-carbinol triggers aryl hydrocarbon receptor-dependent estrogen receptor (ER)alpha protein degradation in breast cancer cells disrupting an ER alpha-GATA3 transcriptional cross-regulatory loop. Estrogen receptor (ER)alpha is a critical target of therapeutic strategies to control the proliferation of hormone-dependent breast cancers. Preferred clinical options have significant adverse side effects that can lead to treatment resistance due to the persistence of active estrogen receptors. We have established the cellular mechanism by which I3C) ablates ER alpha expression, and we have uncovered a critical role for the GATA3 transcription factor in this indole-regulated cascade. I3C-dependent activation of the aryl hydrocarbon receptor (AhR) initiates Rbx-1 E3 ligase-mediated ubiquitination and proteasomal degradation of ERa protein. I3C inhibits endogenous binding of ER alpha with the 3-enhancer region of GATA3 and disrupts endogenous GATA3 interactions with the ER alpha promoter, leading to a loss of GATA3 and ER alpha expression. Ectopic expression of GATA3 has no effect on I3C-induced ER alpha protein degradation but does prevent I3C inhibition of ERÿý promoter activity, demonstrating the importance of GATA3 in this I3C-triggered cascade.<br /> <br /> C. 1-Benzyl-indole-3-carbinol is a novel indole-3-carbinol derivative with significantly enhanced potency of anti-proliferative and anti-estrogenic properties in human breast cancer cells. A new and significantly more potent I3C analogue, 1-benzyl-I3C, was synthesized and in comparison to I3C, this novel derivative displayed an approximate 1000-fold enhanced potency in suppressing the growth of both estrogen responsive (MCF-7) and estrogen-independent (MDA-MB-231) human breast cancer cells (I3C IC50 of 52 microM, and 1-benzyl-I3C IC50 of 0.05 microM). At significantly lower concentrations, 1-benzyl-I3C induced a robust G1 cell cycle arrest and elicited the key I3C-specific effects on expression and activity of G1-acting cell cycle genes including the disruption of endogenous interactions of the Sp1 transcription factor with the CDK6 promoter. Furthermore, in estrogen responsive MCF-7 cells, with enhanced potency 1-benzyl-I3C down-regulated production of ER alpha protein, acts with tamoxifen to arrest breast cancer cell growth more effectively than either compound alone, and inhibited the in vivo growth of human breast cancer cell-derived tumor xenografts in athymic mice.<br /> <br /> Collaborations: We share samples and discuss various aspects of our work with D. Williams (OSU) and J. Pestka (MSU).<br /> <br /> Our studies have identified for the first time a molecular target for I3C provide the basis for further investigations of both the clinical usefulness of the I3C derivatives in hormone-related cancers. The studies also provide further evidence for the modes of action of I3C that will be important in the potential development of more active and less toxic pharmaceuticals based on this indole. We plan to examine the primary molecular events that are responsible for the cytostatic effects of DIM in breast tumor cells. We also plan to further characterize the immune modulation effects of DIM and mechanism of action. We will screen fungi and plants from Indonesia for activities against cancer, immune disorders and neurological problems. The results of our cell culture studies continue to support the notion that certain indoles present in food plants will be useful in the control of some cancers and other hormone related disorders.<br /> <br /> RONALD T. RILEY, K. Voss, N. Zitomer, T. Glenn, C. Bacon, USDA, Athens, GA Exposure and mechanism-based biomarkers are needed to determine if fumonisins are contributing factors in human disease. ARS researchers in Athens, Georgia have developed methods that will be used in Guatemala to measure urinary fumonisin in humans and lipid biomarkers in blood spots. A human subject's research protocol was also approved for a study in the USA to validate our methods for fumonisin in urine and sphingoid base 1-phosphates in blood spots. These studies have revealed that only fumonisin B1 is excreted in urine even though other fumonisins are approximately 30% of the total fumonisin consumed. We found that the amount of fumonisin B1 excreted is less than 1% of the dose and that it is cleared from the urine very rapidly (<96 h). A method was also developed for measuring sphingoid base 1-phosphates in blood spots. Studies were conducted to determine the limits of detection, recoveries and stability of samples in blood spots collected on FTA elute cards and stored dessicated at -20oC.<br /> <br /> The findings from the extrusion study described under objective 4 below have also provided additional information on the relationships between sphingolipid metabolism disruption and toxicity. Both microscopic pathology scores and total Sa concentrations were tightly correlated with the daily FB1 intakes. It is also noteworthy that deoxy Sa was not found in the livers or kidneys. Deoxy Sa, which is produced when alanine is substituted for serine in the first step of de novo sphingolipid biosynthesis, accumulated in the livers of mice following exposure to FB1 via the diet or intraperitoneal injection. The absence of deoxy Sa in rat liver suggest that sphingolipid metabolism in rats and mice differ in some respects and that these differences might influence their target organ-specific responses to fumonisin exposure. Additional studies are warranted to more thoroughly characterize sphingolipid metabolic responses to FB1 in these and other species and to better understand the relationships between disrupted sphingolipid metabolism and nephrotoxicity. Fumonisin B1 (FB1) is found in maize and maize-based food and is a suspected risk factor for cancer or birth defects in humans. Fusarium verticillioides fermented maize grits (Batch-1= 9.7 ppm FB; Batch-= 50 ppm) were extruded without (Batch-1E; Batch-2E) or with 10% glucose supplementation (Batch-1EG; Batch-2EG). FB1 concentrations after cooking were: Batch-1E = 2.7 ppm; Batch-1EG = 0.6 ppm; Batch-2E = 18 ppm; and Batch-2EG = 5.7 ppm: FB1 concentrations were reduced 64% (Batch-2E) to 94% (Batch-1EG). The raw and processed grits were fed (50% w/w in rodent chow) to rats for up to 8 weeks. FB1 intakes averaged 354, 103, and 25.1 µg/kg body weight/day for Batch-1, Batch-1E and Batch-1EG and 1804, 698, and 222 µg/kg body weight/day for the Batch-2, Batch-2E and Batch-2EG, respectively. Dose-dependent kidney effects included apoptotic lesions and elevated sphingoid base concentrations found in the groups fed Batch-1, Batch-1E, Batch-2, Batch-2E, or Batch-2EG. In contrast, kidney lesions and sphingoid base elevations were absent in the Batch-1EG group. Therefore, extrusion with glucose supplementation reduced FB1 concentrations in contaminated maize grits to levels that were not toxic in vivo.<br /> <br /> Developing exposure and mechanistic markers provides us with a tool to pinpoint high risk populations for the studies in humans and will aid us in our goal to reveal the factors (genetic and nutritional) leading to possible increased susceptibility to neural tube defects in populations where maize consumption is high and diets are likely to be deficient in folate. These studies are critical if we are to develop an understanding of fumonisin potential for involvement in human disease. Demonstrating that extrusion cooking alone or with sugar supplementation reduces fumonisin concentrations and in vivo toxicity improves confidence in the efficacy of extrusion for reducing fumonisins without the production of unknown, toxic fumonisin breakdown products.<br /> <br /> OBJECTIVE 3. Discover bioactive compounds that have beneficial or adverse effects on human health.<br /> <br /> Bill Helferich, UNIVERSITY OF ILLINOIS, URBANA (Dr. Judy Yang, Jim Hartman, Wendan Wang) Soy isoflavones, genistein and daidzein, are widely consumed in soy-based foods and dietary supplements for their putative health benefits; however, evidence for potential adverse effects has been obtained from experimental animal studies. An important prerequisite for understanding the pharmacodynamics of isoflavones is better information about pharmacokinetics and bioavailability. This study determined the bioavailability of genistein and daidzein in a mouse model by comparing plasma pharmacokinetics of their aglycone and conjugated forms following administration of identical doses (1.2 mg/kg genistein and 0.55 mg/kg daidzein) by either an intravenous injection (IV) or gavage of the aglycones in 90% aqueous solution vs a bolus administration of equimolar doses delivered in a food pellet prepared using commercial soy protein isolate (SPI) as the isoflavone source. The bioavailability of genistein and daidzein was equivalent for the gavage and dietary routes of administration despite the use of isoflavone aglycones in the former and SPI-derived glucosides in the latter. While absorption of total isoflavones was nearly quantitative from both oral routes [>84% of areas under the curve (AUCs) for IV], presystemic and systemic phase II conjugation greatly attenuated internal exposures to the receptor-active aglycone isoflavones (9-14% for genistein and 29-34% for daidzein based on AUCs for IV). These results show that SPI is an efficient isoflavone delivery vehicle capable of providing significant proportions of the total dose into the circulation in the active aglycone form for distribution to receptor-bearing tissues and subsequent pharmacological effects that determine possible health benefits and/or risks.<br /> <br /> Usefulness of Findings: Tools to study metastasis are limited and here we have used bioluminescence imaging to follow metastasis of a highly metastatic tumor cell line (4T1) from a mouse mammary cancer. The findings presented here indicate that BLI can be used to effectively follow metastatic progression in an animal model.<br /> <br /> MICHAEL S. DENISON, UNIVERSITY OF CALIFORNIA, DAVIS (Dr. B. Zhao, Dr. G. He, Dr. A. Hayashi) The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that plays a key regulatory role in endogenous developmental and physiological processes and also is responsible for mediating the toxic and biological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related halogenated aromatic hydrocarbons (HAHs) and polycyclic aromatic hydrocarbons (PAHs). In addition, agonists/antagonists of the AhR have been shown to exert a variety of anticarcinogenic effects and as such, it has become a target for development of therapeutic agents. Studies from many laboratories have demonstrated that the AhR can bind and be activated by a structurally diverse range of synthetic and naturally-occurring chemicals (including endogenous chemicals), but the lack of crystal structure of the AhR ligand binding domain (LBD) has prevented mechanistic analysis to attempt to explain this binding diversity. Site-directed mutagenesis and ligand binding/activation studies and more recent improvements in our AhR LBD structural homology model, have provided fairly convincing evidence that while structurally distinct AhR agonists produce a similar activation effect on the AhR, they appear to differentially interact with amino acids within the AhR ligand binding pocket. This differential binding hypothesis has been supported by: 1) mechanism-based common reactivity pattern (COREPA) modeling of structurally diverse AhR ligands, 2) demonstration of the ability of mutations of selected amino acids within the AhR LBD to differentially affect the binding and activation of the AhR by various ligands, and 3) our identification of a novel AhR antagonist (CH23191) that can specifically antagonize some AhR ligands (i.e. TCDD and related halogenated aromatic hydrocarbons), but not other ligands (i.e. beta-naphthoflavone, a variety of polycyclic aromatic hydrocarbons (PAHs) and other PAH-like AhR agonists). Taken together, we these results provide key insights into the mechanisms contributing to the demonstrated structural diversity of AhR ligands and raise questions as to whether these differential interactions could contribute to ligand-dependent differences in AhR-dependent toxic and biological effects.<br /> <br /> We have also improved and expanded our recombinant cell-based bioassay systems for detection of AhR agonists and these improved third generation (G3) cell bioassays have a 10-50-fold increased sensitivity and produce more than a 100- to 1,000-fold greater induction response to AhR agonists. These improved G3 cell bioassays have the sensitivity needed for screening of food samples for low level contamination of dioxin and dioxin-like chemicals. These improved bioassays also have significant application for high-throughput screening to identify novel AhR agonists and antagonists that have potential therapeutic applications.<br /> <br /> We have developed and optimized an improved recombinant human cell G3 bioassay for detection and characterization of human AhR ligands (agonists and antagonists). This new bioassay has been used in a variety of applications. It has been used to identify a novel human-specific AhR antagonist that can promote the expansion of human hematopoietic stem cells and thus has significant therapeutic potential. In addition, our human G3 cell bioassay has been used for high-throughput screening of >300,000 compounds from an NIH chemical library to identify AhR agonists (as part of a NIH X01 grant) and initial screening has identified >100 novel compounds that appear to be specific for the AhR (they failed to activate another promiscuous ligand-activated receptor (i.e. the pregnane X receptor (PXR)). These compounds are being further characterized for their ability to specifically activate the AhR and AhR-responses.<br /> <br /> Our analyses of the promiscuity of AhR ligand binding has revealed significant differences in the ability of HAHs (i.e. dioxin and dioxin like compounds) to bind to the AhR in a manner distinctly different than that of nontoxic AhR agonists (i.e. flavonoids, indirubins and PAHs). These observations could suggest that differences in how these toxic and non-toxic AhR ligands bind to the AhR could contribute to their differential ability to produce beneficial and/or adverse effects in exposed animals. We have identified and characterized the ability of CH223191 to selectively antagonize the ability of toxic HAHs to bind to and activate the AhR, with little or no effect on PAHs and other nontoxic AhR ligands. CH223191 is the first ligand-selective AhR identified to date and given its selectivity, it has potential as a therapeutic agent (or lead compound to generate a therapeutic agent) that can block the toxicological and biological effects of toxic HAHs, while not inhibiting the ability of non-toxic/beneficial AhR ligands to bind to and activate the AhR. Our improved third generation recombinant cell-based bioassay systems for detection of AhR agonists are currently being evaluated and subjected to validation studies by the European Union for adoption as an EU approved screening method for dioxins and related HAHs in food. We will continue our characterization and analysis of the binding of naturally-occurring and synthetic chemicals to the AhR by high-throughput gene expression analysis using our improved cell gene expression bioassay systems, molecular docking studies using our improved AhR LBD homology model, and in vitro ligand and DNA binding analysis. Structure-activity relationship analysis of novel AhR agonists (from our high-throughput screening analysis) as well as antagonists (CH223191, its derivatives and several other promising compounds) will also be carried out using AhR-based in vitro and cell-based bioassays as well as molecular docking studies to further understand the mechanisms by which structurally diverse chemicals bind to the AhR LBD to produce agonist or antagonist responses. In addition, we will examine the mechanisms responsible for species-specific antagonist activity of several newly identified compounds.<br /> <br /> Donato F. Romagnolo, Andreas J. Papoutsis, Ornella Selmin, Jamie Borg, University of Arizona The BRCA-1 protein is a tumor suppressor involved in repair of DNA damage. Epigenetic mechanisms contribute to its reduced expression in sporadic breast tumors. Through diet, humans are exposed to a complex mixture of xenobiotics and natural ligands of the aromatic hydrocarbon receptor (AhR), which contribute to the etiology of various types of cancers. The AhR binds xenobiotics, endogenous ligands, and many natural dietary bioactive compounds, including the phytoalexin resveratrol (Res). In estrogen receptor- alpha (ER alpha )-positive and BRCA-1 wild-type MCF-7 breast cancer cells, we investigated the influence of AhR activation with the agonist 2,3,7,8 tetrachlorobenzo(p)dioxin (TCDD) on epigenetic regulation of the BRCA-1 gene and the preventative effects of Res. We found that activation and recruitment of the AhR to the BRCA-1 promoter hampers 17 beta -estradiol (E2)-dependent stimulation of BRCA-1 transcription and protein levels. These inhibitory effects are paralleled by reduced occupancy of ER alpha, acetylated histone (AcH)-4, and AcH3K9. Conversely, the treatment with TCDD increases the association of mono-methylated-H3K9, DNA-methyltransferase-1 (DNMT1), and methyl-binding domain protein-2 with the BRCA-1 promoter and stimulates the accumulation of DNA strand breaks. The AhR-dependent repression of BRCA-1 expression is reversed by small interference for the AhR and DNMT1 or pretreatment with Res, which reduces TCDD-induced DNA strand breaks. These results support the hypothesis that epigenetic silencing of the BRCA-1 gene by the AhR is preventable with Res and provide the molecular basis for the development of dietary strategies based on natural AhR antagonists. This was an exploratory study developed to investigate the opportunities for targeting of cyclooxygenase-2 (COX-2) expression with bioactive food components for the prevention of colon cancer. Factors related to diet and life style have been identified as primary determinants in about 80% of colorectal cancers. Non-steroidal anti-inflammatory drugs (NSAID) and selective (COX-2) inhibitors (COXIB) reduce the relative risk of colon cancer. To overcome systemic COX inhibition associated with NSAID and COXIB, there is a growing interest in developing alternative colon cancer prevention strategies using diet-based approaches that target COX-2. The transition from aberrant crypt foci (ACF) to colon cancer is a multiyear process providing opportunities for nutritional targeting of genes influencing the course of this disease process at early stages of development. The activation of the proinflammatory gene COX-2 and PG production in the colonic mucosa are recognized risk factors in colon cancer. Many natural food components may impact colon cancer risk by interfering with ligand-activated receptors, signal transduction pathways, and transcription factors involved in stimulation of COX-2 expression. In a systematic review of published studies, we highlighted key upstream features of signaling pathways and transcriptional control of the COX-2 gene and discussed opportunities for dietary modulation of COX-2 expression in gastro-intestinal cancers with special emphasis on prevention of colorectal tumors. Review of the experimental evidence suggests that dietary strategies based on specific or cocktails of bioactive food components as well nutritional-pharmacological combinations targeted to regulation of COX-2 expression and activity may prove useful in the prevention of colon cancer. An integrated approach may offer the advantage of combined higher efficacies. Future studies should investigate the efficacy of combinations of bioactive food compounds on epigenetic regulation of the COX-2 gene and characterize potential synergies and amplification effects resulting from the concomitant use of bioactive food components and COX-2 inhibitors.<br /> <br /> We continue our work related to epigenetic silencing of tumor suppressor genes induced by the AhR and are currently developing animal models to test this hypothesis in vivo.<br /> <br /> OBJECTIVE 4. Develop strategies to increase beneficial or decrease adverse effects of bioactive food constituents and microbial contaminants.<br /> <br /> David E. Williams, Roderick Dashwood, Robert Tanguay, Oregon State University This program will continue to focus on mechanisms of cancer prevention by food now with addition funding from the National Cancer Institute to test phytochemicals from cruciferous vegetables (indole-3-carbinol and sulforaphane) and compare the efficacy of these dietary supplements to the whole foods from which they were derived. The focus will be on colon, prostate and transplacental cancer (lymphoma, lung and liver). Studies are also underway to further investigate mechanisms of action of mycotoxins in food, primarily aflatoxin B1, the potential for this mycotoxin to cross the placenta and cause liver cancer later in life in the offspring and how we can supplement the mothers diet to provide protection from that exposure. The program is now partnering closer with The Linus Pauling Institute at Oregon State University to maximize the impact of the research and we have a new emphasis on the exciting area of epigenetics. In summary, this program seeks to identify, understand, and eliminate, in so far as practicable, the specific toxicants in the food supply that contribute to health deficits as well as mechanisms of agent for dietary chemopreventive, beneficial food components. The addition of high-throughput assays utilizing zebrafish embryos allows us to screen many different natural products for beneficial effects against development toxicants.<br /> <br /> Dr. Dashwood has continued to study how the isothiocyanate phytochemical from cruciferous vegetables, sulforaphane, acts as an HDAC (histone deacetylase) inhibitor. HDACs are very important in gene regulation as deacetylation of histone tends to compact the structure of DNA and inhibit transcription. There are numerous HDAC inhibitors, some of which are now being used to treat human disease including cancer. HDAC inhibitors tend to maintain a relatively open chromatin structure enhancing transcription. Dr. Dashwood has determined that the metabolites of sulforaphane are much more potent HDAC inhibitors than the parent compound. He is applying this knowledge to enhance our understanding of the most efficient ways to inhibit cancer (primarily colon) through diet. Dr. Williams is continuing with his work on the transplacental model of cancer chemoprevention. Work underway will determine whether pure phytochemical or whole food is more effective in protection of the fetus from carcinogens that can cross the placenta, when is the critical time of exposure for the fetus for maximum protection. In collaboration with Dr. Dashwood, the mechanism of this protection is under study, i.e., is the mechanism of protection epigenetic? If so, is it possible to carry this protection through to the F3 (great-grandchildren) generation? Both Dr. Williams and Dr. Dashwood are initiating chemoprevention studies with cruciferous vegetables with human volunteers. This enhances the translational nature of the research and the impact on human health.<br /> <br /> There have been many outcomes to our research in chemoprevention by diet. We have published this work in quality journals, been invited to speak at national and international meetings as well as academic institutions. The popular press has also found this story to be very interesting. In 2010, Drs. Dashwood and Williams (along with Dr. Emily Ho from Nutrition and Food Management) obtained 6.8 million dollar, five year grant from the National Cancer Institute of the NIH to continue these studies.

Publications

Wu QX, Crews MS, Draskovic M, Sohn J, Johnson TA, Tenney K, Valeriote FA, Yao XJ, Bjeldanes LF, Crews P. Azonazine, a novel dipeptide from a Hawaiian marine sediment-derived fungus, Aspergillus insulicola.Org Lett. 2010 Sep 24. [Epub ahead of print] PMID: 20866076<br /> <br /> Nguyen HH, Lavrenov SN, Sundar SN, Nguyen DH, Tseng M, Marconett CN, Kung J, Staub RE, Preobrazhenskaya MN, Bjeldanes LF, Firestone GL.1-Benzyl-indole-3-carbinol is a novel indole-3-carbinol derivative with significantly enhanced potency of anti-proliferative and anti-estrogenic properties in human breast cancer cells. Chem Biol Interact. 2010 Aug 5;186(3):255-66. Epub 2010 Jun 2. PMID: 20570586<br /> <br /> Aronchik I, Bjeldanes LF, Firestone GL. Direct inhibition of elastase activity by indole-3-carbinol triggers a CD40-TRAF regulatory cascade that disrupts NF-kappaB transcriptional activity in human breast cancer cells. Cancer Res. 2010 Jun 15;70(12):4961-71. Epub 2010 Jun 8. PMID: 20530686<br /> <br /> Vivar OI, Saunier EF, Leitman DC, Firestone GL, Bjeldanes LF. Selective activation of estrogen receptor-beta target genes by 3,3'-diindolylmethane.Endocrinology. 2010 Apr;151(4):1662-7. Epub 2010 Feb 16. PMID: 20160136<br /> <br /> Marconett CN, Sundar SN, Poindexter KM, Stueve TR, Bjeldanes LF, Firestone GL. Indole-3-carbinol triggers aryl hydrocarbon receptor-dependent estrogen receptor (ER)alpha protein degradation in breast cancer cells disrupting an ERalpha-GATA3 transcriptional cross-regulatory loop. Mol Biol Cell. 2010 Apr 1;21(7):1166-77. Epub 2010 Feb 3. PMID: 20130088<br /> <br /> Iwaniec, U.T., Dube, M.G., Boghossian, S., Song, H., Helferich, W.G., Turner, R.T., and Kalra, S.P., (2009). Body mass influences cortical bone mass independent of leptin signaling. Bone. 44(3): p. 404-12. PMID: 19095090 NIHMSID: NIHMSID98145<br /> <br /> Legette, L.L., Martin, B.R., Shahnazari, M., Lee, W.H., Helferich, W.G., Qian, J., Waters, D.J., Arabshahi, A., Barnes, S., Welch, J., Bostwick, D.G., and Weaver, C.M., (2009). Supplemental dietary racemic equol has modest benefits to bone but has mild uterotropic activity in ovariectomized rats. J Nutr. 139(10):1908-13. PMID: 19710157 PMCID: PMC2744611<br /> <br /> Zhang, Y., Li, Q.,Wan, HY, Helferich,WG, Wong, MS. (2009). Genistein and a Soy Extract Differentially Affect Three-Dimensional Bone Parameters and Bone-Specific Gene Expression in Ovariectomized Mice. J. Nutr., Dec 2009; 139: 2230 - 2236. PMID: 19793844<br /> <br /> Neese, S.L., Wang, V.C., Doerge, D.R., Woodling, K.A., Andrade, J.E., Helferich, W.G., Korol, D.L., and Schantz, S.L., (2010). Impact of dietary genistein and aging on executive function in rats. Neurotoxicol Teratol. 32(2): p. 200-211. PMID: 19945528<br /> <br /> Hsu, A., Bray, T.M., Helferich, W.G., Doerge, D.R., and Ho, E., (2010). Differential effects of whole soy extract and soy isoflavones on apoptosis in prostate cancer cells. Exp. Biol. Med. 2010;235:90-7. PMID: 20404023<br /> <br /> Andrade, J. E., Twaddle, N.C., Helferich, W.G. and Doerge, D.R., (2010). Absolute Bioavailability of Isoflavones from Soy Protein Isolate-Containing Food in Female Balb/c Mice. J Agric Food Chem;58:4529-36. PMID: 20225898<br /> <br /> Cimafranca, M.A., Davila, J., Ekman, G.C., Andrews, R.N., Neese, S.L., Peretz, J., Woodling, K.A., Helferich, W.G., Sarkar, J., Flaws, J.A., Schantz, S.L., Doerge, D.R., and Cooke, P.S. (2010). Acute and chronic effects of oral genistein administration in neonatal mice. Biol Reprod. Biol Reprod 2010;83:114-21. PMID: 20357267<br /> <br /> Hilakivi-Clarke, L. Andrade, J.E., and Helferich. W.G. (2010). Is Soy Consumption good or bad for the breast? J. of Nutrition. 140(12):2326S-34S. Epub 2010 Oct 27. PMID: 20980638 PMCID: PMC2981011 Yang, X., Belosay, A., Du, M., Hartman, J.A., Jackson, M., Fan, T.M., Turner, T.R., Iwaniec, U.T., and Helferich, W.G. (2011). Evaluating Breast Cancer Metastasis Using Bioluminescence Imaging and Murine Models. Submitted<br /> <br /> De Assis, S., Warri, A. , Benitez, C. , Helferich, W.G.,and Hilakivi-Clarke, L.A., (2011). Protective effects of prepubertal genistein exposure on mammary tumorigenesis are dependent on BRCA1 expression. Cancer Prevention Research. In Press.<br /> <br /> Morisseau, C., Merzlikin, O. Lin, A., He, G. Feng, W., Padilla, I., Denison, M.S., Pessah, I.N. and Hammock, B.H. (2009) Toxicology in the fast lane: Application of high-throughput bioassays to detect modulation of key enzymes and receptors, Environ. Health Perspect., 117, 1867-1872. PMC2799460<br /> <br /> Petko, P.I., Rowlands, J.C., Budinsky, R., Zhao, B., Denison, M.S. and Mekenyan, O. (2010) Mechanism based common reactivity pattern (COREPA) modeling of AhR binding affinity, SAR QSAR Environ. Res., 21, 187-214. PMID: 20373220<br /> <br /> Zhao, B., Baston, D.S., Khan, E., Sorrentino, C. and Denison, M.S. (2010) Enhancing the response of CALUX and CAFLUX cell bioassays for quantitative detection of dioxin-like compounds, Science China Chemistry (Science in China Series B) 53, 1010-1016.<br /> <br /> Boitano, A.E., Wang, J., Romeo, R., Bouchez, L.C., Parker, AE., Sutton, S.E., Walker, J.R., Flaveny, C.A., Perdew, G.H., Denison, M.S., Schultz, P.G. and Cooke, M.P. (2010) Aryl hydrocarbon receptor antagonists promote the expansion of human hematopoietic stem cells, Science, 329, 1345-1348. PMID 2068898<br /> <br /> Zhao, B., DeGroot, D., Hayashi, A., He, G. and Denison, M.S. (2010) CH223191 is a ligand-selective antagonist of the Ah (dioxin) Receptor, Toxicol. Sci. 117, 393-403. PMID 20634293<br /> <br /> Nerurkar P, Ray RB. Bitter melon: antagonist to cancer. Pharm Res. 2010 Jun;27(6):1049-53. Epub 2010 Mar 3. PMID: 20198408<br /> <br /> Ray RB, Raychoudhuri A, Steele R, Nerurkar P. Bitter melon (Momordica charantia) extract inhibits breast cancer cell proliferation by modulating cell cycle regulatory genes and promotes apoptosis. Cancer Res. 2010 Mar 1;70(5):1925-31. Epub 2010 Feb 23. PMID: 20179194<br /> <br /> Nerurkar PV*, Lee Y-K and Nerurkar VR. Y-K. Momordica charantia (bitter melon) inhibits primary human adipocyte differentiation by modulating adipogenic genes. BMC Complement Altern Med. 2010 10: 34-41. Epub 2010 July 01. PMCID: 2911406<br /> <br /> Islam, Z., Shinozuka, J., Harkema, J.R., and Pestka, J.J. 2010. Purification and comparative neurotoxicity of the trichothecenes satratoxin G and roridin 12 from Stachybotrys chartarum. J. Toxicol. Environ. Health A., 116(2):433-40. PMC2808125.<br /> <br /> Pestka, J.J. 2010. Deoxynivalenol: mechanisms of action, human exposure, and toxicological relevance. Arch. Toxicol. 84:663-679, PMID 20798930. Pestka, J.J. 2010. Deoxynivalenol-induced proinflammatory gene expression: Mechanisms and pathological sequelae. Toxins 2:1300-1317.<br /> <br /> Lichtenstein, J.H., Molina, R.M., Donaghey, T.C., Amuzie, C.J., Pestka, J.J., Coull, B.A., and Brain, J.D. 2010. Pulmonary responses to Stachybotrys chartarum and its toxins: Mouse strain affects clearance and macrophage cytotoxicity. Toxicol. Sci. 116:113-121, PMID: 203855656.<br /> <br /> Pestka, J.J. 2010. n-3 polyunsaturated fatty acids and autoimmune-mediated glomerulonephritis. Prostaglandins Leukot. Essent. Fatty Acids 82:251-258, PMC2885141.<br /> <br /> Bae, H., Gray, J.S., Li, M., Vines, L., Kim, J., and Pestka, J.J. 2010. Hematopoietic cell kinase associates with the 40S ribosomal subunit and mediates the ribotoxic stress response to deoxynivalenol in mononuclear phagocytes. Toxicol. Sci. 115:444-452, PMC2902856.<br /> <br /> Rakkestad, K.E., Skaar, I., Ansteinsson, V.E., Solhaug, A., Holme, J.A., Pestka, JJ., Sanuelsen, J.T., Dahlman, H.J., Hongslo, J.K., Becher, R. 2010. DNA damage and DNA damage responses in THP-1 monocytes after exposure to spores of either Stachybotrys chartarum or Aspergillus versicolor or to T-2 toxin. Toxicol. Sci. 115:1242-1251, PMC2902923.<br /> <br /> Corps, K.N., Islam, Z., Pestka, J.J., and Harkema, J.R. 2010. Neurotoxic, inflammatory, and mucosecretory responses in the nasal airways of mice repeatedly exposed to the macrocyclic trichothecene mycotoxin roridin A: dose-response and persistence of injury. Toxicol. Pathol. 38:429-451, PMID: 20430879.<br /> <br /> Amuzie, C.J., Islam, Z., Kim, J., Seo, J., and Pestka, J.J. 2010. Kinetics of satratoxin G tissue distribution and excretion following intranasal exposure in the mouse. Toxicol. Sci. 116:433-440, PMID: 20466779.<br /> <br /> Maddox, J.F., Amuzie, C.J., Li, M., Newport, S.W., Sparkenbaugh, E., Cuff, C.F., Pestka, J.J., Cantor, G.H., Roth, R.A., and Ganey, P.E. 2010. Bacterial- and viral-induced inflammation increases sensitivity to acetaminophen hepatotoxicity. J. Toxicol. Environ. Health A 73:58-73, PMID: 19953420.<br /> <br /> Seo, J., Kim, J., and Pestka, J.J. Induction of Apoptosis in Primary Mesangial Cell by Deoxynivalenol. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> Kim, J., Seo, J., Hegg, C., and Pestka, J.J. Role of erk in oxidative stress-induced apoptosis in the op6 olfactory sensory neuron cell line. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> Shimada, N., Kim, J., Shinozuka, J., Hegg, C.C., and Pestka, J.J. Translation-dependent and independent mechanisms for satratoxin g-induced apoptosis. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> Flannery, B., Amuzie, C., Ulrich, A, and Pestka, J.J. Deoxynivalenol ingestion prevents and ameliorates diet-induced obesity in the mouse. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> He, K., Vines, L., and Pestka, J.J. Deoxynivalenol-induced modulation of microrna expression in raw 264.7 macrophagesa potential novel mechanism for translational inhibition. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> Vines, L.L., Langohr, I.M., and Pestka, J.J. Consumption of docosahexaenoic acid attenuates lupus nephritis-related gene expression and disease progression in NZBWF1 Mice. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> Hattori, K., Flannery, B., Amuzie, C., and Pestka, J.J. Modulation of body fat mass and lean weight in deoxynivalenol-induced body weight reduction in the obese mouse. Toxicologist, 2010. Annual Meeting of the Society of Toxicology, Salt Lake City, UT, March 2010.<br /> <br /> O'Donnell, K., Gueidan, C., Sink, S., Johnston,P.R., Crous, P., Glenn, A., Riley, R., Zitomer, N., Colyer, P., Waalwijk, C., van der Lee, T., Moretti, A., Kang, S., Kim, H-S., Geiser, D.M., Juba, J., Baayen, R.P., Cromey, M.G., Bithel, S., Sutton, D.A., Skovgaard, K., Ploetz, R., Kistler, C., Elliott, M., Davis, M. (2009) A two-locus DNA sequence database for typing plant and human pathogens within the Fusarium oxysporum species complex. Fungal Genetics and Biology 46: 936948. 2009<br /> <br /> Voss, K.A., Riley, R.T., Snook, M.E., Gelineau-van Waes, J. (2009) Comparing the reproductive and sphingolipid metabolic effects of fumonisin B1 and its alkaline hydrolysis product in LM/Bc mice: hydrolyzed fumonisin B1 did not cause neural tube defects. Toxicological Sciences 112: 459-67.<br /> <br /> Zitomer NC, Jones, S., Bacon CW, Glenn AE, Baldwin, T. and Riley, R.T. (2010) Sphingoid bases and their 1-phosphates, but not fumonisins, are translocated from roots to aerial tissues of maize seedlings watered with fumonisins. Journal of Agricultural and Food Chemistry 58:7476-7481, 2010<br /> <br /> Riley, R. T., Voss, K. A., Coulombe, R. A., Pestka, J. J. and Williams, D. E. (in press) Developing mechanism-based and exposure biomarkers for mycotoxins in animals. In De Saeger, S. (ed.) Determining Mycotoxins and Mycotoxigenic Fungi in Food and Feed, Ghent University, Woodhead Publishing Limited, Cambridge, UK. pp 245-275.<br /> <br /> Riley, R.T., Voss, K.A., Zitomer, N., Glenn, A., Burns, T., Merrill, A.H. Jr., Torres, O. and Gelineau van Waes, J. (2010) Use of mechanism-based and exposure biomarkers to assess fumonisin toxicity in humans, animals and plants and efficacy of processing methods using mechanism-based bioassays. Proceedings of the VI Latin American Congress of Mycotoxicology and the II International Symposium on Algal and Fungal Toxins for Industry 2010. pp. 40-43 Universidad Nacional Autonoma de Mexico, Mexico City, 2010.<br /> <br /> Papoutsis AJ, Lamore SD, Wondrak GT, Selmin OI, Romagnolo DF. Resveratrol prevents epigenetic silencing of BRCA-1 by the aromatic hydrocarbon receptor in human breast cancer cells. J Nutr. 2010 Sep;140(9):1607-14. Epub 2010 Jul 14.<br /> <br /> Romagnolo DF, Papoutsis AJ, Selmin O. Nutritional targeting of cyclooxygenase-2 for colon cancer prevention. Inflamm Allergy Drug Targets. 2010 Jul 1;9(3):181-91.<br /> <br /> Milner J.A., and Romagnolo D.F. Nutrigenomics and Cancer Biology. In: Bioactive Food Components and Cancer, Humana Press/Springer. Eds. Milner and Romagnolo (2010).<br /> <br /> Romagnolo D.F., Degner SC, and Selmin, O. Aryl Hydrocarbon Receptor-mediated Carcinogenesis and Modulation by Dietary Xenobiotic and Natural Ligands, In: Bioactive Food Components and Cancer, Humana Press/Springer. Eds. Milner and Romagnolo.(2010).<br /> <br /> Swanson, H.I., Njar, V.C.O., Yu, Z., Castro, D.J., Gonzalez, F.J., Williams, D.E., Kong, A.-N.T., Waxman, D.J. and Scott, E.E. (2010) Symposium Article: Targeting Drug Metabolizing Enzymes for Effective Chemoprevention and Chemotherapy. Drug Metabol. Dispos 38:539-544.<br /> <br /> Celius, T., Pansoy, A., Matthews, J., Okey, A.B., Henderson, M.C., Krueger, S.K., and Williams, D.E. (2010) Flavin-Containing Monooxygenase 3: Induction by 3-Methylcholanthrene and Complex Regulation by Xenobiotic Chemicals in Hepatoma Cells in Culture and Mouse Liver. Toxicol. Appl. Pharmacol. 247:60-69.<br /> <br /> Salinas, K., Hemmer, M.J, Serrano, J., Higgins, L., Anderson, L.B., Benninghoff, A.D., Williams, D.E and Walker, C. (2010) Isolation of Estrogen-Responsive Vitelline Envelope Protein Fragments from Rainbow Trout (Oncorhynchus mykiss) Plasma Using Mass Spectrometry. Molec. Reprod. Develop. 77:963-970.<br /> <br /> Larsen, C.A. and Dashwood, R.H. (2010) (-)-Epigallocatechin-3-gallate Inhibits Met Signaling, Proliferation, and Invasiveness in Human Colon Cancer Cells. Arch. Biochem. Biophys. 501:52-57.<br /> <br /> Ho, E. and Dashwood, R.H. (2010) Dietary Manipulation of Histone Structure and Function. World Rev. Nutr. Diet. 101:95-102.<br /> <br /> Larsen, C.A., Dashwood, R.H. and Bisson, W.H. (2010) Tea Catechins as Inhibitors of Receptor Tyrosine Kinases: Mechanistic Insights and Human Relevance. Pharmacol. Res. 62:457-464.<br /> <br /> Huang, H., Huang, C., Wang, L., Ye, X., Bai, C., Simonich, M.T., Tanguay, R.L. and Dong, Q. (2010) Toxicity, Uptake Kinetics and Behavior Assissment in Zebrafish Embryos Following Exposure to Perfluorooctanesulphonicacid (PFOS). Aquat. Toxicol. 98:139-147.<br /> <br /> Hillwalker, W.E., Allan, S.E., Tanguay, R.L. and Anderson, K.A. (2010) Exploiting Lipid-Free Tubing Passive Samplers and Embryonic Zebrafish to Link Site Specific Contaminant Mixtures to Biological Responses. Chemosphere 79:1-7.<br /> <br /> Tal, T.L., Franzosa, J.A. and Tanguay, R.L. (2010) Molecular Signaling Networks that Choreograph Epimorphic Fin Regeneration in Zebrafish- a Mini-Review. Gerontology 56:231-240.<br /> <br /> ODonnell, E.F., Saili, K.S., Koch, D.C., Kopparapu, P.R., Farrer, D., Bisson, W.H., Mathew, L.K., Sengupta, S., Kerkvliet, N.I., Tanguay, R.L. and Kolluri, S.K. (2010) The Anti-Inflammatory Drug Leflunomide is an Agonist of the Aryl Hydrocarbon Receptor. PLoS One Oct 1; 5(10). pii:e13128.<br /> <br /> Truong, L. Harper, S.L. and Tanguay, R.L. (2011) Evaluation of Embryotoxicity Using the Zebrafish Model. Methods Molec. Biol. 691:271-279.<br /> <br /> Wang, R., Dashwood, W.M., Nian, H., Löhr, V.C., Fischer, K.A., Tsuchiya, N., Nakagama, H., Ashktorab, H. and Dashwood, R.H. (2010) NADPH Oxidase Overexpression in Human Colon Cancers and Rat Colon Tumors Induced by 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Int. J. Cancer, in press.<br /> <br /> Hsu, A., Bruno, R.S., Löhr, CV, Taylor, A.W., Dashwood, R.H., Bray, T.M. and Ho, E. (2010) Dietary Soy and Tea Mitigate Chronic Inflammation and Prostate Cancer Via NKkappaB Pathway in the Noble Rat Model. J. Nutr. Biochem., in press.<br /> <br /> Riley, R.T., Voss, K.A., Coulombe, R.A. Jr., Pestka, J.J. and Williams, D.E. (201x) Developing Mechanism-Based and Exposure Biomarkers for Mycotoxins in Animals, in Determining Mycotoxins and Mycotoxigenic Fungi in Food and Feed, S. De Saeger (ed.), Woodhead Publishing Limited, Cambridge, U.K., in press.<br /> <br /> Benninghoff, A.D., Bisson, W.H., Koch, D.C., Ehresman, D.J., Kolluri, S.K. and Williams, D.E. (201x) Estrogen-Like Activity of Perfluoralky Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro. Toxicol. Sci. in press.<br /> <br /> Rajendran, Praveen, Williams, David E., Ho, Emily and Dashwood, Roderick H. (2011) Metabolism as a Key to Histone Deacetylase Inhibition. Crit. Rev. Biochem. Molec. Biol., in press.<br /> <br /> Choi, S.-H.; Lee, S.-H.; Kim, H.-J.; Lee, I.-S.; Kozukue, N.; Levin, C. E.; Friedman, M. Changes in free amino acid, phenolic, chlorophyll, carotenoid, and glycoalkaloid contents in tomatoes during 11 stages of growth and inhibition of cervical and lung human cancer cells by green tomato extracts. J. Agric. Food Chem. 2010, 58, 7547-7556.<br /> <br /> Choi, S. P.; Kim, S. P.; Kang, M. Y.; Nam, S. H.; Friedman, M. Protective effects of black rice bran against chemically-induced inflammation of mouse skin. J. Agric. Food Chem. 2010, 58, 10007-10015. Friedman, M. Origin, microbiology, nutrition, and pharmacology of D-amino acids. Chemistry & Biodiversity. 2010, 7, 1491-1530. Invited review.<br /> <br /> Friedman, M.; Juneja, V. K. Review of antimicrobial and antioxidative activities of chitosans in food. J. Food Protection 2010, 73, 1737-1761.<br /> <br /> Juneja, V. K.; Hwang, C.-A.; Friedman, M. Thermal inactivation and postthermal treatment growth during storage of multiple Salmonella serotypes in ground beef as affected by sodium lactate and oregano oil. J. Food Sci. 2010, 75, M1-M6.<br /> <br /> Jung, J.-K.; Lee, S.-U.; Kozukue, N.; Levin, C. E.; Friedman, M. Distribution of phenolic compounds and antioxidative activities in parts of sweet potato (Ipomoea batata L.) plants and in home processed roots. J. Food Composition and Analysis 2010, 23, published online: http://dx.doi.org/10.1016/j.jfca.2010.1003.1025.<br /> <br /> Rasooly, R.; Do, P. M.; Friedman, M. Inhibition of biological activity of Staphylococcal enterotoxin A (SEA) by apple juice and apple polyphenols. J. Agric. Food Chem. 2010, 58, 5421-5426. R asooly, R.; Do, P. M.; Levin, C. E.; Friedman, M. Inhibition of Shiga toxin 2 (Stx2) in apple juices and its resistance to pasteurization. J. Food Sci. 2010, 75, M296M301.<br /> <br /> Rasooly, R.; Do, P. M.; Griffey, S. M.; Vilches-Moure, J. G.; Friedman, M. Ingestion of Shiga toxin 2 (Stx2) causes histopathological changes in kidney, spleen and thymus tissues and mortality in mice. J. Agric. Food Chem. 2010, 58, 92819286.<br /> <br /> Rayburn, J. R.; Friedman, M. L-cysteine, N-acetyl-L-cysteine, and glutathione protect Xenopus laevis embryos against acrylamide-induced malformations and mortality in the Frog Embryo Teratogenesis Assay (FETAX). J. Agric. Food Chem. 2010, 58(20), 11172-11178. Ravishankar, S.; Zhu, L.; Olsen, C. W.; McHugh, T. H.; Friedman, M. Edible apple film wraps containing plant antimicrobials inactivate foodborne pathogens on meat and poultry products. J. Food Sci. 2009, 74, M440-M445.<br /> <br /> Ravishankar, S.; Zhu, L.; Reyna-Granados, J.; Law, B.; Joens, L.; Friedman, M. Carvacrol and cinnamaldehyde inactivate antibiotic-resistant Salmonella enterica in buffer and on celery and oysters. J. Food Protection. 2010, 73, 234-240.<br /> <br /> Tsuchida, H.; Kozukue, N.; Han, G.-P.; Choi, S.-H.; Levin, C. E.; Friedman, M. Low-temperature storage of cucumbers induces changes in the organic acid content and in citrate synthase activity. Postharvest Biology and Technology 2010, 58, 129-134.

Impact Statements

1. The impact of the studies from UC Berkeley demonstrate the modes of action and potential efficacy of phytochemicals as cancer preventive and therapeutic agents as modulators of estrogen receptor signaling
2. The impact of the studies from the University of Illinois are important because the development of tools to study metastasis allows researcher, for the first time, to follow metastatic progression in vivo using bioluminescence imaging.
3. The impact of studies from the University of California at Davis in which improved bioassays are utilized have significant application for high-throughput screening to identify novel AhR agonists and antagonists that have potential therapeutic applications.
4. The impact of the studies from the University of Hawaii on bitter melon help to demonstrate the efficacy of traditional medicine and identify molecular targets and have the potential that may lead to drug discovery.
5. The impact of the finding from the USDA, Athens, GA indicate that fumonisins have the potential for involvement in human disease and which will likely have an impact on human health.

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Report Information

Participants

Administrative Advisor Michael Harrington (wdal@lamar.colostate.edu) - Colorado State University
Dave Williams (david.williams@oregonstate.edu) - Oregon State University
Len Bjeldanes (lfb@nature.berkeley.edu) - University of California, Berkeley
Roger Coulombe (roger@usu.edu) - Utah State University
Mendel Friedman (mfried@pw.usda.gov) - USDA-WRRC Albany, CA
Bill Helferich (helferic@uiuc.edu) - University of Illinois
Jim Pestka (pestka@msu.edu) - Michigan State University
Ron Riley (ron.riley@ars.usda.gov) - USDA-ARS Athens, GA
Michael Denison (msdenison@ucdavis.edu) - University of California, Davis
Tiffany Weir (Tiffany.Weir@colostate.edu)- Colorado State University
Prathiba Nerurkar (pratibha@hawaii.edu)- University of Hawaii
Marie-Louise Ricketts (mricketts@cabnr.unr.edu)- University of Nevada

Brief Summary of Minutes

W-1122: Beneficial and Adverse Effects of Natural, Bioactive Dietary Chemicals on Human Health and Food Safety Annual meeting of the technical committee, October 12-14, 2011 Calistoga, CA

The annual meeting was called to order at 0830 Thursday morning, October 13th, 2011.

Advisor Michael Harrington provided a report on the updated priorities and administrative structure of USDA NIFA as well as changes to AFRI. He also presented budget projections for FY 2012. Because of the upcoming project renewal the remainder of Dr. Harringtons remarks was focused on determining and communicating the impact of our efforts. This included defining outputs versus impacts and discussion on writing impact statements. After Dr. Harrington's comments the annual reports were given as follows:

Technical Reports
Williams, Dave - Oregon State University
Bjaldanes, Len - University of California at Berkeley
Coulomb, Roger - Utah State University
Weir, Tiffany - Colorado State University
Helferich, William - University of Illinois
Nerurkar, Prathiba - University of Hawaii
Pestka, James - Michigan State University
Friedman, Mendel - USDA-WRRL
Denison, Michael - UC Davis
Ricketts, Marie-Louise  University of Nevada

Writing assignments and revision of the new project plan for the next five years were discussed and changes were made by the group to the draft document. Newly written sections will be submitted to Dr. Coulomb who will compile the final proposal for submission. The W2122 project plan is due January 2012.

The regular business portion of the meeting commenced at 0830 on Friday, October 14th. Estes Park, Colorado was selected as the site for the 2012 meeting. For 2012, Marie-Louise Ricketts was selected to serve as Secretary, Tiffany Weir as Chair-elect and James Pestka as Chair. The meeting was adjourned at around 1200.

Accomplishments

Accomplishments<br /> ACCOMPLISHMENTS FOR THE ENTIRE SPAN OF THE PROJECT ARE SUMMARIZED BEGINNING WITH 2011<br /> The activities described below have addressed specific components of the W2122 Multistate project as outlined in the milestones document for the project. Many of the activities have been collaborative efforts among W2122 participants and all have benefited from the critical review provided by all participants at the annual meetings and throughout the year. Over the five year span of the project, the activities described below have been documented by approximately 300 publications and numerous reports and data provided to industry, consumers, and authoritative bodies. Participants have also disseminated results at meetings of professional societies such as the Phytochemical Society of North America, Society of Toxicology, and at Keystone meetings and Gordon conferences.<br /> OBJECTIVE 1. Consumption of food-borne bioactive compounds can protect against human diseases such as cancer, inflammation, birth defects, and microbial infection. We will determine the mechanisms by which selected compounds exert their protective action.<br /> <br /> 2011<br /> In collaborative efforts with multiple entities, Dr. Friedman at USDA, ARS, Albany found that mushroom extracts inactivated leukemia cells in vitro and reduced tumor size in tumor bearing mice. They also found that rice hull smoke extracts inactivated Salmonella in apple juice and protected infected mice against mortality and alloxan-induced diabetic mice against diabetes. Similarly, carvacrol, the main ingredient of oregano oil, and cinnamaldehyde, the main ingredient of cinnamon oil, facilitated thermal destruction of multiple Salmonella strains in ground chicken.<br /> <br /> The Albany group and collaborators also found that the olive compound hydroxytyrosol inactivated both Staphylococcus aureus bacteria and the Staphylococcus enterotoxin A (SEA) and that an olive extract inhibited Salmonella bacteria on organic leafy greens. An olive extract and onion powder also inactivated E. coli O157:H7 and inhibited the formation of carcinogenic heterocyclic amines in grilled ground beef patties. <br /> <br /> The group in Hawaii demonstrated that noni juice improves glucose and lipid metabolism, and prevents weight gain in high-fat-diet (HFD fed mice. Their work indicates a role for chronic inflammation in the pathophysiology of obesity and Type 2 diabetes, and suggests that noni improves HFD-associated systemic inflammation by reducing secretions of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFa), interferon-gamma (INFg), interleukin 6 (IL-6), and hepatic inflammation. Noni is a Polynesian ethnomedicine, and may be used to alleviate health disparities among culturally sensitive populations such as Native Hawaiians. <br /> At Colorado State University, researchers are conducting a clinical dietary intervention (called BENEFIT) in a colon cancer survivor population to assess the potential for bioactive rice bran and bean phytochemicals to increase the levels of beneficial microbes present in the gut microbial community resulting in modulation of mucosal immune responses and the increased the production of anti-tumerogenic and anti-inflammatory microbial metabolites such as butyrate and other short chain fatty acids (SCFAs). They have identified a target community of potentially harmful and beneficial microbes and are assessing how they may be altered by dietary rice bran or dry bean. These results are important because they could result in new dietary recommendations for colon cancer prevention and identify microbial and metabolite biomarkers that could be used to assess risk or evaluate responses to a particular intervention. <br /> <br /> 2007 to 2010<br /> Researchers from UC-Berkeley examined the mechanism of action of Brassica indoles (indole-3-carbinol and derivatives) as inhibitors of cell proliferation and as modulators of estrogen receptor signaling and determined that direct inhibition of elastase activity by indole-3-carbinol triggers a CD40-TRAF regulatory cascade that disrupts NF-ºB transcriptional activity in human breast cancer cells. Indole-3-carbinol also triggers aryl hydrocarbon receptor-dependent estrogen receptor (ER)a protein degradation in breast cancer cells disrupting an ERa-GATA3 transcriptional cross-regulatory loop. They also identified 1-Benzyl-indole-3-carbinol as a novel indole-3-carbinol derivative with significantly enhanced potency of anti-proliferative and anti-estrogenic properties in human breast cancer cells. <br /> The group from the University of Hawaii examined bitter melon (BM) and noni , two plants used in traditional Polynesian medicine, for anti-obesity and anti-diabetic effects in mouse models. They determined that both plants improved glucose and lipid metabolism and prevented weight gain. BM reduced lipid accumulation and increased lipolysis in primary human adipocytes obtained commercially from overweight individuals and lowered plasma apolipoprotein B (apoB) by improving hepatic insulin receptor phosphorylation and its downstream signaling molecules. Noni improved fasting glucose by inhibiting hepatic gluconeogenesis via transcription factor, forkhead box O (FoxO). These studies help to demonstrate the efficacy of traditional medicine and identify molecular targets that can lead to drug discovery. <br /> Through diet, humans are exposed to a complex mixture of xenobiotics and natural ligands of the aromatic hydrocarbon receptor (AhR), which contribute to the etiology of various types of cancers. A W2122 team from the University of Arizona found that epigenetic silencing of the BRCA-1 breast cancer gene by the AhR is preventable with resveratol and provides a molecular basis for the development of dietary strategies based on natural AhR antagonists. They determined that AhR directly participates in the trans-activation of the COX-2 promoter and that this mechanism is a potential target for dietary agents in the prophylactic management against stimulation of COX-2 expression by AhR agonists. <br /> The Utah State W2122 researchers developed poultry as a model for sensitivity to dietary carcinogens, like aflatoxin B1 (AFB1), and responsiveness to chemopreventives such as phenolic antioxidants. This model offers several advantages over traditional rodent models because the turkeys lack detoxifying glutuathione S-transferases (GSTs) and efficiently bioactivate AFB1 to the reactive exo-AFB1-8,9-epoxide (AFBO) .<br /> The team at Oregon State identified that chlorophyllin and indole-3-carbinol were very effective in inhibition of transplacental carcinogenesis due to administration of the polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DBP) to pregnant mice. <br /> The group at University of Illinois found that breast cancer patients with tamoxifen treatment consume considerable isoflavone supplements, and that the potential combined effect of tamoxifen and genistein, present in isoflavone supplements, may result in significant undesirable outcome on mammary tumors. <br /> W2122 researchers at Michigan State found that trichothecene mycotoxin deoxynivalenol (DON) induced interleukin-6 (IL-6)-dependent IgA nephropathy (IgAN) in mice can be prevented by feeding long chain n-3 polyunsaturated fatty acids (PUFAs) found in fish oil. DON-induced IL-6 expression is CREB-mediated and PKR-dependent and the requisite kinase activities for these pathways were suppressed in macrophages from mice fed docosahexaenoic acid (DHA) for an extended period. <br /> Scientists from USDA-ARS, Albany collaboratively developed a computational model that revealed that the number of hydrogen bonds formed by seven tea catechins with simulated cell membranes correlates with our published observations on relative antimicrobial and inhibitory effects of the same catechins against Bacillus cereus and human cancer cells, respectively. Computational modeling of catechin-cell membrane relationships contribute to understanding of molecular mechanisms of antimicrobial and anticancer activities of catechins. <br /> OBJECTIVE 2. Food-borne toxins and carcinogens are present per se or are induced by processing, preparation, and other post-harvest steps. We will identify mechanisms of action and develop biomarkers of natural and induced toxicants in food for human risk assessment and disease prevention.<br /> <br /> 2011<br /> The Utah group has utilized their poultry (turkey) model for testing extreme sensitivity to dietary carcinogens, like aflatoxin B1 (AFB1), and responsiveness to chemopreventives. They used a genomic approach and biochemical characterization of GSTs aimed at identifying genetic markers related to AFB1 susceptibility and resistance in turkeys. They also identified P450 1A5 as the dominant enzyme responsible for AFB1 bioactivation and metabolism at environmentally-relevant AFB1 concentrations in turkey liver. These results provide a basis for breeding for increased resistance to aflatoxins in farm raised turkeys. <br /> <br /> The group at Michigan State assessed the effects of ingesting the foodborne mycotoxin, deoxynivalenol (DON), on body weight and composition in a high fat (HF) diet-induced obese mouse model. They found that DON induced rapid decreases in body weights and fat mass of but not in decline of lean mass. DON exposure also reduced plasma insulin, leptin, insulin-like growth factor 1 and insulin-like growth factor acid labile subunit as well as increased hypothalamic mRNA level of the orexigenic agouti-related protein. Overall, DON-mediated effects on body weight, fat mass, food intake and hormonal levels were consistent with a state of chronic energy restriction. <br /> The group at Michigan State also devised a short-term mouse model to investigate induction of food refusal by DON. They found that transient and DON dose-dependent induction of anorexia occurred within 2 h of exposure. This short-term mouse bioassay was useful in characterizing DON-induced anorexia and should be applicable to elucidating mechanisms underlying this adverse nutritional effect.<br /> The USDA-ARS, Athens group has collaborated with scientists at the University of Nebraska Medical Center to determine the possible role of fumonisin(FB)-induced elevation of sphingoid base 1-phosphates, ligands for S1P Receptors (S1P1-5) as a risk factor for neural tube defects in mice. They are also exploring urinary FB as an exposure marker and sphingolipid base 1-phospatase as a mechanistic marker. The results strongly suggest that the lysophospholipid receptors known as S1PR could play a key role in fumonisin-induced NTD in mice. This is an important discovery and provides a potential human risk factor which is being explored in a human study conducted in Guatemala. <br /> 2007 to 2010<br /> W2122 researchers at Michigan State found that oral DON exposure perturbs the growth hormone axis by suppressing two clinically relevant growth-related proteins, IGFALS and IGF1. Both have potential to serve as biomarkers of effect in populations exposed to this common foodborne mycotoxin. They also found that young mice are modestly more susceptible than adult mice to the adverse effects of DON and that this might result from a greater toxin tissue burden.<br /> The Michigan State group has also identified mechanisms related to the molecular affects of trichothecene on obesity and growth. This research will identify new targets for controlling the obesity pandemic and will directly inform regulators involved in human risk assessment thus enabling better management of the risks from DON to the U.S. public. This group has also studied translational inhibitors such as DON and ribosomal inactivating proteins (RIPs), which induce mitogen-activated protein kinase (MAPK)-driven chemokine and cytokine production by a mechanism known as the ribotoxic stress response (RSR). They found that ricin cleaves 28S rRNA directly and indirectly via RNase induction whereas DON induces 28S rRNA cleavage only by indirect induction of RNases. They also found that double-stranded RNA-activated protein kinase plays a common role in IL-8 induction by DON and two RIPs, suggesting that this kinase might be a critical factor in ribotoxic stress response. <br /> The group at USDA-ARS, Athens identified lysophospholipid receptors known as S1PR that could play a key role in fumonisin-induced neural tube defects in mice. This is an important discovery and provides a potential human risk factor which could be explored in translational studies. They also developed a questionnaire to identify heavy consumers of maize products in that can be utilized in human trials and a method to measure urinary fumonisin and lipid biomarkers in blood spots. They also made progress in characterizing sphingolipid metabolic responses to FB1 to better understand the relationships between disrupted sphingolipid metabolism and nephrotoxicity. <br /> Researchers from Oregon State have identified Cyp1b1 as a new gene target for chemoprevention of PAH-induced transplacental cancers. These studies have identified a critical window for prevention efficacy. This group also provided the most complete pharmacokinetic analysis ever conducted for AFB1 in humans, and the first evidence that natural chlorophyll can reduce systemic uptake of AFB1 from the GI tract in humans.<br /> The Illinois group showed that the dietary supplement Avlimil, containing 11 different botanicals, had either estrogenic or anti-estrogenic properties depending on the dietary dosage, suggesting that Avlimil may not be safe for women with estrogen-dependent breast cancer. <br /> OBJECTIVE 3. Selected classes of bioactive compounds show potential for beneficial or adverse effects on human health. We will discover bioactive compounds that have beneficial or adverse effects on human health. <br /> 2011 <br /> As part of a large multi-national study, the group at UC-Berkeley has been evaluating microbial and plant sources from Indonesia for anticancer, immune modulating and neurological activities and to provide in vitro bioassay support for discovery of the active components. They continue to employ cell-based assays for cytotoxicity in cultured tumor cells, NF-kB activation or inhibition in cultured macrophages, and opioid G-protein coupled receptor (GPCR) activation or inhibition in cultured human kidney cells as well as conducting follow-up studies in rodents. They have identified a number of bioactive microbial extracts that show selective cytotoxicity in breast cancer cell line MDA-MB-231 and against PC3 and LNCaP prostate tumor cells. An isolated mixture of two flavonoids-like compounds was identified to have cytostatic activity against MCF-7 cells. <br /> <br /> The UC-Berkeley group has also identified a number of lead fractions that show potent anti-inflammatory activity. Fraction H29 was highly active in the RAW-KB assay with low cytostatic activity. One compound was identified as penicillic acid (PCA) and strongly induced phosphorylation of Erk1/2, possibly activating the formyl peptide receptor that activates expression of TNF-a. Other leads are being tested for dose-response and being subjected to further chemical analysis for compound identification.<br /> <br /> The team at UC-Davis has continued to utilize recombinant human cell lines containing an aryl hydrocarbon receptor (AhR)-responsive luciferase gene as a high throughput screen to identify anti-carcinogenic AhR agonists. They have screened a chemical library of >324,000 compounds (counter screened with a pregnane X-receptor cell bioassay) and identified 108 AhR-selective agonists. These compounds have been subsequently screened for their ability to directly bind to and activate the AhR and AhR-dependent gene expression and also to act as both activators and inhibitors of estrogen receptor-dependent gene expression and cell proliferation. Several candidate compounds have been identified and are currently being modified for structure activity relationship analysis to optimize the structure for antiestrogenic functional characteristics. <br /> <br /> UC-DAVIS group has also refined a homology model of the ligand binding domain (LBD) for both analysis of the binding of ligands and ligand-dependent AhR activation. This has resulted in improvements to the model and they are now beginning docking analysis of ligands with the AhR LBD and to use this information to predict binding characteristics of structurally diverse ligands. Results generated by modeling have provided insights into how structurally diverse ligands can bind to the AhR LBD, but still activate the AhR by a common mechanism.<br /> <br /> The UC-Davis group has continued to enhance and improve their cell bioassay systems for AhR. These developments include amplification of the number of AhR DNA binding sites in the luciferase reporter plasmid and stable transfection of this vector into cell lines and the generation of mouse, rat, human and guinea pig third generation recombinant cell lines. These cell lines have been optimized to identify contamination by dioxin-like chemicals in food screening. <br /> <br /> The Colorado State University group is also examining the bioactive components from a fermented Chinese tea that has shown cytotoxic effects against colon cancer cell lines HT-29 and CaCo-2 as well as antimicrobial activity against Staphylococcus aureus and Shigella sonnei. They have identified novel fatty acid amines that likely originate from the fermenting fungus and may contribute to this teas bioactivity in vitro.<br /> <br /> The team from Illinois explored the effects of letrozole on breast cancer metastasis in a rodent model. They developed a BC metastasis model in which mammary tumor cells are injected in to the marrow cavity and metastasis from bone to lung is followed by bioluminescent imaging (BLI). Their goal was to study the effects of letrozole on BC metastasis from bone to lung in mice inoculated with murine 4T1 cancer cells. They observed that there were significantly fewer tumors on the lungs in mice in the Letrozole group compared with the Intact Control group. Letrozole was also effective to inhibit cancer cell proliferation in lungs indicated by Ki-67 staining. As a conclusion, letrozole may inhibit BC metastasis in mice inoculated with murine 4T1 cancer cells, especially in intact mice.<br /> <br /> 2007 to 2010<br /> The research team at UC-Davis developed and optimized an improved recombinant human cell G3 bioassay for detection and characterization of human AhR ligands (agonists and antagonists). This new bioassay has been used in a variety of applications. It has been used to identify a novel human-specific AhR antagonist that can promote the expansion of human hematopoietic stem cells and thus has significant therapeutic potential. <br /> <br /> This group also identified twenty synthetic flavonoids relatively potent AhR agonists, several with relative potencies in the nM range. The ability of these chemicals to inhibit the proliferation of human hepatocarcinoma and breast cancer cell lines, but not those of other AhR-containing cancer cell lines (A431) demonstrated their potential as chemotherapeutic activity in selected cancer cell types. The identification of a novel chemical that can act as an antagonist of the ability of the most potent ligand of the AhR, namely that of the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but not that of the flavonoids, provided strong support for differential ligand binding of chemicals to the AhR.<br /> The UC-Davis team has developed a three-dimensional homology model of the mouse AhR (mAhR) PAS B ligand binding domain by extending this analysis using comparative structural modeling studies of the ligand binding domains of six additional high affinity mammalian AhRs. These results, coupled with site directed mutagenesis and AhR functional analysis, has allowed detection of the "TCDD-binding fingerprint" of conserved residues within the ligand binding cavity necessary for high affinity TCDD binding and TCDD-dependent DNA binding. <br /> Researchers from Oregon State have determined that the metabolites of sulforaphane are much more potent histone deacetylase inhibitors than the parent compound. They are applying this knowledge to enhance understanding of the most efficient ways to inhibit cancer (primarily colon) through diet. <br /> The UC-Berkeley team found that an extract of 22 herbs, MF101, is an estrogen receptor beta agonist. They also isolated liquiritigenin, the most active estrogenic compound from the root of Glycyrrhizae uralensis Fisch, which is one of the plants found in MF101. Liquiritigenin activated multiple ER regulatory elements and native target genes with ERb but not ERa. These results demonstrate that some plants contain highly selective estrogens for ERb. They also demonstrated that DIM binds to the oligomycin binding site on the F1 transmembrane component on mitochondrial F1F0-ATPase and is an ERb-selective compound that might be an alternative to estrogens that are used in hormone therapy, which non-selectively activate both ER subtypes and are associated with increased breast cancer risk. They also showed that DIM can decrease the accumulation and activity of the key angiogenesis regulatory factor, HIF-1a, in hypoxic tumor cells.<br /> N-Alkoxy derivatization of indole-3-carbinol (I3C) increases the efficacy of the G1 cell cycle arrest of human MCF-7 breast cancer cells. The group at UC-Berkeley established the first I3C structure activity relationship for cytostatic activities, and implicates I3C-based N-alkoxy derivatives as a novel class of potentially more potent experimental therapeutics for breast cancer. <br /> The W2122 research team from Hawaii found that momordicosides and triterpenoids from bitter melon specifically demonstrated hypoglycemic effects in diabetic mice, but there appears to be a synergistic effect with the whole food having more activity than the fractionated components. <br /> OBJECTIVE 4. Modifying foods is an increasingly important strategy to improve nutrition and safety. Therefore, we will improve food safety by developing approaches to increase beneficial or decrease adverse effects of bioactive food constituents and microbial contaminants.<br /> 2011<br /> The group at Colorado State University has explored how the bioactivity of certain foods may be potentiated through microbial fermentation. Often anti-oxidant flavonoids and other bioactive chemicals are attached to plant cell wall matrices or are present as poorly absorbed glycosides. Fermentation of foods pre-consumption may enhance both the amount and bioavailability of these compounds by converting them to more easily absorbed aglycone forms or releasing them from ligno-cellulose matrices. The CSU team determined that Sacchromyces boulardii-fermentation of rice bran alters its phytochemical profile and increased cytotoxicity against Raji lymphoma cells and Caco-2 and HT-29 colon cancer cell lines. In vivo pharmacokinetics to study bioavailability of rice bran components are underway. <br /> <br /> The group from USDA-ARS, Albany has developed edible fruit and vegetable based anti-microbial films that can be used to mitigate the presence of food-borne pathogens like E. coli and Salmonella on meat products. <br /> <br /> The team from USDA-ARS, Athens has identified mechanisms of fumosin translocation and disruption of sphingolipid metabolism in maize seedlings. Plant debris in fields can be a significant source of fumonisins and thus the factors which control fumonisin entry into plant parts could reduce the levels of fumonisins in field debris. These results are important because they could result in new strategies for resistance to Fusarium verticilliodes maize seedling diseases. <br /> <br /> 2007 to 2010<br /> The USDA-ARS Athens group demonstrated that extrusion cooking alone or with sugar supplementation reduces fumonisin concentrations and in vivo toxicity, improving confidence in the efficacy of extrusion for reducing fumonisins without the production of unknown, toxic fumonisin breakdown products. <br /> The USDA-ARS, Albany group have found that apple based edible antimicrobial films wrapped on contaminated ham and stored at 23 or 4°C for 72 hrs induced multi-log reductions in Listeria monocytogenes. In a collaborative study we also found that apple and tomato based edible films containing the plant essential oils from allspice, bay leaf, clove bud, thyme, and vanilla inactivated E. coli O157:H7 both in direct contact and in the vapor phase. These finding support the possible commercial use of the films and indicate that they may provide antimicrobial benefits, even when not in contact with the food.<br /> <br /> They also discovered that the addition of a polyphenol-rich apple skin powder to contaminated ground beef reduced by up to two-thirds the time needed to heat-inactivate E. coli O157:H7. This finding suggests possible changes in culinary practice that may benefit consumers. Another study found that cinnamaldehyde, cinnamon oil, carvacrol, oregano oils, 2,5-dihydroxybenzaldeyde, and 2-hydroxy-2-methoxyenzaldehyde inactivated Mycobacterium avium paratuberculosis that infects cattle and contaminates raw milk. Because there are no effective treatments for this organism, this finding offers new possibilities to protect cattle and milk against this virulent pathogen. <br />

Publications

Impact Statements

1. Studies conducted as part of this project have demonstrated that natural chlorophyll and its derivatives can substantially reduce the uptake and distribution of a particular Aflatoxin, AFB1. Aflatoxins are a form of naturally occurring mycotoxins produced by several species of Aspergillus fungi and are perhaps the most carcinogenic substances known. These results have implications for assessing the risk from AFB1 exposure and for people in parts of Asia and Africa where as many as 10% of adults may die of aflatoxin-related liver cancer and in the U.S., where lung and liver cancer kill thousands each year and Hepatitis B and C infections are high.
2. 2. Antioxidants such as BHT (butylated hydroxytoluene) reduce harmful AFB1 in turkey meat products. Finding cancer-preventative strategies in domestic foods like poultry will help American agriculture produce safer products for consumers.
3. 3. Studies in mice fed high fat diets with bitter melon juice showed improved fasting glucose and glucose and insulin tolerance. In addition, the mice had reduced levels of triglycerides, very low density lipoproteins (VLDL), and low density lipoproteins (LDL). At least 47-million Americans are afflicted with a type of metabolic syndrome (hypertension, type 2 diabetes, and cardiovascular diseases). These findings could lead to new dietary strategies for treatment or prevention of obesity-associated type 2 diabetes.
4. 4. Fumonisin, a mycotoxin, contributes to maize seedling disease, causing plants to produce toxic compounds that may impact the plant and animals that eat it. Studies conducted as part of this project have demonstrated that only fumonisin B1 compounds accumulate in the plants leaf tissue, a discovery that could greatly simplify risk assessments, saving millions of taxpayer dollars by focusing monitoring for exposure on only those compounds known to build up.
5. 5. Research conducted as part of this project indicates that Bitter Melon (BM) prevents obesity-associated metabolic disorders such as diabetes and hyperlipidemia. Bitter melon is widely cultivated in Asia, East-Africa, and South America and extensively used in folk medicines as a remedy for diabetes and its complications. BM is available throughout the year and is a staple among ethnic minorities, such as Filipinos. Functional foods like BM therefore will be readily acceptable among some culturally sensitive populations and will offer a cost-effective treatment or preventive strategies in developing nations.
6. 6. Determined mechanism by which trichothecenes and ribotoxic chemicals disrupt immune function. These chemicals can occur in foods through natural contamination or as a result of deliberate use in chemical terrorism or warfare. Improving our understanding of how these chemicals disrupt immune function, we are better positioned to develop science-based strategies for protecting and treating individuals exposed to these toxins.
7. Bioactive chemicals naturally found in foods can be either beneficial or harmful to human health. Through a comprehensive research program, this project is advancing our understanding of the compounds that pose a risk to food safety and those that aid in disease prevention. Extension efforts convey this critical information to consumers and others responsible for ensuring that Americans have a safe, healthy food supply.

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