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Chen G, Xia X, Xie J, Cao Y, Yuan C, Yu G, Wei S, Duan Y, Cai Y, Wang S, Liu J, Jiang J. Dose-dependent toxic effects of triclosan on Rana omeimontis larvae: Insights into potential implications for neurodegenerative diseases. JOURNAL OF HAZARDOUS MATERIALS 2025; 487:137187. [PMID: 39808961 DOI: 10.1016/j.jhazmat.2025.137187] [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: 09/18/2024] [Revised: 12/29/2024] [Accepted: 01/09/2025] [Indexed: 01/16/2025]
Abstract
The widespread use of antimicrobial agent triclosan (TCS) poses significant health risks to both aquatic organisms and humans. The research on its neurotoxicity and underlying mechanisms is, however, limited. Here we first conducted a 32-day exposure experiment with five TCS concentrations (10, 30, 60, 90 and 120 µg/L) to investigate its impact on overall gene expression in Rana omeimontis larvae. Transcriptomics analysis unveiled a strong dose-dependent pattern of gene expression alterations, with a distinct transcriptomic shift observed in the T030 (30 µg/L) group. In addition, neurodegenerative disease pathway and oxidative stress response GO (gene ontology) terms were found to be highly enriched across the regulated genes in all TCS-exposed groups, suggesting potential TCS-induced neurotoxicity. To further explore this, we performed a 40-day experiment with a low (30 µg/L) or high (90 µg/L) TCS concentration. Morphological assessments revealed that TCS-exposed larvae exhibited developmental and growth inhibition. Using RT-qPCR and immunohistochemical analysis, we confirmed that TCS exposure induced neurotoxicity and triggered neurodegenerative diseases as suggested by Tau protein aggregation in the midbrain. Consistent with these findings, TCS-exposed larvae displayed abnormal behaviors. Our study thus for the first time presents a comprehensive assessment of the adverse effects of TCS exposure on amphibian larvae, encompassing morphological, biochemical, and physiological aspects. Notably, we identified RNF112 and Tau as potential molecular targets that may mediate TCS-induced neurotoxicity. These findings advance the knowledge on how organisms respond to environmental changes and highlight the importance of further investigation into the potential neurotoxicity of TCS within aquatic ecosystems and its implications for human health.
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Affiliation(s)
- Guiying Chen
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Xuemei Xia
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Jiahui Xie
- The Faculty Geography Resource Sciences, Sichuan Normal University, Chengdu 610101, China
| | - Yixin Cao
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Chunling Yuan
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Guihua Yu
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Siru Wei
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Yu Duan
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Yanmei Cai
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Shouhong Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China.
| | - Jiongyu Liu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China.
| | - Jianping Jiang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China
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Wolf JC, Green JW, Mingo V, Marini JP, Schneider SZ, Fort DJ, Wheeler JR. Historical control histopathology data from amphibian metamorphosis assays and fathead minnow fish short term reproductive assays: A tool for data interpretation. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 267:106811. [PMID: 38159458 DOI: 10.1016/j.aquatox.2023.106811] [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: 09/20/2023] [Revised: 12/17/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
The Amphibian Metamorphosis Assay (AMA) is used to determine if a tested chemical has potential to impact the hypothalamic-pituitary-thyroid (HPT) axis of Xenopus laevis tadpoles, while the Fish Short Term Reproduction Assay (FSTRA) assesses potential effects on the hypothalamic-pituitary-gonadal (HPG) axis of fish such as the fathead minnow (Pimephales promelas). Several global regulatory programs routinely require these internationally validated tests be performed to determine the potential endocrine activity of chemicals. As such, they are conducted in accordance with standardized protocols and test criteria, which were originally developed more than a decade ago. Sizeable numbers of AMA and FSTRA studies have since been carried out, which allows for the mining of extensive historical control data (HCD). Such data are useful for investigating the existence of outlier results and aberrant control groups, identifying potential confounding variables, providing context for rare diagnoses, discriminating target from non-target effects, and for refining current testing paradigms. The present paper provides histopathology HCD from 55 AMA studies and 45 fathead minnow FSTRA studies, so that these data may become publicly available and thus aid in the interpretation of future study outcomes. Histopathology is a key endpoint in these assays, in which it is considered to be one of the most sensitive indicators of endocrine perturbation. In the current review, granular explorations of HCD data were used to identify background lesions, to assess the utility of particular diagnostic findings for distinguishing endocrine from non-endocrine effects, and to help determine if specific improvements to established regulatory guidance may be warranted. Knowledge gleaned from this investigation, supplemented by information from other recent studies, provided further context for the interpretation of AMA and FSTRA histopathology results. We recommend HCDs for the AMA and FSTRA be maintained to support the interpretation of study results.
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Affiliation(s)
- Jeffrey C Wolf
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA 20166, USA.
| | - John W Green
- John W Green Ecostatistical Consulting, LLC 372 Chickory Way, Newark, DE 19711, USA
| | - Valentin Mingo
- Corteva Agriscience, Riedenburger Str. 7, München 81677, Germany
| | | | | | - Douglas J Fort
- Fort Environmental Laboratories, Stillwater, OK 74074, USA
| | - James R Wheeler
- Corteva Agriscience, Zuid-Oostsingel 24D, Bergen op Zoom 4611 BB, the Netherlands
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3
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Dang Z. Amphibian toxicity testing for identification of thyroid disrupting chemicals. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:120006. [PMID: 35998776 DOI: 10.1016/j.envpol.2022.120006] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 08/04/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Both amphibian metamorphosis assay (AMA) and larval amphibian growth and development assay (LAGDA) can detect thyroid-mediated modality and adversity on the basis of morphological changes during the thyroid hormone-dependent metamorphosis. They are used for identification of thyroid hormone system disrupting chemicals (TDCs) for non-target organisms or the environment. The EU Guidance recommends that the AMA and the LAGDA should be used to address sufficient investigation of the thyroid-mediated modality and adversity, respectively. In the EU discussions over identification of TDCs, the necessity of using LAGDA as a follow-up of positive results of the AMA has been questioned because of the overlap between the endpoints and the exposure of both tests. This study analyzed similarities, differences, and sensitivity of these two assays in detection of TDCs. For agonists and most of antagonists of the hypothalamic-pituitary-thyroid (HPT) axis, both AMA and LAGDA can detect the thyroid-mediated modality and adversity. The LAGDA, as a follow-up of the positive results of the AMA, may not be needed because the results of AMA are considered enough for identification of TDCs. For chemicals like inhibitors of iodotyrosine deiodinase, the LAGDA is considered necessary for identification of TDCs because the thyroid-mediated adversity cannot be detected until Nieuwkoop and Faber (NF) stage 62. Incorporation of mechanistic endpoints into existing test guidelines and the use of Xenopus Eleutheroembryo Thyroid Assay (XETA), extended amphibian metamorphosis assay (EAMA) and adverse outcome pathways (AOPs) for testing and identification of TDCs are further discussed.
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Affiliation(s)
- ZhiChao Dang
- National Institute for Public Health and the Environment, A. van Leeuwenhoeklaan 9, 3720 BA Bilthoven, the Netherlands.
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4
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Liu X, Tu M, Wang S, Wang Y, Wang J, Hou Y, Zheng X, Yan Z. Research on freshwater water quality criteria, sediment quality criteria and ecological risk assessment of triclosan in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151616. [PMID: 34774937 DOI: 10.1016/j.scitotenv.2021.151616] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 10/23/2021] [Accepted: 11/07/2021] [Indexed: 06/13/2023]
Abstract
Triclosan (TCS) is a broad-spectrum antimicrobial agent commonly used in pharmaceuticals and personal care products (PPCPs). The widespread use of TCS makes it frequently detected in various environmental mediums. In view of the high detection frequency of TCS in the aquatic environment and sediments, and its toxic effects on aquatic species, it is critical and necessary to derive Chinese TCS water quality criteria (WQC) and sediment quality criteria (SQC) for protecting Chinese aquatic organisms, and perform the ecological risk assessment. In fact, former research had derived the WQC of TCS mainly based on acute and chronic toxicity data. As an endocrine disrupting chemical (EDC), TCS poses adverse effects on the growth, development and reproduction of aquatic organisms at much lower concentration. Considering nonlethal endpoints are sensitive endpoints for EDCs, TCS long-term water quality criteria (LWQC) was derived based on reproduction and growth related endpoints. In this work, the acute toxicity data of 19 aquatic organisms and the chronic toxicity data of 15 aquatic organisms were obtained through collection and screening. The best fitting model of species sensitivity distribution (SSD) models including Normal, Log-Normal, Logistic and Log-Logistic of toxicity data was selected to derive WQC. The short-term and long-term WQC of TCS for Chinese aquatic organisms were 6.22 μg/L and 0.25 μg/L, respectively. Furthermore, through the phase-equilibrium partitioning method, SQC was derived based on WQC. SQC-low (SQC-L) and SQC-high (SQCH) were 0.13 mg/kg and 3.26 mg/kg, respectively. Moreover, the exposure concentration (EPC) data of TCS in Chinese rivers and sediments were collected. And through the hazard quotient (HQ) method and the joint probability curve (JPC) method we found that there were certain TCS ecological risks in Chinese rivers and sediments. Our work will provide a valuable reference for protecting aquatic organisms and minimizing TCS ecological risk in China.
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Affiliation(s)
- Xinyu Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Mengchen Tu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Shuping Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Yizhe Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Jing Wang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, PR China
| | - Yin Hou
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, PR China
| | - Xin Zheng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China.
| | - Zhenguang Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
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Babalola OO, van Wyk JH. Exposure impacts of Imazapyr formulation on larval development and thyroid histology of Xenopus laevis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:50967-50974. [PMID: 33973123 DOI: 10.1007/s11356-021-14227-4] [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: 09/10/2020] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
There are increased concerns about the thyroidal effects of many anthropogenic substances in the environment. These substances include agricultural pesticides and industrial and pharmaceutical chemicals among others. Their potential thyroidal effects are of serious health and ecological concerns, as thyroid hormones mediate numerous physiological processes, including growth regulation, general metabolism and metamorphosis in metamorphic animals. This study assessed thyroidal activities of Arsenal formulation (Imazapyr) at environmentally relevant concentrations of 0.5, 2.0 and 3.5 mg/L following a Xenopus metamorphosis assay (XEMA). The result shows that the Arsenal formulation significantly delayed the tadpole development, reduced the hind-limb length (HLL) and increased the whole-body mass (WBM) at a concentration of 3.5 mg/L relative to the control exposure. In histopathology, the formulation increased the epithelium height, at all exposure concentrations, but reduced the colloidal area at 0.5 and 2 mg/L, respectively, and the gland area at 2 mg/L relative to the control. Consequently, the Arsenal formulation is thyroid-active at environmentally relevant concentrations and poses a threat to both human and wildlife, especially metamorphic organisms. With this exposure impact, more studies are imperative to further characterise other endocrine-disrupting potential of this formulation, while future applications should be reduced or restricted to less risk environment, if it cannot be stopped from sensitive aquatic systems.
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Affiliation(s)
- Oluwaseun Olusegun Babalola
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.
- Ecotoxicology & Ecophysiology Unit, Department of Zoology & Environmental Biology, Lagos State University, Ojo, Lagos, Nigeria.
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Kenda M, Karas Kuželički N, Iida M, Kojima H, Sollner Dolenc M. Triclocarban, Triclosan, Bromochlorophene, Chlorophene, and Climbazole Effects on Nuclear Receptors: An in Silico and in Vitro Study. ENVIRONMENTAL HEALTH PERSPECTIVES 2020; 128:107005. [PMID: 33064576 PMCID: PMC7567334 DOI: 10.1289/ehp6596] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 09/10/2020] [Accepted: 09/23/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Endocrine-disrupting chemicals can interfere with hormonal homeostasis and have adverse effects for both humans and the environment. Their identification is increasingly difficult due to lack of adequate toxicological tests. This difficulty is particularly problematic for cosmetic ingredients, because in vivo testing is now banned completely in the European Union. OBJECTIVES The aim was to identify candidate preservatives as endocrine disruptors by in silico methods and to confirm endocrine receptors' activities through nuclear receptors in vitro. METHODS We screened preservatives listed in Annex V in the European Union Regulation on cosmetic products to predict their binding to nuclear receptors using the Endocrine Disruptome and VirtualToxLab™ version 5.8 in silico tools. Five candidate preservatives were further evaluated for androgen receptor (AR), estrogen receptor (ER α ), glucocorticoid receptor (GR), and thyroid receptor (TR) agonist and antagonist activities in cell-based luciferase reporter assays in vitro in AR-EcoScreen, hER α -HeLa- 9903 , MDA-kb2, and GH3.TRE-Luc cell lines. Additionally, assays to test for false positives were used (nonspecific luciferase gene induction and luciferase inhibition). RESULTS Triclocarban had agonist activity on AR and ER α at 1 μ M and antagonist activity on GR at 5 μ M and TR at 1 μ M . Triclosan showed antagonist effects on AR, ER α , GR at 10 μ M and TR at 5 μ M , and bromochlorophene at 1 μ M (AR and TR) and at 10 μ M (ER α and GR). AR antagonist activity of chlorophene was observed [inhibitory concentration at 50% (IC50) IC 50 = 2.4 μ M ], as for its substantial ER α agonist at > 5 μ M and TR antagonist activity at 10 μ M . Climbazole showed AR antagonist (IC 50 = 13.6 μ M ), ER α agonist at > 10 μ M , and TR antagonist activity at 10 μ M . DISCUSSION These data support the concerns of regulatory authorities about the endocrine-disrupting potential of preservatives. These data also define the need to further determine their effects on the endocrine system and the need to reassess the risks they pose to human health and the environment. https://doi.org/10.1289/EHP6596.
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Affiliation(s)
- Maša Kenda
- University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia
| | | | | | - Hiroyuki Kojima
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Hokkaido, Japan
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Gyimah E, Dong X, Qiu W, Zhang Z, Xu H. Sublethal concentrations of triclosan elicited oxidative stress, DNA damage, and histological alterations in the liver and brain of adult zebrafish. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:17329-17338. [PMID: 32157542 DOI: 10.1007/s11356-020-08232-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/25/2020] [Indexed: 06/10/2023]
Abstract
Triclosan (TCS), an antimicrobial agent, has been a pollutant of increasing concern owing to its potential health risk on humans and aquatic animals. The present study seeks to test the hypothesis that TCS could alter the oxidative stress-related parameters in the brain and liver, as well as eliciting DNA damage in hepatocytes of adult zebrafish. On the basis of the 96 h LC50 (398.9 μg/L), adult zebrafish were separately exposed to 50, 100, and 150 μg/L TCS for 30 days. The brain and liver tissues from adult zebrafish were excised and assayed for a suite of antioxidant parameters and oxidative stress biomarkers including DNA damage in the liver. The induced effect by TCS on the activity of acetylcholinesterase (AChE) was also analyzed in the brain. Results showed a significant decrease in superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the brain and liver of adult zebrafish. Also, the contents of the glutathione system (GSH and GSSH), as well as the activity of the glutathione reductase (GR), assayed in the liver, were reduced while the contents of malondialdehyde (MDA) were elevated in the liver. A comet assay revealed dose-dependent DNA damage in zebrafish hepatocytes. The 8-hydroxy-2'-deoxyguanosine (8-OHdG), MDA, and carbonyl protein contents in brain tissues significantly increased. Moreover, the AChE in the zebrafish brain was induced. Apparently, no obvious histological changes in brain tissues of zebrafish were observed compared with those of the control whereas atrophy and necrosis of hepatocytes and increased hepatic plate gap were observed in zebrafish hepatocytes after TCS exposure. The obtained results highlight that sublethal concentrations of TCS may be deleterious to the liver and brain of adult zebrafish upon subchronic exposure.
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Affiliation(s)
- Eric Gyimah
- Institute of Environmental Health and Ecological Security, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China
| | - Xing Dong
- Institute of Environmental Health and Ecological Security, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China
| | - Wenhui Qiu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Zhen Zhang
- Institute of Environmental Health and Ecological Security, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China
| | - Hai Xu
- Institute of Environmental Health and Ecological Security, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
- Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, 215009, China.
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Wang Y, Xu P, Chang J, Li W, Yang L, Tian H. Unraveling the toxic effects of neonicotinoid insecticides on the thyroid endocrine system of lizards. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 258:113731. [PMID: 31874442 DOI: 10.1016/j.envpol.2019.113731] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/01/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
The widespread use of neonicotinoids has resulted in large residues in the soil, which has a major impact on the lizards that inhabit the soil. Thyroid hormones play an important role in the growth and development of lizards. In this report, we assessed the disrupting effects of thyroid system on lizards after 28 days of continuous exposure to dinotefuran, thiamethoxam, and imidacloprid, respectively. Neonicotinoid insecticides could seriously affect the concentration of T4 in lizard plasma and the conversion of T4 to T3 in the thyroid gland. Specifically, exposure to dinotefuran affected the intake and utilization of iodine in the thyroid gland, resulting in insufficient thyroid function, which in turn lead to thyroid epithelial hyperplasia and follicular volume enlargement by negative feedback. Exposure to thiamethoxam could activate thyroid function, significantly increasing plasma T3 and T4 concentrations and promoting the binding of T3 and thyroid hormone receptors. Imidacloprid exposure could inhibit the secretion of thyroid hormones, leading to down-regulation of thyroid hormone receptors and related phase II metabolic enzyme genes. This study verified that the continuous exposure of neonicotinoids could affect the lizard thyroid endocrine system. The harm of neonicotinoids to reptiles deserved more attention.
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Affiliation(s)
- Yinghuan Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China
| | - Peng Xu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China
| | - Jing Chang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China
| | - Wei Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China
| | - Lu Yang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China
| | - Haoting Tian
- Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resource and Environment, Linyi University, Linyi 276005, China.
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Stenzel A, Wirt H, Patten A, Theodore B, King-Heiden T. Larval exposure to environmentally relevant concentrations of triclosan impairs metamorphosis and reproductive fitness in zebrafish. Reprod Toxicol 2019; 87:79-86. [PMID: 31102721 DOI: 10.1016/j.reprotox.2019.05.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 05/01/2019] [Accepted: 05/09/2019] [Indexed: 01/05/2023]
Abstract
Developmental exposure to endocrine disruptors can cause organizational changes resulting in latent and transgenerational disease. We exposed zebrafish to environmentally relevant concentrations of triclosan during the critical period of metamorphosis and somatic sex differentiation to determine effects on metamorphosis and reproduction. We use biological and morphological biomarkers to predict potential modes of action. Larval exposure to environmentally relevant concentrations of triclosan was sufficient to cause adverse effects in adults and their offspring. TCS exposure delays metamorphosis and impairs fecundity and fertility. Offspring from TCS-exposed fish show decreased survival and delayed maturation, but their reproductive capacity is not altered. Delays in metamorphosis in conjunction with morphological indicators suggest that toxicity may result from lowered thyroid hormones in parental fish. This work illustrates the importance of evaluating the latent effects of early exposure to environmental contaminants, and that further studies to evaluate the effects of triclosan on the thyroid axis are warranted.
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Affiliation(s)
- Amanda Stenzel
- University of Wisconsin - La Crosse, Department of Biology and River Studies Center, 1725 State Street, La Crosse, WI, 54601, United States
| | - Heidi Wirt
- University of Wisconsin - La Crosse, Department of Biology and River Studies Center, 1725 State Street, La Crosse, WI, 54601, United States
| | - Alyssa Patten
- University of Wisconsin - La Crosse, Department of Biology and River Studies Center, 1725 State Street, La Crosse, WI, 54601, United States
| | - Briannae Theodore
- University of Wisconsin - La Crosse, Department of Biology and River Studies Center, 1725 State Street, La Crosse, WI, 54601, United States
| | - Tisha King-Heiden
- University of Wisconsin - La Crosse, Department of Biology and River Studies Center, 1725 State Street, La Crosse, WI, 54601, United States.
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Thambirajah AA, Koide EM, Imbery JJ, Helbing CC. Contaminant and Environmental Influences on Thyroid Hormone Action in Amphibian Metamorphosis. Front Endocrinol (Lausanne) 2019; 10:276. [PMID: 31156547 PMCID: PMC6530347 DOI: 10.3389/fendo.2019.00276] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/16/2019] [Indexed: 12/31/2022] Open
Abstract
Aquatic and terrestrial environments are increasingly contaminated by anthropogenic sources that include pharmaceuticals, personal care products, and industrial and agricultural chemicals (i. e., pesticides). Many of these substances have the potential to disrupt endocrine function, yet their effect on thyroid hormone (TH) action has garnered relatively little attention. Anuran postembryonic metamorphosis is strictly dependent on TH and perturbation of this process can serve as a sensitive barometer for the detection and mechanistic elucidation of TH disrupting activities of chemical contaminants and their complex mixtures. The ecological threats posed by these contaminants are further exacerbated by changing environmental conditions such as temperature, photoperiod, pond drying, food restriction, and ultraviolet radiation. We review the current knowledge of several chemical and environmental factors that disrupt TH-dependent metamorphosis in amphibian tadpoles as assessed by morphological, thyroid histology, behavioral, and molecular endpoints. Although the molecular mechanisms for TH disruption have yet to be determined for many chemical and environmental factors, several affect TH synthesis, transport or metabolism with subsequent downstream effects. As molecular dysfunction typically precedes phenotypic or histological pathologies, sensitive assays that detect changes in transcript, protein, or metabolite abundance are indispensable for the timely detection of TH disruption. The emergence and application of 'omics techniques-genomics, transcriptomics, proteomics, metabolomics, and epigenomics-on metamorphosing tadpoles are powerful emerging assets for the rapid, proxy assessment of toxicant or environmental damage for all vertebrates including humans. Moreover, these highly informative 'omics techniques will complement morphological, behavioral, and histological assessments, thereby providing a comprehensive understanding of how TH-dependent signal disruption is propagated by environmental contaminants and factors.
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Affiliation(s)
| | | | | | - Caren C. Helbing
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
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Mughal BB, Fini JB, Demeneix BA. Thyroid-disrupting chemicals and brain development: an update. Endocr Connect 2018; 7:R160-R186. [PMID: 29572405 PMCID: PMC5890081 DOI: 10.1530/ec-18-0029] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 03/14/2018] [Indexed: 12/12/2022]
Abstract
This review covers recent findings on the main categories of thyroid hormone-disrupting chemicals and their effects on brain development. We draw mostly on epidemiological and experimental data published in the last decade. For each chemical class considered, we deal with not only the thyroid hormone-disrupting effects but also briefly mention the main mechanisms by which the same chemicals could modify estrogen and/or androgen signalling, thereby exacerbating adverse effects on endocrine-dependent developmental programmes. Further, we emphasize recent data showing how maternal thyroid hormone signalling during early pregnancy affects not only offspring IQ, but also neurodevelopmental disease risk. These recent findings add to established knowledge on the crucial importance of iodine and thyroid hormone for optimal brain development. We propose that prenatal exposure to mixtures of thyroid hormone-disrupting chemicals provides a plausible biological mechanism contributing to current increases in the incidence of neurodevelopmental disease and IQ loss.
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Affiliation(s)
- Bilal B Mughal
- CNRS/UMR7221Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Jean-Baptiste Fini
- CNRS/UMR7221Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
| | - Barbara A Demeneix
- CNRS/UMR7221Muséum National d'Histoire Naturelle, Sorbonne Universités, Paris, France
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Wang F, Liu F, Chen W, Xu R, Wang W. Effects of triclosan (TCS) on hormonal balance and genes of hypothalamus-pituitary- gonad axis of juvenile male Yellow River carp (Cyprinus carpio). CHEMOSPHERE 2018; 193:695-701. [PMID: 29175396 DOI: 10.1016/j.chemosphere.2017.11.088] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/17/2017] [Accepted: 11/18/2017] [Indexed: 05/15/2023]
Abstract
Triclosan (TCS) is a broad spectrum antimicrobial agent which has been widely dispersed and determinated in the aquatic environment. However, the effects of TCS on reproductive endocrine in male fish are poorly understood. In this study, male Yellow River carp (Cyprinus carpio) were exposed to 0, 1/5, 1/10 and 1/20 LC50 (96 h LC50 of TCS to carp) TCS under semi-static conditions for 42 d. Vitellogenin (Vtg), 17β-estradiol (E2), testosterone(T), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, estrogen receptor (Er), and androgen receptor (Ar) by quantitative Real-time Polymerase Chain Reaction (qRT-PCR). TCS induced Vtg levels of hepatopancreas, E2 levels of serum, and inhibited Ar and Er mRNA levels, suggesting that the induction of Vtg production by TCS was indirectly caused by non-Er pathways. TCS-induced Vtg levels by interfering with the reproductive axis at plenty of latent loci of male carps: (a) TCS exposure increased the aromatase mRNA expression of hypothalamus and gonad aromatase, consequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment changed GtH-β and GnRH mRNA expression and secretion, causing the disturbance of reproductive endocrine; (c) TCS exposure decreased Ar mRNA levels, indicating potential Ar-mediated antiandrogen action. These mechanisms showed that TCS may induce Vtg production in male carp by non-Er-mediated pathways.
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Affiliation(s)
- Fan Wang
- School of Biological Science, Luoyang Normal University, Luoyang, 471022, China; Cold Water Fish Breeding Engineering Technology Research Center of Henan Province, Luoyang, 471022, China.
| | - Fei Liu
- School of Biological Science, Luoyang Normal University, Luoyang, 471022, China; Cold Water Fish Breeding Engineering Technology Research Center of Henan Province, Luoyang, 471022, China
| | - Wanguang Chen
- School of Biological Science, Luoyang Normal University, Luoyang, 471022, China; Cold Water Fish Breeding Engineering Technology Research Center of Henan Province, Luoyang, 471022, China
| | - Ruijie Xu
- School of Biological Science, Luoyang Normal University, Luoyang, 471022, China
| | - Wei Wang
- School of Biological Science, Luoyang Normal University, Luoyang, 471022, China
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13
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Chen J, Meng T, Li Y, Gao K, Qin Z. Effects of triclosan on gonadal differentiation and development in the frog Pelophylax nigromaculatus. J Environ Sci (China) 2018; 64:157-165. [PMID: 29478635 DOI: 10.1016/j.jes.2017.05.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/04/2017] [Accepted: 05/27/2017] [Indexed: 06/08/2023]
Abstract
Previous studies have reported that triclosan (TCS) could possess an androgenic activity. We aimed to investigate the effects of TCS on gonadal differentiation and development in the frog Pelophylax nigromaculatus, a sensitive amphibian species to androgenic chemicals. P. nigromaculatus tadpoles at stage 24 were exposed to TCS (3, 30, and 300nmol/L) to stage 46 in a semi-static exposure system. At the end of exposure, gonadal morphology and histology, sex ratio and gonadal expression of sex-biased genes were examined in P. nigromaculatus. In each TCS treatment group, we found several individuals whose gonads exhibited morphological and/or histological abnormalities. Gonadal histological abnormalities were characterized by few oocytes and many somatic cells. Although the percentage of the individuals with abnormal gonads was low (7.8%) among all animals treated with TCS, statistical test revealed the sex ratios in the 3 and 300nmol/L TCS treatment groups were significantly different from the solvent control. In the 30nmol/L TCS treatment group, abnormal gonads were also observed, although the sex ratio was not changed compared with the solvent control, which was possibly due to the smaller sample size in this group. In all the TCS treatment groups, the sex ratios were not obviously male-biased, but the expression levels of some sex-biased genes were significantly altered by TCS. Altogether, our results suggest that TCS, even at environmentally relevant concentrations, could disrupt gonadal differentiation and development in P. nigromaculatus, but we are not sure whether the disrupting effects were associated with masculinization or feminization.
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Affiliation(s)
- Juan Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Tan Meng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuanyuan Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kun Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhanfen Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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14
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Lyndall J, Barber T, Mahaney W, Bock M, Capdevielle M. Evaluation of triclosan in Minnesota lakes and rivers: Part I - ecological risk assessment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 142:578-587. [PMID: 28479123 DOI: 10.1016/j.ecoenv.2017.04.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/19/2017] [Accepted: 04/24/2017] [Indexed: 05/05/2023]
Abstract
Triclosan, an antimicrobial compound found in consumer products, may be introduced into the aquatic environment via residual concentrations in municipal wastewater treatment effluent. We conducted an aquatic risk assessment that incorporated the available measured triclosan data from Minnesota lakes and rivers. Although only data reported from Minnesota were considered in the risk assessment, the developed toxicity benchmarks can be applied to other environments. The data were evaluated using a series of environmental fate models to ensure the data were internally consistent and to fill any data gaps. Triclosan was not detected in over 75% of the 567 surface water and sediment samples. Measured environmental data were used to model the predicted environmental exposures to triclosan in surface water, surface sediment, and biota tissues. Toxicity benchmarks based on fatty acid synthesis inhibition and narcosis were determined for aquatic organisms based, in part, on a species sensitivity distribution of chronic toxicity thresholds from the available literature. Predicted and measured environmental concentrations for surface water, sediment, and tissue were below the effects benchmarks, indicating that exposure to triclosan in Minnesota lakes and rivers would not pose an unacceptable risk to aquatic organisms.
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Affiliation(s)
- Jennifer Lyndall
- Society for Ecological Restoration, 1133 15th St NW, Suite 300, 20005 Washington DC, United States.
| | - Timothy Barber
- Environmental Resources Management, 3333 Richmond Rd, Beachwood, OH 44122, United States.
| | - Wendy Mahaney
- 74 Damascus Dr, Gansevoort, NY 12831, United States.
| | - Michael Bock
- Ramboll Environ, Inc., 136 Commercial Street, Suite 401, Portland, ME 04101, United States.
| | - Marie Capdevielle
- Colgate-Palmolive Company, 909 River Road, Piscataway, NJ 08855, United States.
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15
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Martins D, Monteiro MS, Soares AMVM, Quintaneiro C. Effects of 4-MBC and triclosan in embryos of the frog Pelophylax perezi. CHEMOSPHERE 2017; 178:325-332. [PMID: 28334672 DOI: 10.1016/j.chemosphere.2017.03.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 06/06/2023]
Abstract
The widespread and increasing use of personal care products (PCPs) have led to environmental contamination by substances included in these products. These substances have been detected in aquatic compartments and shown to cause adverse effects on non-target aquatic organisms. In this work toxicity of the antimicrobial triclosan (TCS) and of the UV-filter 3-(4-methylbenzylidene) camphor (4-MBC) was assessed in the embryos of Perez' frog Pelophylax perezi. Lethal and sub-lethal parameters were evaluated in embryos in Gosner stage 8-9 exposed to 0.00013-1.3 mg/l of 4-MBC and 0.25-2.50 mg/l of TCS during 144 h. Survival, malformations, length and hatching were evaluated as apical endpoints. Biomarkers of neurotransmission, oxidative stress, energy metabolism and estrogenicity were determined at the biochemical level through the activities of cholinesterase (ChE), catalase (CAT), glutathione S-transferase (GST), lactate dehydrogenase (LDH) and levels of lipid peroxidation (LPO) and vitellogenin (Vtg). Embryo exposure to 4-MBC led to few developmental malformations (up to 3%) and a GST induction at 0.013 mg/l. Triclosan exposure reduced survival, delayed hatching (at 72 h) and development and induced malformations. In addiction ChE was inhibited in the highest concentrations tested and GST and LDH were induced at 0.79 mg/l, the LOEC registered for TCS in Perez' frogs. Overall, our study showed that TCS might exert adverse effects on P. perezi early life stages, but only at four orders of magnitude above the concentrations found in environment. Furthermore, our results highlight the need to assess PCPs toxicity at different levels of biological organization.
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Affiliation(s)
- Diana Martins
- Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Marta S Monteiro
- Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Amadeu M V M Soares
- Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Carla Quintaneiro
- Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
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16
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Fort DJ, Mathis MB, Pawlowski S, Wolf JC, Peter R, Champ S. Effect of triclosan on anuran development and growth in a larval amphibian growth and development assay. J Appl Toxicol 2017; 37:1182-1194. [DOI: 10.1002/jat.3474] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 01/02/2023]
Affiliation(s)
| | | | | | - Jeffrey C. Wolf
- Experimental Pathology Laboratories, Inc.; Sterling VA 20166 USA
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17
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Chang J, Li W, Guo B, Xu P, Wang Y, Li J, Wang H. Unraveling the different toxic effect of flufenoxuron on the thyroid endocrine system of the Mongolia racerunner (Eremias Argus) at different stages. CHEMOSPHERE 2017; 172:210-216. [PMID: 28073034 DOI: 10.1016/j.chemosphere.2017.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/29/2016] [Accepted: 01/02/2017] [Indexed: 06/06/2023]
Abstract
Flufenoxuron is a widely used pesticide to inhibit the synthesis of chitin during insect development and its effect on the growth of lizards has been little addressed. The hypothalamus-pituitary-thyroid (HPT) axis plays an important role on the development of lizards. In this study, the lizards at different development stages (proliferation and resting stages) were exposed to flufenoxuron for 21 days. The plasma thyroid hormone levels, thyroid gland histopathology and expression profiles of thyroid hormone receptors (trα, trβ), deiodinases (dio1, dio2), and transthyretin (ttr) genes were measured to evaluated the toxic effect of flufenoxuron on the HPT axis at different stages. The flufenoxuron exposure showed more seriously effect on the triiodothyronine (T3) level at resting phase than that at proliferation stage. The follicle epithelium cell height in the thyroid was only significantly increased when the exposed male lizards were at proliferation stage. The alteration of HPT axis-related genes expression was gender and tissue dependent after flufenoxuron treatment. The lizards exposed to flufenoxuron showed that the trα, trβ, dio1, dio2, and ttr genes in the female liver were more sensitive at the proliferation stage than that at the resting stage. In the male brain, the expressions of trα, trβ, dio1, and dio2 gene were significant decreased at proliferation stage while significant increased at resting stage after flufenoxuron exposure. Therefore, the thyroid endocrine system of lizards could be affected by the flufenoxuron exposure and the different development stage should also be considered when study the toxic effect of contaminants on the lizards.
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Affiliation(s)
- Jing Chang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China; University of Chinese Academy of Sciences, Yuquan RD 19 A, Beijing, 100049, China
| | - Wei Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China
| | - Baoyuan Guo
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China
| | - Peng Xu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China
| | - Yinghuan Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China
| | - Jianzhong Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China
| | - Huili Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing, 100085, China.
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18
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Mihaich E, Capdevielle M, Urbach-Ross D, Slezak B. Hypothesis-driven weight-of-evidence analysis of endocrine disruption potential: a case study with triclosan. Crit Rev Toxicol 2017; 47:263-285. [DOI: 10.1080/10408444.2016.1269722] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Ellen Mihaich
- Environmental and Regulatory Resources, LLC, Durham, NC, USA
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19
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Freitas MB, Brown CT, Karasov WH. Warmer temperature modifies effects of polybrominated diphenyl ethers on hormone profiles in leopard frog tadpoles (Lithobates pipiens). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:120-127. [PMID: 27228472 DOI: 10.1002/etc.3506] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 08/17/2015] [Accepted: 05/23/2016] [Indexed: 06/05/2023]
Abstract
Amphibian populations have been declining, and climate change and exposure to environmental contaminants are thought to be involved. Higher water temperature accelerates larval development; however, its combined effects with contaminants and their influence on hormones during metamorphosis are poorly understood. The authors investigated changes in whole-body triiodothyronine (T3) and corticosterone concentrations in developing leopard frogs reared at 23 °C and 28 °C on diets with 0 ng g-1 , 6 ng g-1 , and 37 ng g-1 of a technical mixture of polybrominated diphenyl ethers (PBDE; DE-71) from 10 d to 44 d (premetamorphosis to late climax; Gosner Stages 28 to 46). Unlike controls, PBDE-exposed tadpoles (6 ng g-1 ) reared at 23 °C failed to show any increase in T3 concentrations throughout metamorphosis, and exposed tadpoles reared at 28 °C showed a lower peak at climax compared to controls. Corticosterone levels progressively increased throughout metamorphosis, but the levels were higher in PBDE-exposed tadpoles compared to controls at both temperatures. At the warmer temperature, corticosterone increase occurred earlier (at early climax) in controls and exposed tadpoles compared to tadpoles reared at the cooler temperature (late climax), coinciding with the faster development observed at 28 °C. Tadpoles reared at 28 °C were longer and developed faster than tadpoles reared at 23 °C. At both temperatures, PBDE exposure decreased T3 and increased corticosterone concentrations, which can potentially impair developing tadpoles. Environ Toxicol Chem 2017;36:120-127. © 2016 SETAC.
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Affiliation(s)
- Mariella B Freitas
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Cherry T Brown
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - William H Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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20
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Chai L, Wang H, Zhao H, Deng H. Chronic effects of triclosan on embryonic development of Chinese toad, Bufo gargarizans. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:1600-1608. [PMID: 27599820 DOI: 10.1007/s10646-016-1715-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
Triclosan (TCS) is commonly used worldwide in a range of personal care and sanitizing products. The aim of this study was to evaluate potential effects of TCS exposure on embryonic development of Bufo gargarizans, an endemic frog species in China. Standard Gosner stage 3 B. gargarizans embryos were exposed to 10 ~ 150 μg/L TCS during embryogenesis. Survival, total length, weight, developmental stage, duration of different embryo stages, malformation, and type II and III deiodinase (D2 and D3) expression were measured. Inhibitory effects on embryo developmental stage, total length and weight were found at 30 ~ 150 μg/L TCS. Moreover, the duration of embryonic development was increased at gastrula, neural, circulation, and operculum development stage in TCS-treated groups. In addition, TCS exposure induced morphological malformations in B. gargarizans embryos, which are characterized by hyperplasia, abdominal edema, and axial flexures. Furthermore, our results showed that the expression of D2 in embryos was probably down-regulated at 60 and 150 μg/L TCS, but its spatial expression patterns was not affected by TCS. In summary, our study suggested that TCS exposure not only resulted in delayed growth and development but also caused teratogenic effects in B. gargarizans embryos, and the developmental effects of TCS at high concentrations may be associated with disruption of THs homeostasis. Although further studies are necessary, the present findings could provide a basis for understanding on harmful effects and the potential mechanisms of TCS in amphibian embryos.
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Affiliation(s)
- Lihong Chai
- School of Environmental Science and Engineering, Chang'an University, Xi'an, 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710054, China
| | - Hongyuan Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China.
| | - Hongfeng Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China
| | - Hongzhang Deng
- School of Environmental Science and Engineering, Chang'an University, Xi'an, 710054, China
- Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710054, China
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21
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Olaniyan LWB, Mkwetshana N, Okoh AI. Triclosan in water, implications for human and environmental health. SPRINGERPLUS 2016; 5:1639. [PMID: 27722057 PMCID: PMC5031584 DOI: 10.1186/s40064-016-3287-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 09/11/2016] [Indexed: 01/08/2023]
Abstract
Triclosan (TCS) is a broad spectrum antibacterial agent present as an active ingredient in some personal care products such as soaps, toothpastes and sterilizers. It is an endocrine disrupting compound and its increasing presence in water resources as well as in biosolid-amended soils used in farming, its potential for bioaccumulation in fatty tissues and toxicity in aquatic organisms are a cause for concern to human and environmental health. TCS has also been detected in blood, breast milk, urine and nails of humans. The significance of this is not precisely understood. Data on its bioaccumulation in humans are also lacking. Cell based studies however showed that TCS is a pro-oxidant and may be cytotoxic via a number of mechanisms. Uncoupling of oxidative phosphorylation appears to be prevailing as a toxicity mechanism though the compound's role in apoptosis has been cited. TCS is not known to be carcinogenic per se in vitro but has been reported to promote tumourigenesis in the presence of a carcinogen, in mice. Recent laboratory reports appear to support the view that TCS oestrogenicity as well as its anti-oestrogenicity play significant role in cancer progression. Results from epidemiological studies on the effect of TCS on human health have implicated the compound as responsible for certain allergies and reproductive defects. Its presence in chlorinated water also raises toxicity concern for humans as carcinogenic metabolites such as chlorophenols may be generated in the presence of the residual chlorine. In this paper, we carried out a detailed overview of TCS pollution and the implications for human and environmental health.
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Affiliation(s)
- L. W. B. Olaniyan
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape 5700 South Africa
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700 South Africa
| | - N. Mkwetshana
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700 South Africa
| | - A. I. Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Private Bag X1314, Alice, Eastern Cape 5700 South Africa
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700 South Africa
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22
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Ho JCH, Hsiao CD, Kawakami K, Tse WKF. Triclosan (TCS) exposure impairs lipid metabolism in zebrafish embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 173:29-35. [PMID: 26828895 DOI: 10.1016/j.aquatox.2016.01.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 06/05/2023]
Abstract
Triclosan (TCS) is an active antimicrobial ingredient used in many household products, such as skin creams and toothpaste. It is produced in high volumes, and humans are directly exposed to it and dispose it on a daily basis. TCS has been found to contaminate water worldwide. This study aimed to understand the potential developmental and metabolic abnormalities caused by TCS exposure by using zebrafish as the experimental model. Four developmental stages (70-85% epiboly, 10-12 somite, prim-5, and 5dpf) were selected to perform in situ hybridization staining to investigate the effects of TCS on dorsal ventral patterning, segmentation, brain development, and organ formation. Results showed, in terms of developmental toxicology, that neither phenotypic nor molecular changes were found after 5 days of 250μg/L TCS exposure. However, such dosage of TCS exposure resulted in lipid droplet accumulation in the yolk sac, which might due to the deregulated mRNA expression level of beta-oxidation transcripts. This study showed that 250μg/L TCS exposure does not affect normal embryogenesis or organogenesis; however, there are concerns regarding possible impairment of lipid metabolism.
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Affiliation(s)
- Jeff C H Ho
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - C D Hsiao
- Department of Bioscience Technology, Chung Yuan Christian University, Chung-Li, Taiwan
| | - K Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - William K F Tse
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong.
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23
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Weatherly LM, Kennedy RH, Shim J, Gosse JA. A microplate assay to assess chemical effects on RBL-2H3 mast cell degranulation: effects of triclosan without use of an organic solvent. J Vis Exp 2013:e50671. [PMID: 24300285 DOI: 10.3791/50671] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a process that results in the exocytosis of allergic mediators. Modulation of mast cell degranulation by drugs and toxicants may have positive or adverse effects on human health. Mast cell function has been dissected in detail with the use of rat basophilic leukemia mast cells (RBL-2H3), a widely accepted model of human mucosal mast cells(3-5). Mast cell granule component and the allergic mediator β-hexosaminidase, which is released linearly in tandem with histamine from mast cells(6), can easily and reliably be measured through reaction with a fluorogenic substrate, yielding measurable fluorescence intensity in a microplate assay that is amenable to high-throughput studies(1). Originally published by Naal et al.(1), we have adapted this degranulation assay for the screening of drugs and toxicants and demonstrate its use here. Triclosan is a broad-spectrum antibacterial agent that is present in many consumer products and has been found to be a therapeutic aid in human allergic skin disease(7-11), although the mechanism for this effect is unknown. Here we demonstrate an assay for the effect of triclosan on mast cell degranulation. We recently showed that triclosan strongly affects mast cell function(2). In an effort to avoid use of an organic solvent, triclosan is dissolved directly into aqueous buffer with heat and stirring, and resultant concentration is confirmed using UV-Vis spectrophotometry (using ε280 = 4,200 L/M/cm)(12). This protocol has the potential to be used with a variety of chemicals to determine their effects on mast cell degranulation, and more broadly, their allergic potential.
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Affiliation(s)
- Lisa M Weatherly
- Department of Molecular and Biomedical Sciences, University of Maine, Orono
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24
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Weltje L, Simpson P, Gross M, Crane M, Wheeler JR. Comparative acute and chronic sensitivity of fish and amphibians: a critical review of data. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:984-94. [PMID: 23381988 DOI: 10.1002/etc.2149] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/07/2012] [Accepted: 08/16/2012] [Indexed: 05/18/2023]
Abstract
The relative sensitivity of amphibians to chemicals in the environment, including plant protection product active substances, is the subject of ongoing scientific debate. The objective of this study was to compare systematically the relative sensitivity of amphibians and fish to chemicals. Acute and chronic toxicity data were obtained from the U.S. Environmental Protection Agency (U.S. EPA) ECOTOX database and were supplemented with data from the scientific and regulatory literature. The overall outcome is that fish and amphibian toxicity data are highly correlated and that fish are more sensitive (both acute and chronic) than amphibians. In terms of acute sensitivity, amphibians were between 10- and 100-fold more sensitive than fish for only four of 55 chemicals and more than 100-fold more sensitive for only two chemicals. However, a detailed inspection of these cases showed a similar acute sensitivity of fish and amphibians. Chronic toxicity data for fish were available for 52 chemicals. Amphibians were between 10- and 100-fold more sensitive than fish for only two substances (carbaryl and dexamethasone) and greater than 100-fold more sensitive for only a single chemical (sodium perchlorate). The comparison for carbaryl was subsequently determined to be unreliable and that for sodium perchlorate is a potential artifact of the exposure medium. Only a substance such as dexamethasone, which interferes with a specific aspect of amphibian metamorphosis, might not be detected using fish tests. However, several other compounds known to influence amphibian metamorphosis were included in the analysis, and these did not affect amphibians disproportionately. These analyses suggest that additional amphibian testing is not necessary during chemical risk assessment.
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Affiliation(s)
- Lennart Weltje
- BASF SE, Crop Protection-Ecotoxicology, Limburgerhof, Germany
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Marlatt VL, Veldhoen N, Lo BP, Bakker D, Rehaume V, Vallée K, Haberl M, Shang D, van Aggelen GC, Skirrow RC, Elphick JR, Helbing CC. Triclosan exposure alters postembryonic development in a Pacific tree frog (Pseudacris regilla) Amphibian Metamorphosis Assay (TREEMA). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 126:85-94. [PMID: 23159728 DOI: 10.1016/j.aquatox.2012.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 06/01/2023]
Abstract
The Amphibian Metamorphosis Assay (AMA), developed for Xenopus laevis, is designed to identify chemicals that disrupt thyroid hormone (TH)-mediated biological processes. We adapted the AMA for use on an ecologically-relevant North American species, the Pacific tree frog (Pseudacris regilla), and applied molecular endpoints to evaluate the effects of the antibacterial agent, triclosan (TCS). Premetamorphic (Gosner stage 26-28) tadpoles were immersed for 21 days in solvent control, 1.5 μg/L thyroxine (T(4)), 0.3, 3 and 30 μg/L (nominal) TCS, or combined T(4)/TCS treatments. Exposure effects were scored by morphometric (developmental stage, wet weight, and body, snout-vent and hindlimb lengths) and molecular (mRNA abundance using quantitative real time polymerase chain reaction) criteria. T(4) treatment alone accelerated development concomitant with altered levels of TH receptors α and β, proliferating cell nuclear antigen, and gelatinase B mRNAs in the brain and tail. We observed TCS-induced perturbations in all of the molecular and morphological endpoints indicating that TCS exposure disrupts coordination of postembryonic tadpole development. Clear alterations in molecular endpoints were evident at day 2 whereas the earliest morphological effects appeared at day 4 and were most evident at day 21. Although TCS alone (3 and 30 μg/L) was protective against tadpole mortality, this protection was lost in the presence of T(4). The Pacific tree frog is the most sensitive species examined to date displaying disruption of TH-mediated development by a common antimicrobial agent.
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Pinto PIS, Guerreiro EM, Power DM. Triclosan interferes with the thyroid axis in the zebrafish (Danio rerio). Toxicol Res (Camb) 2013. [DOI: 10.1039/c2tx20005h] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Miyata K, Ose K. Thyroid Hormone-disrupting Effects and the Amphibian Metamorphosis Assay. J Toxicol Pathol 2012; 25:1-9. [PMID: 22481853 PMCID: PMC3320151 DOI: 10.1293/tox.25.1] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 12/05/2011] [Indexed: 11/19/2022] Open
Abstract
There are continued concerns about endocrine-disrupting chemical effects, and appropriate vertebrate models for assessment of risk are a high priority. Frog tadpoles are very sensitive to environmental substances because of their habitat and the complex processes of metamorphosis regulated by the endocrine system, mainly thyroid hormones. During metamorphosis, marked alteration in hormonal factors occurs, as well as dramatic structural and functional changes in larval tissues. There are a variety of mechanisms determining thyroid hormone balance or disruption directly or indirectly. Direct-acting agents can cause changes in thyroxine synthesis and/or secretion in thyroid through effects on peroxidases, thyroidal iodide uptake, deiodinase, and proteolysis. At the same time, indirect action may result from biochemical processes such as sulfation, deiodination and glucuronidation. Because their potential to disrupt thyroid hormones has been identified as an important consideration for the regulation of chemicals, the OECD and the EPA have each established guidelines that make use of larval African clawed frogs (Xenopus laevis) and frog metamorphosis for screening and testing of potential endocrine disrupters. The guidelines are based on evaluation of alteration in the hypothalamic-pituitary-thyroid axis. One of the primary endpoints is thyroid gland histopathology. Others are mortality, developmental stage, hind limb length, snout-vent length and wet body weight. Regarding histopathological features, the guidelines include core criteria and additional qualitative parameters along with grading. Taking into account the difficulties in evaluating amphibian thyroid glands, which change continuously throughout metamorphosis, histopathological examination has been shown to be a very sensitive approach.
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Affiliation(s)
- Kaori Miyata
- Environmental Health Science Laboratory, Sumitomo Chemical Company Limited, 1-98 Kasugadenaka 3 chome, Konohana-ku, Osaka 554-8558, Japan
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Honkisz E, Zieba-Przybylska D, Wojtowicz AK. The effect of triclosan on hormone secretion and viability of human choriocarcinoma JEG-3 cells. Reprod Toxicol 2012; 34:385-92. [PMID: 22677473 DOI: 10.1016/j.reprotox.2012.05.094] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 04/30/2012] [Accepted: 05/25/2012] [Indexed: 12/24/2022]
Abstract
Triclosan is an antimicrobial agent frequently used in pharmaceuticals and personal care products. We analyzed triclosan for its action on placental secretion of progesterone, estradiol and human chorionic gonadotropin in vitro in the JEG-3 cells. We also investigated its action on cell viability, proliferation and apoptosis. The JEG-3 cells were cultured with increasing doses of triclosan (1×10(-9)-1×10(-4) M) for 24, 48 and 72 h. Triclosan was found to increase estradiol and progesterone secretion after short- and long-term exposure. The stimulatory effect was observed up to 10 μM after short- and long-term exposure to triclosan. In addition, triclosan caused an adverse effect on β-hCG secretion. The highest doses of triclosan (50 and 100 μM) showed a strong cytotoxic effect. Anti proliferative and pro-apoptotic effects were also observed. Overall, this study demonstrates that triclosan may indirectly disrupt steroidogenesis which may, in turn, affect placental development and consequently fetal growth.
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Affiliation(s)
- Ewelina Honkisz
- Laboratory of Genomics and Biotechnology, University of Agriculture, Redzina 1B, 30-248 Krakow, Poland
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DeLeo P, Pawlowski S, Barton C, Fort DJ. Comment on "Effects of triclocarban, triclosan, and methyl triclosan on thyroid hormone action and stress in frog and mammalian culture systems". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:10283-10287. [PMID: 21981572 DOI: 10.1021/es202937q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Fort DJ, Mathis M, Pawlowski S. Comment on "Effects of triclocarban, triclosan, and methyl triclosan on thyroid hormone action and stress in frog and mammalian culture systems". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:7602-7601. [PMID: 21786755 DOI: 10.1021/es2021582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Helbing CC, Propper CR, Veldhoen N. Triclosan affects the thyroid axis of amphibians. Toxicol Sci 2011; 123:601-2; author reply 603-5. [PMID: 21852691 DOI: 10.1093/toxsci/kfr127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Fort DJ, Pawlowski S. Triclosan Enhances Larval Amphibian Growth, but Does Not Alter Thyroid-Driven Metamorphosis in Xenopuslaevis. Toxicol Sci 2011. [DOI: 10.1093/toxsci/kfr186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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