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Balaji R, Parani M. Development of an allele-specific PCR (AS-PCR) method for identifying high-methyl eugenol-containing purple Tulsi (Ocimum tenuiflorum L.) in market samples. Mol Biol Rep 2024; 51:439. [PMID: 38520476 DOI: 10.1007/s11033-024-09365-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/19/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Ocimum tenuiflorum L. is a highly traded medicinal with several therapeutic values. Green Tulsi and purple Tulsi are two subtypes in O. tenuiflorum and both have the same medicinal properties. Recent reports have revealed that purple Tulsi contains higher quantities of methyl eugenol (ME), which is moderately toxic and potentially carcinogenic. Therefore, we developed an allele-specific PCR (AS-PCR) method to distinguish the green and purple Tulsi. METHODS AND RESULT Using the green Tulsi as a reference, 12 single nucleotide polymorphisms (SNPs) and 10 insertions/deletions (InDels) were identified in the chloroplast genome of the purple Tulsi. The C > T SNP at the 1,26,029 position in the ycf1 gene was selected for the development of the AS-PCR method. The primers were designed to amplify 521 bp and 291 bp fragments specific to green and purple Tulsi, respectively. This AS-PCR method was validated in 10 accessions from each subtype and subsequently verified using Sanger sequencing. Subsequently, 30 Tulsi powder samples collected from the market were subjected to molecular identification by AS-PCR. The results showed that 80% of the samples were purple Tulsi, and only 3.5% were green Tulsi. About 10% of the samples were a mixture of both green and purple Tulsi. Two samples (6.5%) did not contain O. tenuiflorum and were identified as O. gratissimum. CONCLUSION The market samples of Tulsi were predominantly derived from purple Tulsi. The AS-PCR method will be helpful for quality control and market surveillance of Tulsi herbal powders.
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Affiliation(s)
- Raju Balaji
- Department of Genetic Engineering, College of Engineering and Technology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, Kanchipuram, Chennai, TN, 603203, India
| | - Madasamy Parani
- Department of Genetic Engineering, College of Engineering and Technology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, Kanchipuram, Chennai, TN, 603203, India.
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Kobets T, Hickey C, Johnson G, Duan JD, Etter S, Smith B, Williams GM. Assessment of no-observed-effect-levels for DNA adducts formation by genotoxic carcinogens in fetal turkey livers. Toxicology 2024; 501:153714. [PMID: 38141718 DOI: 10.1016/j.tox.2023.153714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/08/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
For genotoxic carcinogens, covalent binding to DNA is a critical initiating event in tumorigenesis. The present research investigated dose-effect relationships of three genotoxic carcinogens representing different structural classes, 2-acetylaminofluorene (2-AAF), benzo[a]pyrene (B[a]P) and quinoline (QUI), to assess the existence of no-observed-effect-levels (NOELs) for the formation of DNA adducts. Carcinogens were administered into the air sac of fertilized turkey eggs over wide dose ranges in three daily injections on days 22 to 24 of incubation. DNA adducts were measured in the fetal turkey livers by the 32P-nucleotide postlabeling (NPL) assay. B[a]P and QUI produced DNA adducts in a dosage-related manner and exhibited NOELs at 0.65 and 0.35 mg/kg bw/day, respectively. In contrast, 2-AAF formed DNA adducts at all tested dosages down to 0.005 mg/kg bw/day. Benchmark dose (BMD) analysis identified the potencies of 2-AAF and QUI to be similar, while B[a]P was the least potent compound. Overall, findings in fetal turkey livers demonstrated that exposure levels to genotoxic compounds that do not result in DNA adducts can exist but are not evident with all carcinogens of this type. The use of mechanistic dose-effect studies for genotoxic endpoints can provide critical information for prioritization of concerns for risk assessment.
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Affiliation(s)
- Tetyana Kobets
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA.
| | | | | | - Jian-Dong Duan
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
| | | | - Benjamin Smith
- Monell Chemical Senses Center, Philadelphia, PA 19104, USA
| | - Gary M Williams
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
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3
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Davidsen JM, Cohen SM, Eisenbrand G, Fukushima S, Gooderham NJ, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Harman CL, Taylor SV. FEMA GRAS assessment of derivatives of basil, nutmeg, parsley, tarragon and related allylalkoxybenzene-containing natural flavor complexes. Food Chem Toxicol 2023; 175:113646. [PMID: 36804339 DOI: 10.1016/j.fct.2023.113646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/18/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a program for the re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavoring ingredients in food. In this publication, tenth in the series, NFCs containing a high percentage of at least one naturally occurring allylalkoxybenzene constituent with a suspected concern for genotoxicity and/or carcinogenicity are evaluated. In a related paper, ninth in the series, NFCs containing anethole and/or eugenol and relatively low percentages of these allylalkoxybenzenes are evaluated. The Panel applies the threshold of toxicological concern (TTC) concept and evaluates relevant toxicology data on the NFCs and their respective constituent congeneric groups. For NFCs containing allylalkoxybenzene constituent(s), the estimated intake of the constituent is compared to the TTC for compounds with structural alerts for genotoxicity and when exceeded, a margin of exposure (MOE) is calculated. BMDL10 values are derived from benchmark dose analyses using Bayesian model averaging for safrole, estragole and methyl eugenol using EPA's BMDS software version 3.2. BMDL10 values for myristicin, elemicin and parsley apiole were estimated by read-across using relative potency factors. Margins of safety for each constituent congeneric group and MOEs for each allylalkoxybenzene constituent for each NFC were determined that indicate no safety concern. The scope of the safety evaluation contained herein does not include added use in dietary supplements or any products other than food. Ten NFCs, derived from basil, estragon (tarragon), mace, nutmeg, parsley and Canadian snakeroot were determined or affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavor ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.
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Affiliation(s)
- Jeanne M Davidsen
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Dept. of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | - Gerhard Eisenbrand
- University of Kaiserslautern, Germany (Retired), Kühler Grund 48/1, 69126, Heidelberg, Germany
| | - Shoji Fukushima
- Japan Bioassay Research Center, 2445 Hirasawa, Hadano, Kanagawa, 257-0015, Japan
| | - Nigel J Gooderham
- Dept. of Metabolism, Digestion, Reproduction, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, United Kingdom
| | - F Peter Guengerich
- Dept. of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Dept. of Laboratory Medicine and Pathology, Cancer and Cardiovascular Research Building, 2231 6th St, S.E, Minneapolis, MN, 55455, USA
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 6708 WE, Wageningen, the Netherlands
| | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, 1 Ohio University, Athens, OH, 45701, USA
| | - Christie L Harman
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Sean V Taylor
- Scientific Secretary to the FEMA Expert Panel, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA.
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4
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Kobets T, Smith BPC, Williams GM. Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk. Foods 2022; 11:foods11182828. [PMID: 36140952 PMCID: PMC9497933 DOI: 10.3390/foods11182828] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.
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Affiliation(s)
- Tetyana Kobets
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
- Correspondence: ; Tel.: +1-914-594-3105; Fax: +1-914-594-4163
| | - Benjamin P. C. Smith
- Future Ready Food Safety Hub, Nanyang Technological University, Singapore 639798, Singapore
| | - Gary M. Williams
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
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5
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Takada M, Sakamoto M, Yamada H, Kishikawa N, Mutoh J, Shiraishi Y, Kuroda N, Wada M. HPLC Fluorescence Method for Eugenols in Basil Products Derivatized with DIBI. Chem Pharm Bull (Tokyo) 2022; 70:37-42. [PMID: 34980731 DOI: 10.1248/cpb.c21-00575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eugenols (Eugs) such as eugenol (Eug), methyleugenol (MeEug), and linalool (Lin) in basil product are the main bioactive components of basil products and have a terminal double-bond. A sensitive HPLC-fluorescence method for Eugs derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)iodobenzene (DIBI) was developed. Good separation of DIB-Eugs was achieved within 20 min on an Atlantis T3 column (50 × 2.1 mm i.d., 3 µm) with a mobile phase of methanol-water. The calibration curves obtained with Eug standards showed good linearities in the range of 0.1-50 µM (r ≥ 0.999). The limits of detection at a signal-to-noise ratio (S/N) = 3 for Eug, MeEug, and Lin were 1.0, 6.0, and 4.8 nM, respectively. The limits of quantitation (S/N = 10) of the Eugs were lower than 19.9 nM. The accuracies for the Eugs were within 96.8-104.6%. The intra- and inter-day precisions as relative standard deviations for the Eugs were less than 1.2 and 9.6% (n = 3). The recoveries of Eug, MeEug, and Lin were 99.0 ± 0.1, 98.0 ± 0.2, and 96.0 ± 0.4% (n = 3), respectively. The DIB-Eugs were confirmed to be stable for 2 h (>90%) at room temperature and 24 h (>95%) at 4 °C. These parameters of the proposed method were useful for the simultaneous determination of Eugs in basil products. Therefore, the developed method may be a powerful tool for the quality evaluation of dried commercially available basil products.
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Affiliation(s)
- Makoto Takada
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University
| | | | | | | | - Junpei Mutoh
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University
| | | | - Naotaka Kuroda
- Graduate School of Biomedical Sciences, Nagasaki University
| | - Mitsuhiro Wada
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University
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Gooderham NJ, Cohen SM, Eisenbrand G, Fukushima S, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Bastaki M, Linman MJ, Taylor SV. The safety evaluation of food flavoring substances: the role of genotoxicity studies. Crit Rev Toxicol 2020; 50:1-27. [PMID: 32162576 DOI: 10.1080/10408444.2020.1712589] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Flavor and Extract Manufacturers Association (FEMA) Expert Panel relies on the weight of evidence from all available data in the safety evaluation of flavoring substances. This process includes data from genotoxicity studies designed to assess the potential of a chemical agent to react with DNA or otherwise cause changes to DNA, either in vitro or in vivo. The Panel has reviewed a large number of in vitro and in vivo genotoxicity studies during the course of its ongoing safety evaluations of flavorings. The adherence of genotoxicity studies to standardized protocols and guidelines, the biological relevance of the results from those studies, and the human relevance of these studies are all important considerations in assessing whether the results raise specific concerns for genotoxic potential. The Panel evaluates genotoxicity studies not only for evidence of genotoxicity hazard, but also for the probability of risk to the consumer in the context of exposure from their use as flavoring substances. The majority of flavoring substances have given no indication of genotoxic potential in studies evaluated by the FEMA Expert Panel. Examples illustrating the assessment of genotoxicity data for flavoring substances and the consideration of the factors noted above are provided. The weight of evidence approach adopted by the FEMA Expert Panel leads to a rational assessment of risk associated with consumer intake of flavoring substances under the conditions of use.
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Affiliation(s)
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Gerhard Eisenbrand
- Food Chemistry & Toxicology, University of Kaiserslautern (retired), Heidelberg, Germany
| | | | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | | | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Maria Bastaki
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Matthew J Linman
- Flavor and Extract Manufacturers Association, Washington, DC, USA
| | - Sean V Taylor
- Flavor and Extract Manufacturers Association, Washington, DC, USA
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7
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Yang XN, Wang YK, Zhu X, Xiao XR, Dai MY, Zhang T, Qu Y, Yang XW, Qin HB, Gonzalez FJ, Li F. Metabolic Activation of Elemicin Leads to the Inhibition of Stearoyl-CoA Desaturase 1. Chem Res Toxicol 2019; 32:1965-1976. [PMID: 31468958 DOI: 10.1021/acs.chemrestox.9b00112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Elemicin is a constituent of natural aromatic phenylpropanoids present in many herbs and spices. However, its potential to cause toxicity remains unclear. To examine the potential toxicity and associated mechanism, elemicin was administered to mice for 3 weeks and serum metabolites were examined. Enlarged livers were observed in elemicin-treated mice, which were accompanied by lower ratios of unsaturated- and saturated-lysophosphatidylcholines in plasma, and inhibition of stearoyl-CoA desaturase 1 (Scd1) mRNA expression in liver. Administration of the unsaturated fatty acid oleic acid reduced the toxicity of 1'-hydroxylelemicin, the primary oxidative metabolite of elemicin, while treatment with the SCD1 inhibitor A939572 potentiated its toxicity. Furthermore, the in vitro use of recombinant human CYPs and chemical inhibition of CYPs in human liver microsomes revealed that CYP1A1 and CYP1A2 were the primary CYPs responsible for elemicin bioactivation. Notably, the CYP1A2 inhibitor α-naphthoflavone could attenuate the susceptibility of mice to elemicin-induced hepatomegaly. This study revealed that metabolic activation of elemicin leads to SCD1 inhibition in liver, suggesting that upregulation of SCD1 may serve as potential intervention strategy for elemicin-induced toxicity.
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Affiliation(s)
- Xiao-Nan Yang
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China.,Guangxi Key Laboratory of Medicinal Resources Protection and Genetic Improvement , Guangxi Botanical Garden of Medicinal Plant , Nanning 530023 , China
| | - Yi-Kun Wang
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China.,University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xu Zhu
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China.,University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xue-Rong Xiao
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China
| | - Man-Yun Dai
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China.,University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Ting Zhang
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China.,University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yan Qu
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China
| | - Xiu-Wei Yang
- School of Pharmaceutical Sciences, Peking University Health Science Center , Peking University , Beijing 100191 , China
| | - Hong-Bo Qin
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research , National Cancer Institute , National Institutes of Health, Bethesda , Maryland 20892 , United States
| | - Fei Li
- States Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany , Chinese Academy of Sciences , Kunming 650201 , China
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8
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Wen B, Gorycki P. Bioactivation of herbal constituents: mechanisms and toxicological relevance. Drug Metab Rev 2019; 51:453-497. [DOI: 10.1080/03602532.2019.1655570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Bo Wen
- Department of Drug Metabolism and Pharmacokinetics, GlaxoSmithKline, Collegeville, PA, USA
| | - Peter Gorycki
- Department of Drug Metabolism and Pharmacokinetics, GlaxoSmithKline, Collegeville, PA, USA
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9
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Kobets T, Cartus AT, Fuhlbrueck JA, Brengel A, Stegmüller S, Duan JD, Brunnemann KD, Williams GM. Assessment and characterization of DNA adducts produced by alkenylbenzenes in fetal turkey and chicken livers. Food Chem Toxicol 2019; 129:424-433. [PMID: 31077736 DOI: 10.1016/j.fct.2019.05.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/04/2019] [Accepted: 05/07/2019] [Indexed: 01/22/2023]
Abstract
Formation of DNA adducts by five alkenylbenzenes, safrole, methyl eugenol, eugenol, and asarone with either α- or β-conformation, was analyzed in fetal avian livers in two in ovo models. DNA reactivity of the carcinogens safrole and methyl eugenol was previously demonstrated in the turkey egg model, whereas non-genotoxic eugenol was negative. In the current study, alkenylbenzenes were also tested in the chicken egg model. Injections with alkenylbenzenes were administered to fertilized turkey or chicken eggs for three consecutive days. Three hours after the last injection, liver samples were evaluated for DNA adduct formation using the 32P-nucleotide postlabeling assay. DNA samples from turkey livers were also analyzed for adducts using mass spectrometry. In both species, genotoxic alkenylbenzenes safrole, methyl eugenol, α- and β-asarone produced DNA adducts, the presence and nature of which, with exception of safrole, were confirmed by mass spectrometry, validating the sensitivity of the 32P-postlabeling assay. Overall, the results of testing were congruent between fetal turkey and chicken livers, confirming that these organisms can be used interchangeably. Moreover, data obtained in both models is comparable to genotoxicity findings in other species, supporting the usefulness of avian models for the assessment of genotoxicity as a potential alternative to animal models.
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Affiliation(s)
- Tetyana Kobets
- New York Medical College, Department of Pathology, 40 Sunshine Cottage Road, Valhalla, NY, 10595, USA.
| | - Alexander T Cartus
- University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schrödinger-Strasse 52, 67663, Kaiserslautern, Germany
| | - Julia A Fuhlbrueck
- University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schrödinger-Strasse 52, 67663, Kaiserslautern, Germany
| | - Alexander Brengel
- University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schrödinger-Strasse 52, 67663, Kaiserslautern, Germany
| | - Simone Stegmüller
- University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schrödinger-Strasse 52, 67663, Kaiserslautern, Germany
| | - Jian-Dong Duan
- New York Medical College, Department of Pathology, 40 Sunshine Cottage Road, Valhalla, NY, 10595, USA
| | - Klaus D Brunnemann
- New York Medical College, Department of Pathology, 40 Sunshine Cottage Road, Valhalla, NY, 10595, USA
| | - Gary M Williams
- New York Medical College, Department of Pathology, 40 Sunshine Cottage Road, Valhalla, NY, 10595, USA
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Williams GM, Kobets T, Duan JD, Iatropoulos MJ. Assessment of DNA Binding and Oxidative DNA Damage by Acrylonitrile in Two Rat Target Tissues of Carcinogenicity: Implications for the Mechanism of Action. Chem Res Toxicol 2017; 30:1470-1480. [DOI: 10.1021/acs.chemrestox.7b00105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gary M. Williams
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Tetyana Kobets
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Jian-Dong Duan
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
| | - Michael J. Iatropoulos
- Chemical Safety Program,
Department of Pathology, New York Medical College, Valhalla, New York 10595, United States
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11
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Methyleugenol DNA adducts in human liver are associated with SULT1A1 copy number variations and expression levels. Arch Toxicol 2017; 91:3329-3339. [PMID: 28326452 DOI: 10.1007/s00204-017-1955-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/09/2017] [Indexed: 10/19/2022]
Abstract
Methyleugenol is a rodent hepatocarcinogen occurring in many herbs and spices as well as essential oils used for flavoring. Following metabolic activation by cytochromes P450 (CYPs) and sulfotransferases (SULTs), methyleugenol can form DNA adducts. Previously, we showed that DNA adduct formation by methyleugenol in mouse liver is dependent on SULT1A1 expression and that methyleugenol DNA adducts are abundant in human liver specimens. In humans, SULT1A1 activity is affected by genetic polymorphisms, including single-nucleotide polymorphisms (SNPs) and copy number variations (CNVs). Here we investigated the relationship between individual methyleugenol DNA adduct levels and SULT1A1 in human liver samples. Using isotope-dilution ultraperformance liquid chromatography coupled with tandem mass spectrometry, we quantified methyleugenol DNA adducts in 121 human surgical liver samples. Frequent CNVs, including deletions (f = 3.3%) and duplications (f = 36.4%) of SULT1A1, were identified using qPCR and TaqMan assays in the donors' genomic DNA. SULT1A1 mRNA and protein levels were quantified using microarray data and Western blot analysis, respectively. Methyleugenol DNA adducts were detected in all 121 liver samples studied. Their levels varied 122-fold between individuals and were significantly correlated to both mRNA and protein levels of SULT1A1 (r s = 0.43, and r s = 0.44, respectively). Univariate and multivariate statistical analysis identified significant associations of SULT1A1 CNVs with mRNA (p = 1.7 × 10-06) and protein (p = 4.4 × 10- 10) levels as well as methyleugenol DNA adduct levels (p = 0.003). These data establish the importance of SULT1A1 genotype for hepatic methyleugenol DNA adducts in humans, and they confirm a strong impact of SULT1A1 CNVs on SULT1A1 hepatic phenotype.
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12
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Hemeryck LY, Vanhaecke L. Diet-related DNA adduct formation in relation to carcinogenesis. Nutr Rev 2016; 74:475-89. [PMID: 27330144 DOI: 10.1093/nutrit/nuw017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The human diet contributes significantly to the initiation and promotion of carcinogenesis. It has become clear that the human diet contains several groups of natural foodborne chemicals that are at least in part responsible for the genotoxic, mutagenic, and carcinogenic potential of certain foodstuffs. Electrophilic chemicals are prone to attack nucleophilic sites in DNA, resulting in the formation of altered nucleobases, also known as DNA adducts. Since DNA adduct formation is believed to signal the onset of chemically induced carcinogenesis, the DNA adduct-inducing potential of certain foodstuffs has been investigated to gain more insight into diet-related pathways of carcinogenesis. Many studies have investigated diet-related DNA adduct formation. This review summarizes work on known or suspected dietary carcinogens and the role of DNA adduct formation in hypothesized carcinogenesis pathways.
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Affiliation(s)
- Lieselot Y Hemeryck
- L.Y. Hemeryck and L. Vanhaecke are with the Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Lynn Vanhaecke
- L.Y. Hemeryck and L. Vanhaecke are with the Laboratory of Chemical Analysis, Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Williams GM, Kobets T, Iatropoulos MJ, Duan JD, Brunnemann KD. GRAS determination scientific procedures and possible alternatives. Regul Toxicol Pharmacol 2016; 79 Suppl 2:S105-11. [PMID: 27328372 DOI: 10.1016/j.yrtph.2016.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 11/27/2022]
Abstract
The use of a food substance is Generally Recognized as Safe (GRAS) through scientific procedures or experience based on common use in food. The pivotal data used for GRAS determination must be of common knowledge and should include evidence for safety under the conditions of intended use of the substance. Such evidence includes data on the identity and specifications of the substance, its properties of absorption, distribution, metabolism and excretion, and depending on the level of concern, data on genotoxicity, acute and subchronic toxicity, reproductive and developmental toxicity and carcinogenicity. Several alternative procedures can be used as the replacement for standard scientific procedures in order to improve the GRAS process.
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Affiliation(s)
- Gary M Williams
- Department of Pathology, New York Medical College, 40Sunshine Cottage Road, BSB # 413, Valhalla, NY, 10595, USA.
| | - Tetyana Kobets
- Department of Pathology, New York Medical College, 40Sunshine Cottage Road, BSB # 413, Valhalla, NY, 10595, USA
| | - Michael J Iatropoulos
- Department of Pathology, New York Medical College, 40Sunshine Cottage Road, BSB # 413, Valhalla, NY, 10595, USA
| | - Jian-Dong Duan
- Department of Pathology, New York Medical College, 40Sunshine Cottage Road, BSB # 413, Valhalla, NY, 10595, USA
| | - Klaus D Brunnemann
- Department of Pathology, New York Medical College, 40Sunshine Cottage Road, BSB # 413, Valhalla, NY, 10595, USA
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Punt A, Paini A, Spenkelink A, Scholz G, Schilter B, van Bladeren PJ, Rietjens IMCM. Evaluation of Interindividual Human Variation in Bioactivation and DNA Adduct Formation of Estragole in Liver Predicted by Physiologically Based Kinetic/Dynamic and Monte Carlo Modeling. Chem Res Toxicol 2016; 29:659-68. [PMID: 26952143 DOI: 10.1021/acs.chemrestox.5b00493] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Estragole is a known hepatocarcinogen in rodents at high doses following metabolic conversion to the DNA-reactive metabolite 1'-sulfooxyestragole. The aim of the present study was to model possible levels of DNA adduct formation in (individual) humans upon exposure to estragole. This was done by extending a previously defined PBK model for estragole in humans to include (i) new data on interindividual variation in the kinetics for the major PBK model parameters influencing the formation of 1'-sulfooxyestragole, (ii) an equation describing the relationship between 1'-sulfooxyestragole and DNA adduct formation, (iii) Monte Carlo modeling to simulate interindividual human variation in DNA adduct formation in the population, and (iv) a comparison of the predictions made to human data on DNA adduct formation for the related alkenylbenzene methyleugenol. Adequate model predictions could be made, with the predicted DNA adduct levels at the estimated daily intake of estragole of 0.01 mg/kg bw ranging between 1.6 and 8.8 adducts in 10(8) nucleotides (nts) (50th and 99th percentiles, respectively). This is somewhat lower than values reported in the literature for the related alkenylbenzene methyleugenol in surgical human liver samples. The predicted levels seem to be below DNA adduct levels that are linked with tumor formation by alkenylbenzenes in rodents, which were estimated to amount to 188-500 adducts per 10(8) nts at the BMD10 values of estragole and methyleugenol. Although this does not seem to point to a significant health concern for human dietary exposure, drawing firm conclusions may have to await further validation of the model's predictions.
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Affiliation(s)
- Ans Punt
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Alicia Paini
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands.,Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Albertus Spenkelink
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Gabriele Scholz
- Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Benoit Schilter
- Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Peter J van Bladeren
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands.,Nestec S.A , Avenue Nestlé 55, 1800 Vevey, Switzerland
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
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15
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Kobets T, Duan JD, Brunnemann KD, Etter S, Smith B, Williams GM. Structure-Activity Relationships for DNA Damage by Alkenylbenzenes in Turkey Egg Fetal Liver. Toxicol Sci 2015; 150:301-11. [DOI: 10.1093/toxsci/kfv322] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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16
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Iatropoulos MJ, Duan JD, Schmuck G, Williams GM. The urinary bladder carcinogen propoxur does not produce genotoxic effects in the urinary bladder of Wistar male rats. ACTA ACUST UNITED AC 2015; 67:453-8. [PMID: 26164753 DOI: 10.1016/j.etp.2015.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/03/2015] [Accepted: 06/08/2015] [Indexed: 11/19/2022]
Abstract
Propoxur (PPX) is a carbamate insecticide which induced urinary bladder cancer in Wistar rats when fed at 5000ppm in Altromin 1321 diet (1321). In the present investigation, PPX was studied for induction of several key events related to modes of action (MOA) of carcinogenicity in urinary bladders (UBs). Wistar rats were administered the compound for 28 days at 8000ppm in Provini Liba SA 3883 diet, which is similar to the 1321 diet. o-Anisidine HCl (AH) was used as a genotoxic UB carcinogenic comparator, and trisodium nitrilotriacetate (NTA) as an epigenetic UB carcinogen comparator. Along with the non-dosed control and three test substance groups (PPX, AH, NTA), four more groups were additionally fed 2% ammonium chloride (AC) in the diet to acidify the urine, since 1321 was reported to increase urinary pH. AC did acidify the urine, as expected, although the 3883 diet itself did not increase pH values above 8. In the alkaline comet assay, AH produced DNA single strand breaks (SSBs) in the UB urothelium (UBU) irrespective of AC administration, whereas PPX and NTA did not. In the nucleotide (32)P-postlabeling assay (NPL), AH produced DNA adducts irrespective of AC administration, whereas PPX and NTA did not. Routine (H&E) histopathology evaluation of the UBU did not reveal any hyperplasia or evidence of luminal microprecipitates or calculi in any of the groups. Assessment of UBU proliferation as measured by immunohistochemistry of proliferating cell nuclear antigen, revealed that NTA and NTA plus AC increased the replicating fraction (RF). Also AH plus AC, but not AH alone, increased the RF of UBU, whereas PPX groups were not significantly different from controls. Thus, the results reveal no evidence for DNA SSBs, binding, or alteration of DNA synthesis in the UBU by PPX, while demonstrating UBU DNA damage by AH and showing that NTA does not damage DNA, but causes increased UBU proliferation. The findings are in accord with a genotoxic MOA for AH, and an epigenetic MOA for NTA. The MOA of PPX does not involve genotoxicity and may be specific to the 1321 diet.
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Affiliation(s)
| | - J-D Duan
- New York Medical College, Valhalla, NY 10595, USA
| | - G Schmuck
- Bayer Schering Pharma AG, D-42096 Wuppertal, Germany
| | - G M Williams
- New York Medical College, Valhalla, NY 10595, USA.
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Hassam M, Taher A, Arnott GE, Green IR, van Otterlo WAL. Isomerization of Allylbenzenes. Chem Rev 2015; 115:5462-569. [DOI: 10.1021/acs.chemrev.5b00052] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Mohammad Hassam
- Department
of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Abu Taher
- Department
of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Gareth E. Arnott
- Department
of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Ivan R. Green
- Department
of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
| | - Willem A. L. van Otterlo
- Department
of Chemistry and Polymer Science, Stellenbosch University, Private Bag
X1, Matieland 7602, South Africa
- School
of Chemistry, University of the Witwatersrand, Braamfontein, Johannesburg 2000, South Africa
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Ding W, Levy DD, Bishop ME, Pearce MG, Davis KJ, Jeffrey AM, Duan JD, Williams GM, White GA, Lyn-Cook LE, Manjanatha MG. In vivo genotoxicity of estragole in male F344 rats. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:356-365. [PMID: 25361439 DOI: 10.1002/em.21918] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/03/2014] [Indexed: 06/04/2023]
Abstract
Estragole, a naturally occurring constituent of various herbs and spices, is a rodent liver carcinogen which requires bio-activation. To further understand the mechanisms underlying its carcinogenicity, genotoxicity was assessed in F344 rats using the comet, micronucleus (MN), and DNA adduct assays together with histopathological analysis. Oxidative damage was measured using human 8-oxoguanine-DNA-N-glycosylase (hOGG1) and EndonucleaseIII (EndoIII)-modified comet assays. Results with estragole were compared with the structurally related genotoxic carcinogen, safrole. Groups of seven-week-old male F344 rats received corn oil or corn oil containing 300, 600, or 1,000 mg/kg bw estragole and 125, 250, or 450 mg/kg bw safrole by gavage at 0, 24, and 45 hr and terminated at 48 hr. Estragole-induced dose-dependent increases in DNA damage following EndoIII or hOGG1 digestion and without enzyme treatment in liver, the cancer target organ. No DNA damage was detected in stomach, the non-target tissue for cancer. No elevation of MN was observed in reticulocytes sampled from peripheral blood. Comet assays, both without digestion or with either EndoIII or hOGG1 digestion, also detected DNA damage in the liver of safrole-dosed rats. No DNA damage was detected in stomach, nor was MN elevated in peripheral blood following dosing with safrole suggesting that, as far both safrole and estragole, oxidative damage may contribute to genotoxicity. Taken together, these results implicate multiple mechanisms of estragole genotoxicity. DNA damage arises from chemical-specific interaction and is also mediated by oxidative species.
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Affiliation(s)
- Wei Ding
- Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, Arkansas
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The natural basil flavonoid nevadensin protects against a methyleugenol-induced marker of hepatocarcinogenicity in male F344 rat. Food Chem Toxicol 2014; 74:28-34. [DOI: 10.1016/j.fct.2014.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/28/2014] [Accepted: 08/24/2014] [Indexed: 11/22/2022]
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Herrmann K, Engst W, Meinl W, Florian S, Cartus AT, Schrenk D, Appel KE, Nolden T, Himmelbauer H, Glatt H. Formation of hepatic DNA adducts by methyleugenol in mouse models: drastic decrease by Sult1a1 knockout and strong increase by transgenic human SULT1A1/2. Carcinogenesis 2013; 35:935-41. [PMID: 24318996 DOI: 10.1093/carcin/bgt408] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Methyleugenol--a natural constituent of herbs and spices--is hepatocarcinogenic in rodent models. It can form DNA adducts after side-chain hydroxylation and sulfation. We previously demonstrated that human sulfotransferases (SULTs) 1A1 and 1A2 as well as mouse Sult1a1, expressed in Salmonella target strains, are able to activate 1'-hydroxymethyleugenol (1'-OH-ME) and 3'-hydroxymethylisoeugenol (3'-OH-MIE) to mutagens. Now we investigated the role of these enzymes in the formation of hepatic DNA adducts by methyleugenol in the mouse in vivo. We used FVB/N mice [wild-type (wt)] and genetically modified strains in this background: Sult1a1 knockout (ko), transgenic for human SULT1A1/2 (tg) and the combination of both modifications (ko-tg). Methyleugenol (50mg/kg body mass) formed 23, 735, 3770 and 4500 N (2)-(trans-methylisoeugenol-3'-yl)-2'-deoxyguanosine adducts per 10(8) 2'-deoxyribonucleosides (dN) in ko, wt, ko-tg and tg mice, respectively. The corresponding values for an equimolar dose of 1'-OH-ME were 12, 1490, 12 400 and 13 300 per 10(8) dN. Similar relative levels were observed for the minor adduct, N (6)-(trans-methylisoeugenol-3'-yl)-2'-deoxyadenosine. Thus, the adduct formation by both compounds was nearly completely dependent on the presence of SULT1A enzymes, with human SULT1A1/2 producing stronger effects than mouse Sult1a1. Moreover, a dose of 0.05 mg/kg methyleugenol (one-fourth of the estimated average daily exposure of humans) was sufficient to form detectable adducts in humanized (ko-tg) mice. Although 3'-OH-MIE was equally mutagenic to 1'-OH-ME in Salmonella strains expressing human SULT1A1 or 1A2, it only formed 0.14% of hepatic adducts in ko-tg mice compared with an equimolar dose of 1'-OH-ME, suggesting an important role of detoxifying pathways for this isomer in vivo.
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Affiliation(s)
- Kristin Herrmann
- Department of Nutritional Toxicology, German Institute of Human Nutrition (DIfE) Potsdam-Rehbruecke, 14558 Nuthetal, Germany
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