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Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, (Ron) Hoogenboom L, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Wallace H, Benford D, Fürst P, Hart A, Rose M, Schroeder H, Vrijheid M, Ioannidou S, Nikolič M, Bordajandi LR, Vleminckx C. Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food. EFSA J 2024; 22:e8497. [PMID: 38269035 PMCID: PMC10807361 DOI: 10.2903/j.efsa.2024.8497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
The European Commission asked EFSA to update its 2011 risk assessment on polybrominated diphenyl ethers (PBDEs) in food, focusing on 10 congeners: BDE-28, -47, -49, -99, -100, -138, -153, -154, -183 and ‑209. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour and reproductive/developmental effects are the critical effects in rodent studies. For four congeners (BDE-47, -99, -153, -209) the Panel derived Reference Points, i.e. benchmark doses and corresponding lower 95% confidence limits (BMDLs), for endpoint-specific benchmark responses. Since repeated exposure to PBDEs results in accumulation of these chemicals in the body, the Panel estimated the body burden at the BMDL in rodents, and the chronic intake that would lead to the same body burden in humans. For the remaining six congeners no studies were available to identify Reference Points. The Panel concluded that there is scientific basis for inclusion of all 10 congeners in a common assessment group and performed a combined risk assessment. The Panel concluded that the combined margin of exposure (MOET) approach was the most appropriate risk metric and applied a tiered approach to the risk characterisation. Over 84,000 analytical results for the 10 congeners in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary Lower Bound exposure to PBDEs were meat and meat products and fish and seafood. Taking into account the uncertainties affecting the assessment, the Panel concluded that it is likely that current dietary exposure to PBDEs in the European population raises a health concern.
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Latchney SE, Majewska AK. Persistent organic pollutants at the synapse: Shared phenotypes and converging mechanisms of developmental neurotoxicity. Dev Neurobiol 2021; 81:623-652. [PMID: 33851516 DOI: 10.1002/dneu.22825] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 02/27/2021] [Accepted: 04/09/2021] [Indexed: 12/18/2022]
Abstract
The developing nervous system is sensitive to environmental and physiological perturbations in part due to its protracted period of prenatal and postnatal development. Epidemiological and experimental studies link developmental exposures to persistent organic pollutants (POPs) including polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polybrominated diphenyl ethers, and benzo(a)pyrene to increased risk for neurodevelopmental disorders in children. Mechanistic studies reveal that many of the complex cellular processes that occur during sensitive periods of rapid brain development are cellular targets for developmental neurotoxicants. One area of research interest has focused on synapse formation and plasticity, processes that involve the growth and retraction of dendrites and dendritic spines. For each chemical discussed in this review, we summarize the morphological and electrophysiological data that provide evidence that developmental POP exposure produces long-lasting effects on dendritic morphology, spine formation, glutamatergic and GABAergic signaling systems, and synaptic transmission. We also discuss shared intracellular mechanisms, with a focus on calcium and thyroid hormone homeostasis, by which these chemicals act to modify synapses. We conclude our review highlighting research gaps that merit consideration when characterizing synaptic pathology elicited by chemical exposure. These gaps include low-dose and nonmonotonic dose-response effects, the temporal relationship between dendritic growth, spine formation, and synaptic activity, excitation-inhibition balance, hormonal effects, and the need for more studies in females to identify sex differences. By identifying converging pathological mechanisms elicited by POP exposure at the synapse, we can define future research directions that will advance our understanding of these chemicals on synapse structure and function.
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Affiliation(s)
- Sarah E Latchney
- Department of Biology, St. Mary's College of Maryland, St. Mary's City, MD, USA.,Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA
| | - Ania K Majewska
- Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, USA.,Center for Visual Science, University of Rochester Medical Center, Rochester, NY, USA
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Gao J, Zhang H, Xiong P, Yan X, Liao C, Jiang G. Application of electrophysiological technique in toxicological study: From manual to automated patch-clamp recording. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Maddela NR, Venkateswarlu K, Kakarla D, Megharaj M. Inevitable human exposure to emissions of polybrominated diphenyl ethers: A perspective on potential health risks. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115240. [PMID: 32698055 DOI: 10.1016/j.envpol.2020.115240] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 05/24/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) serve as flame retardants in many household materials such as electrical and electronic devices, furniture, textiles, plastics, and baby products. Though the use of PBDEs like penta-, octa- and deca-BDE greatly reduces the fire damage, indoor pollution by these toxic emissions is ever-growing. In fact, a boom in the global market projections of PBDEs threatens human health security. Therefore, efforts are made to minimize PBDEs pollution in USA and Europe by encouraging voluntary phasing out of the production or imposing compelled regulations through Stockholm Convention, but >500 kilotons of PBDEs still exist globally. Both 'environmental persistence' and 'bioaccumulation tendencies' are the hallmarks of PBDE toxicities; however, both these issues concerning household emissions of PBDEs have been least addressed theoretically or practically. Critical physiological functions, lipophilicity and toxicity, trophic transfer and tissue specificities are of utmost importance in the benefit/risk assessments of PBDEs. Since indoor debromination of deca-BDE often yields many products, a better understanding on their sorption propensity, environmental fate and human toxicities is critical in taking rigorous measures on the ever-growing global deca-BDE market. The data available in the literature on human toxicities of PBDEs have been validated following meta-analysis. In this direction, the intent of the present review was to provide a critical evaluation of the key aspects like compositional patterns/isomer ratios of PBDEs implicated in bioaccumulation, indoor PBDE emissions versus human exposure, secured technologies to deal with the toxic emissions, and human toxicity of PBDEs in relation to the number of bromine atoms. Finally, an emphasis has been made on the knowledge gaps and future research directions related to endurable flame retardants which could fit well into the benefit/risk strategy.
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Affiliation(s)
- Naga Raju Maddela
- Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo, 130105, Ecuador; Facultad la Ciencias la Salud, Universidad Técnica de Manabí, Portoviejo, 130105, Ecuador
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, 515003, India
| | - Dhatri Kakarla
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW, 2308, Australia.
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Stojak BL, van Ginkel RA, Ivanco TL, Tomy GT, Fry WM. Acute β-tetrabromoethylcyclohexane (β-TBECH) treatment inhibits the electrical activity of rat Purkinje neurons. CHEMOSPHERE 2019; 231:301-307. [PMID: 31129411 DOI: 10.1016/j.chemosphere.2019.05.102] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 06/09/2023]
Abstract
Brominated flame-retardants are environmentally pervasive and persistent synthetic chemicals, some of which have been demonstrated to disrupt neuroendocrine signaling and electrical activity of neurons. 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH) lacks the toxicity of other classes of BFRs, however its safety is still questioned, as little is known of its neurological effects. Therefore, we sought to determine if TBECH could acutely alter the electrical activity of Purkinje neurons maintained in vitro. Briefly, cerebella from gestational day 20 rats were dissociated and maintained for up to three weeks in culture. Action potentials of Purkinje neurons were detected by cell-attached patch clamp before, during, and after application of β-TBECH. β-TBECH decreased action potential activity in a dose-dependent manner with an apparent EC50 of 396 nM. β-TBECH did not significantly alter the coefficient of variation, a measure of the regularity of firing, suggesting that the mechanism of β-TBECH's effects on firing frequency may be independent of Purkinje neuron intracellular calcium handling. Because levels of β-TBECH in exposed individuals may not approach the EC50, these data suggest that any abnormal neurodevelopment or behavior linked with β-TBECH exposure may result from endocrinological effects as opposed to direct disruption of electrical activity.
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Affiliation(s)
- Brittany L Stojak
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Rebecca A van Ginkel
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Tammy L Ivanco
- Department of Psychology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gregg T Tomy
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - W Mark Fry
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
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Jing L, Sun Y, Wang Y, Liang B, Chen T, Zheng D, Zhao X, Zhou X, Sun Z, Shi Z. Cardiovascular toxicity of decabrominated diphenyl ethers (BDE-209) and decabromodiphenyl ethane (DBDPE) in rats. CHEMOSPHERE 2019; 223:675-685. [PMID: 30802833 DOI: 10.1016/j.chemosphere.2019.02.115] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/24/2019] [Accepted: 02/17/2019] [Indexed: 05/08/2023]
Abstract
Recent reports indicated that decabrominated diphenyl ether (BDE-209) and decabromodiphenyl ethane (DBDPE) exist extensively in the environment. The toxicity of BDE-209 has been reported in quite a few studies, whereas the data of DBDPE are relatively rare. However, databases regarding cardiovascular toxicities of both BDE-209 and DBDPE are lacking. In this study, we investigated the vascular/cardiac trauma induced by DBDPE after oral exposure and compared the results with those of BDE-209 using rat model. Male rats were orally administered with corn oil containing DBDPE or BDE-209 (5, 50, 500 mg/kg/day) for 28 days, then oxidative stress, morphological and ultrastructural changes of the heart and abdominal aorta, levels of creatine kinase (CK) and lactate dehydrogenase (LDH), inflammatory cytokines, endothelin-1 (ET-1), and intercellular adhesion molecule-1 (ICAM-1) in the serum were monitored. Results showed that BDE-209 and DBDPE caused heart and abdominal aorta morphological and ultrastructural damage, serum CK and LDH elevation, and antioxidant enzyme activity changes. BDE-209 and DBDPE-induced inflammation was characterized by the upregulation of key inflammatory mediators, including interleukin-1beta (IL-1β), IL-6, IL-10, and tumor necrosis factor alpha (TNFα). Additionally, BDE-209 and DBDPE led to endothelial dysfunction, as evidenced by the ET-1 and ICAM-1 elevation. Our findings demonstrated that BDE-209 and DBDPE could induce oxidative stress, inflammation, and eventually lead to endothelial dysfunction and cardiovascular injury. Compared to DBDPE, these toxic responses were stronger in the hearts and abdominal aorta of Sprague-Dawley rats exposed to BDE-209. Our findings indicated a potential deleterious effect of BDE-209 and DBDPE on the cardiovascular system.
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Affiliation(s)
- Li Jing
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Yanmin Sun
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Yuwei Wang
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Baolu Liang
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Tian Chen
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Dan Zheng
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Xuezhen Zhao
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Xianqing Zhou
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Zhiwei Sun
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China
| | - Zhixiong Shi
- School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, China.
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Roubeau Dumont E, Larue C, Pujol B, Lamaze T, Elger A. Environmental variations mediate duckweed (Lemna minor L.) sensitivity to copper exposure through phenotypic plasticity. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:14106-14115. [PMID: 30852756 DOI: 10.1007/s11356-019-04630-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
Environmentally mediated sensitivity of Lemna minor to copper (Cu) was evaluated for the first time in three experiments: the effects of two levels of nutrient concentration, light irradiance or Cu pre-exposure were tested. Various Cu concentrations (ranging from 0.05 to 0.25 mg/L) were used to assess the sensitivity of L. minor to this metal, using one common strain previously acclimatized to two different levels of light intensity, nutrient enrichment and Cu pre-exposure. Our results showed a phenotypic plastic response of the relative growth rates based on frond number and fresh mass production, and maximum quantum yield of photosystem II (Fv/Fm). Growth was affected by the three environmental conditions both prior and during Cu exposure, whereas Fv/Fm was mostly affected during Cu exposure. Copper significantly influenced all the parameters measured in the three experiments. Environmental conditions significantly modified L. minor sensitivity to Cu in all experiments, with up to twofold difference depending on the treatment. Growth rate was the parameter that was most impacted. Our study revealed for the first time the existence of phenotypic plasticity in L. minor sensitivity to chemical contamination, and implies that environmental context needs to be taken into account for a relevant risk assessment.
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Affiliation(s)
- Eva Roubeau Dumont
- EcoLab, CNRS, Université de Toulouse, Toulouse, France.
- EcoLab, Campus INPT-ENSAT, Avenue de l'Agrobiopole - BP 32607, 31326, Castanet Tolosan Cedex, France.
| | - Camille Larue
- EcoLab, CNRS, Université de Toulouse, Toulouse, France
| | - Benoît Pujol
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), CNRS, IRD, UPS, Université Fédérale de Toulouse Midi-Pyrénées, Toulouse, France
- EPHE, CNRS, UPVD, PSL Research University, USR 3278 CRIOBE, F-66360, Perpignan, France
| | - Thierry Lamaze
- Laboratoire CESBIO, CNRS, IRD, CNES, UPS, Université de Toulouse, Toulouse, France
| | - Arnaud Elger
- EcoLab, CNRS, Université de Toulouse, Toulouse, France
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Chen J, Li X, Li X, Chen D. The environmental pollutant BDE-209 regulates NO/cGMP signaling through activation of NMDA receptors in neurons. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:3397-3407. [PMID: 29151189 DOI: 10.1007/s11356-017-0651-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
The common flame retardant decabrominated diphenyl ether (BDE-209) is a persistent organic pollutant. Epidemiological studies have revealed that prenatal or postnatal exposure to BDE-209 can result in delayed cognitive development, and BDE-209 has been shown to be toxic to cultured neurons with maturation interference effects. However, its neurotoxic mechanism remains unclear. Nitric oxide/cyclic guanosine monophosphate (NO/cGMP) signaling plays an important role in regulating neuronal maturation. We examined the influence of BDE-209 (100, 200, and 400 nM) on NO production and cGMP levels signaling in rodent neurons in vitro, with or without pretreatment N-methyl-D-aspartate (NMDA) receptor antagonism. We found that nanomolar concentrations of BDE-209 affected levels of the second messengers NO and cGMP, and that these effects could be blocked by NMDA receptor antagonism. Moreover, BDE-209 activation of NMDA receptors inhibited the expression of phosphodiesterases (PDEs), which modulate intracellular cGMP levels, and increased the Bcl-2/Bax ratio, favoring apoptosis induction. Our studies implicate the NMDA-NO/cGMP pathway in the pathogenic mechanism through which BDE-209 induces neurotoxicity.
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Affiliation(s)
- Jingsi Chen
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China
| | - Xiuying Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Xiaomei Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Dunjin Chen
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China.
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China.
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China.
- , No.63, Duobao Road, Guangzhou, 510150, China.
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Zhang H, Yolton K, Webster GM, Sjödin A, Calafat AM, Dietrich KN, Xu Y, Xie C, Braun JM, Lanphear BP, Chen A. Prenatal PBDE and PCB Exposures and Reading, Cognition, and Externalizing Behavior in Children. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:746-752. [PMID: 27385187 PMCID: PMC5381998 DOI: 10.1289/ehp478] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 05/21/2016] [Accepted: 06/10/2016] [Indexed: 05/21/2023]
Abstract
BACKGROUND Prenatal polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) exposures may influence children's neurodevelopment. OBJECTIVE We examined the association of prenatal PBDE and PCB exposures with children's reading skills at ages 5 and 8 years, Full-Scale Intelligence Quotient (FSIQ), and externalizing behavior problems at age 8 years. METHODS From 239 mother-child pairs recruited (2003-2006) in Cincinnati, Ohio, we measured maternal serum PBDE and PCB concentrations, assessed child's reading skills using the Woodcock-Johnson Tests of Achievement III (WJ-III) at age 5 years and the Wide Range Achievement Test-4 (WRAT-4) at age 8 years, tested FSIQ using the Wechsler Intelligence Scale for Children-IV (WISC-IV), and externalizing behavior problems using the Behavioral Assessment System for Children-2 (BASC-2) at age 8 years. We used multiple linear regression to examine the association of prenatal PBDE and PCB concentrations and reading, FSIQ, and externalizing behavior problems after adjusting for covariates. RESULTS An increase of Sum4PBDEs (BDE-47, BDE-99, BDE-100, and BDE-153) by 10 times was not significantly associated with reading scores at age 5 years at the p = 0.05 level but was inversely associated with Reading Composite scores (β: -6.2, 95% CI: -11.7, -0.6) and FSIQ (β: -5.3, 95% CI: -10.6, -0.02) at age 8 years; it was positively associated with the score for externalizing behavior problems (β: 3.5, 95% CI: -0.1, 7.2) at age 8 years. Prenatal Sum4PCBs (PCB-118, -153, -138-158, and -180) was not significantly associated with a child's reading skills, FSIQ, and externalizing behavior problems. CONCLUSION Prenatal PBDE concentration was inversely associated with reading skills and FSIQ and positively associated with externalizing behavior problems at age 8 years. No significant associations were found in prenatal PCB concentration.
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Affiliation(s)
- Hongmei Zhang
- Department of Environmental Health, School of Public Health, Shanxi Medical University, Taiyuan, Shanxi Province, China
| | - Kimberly Yolton
- Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Glenys M. Webster
- Child and Family Research Institute, BC Children’s and Women’s Hospital and Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Andreas Sjödin
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Antonia M. Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Kim N. Dietrich
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Yingying Xu
- Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Changchun Xie
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Joseph M. Braun
- Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island, USA.
| | - Bruce P. Lanphear
- Child and Family Research Institute, BC Children’s and Women’s Hospital and Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Aimin Chen
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Hendriks HS, Westerink RH. Neurotoxicity and risk assessment of brominated and alternative flame retardants. Neurotoxicol Teratol 2015; 52:248-69. [DOI: 10.1016/j.ntt.2015.09.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 09/01/2015] [Accepted: 09/01/2015] [Indexed: 11/29/2022]
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Feng Y, Hu Q, Meng G, Wu X, Zeng W, Zhang X, Yu Y, Wang Y. Simulating long-term occupational exposure to decabrominated diphenyl ether using C57BL/6 mice: biodistribution and pathology. CHEMOSPHERE 2015; 128:118-124. [PMID: 25687576 DOI: 10.1016/j.chemosphere.2015.01.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/30/2014] [Accepted: 01/07/2015] [Indexed: 06/04/2023]
Abstract
Decabrominated biphenyl ether (BDE-209) is a fully brominated diphenyl ether compound used widely as an additive brominated flame retardant in a variety of consumer products. In recent years, BDE-209 has been reported to be abundant and persistent in the environment, and comparatively high burdens have been found in occupational environmental compartments and exposed individuals. In the present study, an animal model for simulating long-term occupational exposure to BDE-209 was set up. Female C57BL/6 mice (n=10) were intragastrically administered BDE-209 at a dose of 800 mg kg(-1) bw at 2-d intervals for 2 years with an internal blood level of approximately 200 ng mL(-1), which was comparable to the high level of BDE-209 detected in the occupational population, and the biodistribution and biological effects were evaluated systematically. The results showed that large amounts of the chemical accumulated in most tissues, and the preferential organs were the ovary and uterus, liver and lung. Decreased survival was observed in the exposed mice. The subsequent pathological analysis revealed hepatomegaly in the exposed mice, accompanied by obvious histopathological changes in the liver, lung, brain, spleen, kidney and ovary. No neoplastic lesions were observed in this lifetime exposure study. Although the number of experimental mice was limited, our observations offer a comprehensive understanding of the chronic toxicology of BDE-209 after continuous high-dose exposure.
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Affiliation(s)
- Yan Feng
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Qingliang Hu
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Ge Meng
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Xiaomeng Wu
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Weihong Zeng
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Xing Zhang
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Yingxin Yu
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
| | - Yan Wang
- Faculty of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China.
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12
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Zhang ZF, Zhang YQ, Fan SH, Zhuang J, Zheng YL, Lu J, Wu DM, Shan Q, Hu B. Troxerutin protects against 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-induced liver inflammation by attenuating oxidative stress-mediated NAD⁺-depletion. JOURNAL OF HAZARDOUS MATERIALS 2014; 283:98-109. [PMID: 25262482 DOI: 10.1016/j.jhazmat.2014.09.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/30/2014] [Accepted: 09/08/2014] [Indexed: 06/03/2023]
Abstract
Emerging evidence indicates that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) induces liver injury through enhanced ROS production and lymphocytic infiltration, which may promote a liver inflammatory response. Antioxidants have been reported to attenuate the cellular toxicity associated with polybrominated diphenyl ethers (PBDEs). In this study, we investigated the effect of troxerutin, a trihydroxyethylated derivative of the natural bioflavonoid rutin, on BDE-47-induced liver inflammation and explored the potential mechanisms underlying this effect. Our results showed that NAD(+)-depletion was involved in the oxidative stress-mediated liver injury in a BDE-47 treated mouse model, which was confirmed by Vitamin E treatment. Furthermore, our data revealed that troxerutin effectively alleviated liver inflammation by mitigating oxidative stress-mediated NAD(+)-depletion in BDE-47 treated mice. Consequently, troxerutin remarkably restored SirT1 protein expression and activity in the livers of BDE-47-treated mice. Mechanistically, troxerutin dramatically repressed the nuclear translocation of NF-κB p65 and the acetylation of NF-κB p65 (Lys 310) and Histone H3 (Lys9) to abate the transcription of inflammatory genes in BDE-47-treated mouse livers. These inhibitory effects of troxerutin were markedly blunted by EX527 (SirT1 inhibitor) treatment. This study provides novel mechanistic insights into the toxicity of BDE-47 and indicates that troxerutin might be used in the prevention and therapy of BDE-47-induced hepatotoxicity.
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Affiliation(s)
- Zi-Feng Zhang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, PR China; Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
| | - Yan-Qiu Zhang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, PR China
| | - Shao-Hua Fan
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
| | - Juan Zhuang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, PR China
| | - Yuan-Lin Zheng
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China.
| | - Jun Lu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
| | - Dong-Mei Wu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
| | - Qun Shan
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
| | - Bin Hu
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, 101 Shanghai Road, Xuzhou 221116, Jiangsu Province, PR China
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Westerink RHS. Modulation of cell viability, oxidative stress, calcium homeostasis, and voltage- and ligand-gated ion channels as common mechanisms of action of (mixtures of) non-dioxin-like polychlorinated biphenyls and polybrominated diphenyl ethers. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:6373-6383. [PMID: 23686757 DOI: 10.1007/s11356-013-1759-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) and polybrominated diphenyl ethers (PBDEs) are environmental pollutants that exert neurodevelopmental and neurobehavioral effects in vivo in humans and animals. Acute in vitro neurotoxic effects include changes in cell viability, oxidative stress, and basal intracellular calcium levels. Though these acute cellular effects could partly explain the observed in vivo effects, other mechanisms, such as effects on calcium influx and neurotransmitter receptor function, likely contribute to the disturbance in neurotransmission. This concise review combines in vitro data on cell viability, oxidative stress and basal calcium levels with recent data that clearly demonstrate that (hydroxylated) PCBs and (hydroxylated) PBDEs can exert acute effects on voltage-gated Ca(2+) channels as well as on excitatory and inhibitory neurotransmitter receptors in vitro. These novel mechanisms of action are shared by NDL-PCBs, OH-PBDEs, and some other persistent organic pollutants, such as tetrabromobisphenol-A, and could have profound effects on neurodevelopment, neurotransmission, and neurobehavior in vivo.
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Affiliation(s)
- Remco H S Westerink
- Neurotoxicology Research Group, Toxicology Division, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.177, 3508 TD, Utrecht, The Netherlands,
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Perinatal exposure to BDE-99 causes learning disorders and decreases serum thyroid hormone levels and BDNF gene expression in hippocampus in rat offspring. Toxicology 2013; 308:122-8. [DOI: 10.1016/j.tox.2013.03.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 03/25/2013] [Accepted: 03/25/2013] [Indexed: 01/08/2023]
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Dingemans MML, van den Berg M, Westerink RHS. Neurotoxicity of brominated flame retardants: (in)direct effects of parent and hydroxylated polybrominated diphenyl ethers on the (developing) nervous system. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:900-7. [PMID: 21245014 PMCID: PMC3223008 DOI: 10.1289/ehp.1003035] [Citation(s) in RCA: 240] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 01/18/2011] [Indexed: 05/17/2023]
Abstract
BACKGROUND/OBJECTIVE Polybrominated diphenyl ethers (PBDEs) and their hydroxylated (OH-) or methoxylated forms have been detected in humans. Because this raises concern about adverse effects on the developing brain, we reviewed the scientific literature on these mechanisms. DATA SYNTHESIS Many rodent studies reported behavioral changes after developmental, neonatal, or adult exposure to PBDEs, and other studies documented subtle structural and functional alterations in brains of PBDE-exposed animals. Functional effects have been observed on synaptic plasticity and the glutamate-nitric oxide-cyclic guanosine monophosphate pathway. In the brain, changes have been observed in the expression of genes and proteins involved in synapse and axon formation, neuronal morphology, cell migration, synaptic plasticity, ion channels, and vesicular neurotransmitter release. Cellular and molecular mechanisms include effects on neuronal viability
(via apoptosis and oxidative stress), neuronal differentiation and migration, neurotransmitter release/uptake, neurotransmitter receptors and ion channels, calcium (Ca²⁺) homeostasis, and intracellular signaling pathways. DISCUSSION Bioactivation of PBDEs by hydroxylation has been observed for several endocrine end points. This has also been observed for mechanisms related to neurodevelopment, including binding to thyroid hormone receptors and transport proteins, disruption of Ca²⁺ homeostasis, and modulation of GABA and nicotinic acetylcholine receptor function. CONCLUSIONS The increased hazard for developmental neurotoxicity by hydroxylated (OH-)PBDEs compared with their parent congeners via direct neurotoxicity and thyroid disruption clearly warrants further investigation into a) the role of oxidative metabolism in producing active metabolites of PBDEs and their impact on brain development; b) concentrations of parent and OH-PBDEs in the brain; and c) interactions between different environmental contaminants during exposure to mixtures, which may increase neurotoxicity.
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Affiliation(s)
- Milou M L Dingemans
- Neurotoxicology Research Group, Toxicology Division, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
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Is decabromodiphenyl ether (BDE-209) a developmental neurotoxicant? Neurotoxicology 2010; 32:9-24. [PMID: 21182867 DOI: 10.1016/j.neuro.2010.12.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/13/2010] [Accepted: 12/13/2010] [Indexed: 11/24/2022]
Abstract
Polybrominated diphenyl ether (PBDE) flame retardants have become ubiquitous environmental pollutants. The relatively higher body burden in toddlers and children has raised concern for their potential developmental neurotoxicity, which has been suggested by animal studies, in vitro experiments, and recent human epidemiological evidence. While lower brominated PBDEs have been banned in several countries, the fully brominated decaBDE (BDE-209) is still utilized, though manufacturers will discontinue production in the U.S.A. in 2013. The recent decision by the U.S. Environmental Protection Agency to base the reference dose (RfD) for BDE-209 on a developmental neurotoxicity study has generated some controversy. Because of its bulky configuration, BDE-209 is poorly absorbed and does not easily penetrate the cell wall. Its acute and chronic toxicities are relatively low, with the liver and the thyroid as the primary targets, though there is some evidence of carcinogenicity. A few animal studies have indicated that BDE-209 may cause developmental neurotoxicity, affecting motor and cognitive domains, as seen for other PBDEs. Limited in vivo and in vitro studies have also evidenced effects of BDE-209 on thyroid hormone homeostasis and direct effects on nervous cells, again similar to what found with other lower brominated PBDEs. In contrast, a recent developmental neurotoxicity study, carried out according to international guidelines, has provided no evidence of adverse effects on neurodevelopment, and this should be considered in a future re-evaluation of BDE-209. While estimated exposure to BDE-209 in children is believed to be several orders of magnitude below the most conservative RfD proposed by the USEPA, questions remain on the extent and relevance of BDE-209 metabolism to lower brominated PBDEs in the environment and in humans.
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