1
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Borgert CJ, Burgoon LD, Matthews JC. The physiological and biochemical basis of potency thresholds modeled using human estrogen receptor alpha: implications for identifying endocrine disruptors. Arch Toxicol 2024; 98:1795-1807. [PMID: 38704805 PMCID: PMC11106131 DOI: 10.1007/s00204-024-03723-4] [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: 11/05/2023] [Accepted: 02/29/2024] [Indexed: 05/07/2024]
Abstract
The endocrine system functions by interactions between ligands and receptors. Ligands exhibit potency for binding to and interacting with receptors. Potency is the product of affinity and efficacy. Potency and physiological concentration determine the ability of a ligand to produce physiological effects. The kinetic behavior of ligand-receptor interactions conforms to the laws of mass action. The laws of mass action define the relationship between the affinity of a ligand and the fraction of cognate receptors that it occupies at any physiological concentration. We previously identified the minimum ligand potency required to produce clinically observable estrogenic agonist effects via the human estrogen receptor-alpha (ERα). By examining data on botanical estrogens and dietary supplements, we demonstrated that ERα ligands with potency lower than one one-thousandth that of the primary endogenous hormone 17β-estradiol (E2) do not produce clinically observable estrogenic effects. This allowed us to propose a Human-Relevant Potency Threshold (HRPT) for ERα ligands of 1 × 10-4 relative to E2. Here, we test the hypothesis that the HRPT for ERα arises from the receptor occupancy by the normal metabolic milieu of endogenous ERα ligands. The metabolic milieu comprises precursors to hormones, metabolites of hormones, and other normal products of metabolism. We have calculated fractional receptor occupancies for ERα ligands with potencies below and above the previously established HRPT when normal circulating levels of some endogenous ERα ligands and E2 were also present. Fractional receptor occupancy calculations showed that individual ERα ligands with potencies more than tenfold higher than the HRPT can compete for occupancy at ERα against individual components of the endogenous metabolic milieu and against mixtures of those components at concentrations found naturally in human blood. Ligands with potencies less than tenfold higher than the HRPT were unable to compete successfully for ERα. These results show that the HRPT for ERα agonism (10-4 relative to E2) proposed previously is quite conservative and should be considered strong evidence against the potential for disruption of the estrogenic pathway. For chemicals with potency 10-3 of E2, the potential for estrogenic endocrine disruption must be considered equivocal and subject to the presence of corroborative evidence. Most importantly, this work demonstrates that the endogenous metabolic milieu is responsible for the observed ERα agonist HRPT, that this HRPT applies also to ERα antagonists, and it provides a compelling mechanistic explanation for the HRPT that is grounded in basic principles of molecular kinetics using well characterized properties and concentrations of endogenous components of normal metabolism.
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Affiliation(s)
- Christopher J Borgert
- Applied Pharmacology and Toxicology, Inc. and CEHT, Univ. FL College of Vet. Med., Gainesville, FL, USA.
| | | | - John C Matthews
- University of Mississippi School of Pharmacy, University, MS, USA
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2
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Guo X, Liu B, Liu H, Du X, Chen X, Wang W, Yuan S, Zhang B, Wang Y, Guo H, Zhang H. Research advances in identification procedures of endocrine disrupting chemicals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:83113-83137. [PMID: 37347330 DOI: 10.1007/s11356-023-27755-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/15/2023] [Indexed: 06/23/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are increasingly concerned substance endangering human health and environment. However, there is no unified standard for identifying chemicals as EDCs, which is also controversial internationally. In this review, the procedures for EDC identification in different organizations/countries were described. Importantly, three aspects to be considered in identifying chemical substances as EDCs were summarized, which were mechanistic data, animal experiments, and epidemiological information. The relationships between them were also discussed. To elaborate more clearly on these three aspects of evidence, scientific data on some chemicals including bisphenol A, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane and perchlorate were collected and evaluated. Altogether, the above three chemicals were assessed for interfering with hormones and elaborated their health hazards from macroscopic to microscopic. This review is helpful for standardizing the identification procedure of EDCs.
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Affiliation(s)
- Xing Guo
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Bing Liu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Haohao Liu
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Xinghai Chen
- Department of Chemistry and Biochemistry, St Mary's University, San Antonio, TX, USA
| | - Wenjun Wang
- College of Nursing, Jining Medical University, Jining, Shandong, People's Republic of China
| | - Shumeng Yuan
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Bingyu Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Yongshui Wang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Hongxiang Guo
- College of Life Sciences, Henan Agricultural University, Zhengzhou, Henan, 450001, People's Republic of China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan, 450001, People's Republic of China.
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3
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Clahsen SCS, Moss L, van Kamp I, Vermeire TG, Garssen BJ, Piersma AH, Lebret E. Analysis of different preferences for the EU's regulatory options for endocrine disruptor identification criteria using argumentation theory. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 740:140076. [PMID: 32563877 DOI: 10.1016/j.scitotenv.2020.140076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 06/11/2023]
Abstract
What criteria are most suitable to identify endocrine disrupting substances (EDSs) for regulatory purposes in the EU? The results of the European Commission's public consultation, as part of the process to establish identification criteria for EDSs, show that different regulatory options are supported. Some respondents prefer an option including hazard characterization considerations, whereas others prefer an option that avoids these considerations and introduces several hazard-identification based weight-of-evidence categories. In this study, the argumentation underlying the different preferences for identification criteria are analyzed and compared using pragma-dialectical argumentation theory (PDAT). All responses of non-anonymous, national governments that submitted a response in English (n = 17) were included. Responses of other stakeholder organizations were included if a Google News search returned an opinionated presence in the media on the subject (n = 9). Five topical themes and 21 underlying issues were identified. The themes are 1) mechanistic understanding of EDSs, 2) regulatory considerations related to the identification of EDSs, 3) consistency with existing regulatory frameworks, and 4) evaluations of specific issues related to a category approach and 5) related to including potency. We argue that two overarching (implicit) 'advocacy coalitions' can be discerned, that adopted contrasting positions towards the identified themes and issues. Among these 'coalitions', there appears to be consensus about the necessity of having 'science-based' criteria, though different perspectives exist as to what the most accurate mechanistic understanding of EDSs entails. To move the discussion forward, we argue that a societal dialogue would be beneficial, where EDS science and regulation are discussed as interrelated themes.
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Affiliation(s)
- Sander C S Clahsen
- Centre for Sustainability, Environment and Health, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA Bilthoven, the Netherlands; Institute for Risk Assessment Sciences - IRAS, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, the Netherlands.
| | - Lana Moss
- Centre for Sustainability, Environment and Health, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA Bilthoven, the Netherlands; Department of Speech Communication, Argumentation Theory and Rhetoric, University of Amsterdam, 12 Spuistraat 134, 1012 VB Amsterdam, the Netherlands
| | - Irene van Kamp
- Centre for Sustainability, Environment and Health, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA Bilthoven, the Netherlands
| | - Theo G Vermeire
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA, Bilthoven, the Netherlands
| | - Bart J Garssen
- Department of Speech Communication, Argumentation Theory and Rhetoric, University of Amsterdam, 12 Spuistraat 134, 1012 VB Amsterdam, the Netherlands
| | - Aldert H Piersma
- Institute for Risk Assessment Sciences - IRAS, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, the Netherlands; Centre for Health Protection, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA Bilthoven, the Netherlands
| | - Erik Lebret
- Centre for Sustainability, Environment and Health, National Institute for Public Health and the Environment - RIVM, P.O. Box 1, 3720 BA Bilthoven, the Netherlands; Institute for Risk Assessment Sciences - IRAS, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, the Netherlands
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4
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Hengstler J, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? Toxicol Lett 2020; 331:259-264. [PMID: 32360654 DOI: 10.1016/j.toxlet.2020.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Herman Autrup
- Institute of Public Health, University of Aarhus, Aarhus, Denmark
| | - Frank A Barile
- College of Pharmacy and Health Sciences, St John's University, Queens, NY, USA
| | | | - Bas J Blaauboer
- Division of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands
| | - Alan Boobis
- National Heart & Lung Institute, Imperial College, London, UK
| | - Herrmann Bolt
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), TU Dortmund, Dortmund, Germany
| | | | - Wolfgang Dekant
- Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany
| | - Daniel Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Jose L Domingo
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat 'Rovira i Virgili', Reus, Spain
| | | | - Helmut Greim
- Technical University of Munich, Hohenbachernstrasse 15-17, D-85350, Freising, Weihenstephan, Germany.
| | - Jan Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), TU Dortmund, Dortmund, Germany
| | - Sam Kacew
- McLaughlin Centre for Risk Assessment, University of Ottawa, Ottawa, Canada
| | | | - Olavi Pelkonen
- Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Kai Savolainen
- Nanosafety Research Centre, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Pat Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Nico P Vermeulen
- Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit, Amsterdam, the Netherlands
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5
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Hengstler J, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 78:103396. [PMID: 32391796 DOI: 10.1016/j.etap.2020.103396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Theoretically, both synthetic endocrine disrupting chemicals (S-EDCs) and natural (exogenous and endogenous) endocrine disrupting chemicals (N-EDCs) can interact with endocrine receptors and disturb hormonal balance. However, compared to endogenous hormones, S-EDCs are only weak partial agonists with receptor affinities several orders of magnitude lower. Thus, to elicit observable effects, S-EDCs require considerably higher concentrations to attain sufficient receptor occupancy or to displace natural hormones and other endogenous ligands. Significant exposures to exogenous N-EDCs may result from ingestion of foods such as soy-based diets, green tea and sweet mustard. While their potencies are lower as compared to natural endogenous hormones, they usually are considerably more potent. Effects of exogenous N-EDCs on the endocrine system were observed at high dietary intakes. A causal relation between their mechanism of action and these effects is established and biologically plausible. In contrast, the assumption that the much lower human exposures to S-EDCs may induce observable endocrine effects is not plausible. Hence, it is not surprising that epidemiological studies searching for an association between S-EDC exposure and health effects have failed. Regarding testing for potential endocrine effects, a scientifically justified screen should use in vitro tests to compare potencies of S-EDCs with those of reference N-EDCs. When the potency of the S-EDC is similar or smaller than that of the N-EDC, further testing in laboratory animals and regulatory consequences are not warranted.
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Affiliation(s)
- Herman Autrup
- Institute of Public Health, University of Aarhus, Aarhus, Denmark
| | - Frank A Barile
- College of Pharmacy and Health Sciences, St John's University, Queens, New York, USA
| | | | - Bas J Blaauboer
- Division of Toxicology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Alan Boobis
- National Heart & Lung Institute, Imperial College, London, UK
| | - Herrmann Bolt
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), TU Dortmund, Dortmund, Germany
| | | | - Wolfgang Dekant
- Department of Toxicology, University of Wuerzburg, Wuerzburg, Germany.
| | - Daniel Dietrich
- Human and Environmental Toxicology, University of Konstanz, Konstanz, Germany
| | - Jose L Domingo
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat 'Rovira i Virgili', Reus, Spain
| | | | - Helmut Greim
- Institute of Public Health, University of Aarhus, Aarhus, Denmark.
| | - Jan Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), TU Dortmund, Dortmund, Germany
| | - Sam Kacew
- McLaughlin Centre for Risk Assessment, University of Ottawa, Ottawa, Canada
| | | | - Olavi Pelkonen
- Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Kai Savolainen
- Nanosafety Research Centre, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Pat Heslop-Harrison
- Department of Genetics and Genome Biology University of Leicester, Leicester, UK
| | - Nico P Vermeulen
- Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit, Amsterdam, The Netherlands
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6
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Hengstler J, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? Food Chem Toxicol 2020; 142:111349. [DOI: 10.1016/j.fct.2020.111349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/17/2022]
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7
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Hengstler J, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? Chem Biol Interact 2020; 326:109099. [DOI: 10.1016/j.cbi.2020.109099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Autrup H, Barile FA, Berry SC, Blaauboer BJ, Boobis A, Bolt H, Borgert CJ, Dekant W, Dietrich D, Domingo JL, Gori GB, Greim H, Hengstler J, Kacew S, Marquardt H, Pelkonen O, Savolainen K, Heslop-Harrison P, Vermeulen NP. Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2020; 83:485-494. [PMID: 32552445 DOI: 10.1080/15287394.2020.1756592] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Theoretically, both synthetic endocrine-disrupting chemicals (S-EDCs) and natural (exogenous and endogenous) endocrine-disrupting chemicals (N-EDCs) can interact with endocrine receptors and disturb hormonal balance. However, compared to endogenous hormones, S-EDCs are only weak partial agonists with receptor affinities several orders of magnitude lower than S-EDCs. Thus, to elicit observable effects, S-EDCs require considerably higher concentrations to attain sufficient receptor occupancy or to displace natural hormones and other endogenous ligands. Significant exposures to exogenous N-EDCs may result from ingestion of foods such as soy-based diets, green tea, and sweet mustard. While their potencies are lower as compared to natural endogenous hormones, they usually are considerably more potent than S-EDCs. Effects of exogenous N-EDCs on the endocrine system were observed at high dietary intakes. A causal relation between their mechanism of action and these effects is established and biologically plausible. In contrast, the assumption that the much lower human exposures to S-EDCs may induce observable endocrine effects is not plausible. Hence, it is not surprising that epidemiological studies searching for an association between S-EDC exposure and health effects have failed. Regarding testing for potential endocrine effects, a scientifically justified screen should use in vitro tests to compare potencies of S-EDCs with those of reference N-EDCs. When the potency of the S-EDC is similar or smaller than that of the N-EDC, further testing in laboratory animals and regulatory consequences are not warranted.
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Affiliation(s)
- Herman Autrup
- Institute of Public Health, University of Aarhus , Aarhus, Denmark
| | - Frank A Barile
- College of Pharmacy and Health Sciences, St John's University , Queens, USA
| | | | - Bas J Blaauboer
- Division of Toxicology, Institute for Risk Assessment Sciences, Utrecht University , Utrecht, The Netherlands
| | - Alan Boobis
- National Heart & Lung Institute, Imperial College , London, UK
| | - Herrmann Bolt
- Leibniz Research Centre for Working Environment and Human Factors (Ifado), TU Dortmund , Dortmund, Germany
| | | | - Wolfgang Dekant
- Department of Toxicology, University of Wuerzburg , Wuerzburg, Germany
| | - Daniel Dietrich
- Human and Environmental Toxicology, University of Konstanz , Konstanz, Germany
| | - Jose L Domingo
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat 'Rovira I Virgili' , Reus, Spain
| | | | - Helmut Greim
- Technical University of Munich D-85350, Freising-Weihenstephan, Germany
| | - Jan Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (Ifado), TU Dortmund , Dortmund, Germany
| | - Sam Kacew
- McLaughlin Centre for Risk Assessment, University of Ottawa , Ottawa, Canada
| | | | - Olavi Pelkonen
- Department of Pharmacology and Toxicology, University of Oulu , Finland
| | - Kai Savolainen
- Nanosafety Research Centre, Finnish Institute of Occupational Health , Helsinki, Finland
| | - Pat Heslop-Harrison
- Department of Genetics and Genome Biology, University of Leicester , Leicester, UK
| | - Nico P Vermeulen
- Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit , Amsterdam, The Netherlands
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9
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Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity: how to evaluate the risk of the S-EDCs? Arch Toxicol 2020; 94:2549-2557. [PMID: 32514609 PMCID: PMC7367909 DOI: 10.1007/s00204-020-02800-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/21/2022]
Abstract
Theoretically, both synthetic endocrine disrupting chemicals (S-EDCs) and natural (exogenous and endogenous) endocrine disrupting chemicals (N-EDCs) can interact with endocrine receptors and disturb hormonal balance. However, compared to endogenous hormones, S-EDCs are only weak partial agonists with receptor affinities several orders of magnitude lower. Thus, to elicit observable effects, S-EDCs require considerably higher concentrations to attain sufficient receptor occupancy or to displace natural hormones and other endogenous ligands. Significant exposures to exogenous N-EDCs may result from ingestion of foods such as soy-based diets, green tea and sweet mustard. While their potencies are lower as compared to natural endogenous hormones, they usually are considerably more potent than S-EDCs. Effects of exogenous N-EDCs on the endocrine system were observed at high dietary intakes. A causal relation between their mechanism of action and these effects is established and biologically plausible. In contrast, the assumption that the much lower human exposures to S-EDCs may induce observable endocrine effects is not plausible. Hence, it is not surprising that epidemiological studies searching for an association between S-EDC exposure and health effects have failed. Regarding testing for potential endocrine effects, a scientifically justified screen should use in vitro tests to compare potencies of S-EDCs with those of reference N-EDCs. When the potency of the S-EDC is similar or smaller than that of the N-EDC, further testing in laboratory animals and regulatory consequences are not warranted.
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10
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Human exposure to synthetic endocrine disrupting chemicals (S-EDCs) is generally negligible as compared to natural compounds with higher or comparable endocrine activity. How to evaluate the risk of the S-EDCs? Toxicol In Vitro 2020; 67:104861. [PMID: 32360643 DOI: 10.1016/j.tiv.2020.104861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Theoretically, both synthetic endocrine disrupting chemicals (S-EDCs) and natural (exogenous and endogenous) endocrine disrupting chemicals (N-EDCs) can interact with endocrine receptors and disturb hormonal balance. However, compared to endogenous hormones, S-EDCs are only weak partial agonists with receptor affinities several orders of magnitude lower. Thus, to elicit observable effects, S-EDCs require considerably higher concentrations to attain sufficient receptor occupancy or to displace natural hormones and other endogenous ligands. Significant exposures to exogenous N-EDCs may result from ingestion of foods such as soy-based diets, green tea and sweet mustard. While their potencies are lower as compared to natural endogenous hormones, they usually are considerably more potent than S-EDCs. Effects of exogenous N-EDCs on the endocrine system were observed at high dietary intakes. A causal relation between their mechanism of action and these effects is established and biologically plausible. In contrast, the assumption that the much lower human exposures to S-EDCs may induce observable endocrine effects is not plausible. Hence, it is not surprising that epidemiological studies searching for an association between S-EDC exposure and health effects have failed. Regarding testing for potential endocrine effects, a scientifically justified screen should use in vitro tests to compare potencies of S-EDCs with those of reference N-EDCs. When the potency of the S-EDC is similar or smaller than that of the N-EDC, further testing in laboratory animals and regulatory consequences are not warranted.
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11
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Brescia S. Thresholds of adversity and their applicability to endocrine disrupting chemicals. Crit Rev Toxicol 2020; 50:213-218. [PMID: 32228218 DOI: 10.1080/10408444.2020.1740973] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Within the European Union, various legislative acts contain specific provisions on endocrine disruption, requiring the regulation of substances with endocrine disrupting properties via a hazard-based approach. Presumably this is due to an assumed lack of thresholds for the adverse effects of such substances. Conversely, in other jurisdictions, such as USA, Canada, Australia and Japan, endocrine disruptors (EDs) are regulated using a risk-based approach. As a consequence, in recent years there has been increasing controversy on whether thresholds can be inferred for endocrine-mediated effects. There is concern that the endocrine system is too complex to allow estimation of safe levels of exposure to such chemicals. This brief review aims to evaluate the available scientific evidence in this area and offer a sound and robust conclusion supported by this analysis. It is concluded that there is nothing special or unique about endocrine disruption or greater uncertainties in its assessment compared to other non-genotoxic forms of toxicity to justify adopting a non-threshold approach by default. Biology predicts that thresholds of adversity exist and are the rule for all endpoints, including those arising from endocrine disruption. A threshold approach to the risk assessment of endocrine disrupting chemicals is scientifically justified.
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Affiliation(s)
- Susy Brescia
- Health and Safety Executive (HSE), Chemicals Regulation Division (CRD), Merseyside, UK
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12
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Camacho L, Lewis S, Vanlandingham M, Olson G, Davis K, Patton R, Twaddle N, Doerge D, Churchwell M, Bryant M, McLellen F, Woodling K, Felton R, Maisha M, Juliar B, Gamboa da Costa G, Delclos K. A two-year toxicology study of bisphenol A (BPA) in Sprague-Dawley rats: CLARITY-BPA core study results. Food Chem Toxicol 2019; 132:110728. [DOI: 10.1016/j.fct.2019.110728] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 02/06/2023]
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13
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Miller MM, McMullen PD, Andersen ME, Clewell RA. Multiple receptors shape the estrogen response pathway and are critical considerations for the future of in vitro-based risk assessment efforts. Crit Rev Toxicol 2017; 47:564-580. [DOI: 10.1080/10408444.2017.1289150] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Safe S, Li X. Endocrine disruption: Relevance of experimental studies in female animals to human studies. CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Solecki R, Kortenkamp A, Bergman Å, Chahoud I, Degen GH, Dietrich D, Greim H, Håkansson H, Hass U, Husoy T, Jacobs M, Jobling S, Mantovani A, Marx-Stoelting P, Piersma A, Ritz V, Slama R, Stahlmann R, van den Berg M, Zoeller RT, Boobis AR. Scientific principles for the identification of endocrine-disrupting chemicals: a consensus statement. Arch Toxicol 2016; 91:1001-1006. [PMID: 27714423 PMCID: PMC5306068 DOI: 10.1007/s00204-016-1866-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 09/29/2016] [Indexed: 11/02/2022]
Abstract
Endocrine disruption is a specific form of toxicity, where natural and/or anthropogenic chemicals, known as "endocrine disruptors" (EDs), trigger adverse health effects by disrupting the endogenous hormone system. There is need to harmonize guidance on the regulation of EDs, but this has been hampered by what appeared as a lack of consensus among scientists. This publication provides summary information about a consensus reached by a group of world-leading scientists that can serve as the basis for the development of ED criteria in relevant EU legislation. Twenty-three international scientists from different disciplines discussed principles and open questions on ED identification as outlined in a draft consensus paper at an expert meeting hosted by the German Federal Institute for Risk Assessment (BfR) in Berlin, Germany on 11-12 April 2016. Participants reached a consensus regarding scientific principles for the identification of EDs. The paper discusses the consensus reached on background, definition of an ED and related concepts, sources of uncertainty, scientific principles important for ED identification, and research needs. It highlights the difficulty in retrospectively reconstructing ED exposure, insufficient range of validated test systems for EDs, and some issues impacting on the evaluation of the risk from EDs, such as non-monotonic dose-response and thresholds, modes of action, and exposure assessment. This report provides the consensus statement on EDs agreed among all participating scientists. The meeting facilitated a productive debate and reduced a number of differences in views. It is expected that the consensus reached will serve as an important basis for the development of regulatory ED criteria.
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Affiliation(s)
| | - Andreas Kortenkamp
- Institute of Environment, Health and Societies, Brunel University, London, Uxbridge, UK
| | - Åke Bergman
- Swedish Toxicology Sciences Research Center, Södertälje, Sweden
| | | | | | | | | | - Helen Håkansson
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ulla Hass
- Technical University of Denmark, DTU, Søborg, Denmark
| | - Trine Husoy
- Norwegian Institute of Public Health, Oslo, Norway
| | | | - Susan Jobling
- Institute of Environment, Health and Societies, Brunel University, London, Uxbridge, UK
| | | | | | | | - Vera Ritz
- Federal Institute for Risk Assessment, Berlin, Germany
| | - Remy Slama
- Inserm, CNRS and University Grenoble-Alpes Joint Research Centre, Grenoble, France
| | | | - Martin van den Berg
- Institute of Risk Assessment Studies (IRAS), Utrecht University, Utrecht, The Netherlands
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16
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Trasande L, Vandenberg LN, Bourguignon JP, Myers JP, Slama R, Vom Saal F, Zoeller RT. Peer-reviewed and unbiased research, rather than 'sound science', should be used to evaluate endocrine-disrupting chemicals. J Epidemiol Community Health 2016; 70:1051-1056. [PMID: 27417427 DOI: 10.1136/jech-2016-207841] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/21/2016] [Indexed: 12/31/2022]
Abstract
Evidence increasingly confirms that synthetic chemicals disrupt the endocrine system and contribute to disease and disability across the lifespan. Despite a United Nations Environment Programme/WHO report affirmed by over 100 countries at the Fourth International Conference on Chemicals Management, 'manufactured doubt' continues to be cast as a cloud over rigorous, peer-reviewed and independently funded scientific data. This study describes the sources of doubt and their social costs, and suggested courses of action by policymakers to prevent disease and disability. The problem is largely based on the available data, which are all too limited. Rigorous testing programmes should not simply focus on oestrogen, androgen and thyroid. Tests should have proper statistical power. 'Good laboratory practice' (GLP) hardly represents a proper or even gold standard for laboratory studies of endocrine disruption. Studies should be evaluated with regard to the contamination of negative controls, responsiveness to positive controls and dissection techniques. Flaws in many GLP studies have been identified, yet regulatory agencies rely on these flawed studies. Peer-reviewed and unbiased research, rather than 'sound science', should be used to evaluate endocrine-disrupting chemicals.
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Affiliation(s)
- Leonardo Trasande
- Department of Pediatrics, New York University School of Medicine, New York, New York, USA Department of Environmental Medicine and Population Health, New York University School of Medicine, New York, New York, USA Department of Population Health, New York University School of Medicine, New York, New York, USA NYU Wagner School of Public Service, New York, New York, USA Department of Nutrition, Food & Public Health, NYU Steinhardt School of Culture, Education and Human Development, New York, New York, USA NYU Global Institute of Public Health, New York, New York, USA
| | - Laura N Vandenberg
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts-Amherst, Amherst, Massachusetts, USA
| | - Jean-Pierre Bourguignon
- Pediatric Endocrinology, CHU Liège and Neuroendocrinology Unit, GIGA Neurosciences, Universite de Liege, Liège, Belgium
| | | | - Remy Slama
- Inserm, CNRS and Univ. Grenoble Alpes joint research center (IAB), Team of Environmental Epidemiology, Grenoble, France
| | - Frederick Vom Saal
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, Missouri, USA
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17
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Borgert CJ, Becker RA, Carlton BD, Hanson M, Kwiatkowski PL, Sue Marty M, McCarty LS, Quill TF, Solomon K, Van Der Kraak G, Witorsch RJ, Yi KD. Does GLP enhance the quality of toxicological evidence for regulatory decisions? Toxicol Sci 2016; 151:206-13. [PMID: 27208076 PMCID: PMC4880141 DOI: 10.1093/toxsci/kfw056] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
There is debate over whether the requirements of GLP are appropriate standards for evaluating the quality of toxicological data used to formulate regulations. A group promoting the importance of non-monotonic dose responses for endocrine disruptors contend that scoring systems giving primacy to GLP are biased against non-GLP studies from the literature and are merely record-keeping exercises to prevent fraudulent reporting of data from non-published guideline toxicology studies. They argue that guideline studies often employ insensitive species and outdated methods, and ignore the perspectives of subject-matter experts in endocrine disruption, who should be the sole arbiters of data quality. We believe regulatory agencies should use both non-GLP and GLP studies, that GLP requirements assure fundamental tenets of study integrity not typically addressed by journal peer-review, and that use of standardized test guidelines and GLP promotes consistency, reliability, comparability, and harmonization of various types of studies used by regulatory agencies worldwide. This debate suffers two impediments to progress: a conflation of different phases of study interpretation and levels of data validity, and a misleading characterization of many essential components of GLP and regulatory toxicology. Herein we provide clarifications critical for removing those impediments.
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Affiliation(s)
- Christopher J Borgert
- Dept. Physiol. Sciences, Univ. FL College of Veterinary Medicine, Applied Pharmacology and Toxicology, Inc, and C.E.H.T, Gainesville, Florida 32605;
| | - Richard A Becker
- American Chemistry Council, Washington, District of Columbia 20002
| | - Betsy D Carlton
- Bluestar Silicones USA Corp 10520 Whitestone Rd., Raleigh, North Carolina 27615
| | - Mark Hanson
- Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Mary Sue Marty
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674
| | - Lynn S McCarty
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674
| | - Terry F Quill
- Quill Law Group, LLC, Washington, District of Columbia 20006
| | - Keith Solomon
- University of Guelph, Centre for Toxicology, School of Environmental Science, Guelph, Ontario N1G 2W1, Canada
| | - Glen Van Der Kraak
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Raphael J Witorsch
- Department of Physiology & Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0551
| | - Kun Don Yi
- Syngenta Crop Protection, Inc, Greensboro, North Carolina 27419-8300
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18
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Lamb JC, Boffetta P, Foster WG, Goodman JE, Hentz KL, Rhomberg LR, Staveley J, Swaen G, Van Der Kraak G, Williams AL. Comments on the opinions published by Bergman et al. (2015) on Critical Comments on the WHO-UNEP State of the Science of Endocrine Disrupting Chemicals (Lamb et al., 2014). Regul Toxicol Pharmacol 2015; 73:754-7. [PMID: 26550933 DOI: 10.1016/j.yrtph.2015.10.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 01/01/2023]
Abstract
Recently Bergman et al. (2015) took issue with our comments (Lamb et al., 2014) on the WHO-UNEP(1) report entitled the "State of the Science of Endocrine Disrupting Chemicals - 2012" (WHO 2013a). We find several key differences between their view and ours regarding the selection of studies and presentation of data related to endocrine disrupting chemicals (EDCs) under the WHO-IPCS(2) definition (2002). In this response we address the factors that we think are most important: 1. the difference between hazard and risk; 2. the different approaches for hazard identification (weight of the evidence [WOE] vs. emphasizing positive findings over null results); and 3. the lack of a justification for conceptual or practical differences between EDCs and other groups of agents.
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Affiliation(s)
- James C Lamb
- Exponent, 1800 Diagonal Road, Suite #500, Alexandria, VA 22314, USA.
| | - Paolo Boffetta
- The Tisch Cancer Institute and Institute for Translational Epidemiology, Icahn School of Medicine at Mount Sinai, 17 East 102 Street Floor West Tower, 5th Floor Room 5-142, New York, NY 10029, USA.
| | - Warren G Foster
- Department of Obstetrics & Gynecology, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada.
| | | | - Karyn L Hentz
- Exponent, 1800 Diagonal Road, Suite #500, Alexandria, VA 22314, USA.
| | | | - Jane Staveley
- Exponent, 1800 Diagonal Road, Suite #500, Alexandria, VA 22314, USA.
| | | | - Glen Van Der Kraak
- Department of Integrative Biology, University of Guelph, Guelph ON N1G 2W1, Canada.
| | - Amy L Williams
- Exponent, 1800 Diagonal Road, Suite #500, Alexandria, VA 22314, USA.
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19
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Toxicology: a discipline in need of academic anchoring--the point of view of the German Society of Toxicology. Arch Toxicol 2015; 89:1881-93. [PMID: 26314262 PMCID: PMC4572062 DOI: 10.1007/s00204-015-1577-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/10/2015] [Indexed: 12/29/2022]
Abstract
The paper describes the importance of toxicology as a discipline, its past achievements, current scientific challenges, and future development. Toxicological expertise is instrumental in the reduction of human health risks arising from chemicals and drugs. Toxicological assessment is needed to evaluate evidence and arguments, whether or not there is a scientific base for concern. The immense success already achieved by toxicological work is exemplified by reduced pollution of air, soil, water, and safer working places. Predominantly predictive toxicological testing is derived from the findings to assess risks to humans and the environment. Assessment of the adversity of molecular effects (including epigenetic effects), the effects of mixtures, and integration of exposure and biokinetics into in vitro testing are emerging challenges for toxicology. Toxicology is a translational science with its base in fundamental science. Academic institutions play an essential part by providing scientific innovation and education of young scientists.
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