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Effects of Chlorophyll a and b in Reducing Genotoxicity of 2-Amino-3,8-dimethylimidazo[4,5-F]quinoxaline (MeIQx). BIOLOGY 2022; 11:biology11040602. [PMID: 35453801 PMCID: PMC9028374 DOI: 10.3390/biology11040602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 11/17/2022]
Abstract
In this study, the protective effects of chlorophyll a and chlorophyll b (0.5 and 1 µM) against the heterocyclic amine compound 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx, 4.69 µM, 9.38 µM, 23.45 µM) with somatic mutation and recombination test in Drosophila melanogaster are investigated. Chronic applications are performed to transheterozygous larvae with respect to two recessive genes, mwh (multiple wing hair) and flr3 (flare), by using Drosophila strains. The genotoxic effects of MeIQx are primarily determined for third instars larvae. In antigenotoxicity studies, two different application groups are constituted. While for the first group doses of chlorophyll a, b, and MeIQx are given to the third instars larvae simultaneously, for the second group doses of MeIQx are applied at the third instars after doses of chlorophyll a and b are given to at the second instars larvae. Chlorophyll a and b are effective in reducing genotoxic effects of MeIQx by both applications on individuals and it is observed that the pretreatment method is much more effective than the simultaneous one. There are similar results for chlorophyll a and b in efficacy.
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Hartwig A, Arand M, Epe B, Guth S, Jahnke G, Lampen A, Martus HJ, Monien B, Rietjens IMCM, Schmitz-Spanke S, Schriever-Schwemmer G, Steinberg P, Eisenbrand G. Mode of action-based risk assessment of genotoxic carcinogens. Arch Toxicol 2020; 94:1787-1877. [PMID: 32542409 PMCID: PMC7303094 DOI: 10.1007/s00204-020-02733-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 12/16/2022]
Abstract
The risk assessment of chemical carcinogens is one major task in toxicology. Even though exposure has been mitigated effectively during the last decades, low levels of carcinogenic substances in food and at the workplace are still present and often not completely avoidable. The distinction between genotoxic and non-genotoxic carcinogens has traditionally been regarded as particularly relevant for risk assessment, with the assumption of the existence of no-effect concentrations (threshold levels) in case of the latter group. In contrast, genotoxic carcinogens, their metabolic precursors and DNA reactive metabolites are considered to represent risk factors at all concentrations since even one or a few DNA lesions may in principle result in mutations and, thus, increase tumour risk. Within the current document, an updated risk evaluation for genotoxic carcinogens is proposed, based on mechanistic knowledge regarding the substance (group) under investigation, and taking into account recent improvements in analytical techniques used to quantify DNA lesions and mutations as well as "omics" approaches. Furthermore, wherever possible and appropriate, special attention is given to the integration of background levels of the same or comparable DNA lesions. Within part A, fundamental considerations highlight the terms hazard and risk with respect to DNA reactivity of genotoxic agents, as compared to non-genotoxic agents. Also, current methodologies used in genetic toxicology as well as in dosimetry of exposure are described. Special focus is given on the elucidation of modes of action (MOA) and on the relation between DNA damage and cancer risk. Part B addresses specific examples of genotoxic carcinogens, including those humans are exposed to exogenously and endogenously, such as formaldehyde, acetaldehyde and the corresponding alcohols as well as some alkylating agents, ethylene oxide, and acrylamide, but also examples resulting from exogenous sources like aflatoxin B1, allylalkoxybenzenes, 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), benzo[a]pyrene and pyrrolizidine alkaloids. Additionally, special attention is given to some carcinogenic metal compounds, which are considered indirect genotoxins, by accelerating mutagenicity via interactions with the cellular response to DNA damage even at low exposure conditions. Part C finally encompasses conclusions and perspectives, suggesting a refined strategy for the assessment of the carcinogenic risk associated with an exposure to genotoxic compounds and addressing research needs.
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Affiliation(s)
- Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany.
| | - Michael Arand
- Institute of Pharmacology and Toxicology, University of Zurich, 8057, Zurich, Switzerland
| | - Bernd Epe
- Institute of Pharmacy and Biochemistry, University of Mainz, 55099, Mainz, Germany
| | - Sabine Guth
- Department of Toxicology, IfADo-Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Gunnar Jahnke
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Alfonso Lampen
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Hans-Jörg Martus
- Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Bernhard Monien
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Simone Schmitz-Spanke
- Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Henkestr. 9-11, 91054, Erlangen, Germany
| | - Gerlinde Schriever-Schwemmer
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Pablo Steinberg
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany
| | - Gerhard Eisenbrand
- Retired Senior Professor for Food Chemistry and Toxicology, Kühler Grund 48/1, 69126, Heidelberg, Germany.
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Prasad V, Mishra N, Agrahari AK, Singh SK, Mohapatra PP, Tiwari VK. Cycloelimination-assisted Combinatorial Synthesis of Diverse Heterocyclic Scaffolds of Chemotherapeutic Values. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666190405145805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent advances in high-throughput, automated techniques combined with the identification of new therapeutic targets in genome sequencing and molecular biology have generated a need for a large collection of diverse heterocyclic scaffolds. This inspires toward the development of novel reaction sequences and linking strategies to generate libraries of diverse simple to complex heterocyclic systems. In this regard, combinatorial chemistry has emerged as an excellent technology platform for the rapid assembly of building blocks to synthesize complex molecular structures with great ease in a few synthetic steps. By means of the implementation of high-throughput screening for the biological evaluation of hits and leads, combinatorial libraries have become important assets in drug discovery and development. In the last two decades, the cyclorelease strategy that minimizes the chemical and tethering implications by releasing the intact desired target molecule in the final step of reaction has attracted much attention. Recently, a particular interest is developing in linking strategies, where loading and cleavage steps contribute to the complexity of the target structure rather than only extraneous manipulations. This review summarises the practical and high-yielding approaches of solid phase combinatorial synthesis for diverse high-purity heterocyclic skeletons of pharmacological importance involving the cycloelimination strategy.
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Affiliation(s)
- Virendra Prasad
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Nidhi Mishra
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Anand K. Agrahari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Sumit K. Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | | | - Vinod K. Tiwari
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-221005, India
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Kirkland D, Kasper P, Martus HJ, Müller L, van Benthem J, Madia F, Corvi R. Updated recommended lists of genotoxic and non-genotoxic chemicals for assessment of the performance of new or improved genotoxicity tests. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 795:7-30. [DOI: 10.1016/j.mrgentox.2015.10.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 01/09/2023]
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Roemer E, Meisgen T, Diekmann J, Conroy L, Stabbert R. Heterocyclic aromatic amines and their contribution to the bacterial mutagenicity of the particulate phase of cigarette smoke. Toxicol Lett 2015; 243:40-7. [PMID: 26724587 DOI: 10.1016/j.toxlet.2015.12.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/18/2015] [Accepted: 12/21/2015] [Indexed: 11/26/2022]
Abstract
Heterocyclic aromatic amines (HAAs) rank among the strongest known mutagens. Approximately 30 HAAs have been found in cooked foods (broiled, fried, and grilled) and several HAAs have been characterized as animal carcinogens. Nine HAAs have also been reported to be constituents of cigarette smoke (CS) raising concerns that HAAs might contribute significantly to the known carcinogenicity of CS. As HAAs are found predominantly in the total particulate matter (TPM) of CS, an improved method for the quantification of HAAs in TPM is reported allowing detection and quantification of 8 HAAs in a single run. The mutagenic potency of these HAAs and that of TPM from the reference cigarette 2R4F was determined in the Salmonella Reverse Mutation Assay (Ames assay) with tester strain TA98 and a metabolic activation system. The 8 HAAs, when applied together in the Ames assay, showed a clear sub-additive response. Likewise, the combination of HAAs and TPM, if at all, gave rise to a slight sub-additive response. In both cases, however, the sub-additive response in the Ames assay was observed at HAA doses that are far above the amounts found in CS. The contribution of the individual HAAs to the total mutagenic activity of TPM was calculated and experimentally confirmed to be approximately 1% of the total mutagenic activity. Thus, HAAs do not contribute significantly to the bacterial in vitro mutagenicity of CS TPM.
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Affiliation(s)
- Ewald Roemer
- Philip Morris Products S.A., Philip Morris International R&D, Rue des Usines 90, 2000 Neuchâtel, Switzerland
| | - Thomas Meisgen
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstr. 3, 51149 Cologne, Germany
| | - Joerg Diekmann
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstr. 3, 51149 Cologne, Germany
| | - Lynda Conroy
- Philip Morris International R&D, Philip Morris Research Laboratories GmbH, Fuggerstr. 3, 51149 Cologne, Germany
| | - Regina Stabbert
- Philip Morris Products S.A., Philip Morris International R&D, Rue des Usines 90, 2000 Neuchâtel, Switzerland.
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Soeteman-Hernández LG, Johnson GE, Slob W. Estimating the carcinogenic potency of chemicals from the in vivo micronucleus test. Mutagenesis 2015; 31:347-58. [PMID: 26163673 DOI: 10.1093/mutage/gev043] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we investigated the applicability of using in vivo mouse micronucleus (MN) data to derive cancer potency information. We also present a new statistical methodology for correlating estimated potencies between in vivo MN tests and cancer studies, which could similarly be used for other systems (e.g. in vitro vs. in vivo genotoxicity tests). The dose-response modelling program PROAST was used to calculate benchmark doses (BMDs) for estimating the genotoxic and carcinogenic potency for 48 compounds in mice; most of the data were retrieved from the National Toxicology Program (NTP) database, while some additional data were retrieved from the Carcinogenic Potency Database and published studies. BMD05s (doses with 5% increase in MN frequency) were derived from MN data, and BMD10s (doses with 10% extra cancer risk) were derived from carcinogenicity data, along with their respective lower (BMDL) and upper (BMDU) confidence bounds. A clear correlation between the in vivo MN BMD05s and the cancer BMD10s was observed when the lowest BMD05 from the in vivo MN was plotted against the lowest BMD10 from the carcinogenicity data for each individual compound. By making a further selection of BMDs related to more or less equally severe cancer lesions, the correlation was considerably improved. Getting a general scientific consensus on how we can quantitatively compare different tumour lesion types and investigating the impact of MN study duration are needed to refine this correlation analysis. Nevertheless, our results suggest that a BMD derived from genotoxicity data might provide a prediction of the tumour potency (BMD10) with an uncertainty range spanning roughly a factor of 100.
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Affiliation(s)
| | - George E Johnson
- Institute of Life Science, Swansea University, Singleton Park, Swansea SA2 8PP Wales, UK
| | - Wout Slob
- Centre for Nutrition, Prevention and Care, National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA, Bilthoven, The Netherlands
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Guth S, Habermeyer M, Baum M, Steinberg P, Lampen A, Eisenbrand G. Thermally induced process-related contaminants: the example of acrolein and the comparison with acrylamide: opinion of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG). Mol Nutr Food Res 2013; 57:2269-82. [PMID: 23970446 DOI: 10.1002/mnfr.201300418] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 06/07/2013] [Accepted: 06/17/2013] [Indexed: 12/11/2022]
Abstract
α,β-Unsaturated aliphatic carbonyl compounds are naturally widespread in food, but are also formed during the thermal treatment of food. This applies, for example, to the genotoxic carcinogen acrylamide (AA), but also to acrolein (AC), the simplest α,β-unsaturated aldehyde. First observations indicate that human exposure to AC may be higher than the exposure to AA. The DFG Senate Commission on Food Safety therefore compared data on AC and AA available in the scientific literature, evaluating current knowledge on formation, occurrence, exposure, metabolism, biological effects, toxicity, and carcinogenicity and defined knowledge gaps as well as research needs in an opinion on November 19, 2012, in German. The English version was agreed on April 17, 2013.
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Affiliation(s)
- Sabine Guth
- Department of Food Chemistry and Toxicology, University of Kaiserslautern, Kaiserslautern, Germany
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Watzek N, Böhm N, Feld J, Scherbl D, Berger F, Merz KH, Lampen A, Reemtsma T, Tannenbaum SR, Skipper PL, Baum M, Richling E, Eisenbrand G. N7-glycidamide-guanine DNA adduct formation by orally ingested acrylamide in rats: a dose-response study encompassing human diet-related exposure levels. Chem Res Toxicol 2012; 25:381-90. [PMID: 22211389 DOI: 10.1021/tx200446z] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acrylamide (AA) is formed during the heating of food and is classified as a genotoxic carcinogen. The margin of exposure (MOE), representing the distance between the bench mark dose associated with 10% tumor incidence in rats and the estimated average human exposure, is considered to be of concern. After ingestion, AA is converted by P450 into the genotoxic epoxide glycidamide (GA). GA forms DNA adducts, primarily at N7 of guanine (N7-GA-Gua). We performed a dose-response study with AA in female Sprague-Dawley (SD) rats. AA was given orally in a single dosage of 0.1-10 000 μg/kg bw. The formation of urinary mercapturic acids and of N7-GA-Gua DNA adducts in liver, kidney, and lung was measured 16 h after application. A mean of 37.0 ± 11.5% of a given AA dose was found as mercapturic acids (MAs) in urine. MA excretion in urine of untreated controls indicated some background exposure from endogenous AA. N7-GA-Gua adduct formation was not detectable in any organ tested at 0.1 μg AA/kg bw. At a dose of 1 μg/kg bw, adducts were found in kidney (around 1 adduct/10(8) nucleotides) and lung (below 1 adduct/10(8) nucleotides) but not in liver. At 10, respectively, 100 μg/kg bw, adducts were found in all three organs, at levels close to those found at 1 μg AA/kg, covering a range of about 1-2 adducts/10(8) nucleotides. As compared to DNA adduct levels from electrophilic genotoxic agents of various origin found in human tissues, N7-GA-Gua adduct levels within the dose range of 0.1-100 μg AA/kg bw were at the low end of this human background. We propose to take the background level of DNA lesions in humans more into consideration when doing risk assessment of food-borne genotoxic carcinogens.
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Affiliation(s)
- Nico Watzek
- Department of Chemistry, Division of Food Chemistry and Toxicology, University of Kaiserslautern , Erwin-Schroedinger-Strasse 52, 67663 Kaiserslautern, Germany
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Cyclo-Release Strategy in Solid-Phase Combinatorial Synthesis of Heterocyclic Skeletons. ADVANCES IN HETEROCYCLIC CHEMISTRY VOLUME 107 2012. [DOI: 10.1016/b978-0-12-396532-5.00002-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Katic J, Cemeli E, Baumgartner A, Laubenthal J, Bassano I, Stølevik SB, Granum B, Namork E, Nygaard UC, Løvik M, Leeuwen DV, Loock KV, Anderson D, Fučić A, Decordier I. Evaluation of the genotoxicity of 10 selected dietary/environmental compounds with the in vitro micronucleus cytokinesis-block assay in an interlaboratory comparison. Food Chem Toxicol 2010; 48:2612-23. [DOI: 10.1016/j.fct.2010.06.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 06/10/2010] [Accepted: 06/17/2010] [Indexed: 02/02/2023]
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