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Xiao Q, Hou X, Kang C, Xiagedeer B, Hu H, Meng Q, Jiang J, Hao W. Effects of prenatal chlorocholine chloride exposure on pubertal development and reproduction of male offspring in rats. Toxicol Lett 2021; 351:28-36. [PMID: 34411681 DOI: 10.1016/j.toxlet.2021.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/31/2021] [Accepted: 08/13/2021] [Indexed: 11/18/2022]
Abstract
Chlorocholine chloride (CCC) promote plant growth as a regulator. Emerging evidence by our group showed that CCC might restrain the puberty onset and impair the reproductive functions in male rats through HPT axis. In this study, we further investigated the effects of prenatal CCC exposure on pubertal development, reproduction of male offspring in rats and explored the underlying mechanisms. The results showed that CCC of 137.5 and 200 mg/kg bw/day delayed the age of preputial separation (PPS), decreased the sperm motility of male offspring. PP1γ2 which is an essential protein in spermatogenesis reduced in 137.5 and 200 mg/kg bw/day groups. Crucial hormones involved in hypothalamic-puititary-testicular (HPT) axis decreased at postnatal day (PND) 30. It was indicated that CCC exposure in pregnancy might disturb the pubertal development, reproductive functions of male offspring through HPT axis and disturb the sperm motility through PP1γ2.
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Affiliation(s)
- Qianqian Xiao
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Xiaohong Hou
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Chenping Kang
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Bayindala Xiagedeer
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Hong Hu
- Department of Preventive Medicine, School of Public Health, Fujian Medical University, Fuzhou, 350122, PR China
| | - Qinghe Meng
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Jianjun Jiang
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China
| | - Weidong Hao
- Department of Toxicology, School of Public Health, Peking University, Beijing, 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, 100191, PR China.
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2
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Ijaz MU, Anwar H, Iqbal S, Ismail H, Ashraf A, Mustafa S, Samad A. Protective effect of myricetin on nonylphenol-induced testicular toxicity: biochemical, steroidogenic, hormonal, spermatogenic, and histological-based evidences. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:22742-22757. [PMID: 33423203 DOI: 10.1007/s11356-020-12296-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Nonylphenol (NP) is an environmental contaminant, which induces testicular toxicity through oxidative stress. Myricetin (MYR) is a naturally occurring flavonol having powerful antioxidant activity. The current research was planned to examine the ameliorative role of MYR against NP-induced testicular damage. A total of 24 adult male Sprague-Dawley rats were randomly divided into 4 equivalent groups: control (0.1% DMSO), NP group (50 mg kg-1), NP + MYR group (50 mg kg-1; 100 mg kg-1), and MYR-treated group (100 mg kg-1). NP administration significantly (p < 0.05) decreased the activity of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GSR), and protein content while significantly (p < 0.05) elevating the thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS) levels. Additionally, NP significantly (p < 0.05) reduced the sperm motility, gene expression of testicular steroidogenic enzymes (3β-HSD, 3β-hydroxysteroid dehydrogenase; 17β-HSD, 17β-hydroxysteroid dehydrogenase; StAR, steroidogenic-acute regulatory protein), level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), plasma testosterone, and daily sperm production (DSP). On the other hand, it raised the testicular cholesterol, dead sperms, and head, midpiece, and tail abnormalities along with abnormal histomorphometry. However, MYR remarkably abrogated NP-induced damages. In conclusion, the outcomes of the study suggest that MYR can effectively alleviate the NP-induced oxidative stress and testicular damages.
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Affiliation(s)
- Muhammad Umar Ijaz
- Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad, Pakistan
| | - Haseeb Anwar
- Department of Physiology, Government College University, Faisalabad, Pakistan
| | - Shabnoor Iqbal
- Department of Zoology, Government College University, Faisalabad, Pakistan
| | - Hammad Ismail
- Department of Biochemistry and Biotechnology, University of Gujrat, Gujrat, Pakistan
| | - Asma Ashraf
- Department of Zoology, Government College University, Faisalabad, Pakistan
| | - Shama Mustafa
- Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad, Pakistan
| | - Abdul Samad
- Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad, Pakistan.
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3
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Hassan MA, El Bohy KM, El Sharkawy NI, Imam TS, El-Metwally AE, Hamed Arisha A, Mohammed HA, Abd-Elhakim YM. Iprodione and chlorpyrifos induce testicular damage, oxidative stress, apoptosis and suppression of steroidogenic- and spermatogenic-related genes in immature male albino rats. Andrologia 2021; 53:e13978. [PMID: 33586219 DOI: 10.1111/and.13978] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/30/2020] [Accepted: 01/01/2021] [Indexed: 12/30/2022] Open
Abstract
The fungicide iprodione (IPR) and the insecticide chlorpyrifos (CPF) are concurrently applied for early disease control in fruits and other crops. However, there are no available data about the impacts of their co-exposure. Additionally, IPR and CPF are known as endocrine disruptors that can cause reproductive toxicity. The outcomes of their co-exposure on the development of male reproductive organs are still unknown. Therefore, this study aimed to assess the risk of exposure to these pesticides, particularly on the postnatal development of the male albino rat reproductive system from postnatal days 23-60. The results revealed that a single IPR or CPF exposure has harmful consequences on the reproductive development and function manifested by reduced testicular weight, serious changes in sperm characteristics, reproductive hormone level imbalance, testicular enzymes, oxidative stress and apoptosis-related enzymes, which correlated with transcription levels of steroidogenic- and spermatogenic-related genes. Histopathologically, both compounds caused severe damage in the testis and accessory glands architecture. Notably, co-exposure to IPR and CPF in rats caused more serious damage, indicative of an additive effect than individual exposure, so concurrent exposure should be avoided as it is more hazardous, especially on male fertility.
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Affiliation(s)
- Mona A Hassan
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Khlood M El Bohy
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Nabela I El Sharkawy
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Tamer S Imam
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Abeer E El-Metwally
- Department of Pathology, Animal Reproduction Research Institute, Giza, Egypt
| | - Ahmed Hamed Arisha
- Department of Animal Physiology and Biochemistry, Faculty of Veterinary Medicine, Badr University in Cairo (BUC), Badr city, Egypt.,Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Haiam A Mohammed
- Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Yasmina M Abd-Elhakim
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
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4
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Alam MS, Kurohmaru M. Di-n-butyl phthalate diminishes testicular steroidogenesis by blocking the hypothalamic-pituitary-testicular axis: relationship with germ cell apoptosis in Japanese quail. Reprod Fertil Dev 2021; 33:319-327. [PMID: 33632378 DOI: 10.1071/rd20150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 11/06/2020] [Indexed: 11/23/2022] Open
Abstract
Although di-n-butyl phthalate (DBP) induces germ cell apoptosis, the underlying mechanism is not yet clear in quail. In this study, prepubertal quails were given a single dose of 500mg kg-1 DBP by gavage and were then killed 3, 6 and 24h after treatment. There was a significant reduction in intratesticular testosterone (ITT) concentrations and testicular steroidogenic enzyme mRNA expression and a significant increase in germ cell apoptosis in DBP-treated compared with control quails at all time points. Maximum apoptosis was detected 6h after treatment and the maximum reduction in testosterone concentrations was at 3h. To investigate whether DBP suppressed testicular steroidogenesis by affecting the hypothalamic-pituitary-testicular axis, we analysed pituitary LH subunit β (Lhb) mRNA expression and serum LH concentrations. At all time points, pituitary Lhb expression and serum LH concentrations were significantly decreased following DBP treatment. The present observations suggest the possibility that DBP blocked LH secretion from the hypothalamus and/or pituitary, thereby decreasing LH stimulation of Leydig cells and reducing ITT concentrations. DBP-induced decreases in ITT concentrations may cause changes to the physical structure of Sertoli cells, which, in turn, may induce germ cell apoptosis.
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Affiliation(s)
- Mohammad Shah Alam
- Department of Anatomy and Histology, Faculty of Veterinary Medicine and Animal Sciences, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh; and Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; and Corresponding author.
| | - Masamichi Kurohmaru
- Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Okayama University of Science, Imabari, Ehime 794-8555, Japan; and Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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5
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Hou X, Hu H, Xiagedeer B, Wang P, Kang C, Zhang Q, Meng Q, Hao W. Effects of chlorocholine chloride on pubertal development and reproductive functions in male rats. Toxicol Lett 2020; 319:1-10. [DOI: 10.1016/j.toxlet.2019.10.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/29/2019] [Accepted: 10/27/2019] [Indexed: 01/21/2023]
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Arzuaga X, Walker T, Yost EE, Radke EG, Hotchkiss AK. Use of the Adverse Outcome Pathway (AOP) framework to evaluate species concordance and human relevance of Dibutyl phthalate (DBP)-induced male reproductive toxicity. Reprod Toxicol 2019; 96:445-458. [PMID: 31260805 PMCID: PMC10067323 DOI: 10.1016/j.reprotox.2019.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 06/05/2019] [Accepted: 06/25/2019] [Indexed: 12/14/2022]
Abstract
Dibutyl phthalate (DBP) is a phthalate ester used as a plasticizer, and solvent. Studies using rats consistently report that DBP exposure disrupts normal development of the male reproductive system in part via inhibition of androgen synthesis. However, studies using xenograft models report that in human fetal testis DBP exposure is unlikely to impair testosterone synthesis. These results question the validity of the rat model for assessment of male reproductive effects caused by DBP. The Adverse Outcome Pathway (AOP) framework was used to evaluate the available evidence for DBP-induced toxicity to the male reproductive system. Three relevant biological elements were identified: 1) fetal rats are more sensitive than other rodents and human fetal xenografts to DBP-induced anti-androgenic effects, 2) DBP-induced androgen-independent adverse outcomes are conserved amongst different mammalian models and human fetal testis xenografts, and 3) DBP-induced anti-androgenic effects are conserved in different mammalian species when exposure occurs during postnatal life stages.
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Affiliation(s)
- Xabier Arzuaga
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Washington, DC, United States of America.
| | - Teneille Walker
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Washington, DC, United States of America
| | - Erin E Yost
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Research Triangle Park, NC, United States of America
| | - Elizabeth G Radke
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Washington, DC, United States of America
| | - Andrew K Hotchkiss
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, Research Triangle Park, NC, United States of America
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Arzuaga X, Smith MT, Gibbons CF, Skakkebæk NE, Yost EE, Beverly BEJ, Hotchkiss AK, Hauser R, Pagani RL, Schrader SM, Zeise L, Prins GS. Proposed Key Characteristics of Male Reproductive Toxicants as an Approach for Organizing and Evaluating Mechanistic Evidence in Human Health Hazard Assessments. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:65001. [PMID: 31199676 PMCID: PMC6792367 DOI: 10.1289/ehp5045] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/22/2019] [Accepted: 05/30/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Assessing chemicals for their potential to cause male reproductive toxicity involves the evaluation of evidence obtained from experimental, epidemiological, and mechanistic studies. Although mechanistic evidence plays an important role in hazard identification and evidence integration, the process of identifying, screening and analyzing mechanistic studies and outcomes is a challenging exercise due to the diversity of research models and methods and the variety of known and proposed pathways for chemical-induced toxicity. Ten key characteristics of carcinogens provide a valuable tool for organizing and assessing chemical-specific data by potential mechanisms for cancer-causing agents. However, such an approach has not yet been developed for noncancer adverse outcomes. OBJECTIVES The objective in this study was to identify a set of key characteristics that are frequently exhibited by exogenous agents that cause male reproductive toxicity and that could be applied for identifying, organizing, and summarizing mechanistic evidence related to this outcome. DISCUSSION The identification of eight key characteristics of male reproductive toxicants was based on a survey of known male reproductive toxicants and established mechanisms and pathways of toxicity. The eight key characteristics can provide a basis for the systematic, transparent, and objective organization of mechanistic evidence relevant to chemical-induced effects on the male reproductive system. https://doi.org/10.1289/EHP5045.
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Affiliation(s)
- Xabier Arzuaga
- National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington, DC, USA
| | - Martyn T. Smith
- University of California, Berkeley, School of Public Health, Berkeley, California, USA
| | - Catherine F. Gibbons
- National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington, DC, USA
| | - Niels E. Skakkebæk
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Erin E. Yost
- National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Brandiese E. J. Beverly
- Office of Health Assessment and Translation, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, USA
| | - Andrew K. Hotchkiss
- National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Russ Hauser
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Rodrigo L. Pagani
- Department of Urology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Steven M. Schrader
- National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA (retired)
| | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Sacramento, California, USA
| | - Gail S. Prins
- Department of Urology, University of Illinois at Chicago, Chicago, Illinois, USA
- School of Public Health, University of Illinois at Chicago, Chicago, Illinois, USA
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8
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A human-derived prostate co-culture microtissue model using epithelial (RWPE-1) and stromal (WPMY-1) cell lines. Toxicol In Vitro 2019; 60:203-211. [PMID: 31154061 DOI: 10.1016/j.tiv.2019.05.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/29/2019] [Indexed: 01/08/2023]
Abstract
The development and normal function of prostate tissue depends on signalling interactions between stromal and epithelial compartments. Development of a prostate microtissue composed of these two components can help identify substance exposures that could cause adverse effects in humans as part of a non-animal risk assessment. In this study, prostate microtissues composed of human derived stromal (WPMY-1) and epithelial (RWPE-1) cell lines grown in scaffold-free hydrogels were developed and characterized using immunohistochemistry, light microscopy, and qRT-PCR. Within 5 days after seeding, the microtissues self-organized into spheroids consisting of a core of stromal WPMY-1 cells surrounded by epithelial RWPE-1 cells. The RWPE-1 layer is reflective of intermediate prostatic epithelium, expressing both characteristics of the luminal (high expression of PSA) and basal (high expression of cytokeratins 5/6 and 14) epithelial cells. The response of the microtissues to an androgen (dihydrotestosterone, DHT) and an anti-androgen (flutamide) was also investigated. Treatment with DHT, flutamide or a mixture of DHT and flutamide indicated that the morphology and self-organization of the microtissues is androgen dependent. qRT-PCR data showed that a saturating concentration of DHT increased the expression of genes coding for the estrogen receptors (ESR1 and ESR2) and decreased the expression of CYP1B1 without affecting the expression of the androgen receptor. With further development and optimization RWPE-1/WPMY-1 microtissues can play an important role in non-animal risk assessments.
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Dent MP, Li H, Carmichael PL, Martin FL. Employing Dietary Comparators to Perform Risk Assessments for Anti-Androgens Without Using Animal Data. Toxicol Sci 2019; 167:375-384. [PMID: 30247711 PMCID: PMC6358230 DOI: 10.1093/toxsci/kfy245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This study investigated the use of androgen receptor (AR) reporter gene assay data in a non-animal exposure-led risk assessment in which in vitro anti-androgenic activity and exposure data were put into context using a naturally occurring comparator substance with a history of dietary consumption. First, several dietary components were screened to identify which selectively interfered with AR signaling in vitro, using the AR CALUX® test. The IC50 values from these dose-response data together with measured or predicted human exposure levels were used to calculate exposure: activity ratios (EARs) for the dietary components and a number of other well-known anti-androgenic substances. Both diindolylmethane (DIM) and resveratrol are specifically acting dietary anti-androgens. The EARs for several anti-androgens were therefore expressed relative to the EAR of DIM, and how this 'dietary comparator ratio' (DCR) approach may be used to make safety decisions was assessed using an exposure-led case study for an anti-androgenic botanical ingredient. This highlights a pragmatic approach which allows novel chemical exposures to be put into context against dietary exposures to natural anti-androgenic substances. The DCR approach may have utility for other modes of action where appropriate comparators can be identified.
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Affiliation(s)
- Matthew P Dent
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Bedfordshire MK44 1LQ, UK
| | - Hequn Li
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Bedfordshire MK44 1LQ, UK
| | - Paul L Carmichael
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Bedfordshire MK44 1LQ, UK
| | - Francis L Martin
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, UK
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10
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Radke EG, Braun JM, Meeker JD, Cooper GS. Phthalate exposure and male reproductive outcomes: A systematic review of the human epidemiological evidence. ENVIRONMENT INTERNATIONAL 2018; 121:764-793. [PMID: 30336412 PMCID: PMC10825890 DOI: 10.1016/j.envint.2018.07.029] [Citation(s) in RCA: 247] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/22/2018] [Accepted: 07/20/2018] [Indexed: 05/21/2023]
Abstract
OBJECTIVE We performed a systematic review of the epidemiology literature to identify the male reproductive effects associated with phthalate exposure. DATA SOURCES AND STUDY ELIGIBILITY CRITERIA Six phthalates were included in the review: di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), butyl benzyl phthalate (BBP), and diethyl phthalate (DEP). The initial literature search (of PubMed, Web of Science, and Toxline) included all studies of male reproductive effects in humans, and outcomes were selected for full systematic review based on data availability. STUDY EVALUATION AND SYNTHESIS METHODS For each outcome, studies were evaluated using criteria defined a priori for risk of bias and sensitivity by two reviewers using a domain-based approach. Evidence was synthesized by outcome and phthalate and strength of evidence was summarized using a structured framework. RESULTS The primary outcomes reviewed here are (number of included/excluded studies in parentheses): anogenital distance (6/1), semen parameters (15/9), time to pregnancy (3/5), testosterone (13/8), timing of pubertal development (5/15), and hypospadias/cryptorchidism (4/10). Looking at the overall hazard, there was robust evidence of an association between DEHP and DBP exposure and male reproductive outcomes; this was based primarily on studies of anogenital distance, semen parameters, and testosterone for DEHP and semen parameters and time to pregnancy for DBP. There was moderate evidence of an association between DINP and BBP exposure and male reproductive outcomes based on testosterone and semen parameters for DINP and semen parameters and time to pregnancy for BBP. DIBP and DEP were considered to have slight evidence of an association. For DIBP, the less conclusive evidence was attributed to a more limited literature base (i.e., fewer studies) and lower exposure levels in the population, decreasing the ability to observe an effect. For DEP, the findings were consistent with experimental animal data that suggest DEP does not haves as strong an anti-androgenic effect as other phthalates. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS Overall, despite some inconsistencies across phthalates in the specific outcomes associated with exposure, these results support that phthalate exposure at levels seen in human populations may have male reproductive effects, particularly DEHP and DBP. The relative strength of the evidence reflects differing levels of toxicity as well as differences in the range of exposures studied and the number of available studies. The views expressed are those of the authors and do not necessarily represent the views or policies of the U.S. EPA.
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Affiliation(s)
- Elizabeth G Radke
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, United States.
| | - Joseph M Braun
- Brown University, School of Public Health, United States
| | - John D Meeker
- University of Michigan, School of Public Health, United States
| | - Glinda S Cooper
- U.S. Environmental Protection Agency, National Center for Environmental Assessment, United States; The Innocence Project, United States
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11
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Dal Negro G, Eskes C, Belz S, Bertein C, Chlebus M, Corvaro M, Corvi R, Dhalluin S, Halder M, Harvey J, Hermann M, Hoffmann-Dörr S, Kilian K, Lambrigts D, Laroche C, Louhimies S, Mahony C, Manou I, McNamee P, Prieto P, Reid K, Roggen E, Schutte K, Stirling C, Uhlrich S, Weissenhorn R, Whelan M. One science-driven approach for the regulatory implementation of alternative methods: A multi-sector perspective. Regul Toxicol Pharmacol 2018; 99:33-49. [PMID: 30098372 DOI: 10.1016/j.yrtph.2018.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 08/05/2018] [Indexed: 12/28/2022]
Abstract
EU regulations call for the use of alternative methods to animal testing. During the last decade, an increasing number of alternative approaches have been formally adopted. In parallel, new 3Rs-relevant technologies and mechanistic approaches have increasingly contributed to hazard identification and risk assessment evolution. In this changing landscape, an EPAA meeting reviewed the challenges that different industry sectors face in the implementation of alternative methods following a science-driven approach. Although clear progress was acknowledged in animal testing reduction and refinement thanks to an integration of scientifically robust approaches, the following challenges were identified: i) further characterization of toxicity pathways; ii) development of assays covering current scientific gaps, iii) better characterization of links between in vitro readouts and outcome in the target species; iv) better definition of alternative method applicability domains, and v) appropriate implementation of the available approaches. For areas having regulatory adopted alternative methods (e.g., vaccine batch testing), harmonised acceptance across geographical regions was considered critical for broader application. Overall, the main constraints to the application of non-animal alternatives are the still existing gaps in scientific knowledge and technological limitations. The science-driven identification of most appropriate methods is key for furthering a multi-sectorial decrease in animal testing.
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Affiliation(s)
- Gianni Dal Negro
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, United Kingdom
| | - Chantra Eskes
- SeCAM Services and Consultation on Alternative Methods, Via Campagnora 1, 6983, Magliaso, Switzerland.
| | - Susanne Belz
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749, 21017, Ispra, Italy
| | | | - Magda Chlebus
- European Federation of Pharmaceutical Industries and Associations (EFPIA), Rue du Trône 108, 1050, Brussels, Belgium
| | - Marco Corvaro
- ECPA - the European Crop Protection Association, 6 Avenue E. Van Nieuwenhuyse, 1160, Brussels, Belgium
| | - Raffaella Corvi
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749, 21017, Ispra, Italy
| | - Stephane Dhalluin
- L'Oréal Research & Innovation, 9 rue Pierre Dreyfus, 92110, Clichy, France
| | - Marlies Halder
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749, 21017, Ispra, Italy
| | - Jim Harvey
- GlaxoSmithKline, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, United Kingdom
| | - Martina Hermann
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589, Duesseldorf, Germany
| | | | - Karin Kilian
- European Commission, Directorate General for the Environment (DG ENV), Brussels, Belgium
| | - Denis Lambrigts
- GlaxoSmithKline Vaccines, 20 Avenue Fleming, 1300, Wavre, Belgium
| | - Charles Laroche
- European Partnership for Alternative Approaches to Animal Testing (EPAA), Av. Herrmann-Debroux 40, 1160, Brussels, Belgium
| | - Susanna Louhimies
- European Commission, Directorate General for the Environment (DG ENV), Brussels, Belgium
| | - Catherine Mahony
- The Procter & Gamble Company, Whitehall Lane, Egham, Surrey TW20 9NW, United Kingdom
| | - Irene Manou
- European Partnership for Alternative Approaches to Animal Testing (EPAA), Av. Herrmann-Debroux 40, 1160, Brussels, Belgium
| | - Pauline McNamee
- The Procter & Gamble Company, Whitehall Lane, Egham, Surrey TW20 9NW, United Kingdom
| | - Pilar Prieto
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749, 21017, Ispra, Italy
| | - Kirsty Reid
- European Federation of Pharmaceutical Industries and Associations (EFPIA), Rue du Trône 108, 1050, Brussels, Belgium
| | - Erwin Roggen
- 3Rs Management and Consulting, Asavænget 14, 2800, Kongens Lyngby, Denmark
| | - Katrin Schutte
- European Commission, Directorate General for the Environment (DG ENV), Brussels, Belgium
| | | | - Sylvie Uhlrich
- Sanofi Pasteur, 1541 Av. Marcel Merieux, 69280, Marcy l'Etoile, France
| | - Renate Weissenhorn
- European Commission, Directorate General for Internal Market, Industry, Enterpreneurship and SME, Brussels, Belgium
| | - Maurice Whelan
- European Commission, Joint Research Centre (JRC), Via E. Fermi 2749, 21017, Ispra, Italy
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12
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Pubertal chlorocholine chloride exposure inhibits testicular testosterone synthesis by down-regulating steroidogenic enzymes in adult rats. Toxicol Lett 2018; 288:17-24. [DOI: 10.1016/j.toxlet.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/02/2018] [Accepted: 02/10/2018] [Indexed: 11/16/2022]
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13
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Allen TEH, Goodman JM, Gutsell S, Russell PJ. A History of the Molecular Initiating Event. Chem Res Toxicol 2016; 29:2060-2070. [PMID: 27989138 DOI: 10.1021/acs.chemrestox.6b00341] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The adverse outcome pathway (AOP) framework provides an alternative to traditional in vivo experiments for the risk assessment of chemicals. AOPs consist of a number of key events (KEs) linked by key event relationships across a range of biological organization backed by scientific evidence. The first KE in the pathway is the molecular initiating event (MIE)-the initial chemical trigger that starts an AOP. Over the past 3 years the AOP conceptual framework has gained a large amount of momentum in toxicology as an alternative to animal methods, and so the MIE has come into the spotlight. What is an MIE? How can MIEs be measured or predicted? What research is currently contributing to our understanding of MIEs? In this Perspective we outline answers to these key questions.
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Affiliation(s)
- Timothy E H Allen
- Centre for Molecular Informatics, Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Jonathan M Goodman
- Centre for Molecular Informatics, Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Steve Gutsell
- Unilever Safety and Environmental Assurance Centre , Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Paul J Russell
- Unilever Safety and Environmental Assurance Centre , Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
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14
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Overcoming barriers to non-animal risk assessments for anti-androgenic effects in humans. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.1592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Yang X, Liu H, Liu J, Li F, Li X, Shi L, Chen J. Rational Selection of the 3D Structure of Biomacromolecules for Molecular Docking Studies on the Mechanism of Endocrine Disruptor Action. Chem Res Toxicol 2016; 29:1565-70. [PMID: 27556396 DOI: 10.1021/acs.chemrestox.6b00245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular modeling has become an essential tool in predicting and simulating endocrine disrupting effects of chemicals. A key prerequisite for successful application of molecular modeling lies in the correctness of 3D structure for biomacromolecules to be simulated. To date, there are several databases that can provide the experimentally-determined 3D structures. However, commonly, there are many challenges or disadvantageous factors, e.g., (a) lots of 3D structures for a given biomacromolecular target in the protein database; (b) the quality variability for those structures; (c) belonging to different species; (d) mutant amino acid residue in key positions, and so on. Once an inappropriate 3D structure of a target biomacromolecule was selected in molecular modeling, the accuracy and scientific nature of the modeling results could be inevitably affected. In this article, based on literature survey and an analysis of the 3D structure characterization of biomacromolecular targets belonging to the endocrine system in protein databases, six principles were proposed to guide the selection of the appropriate 3D structure of biomacromolecules. The principles include considering the species diversity, the mechanism of action, whether there are mutant amino acid residues, whether the number of protein chains is correct, the degree of structural similarity between the ligand in 3D structure and the target compounds, and other factors, e.g., the experimental pH conditions of the structure determined process and resolution.
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Affiliation(s)
- Xianhai Yang
- Nanjing Institute of Environmental Science , Ministry of Environmental Protection, Nanjing 210042, China
| | - Huihui Liu
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing 210094, China
| | - Jining Liu
- Nanjing Institute of Environmental Science , Ministry of Environmental Protection, Nanjing 210042, China
| | - Fei Li
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences , Yantai 264003, China
| | - Xuehua Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
| | - Lili Shi
- Nanjing Institute of Environmental Science , Ministry of Environmental Protection, Nanjing 210042, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Dalian 116024, China
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16
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Heys KA, Shore RF, Pereira MG, Jones KC, Martin FL. Risk assessment of environmental mixture effects. RSC Adv 2016. [DOI: 10.1039/c6ra05406d] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Determining interactions of multi-component environmental mixtures towards accurate risk assessment.
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Affiliation(s)
- Kelly A. Heys
- Centre for Biophotonics
- Lancaster Environment Centre
- Lancaster University
- Lancaster LA1 4YQ
- UK
| | - Richard F. Shore
- Centre of Ecology and Hydrology
- Lancaster University
- Lancaster LA1 4YQ
- UK
| | - M. Glória Pereira
- Centre of Ecology and Hydrology
- Lancaster University
- Lancaster LA1 4YQ
- UK
| | - Kevin C. Jones
- Centre for Biophotonics
- Lancaster Environment Centre
- Lancaster University
- Lancaster LA1 4YQ
- UK
| | - Francis L. Martin
- Centre for Biophotonics
- Lancaster Environment Centre
- Lancaster University
- Lancaster LA1 4YQ
- UK
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17
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Sanderson PN, Simpson W, Cubberley R, Aleksic M, Gutsell S, Russell PJ. Mechanistic understanding of molecular initiating events (MIEs) using NMR spectroscopy. Toxicol Res (Camb) 2015; 5:34-44. [PMID: 30090324 DOI: 10.1039/c5tx00246j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 09/11/2015] [Indexed: 11/21/2022] Open
Abstract
Toxicological risk assessments in the 21st century are increasingly being driven by the Adverse Outcome Pathways (AOP) conceptual framework in which the Molecular Initiating Event (MIE) is of fundamental importance to pathway progression. For those MIEs that involve covalent chemical reactions, such as protein haptenation, determination of relative rates and mechanisms of reactions is a prerequisite for their understanding. The utility of NMR spectroscopy as an experimental technique for effectively providing reaction rate and mechanistic information for early assessment of likely MIE(s) has been demonstrated. To demonstrate the concept, model systems exemplifying common chemical reactions involved in the covalent modification of proteins were utilized; these involved chemical reactions of electrophilic species (representing different mechanistic classes) with simple amine and thiol nucleophiles acting as surrogates for the reactive groups of lysine and cysteine protein side chains respectively. Such molecular interactions are recognized as critical mechanisms in a variety of chemical and drug toxicities, including respiratory and skin sensitization and liver toxicity as well as being the key mechanism of action for a number of therapeutic agents.
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Affiliation(s)
- Paul N Sanderson
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
| | - Wendy Simpson
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
| | - Richard Cubberley
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
| | - Maja Aleksic
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
| | - Stephen Gutsell
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
| | - Paul J Russell
- Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .
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