1
|
Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Wallace H, Benford D, Hart A, Schroeder H, Rose M, Vrijheid M, Kouloura E, Bordajandi LR, Riolo F, Vleminckx C. Update of the scientific opinion on tetrabromobisphenol A (TBBPA) and its derivatives in food. EFSA J 2024; 22:e8859. [PMID: 39010865 PMCID: PMC11247339 DOI: 10.2903/j.efsa.2024.8859] [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: 07/17/2024] Open
Abstract
The European Commission asked EFSA to update its 2011 risk assessment on tetrabromobisphenol A (TBBPA) and five derivatives in food. Neurotoxicity and carcinogenicity were considered as the critical effects of TBBPA in rodent studies. The available evidence indicates that the carcinogenicity of TBBPA occurs via non-genotoxic mechanisms. Taking into account the new data, the CONTAM Panel considered it appropriate to set a tolerable daily intake (TDI). Based on decreased interest in social interaction in male mice, a lowest observed adverse effect level (LOAEL) of 0.2 mg/kg body weight (bw) per day was identified and selected as the reference point for the risk characterisation. Applying the default uncertainty factor of 100 for inter- and intraspecies variability, and a factor of 3 to extrapolate from the LOAEL to NOAEL, a TDI for TBBPA of 0.7 μg/kg bw per day was established. Around 2100 analytical results for TBBPA in food were used to estimate dietary exposure for the European population. The most important contributors to the chronic dietary LB exposure to TBBPA were fish and seafood, meat and meat products and milk and dairy products. The exposure estimates to TBBPA were all below the TDI, including those estimated for breastfed and formula-fed infants. Accounting for the uncertainties affecting the assessment, the CONTAM Panel concluded with 90%-95% certainty that the current dietary exposure to TBBPA does not raise a health concern for any of the population groups considered. There were insufficient data on the toxicity of any of the TBBPA derivatives to derive reference points, or to allow a comparison with TBBPA that would support assignment to an assessment group for the purposes of combined risk assessment.
Collapse
|
2
|
An T, Lu L, Li G. Daily exposure to low concentrations Tetrabromobisphenol A interferes with the thyroid hormone pathway in HepG2 cells. FUNDAMENTAL RESEARCH 2023; 3:384-391. [PMID: 38933766 PMCID: PMC11197689 DOI: 10.1016/j.fmre.2022.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 01/31/2023] Open
Abstract
Tetrabromobisphenol A (TBBPA) is a flame retardant that adversely affects the environment and human health. The present study exposed HepG2 cells to low concentrations of TBBPA daily to investigate the changes in gene regulation, mainly related to pathways associated with the endocrine system. The quantitative polymerase chain reaction (qPCR) confirmed that prolonged exposure gradually activated the thyroid hormone and parathyroid hormone signaling pathways. The expression levels of genes related to the thyroid hormone signaling pathway were upregulated (1.15-8.54 times) after five generations of exposure to 1 and 81 nM TBBPA. Furthermore, co-exposure to 81 nM TBBPA and 0.5 nM thyroid hormone receptor antagonist for five generations significantly reduced the expression of thyroid hormone and parathyroid hormone receptors. Meanwhile, 81 nM TBBPA inhibited the activation of the Ras pathway and downregulated Ras gene expression level (3.7 times), indicating the association between the toxic effect and thyroid hormone receptors. Additionally, our experiments revealed that the thyroid hormone pathway regulated the induction of the Ras signaling pathway by TBBPA. The study thus proves that daily exposure to TBBPA interferes with the thyroid hormone signaling pathway and subsequently the endocrine system.
Collapse
Affiliation(s)
- Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Lirong Lu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| |
Collapse
|
3
|
Ultrasonic Preparation of PN for the Photodegradation of 17β-Estradiol in Water and Biotoxicity Assessment of 17β-Estradiol after Degradation. Catalysts 2023. [DOI: 10.3390/catal13020332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study prepares a novel phosphorene (PN) and loads it onto TiO2 to fabricate PN-TiO2 and effectively photodegrade the hydrophobic environmental hormone 17β-estradiol in aqueous solutions. The effect of the PN on degradation efficiency is systematically investigated. It is observed that the doping of TiO2 with PN significantly enhances its photocatalytic and adsorption properties compared with that in the absence of PN; that is, the addition improves the adsorption capability of the composite. The optimal PN weight content is found to be 0.5%. The performance of the PN-TiO2 photocatalyst in degrading E2 is around 67.5%. However, its photodegradation efficiency gradually decreases when the PN content is further increased. This optimal PN content directly suggests synergistic interactions affecting the photodegrading efficiency. Compared with other PN-based photocatalysts mentioned in the literature, this PN-based material possesses striking advantages, such as higher energy efficiency, greater removal capacity, and superior cost-effectiveness. Further, the decrease in the biotoxicity of the water after treatment is evident in observing the development of zebrafish embryos. The studies of the catalyst performed on the zebrafish show that it results in a higher mortality rate at 96 h with a superior hatching rate and healthy fish development. In summary, the prepared PN-based materials exhibited promising photocatalytic capabilities for the removal and biotoxicity reduction of 17β-estradiol in aqueous solutions.
Collapse
|
4
|
Tribondeau A, Sachs LM, Buisine N. Tetrabromobisphenol A effects on differentiating mouse embryonic stem cells reveals unexpected impact on immune system. Front Genet 2022; 13:996826. [PMID: 36386828 PMCID: PMC9640982 DOI: 10.3389/fgene.2022.996826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/06/2022] [Indexed: 07/27/2023] Open
Abstract
Tetrabromobisphenol A (TBBPA) is a potent flame retardant used in numerous appliances and a major pollutant in households and ecosystems. In vertebrates, it was shown to affect neurodevelopment, the hypothalamic-pituitary-gonadal axis and thyroid signaling, but its toxicity and modes of actions are still a matter of debate. The molecular phenotype resulting from exposure to TBBPA is only poorly described, especially at the level of transcriptome reprogramming, which further limits our understanding of its molecular toxicity. In this work, we combined functional genomics and system biology to provide a system-wide description of the transcriptomic alterations induced by TBBPA acting on differentiating mESCs, and provide potential new toxicity markers. We found that TBBPA-induced transcriptome reprogramming affect a large collection of genes loosely connected within the network of biological pathways, indicating widespread interferences on biological processes. We also found two hotspots of action: at the level of neuronal differentiation markers, and surprisingly, at the level of immune system functions, which has been largely overlooked until now. This effect is particularly strong, as terminal differentiation markers of both myeloid and lymphoid lineages are strongly reduced: the membrane T cell receptor (Cd79a, Cd79b), interleukin seven receptor (Il7r), macrophages cytokine receptor (Csf1r), monocyte chemokine receptor (Ccr2). Also, the high affinity IgE receptor (Fcer1g), a key mediator of allergic reactions, is strongly induced. Thus, the molecular imbalance induce by TBBPA may be stronger than initially realized.
Collapse
|
5
|
Barańska A, Bukowska B, Michałowicz J. Determination of Apoptotic Mechanism of Action of Tetrabromobisphenol A and Tetrabromobisphenol S in Human Peripheral Blood Mononuclear Cells: A Comparative Study. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27186052. [PMID: 36144785 PMCID: PMC9500834 DOI: 10.3390/molecules27186052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022]
Abstract
Background: Tetrabromobisphenol A (TBBPA) is the most commonly used brominated flame retardant (BFR) in the industry. TBBPA has been determined in environmental samples, food, tap water, dust as well as outdoor and indoor air and in the human body. Studies have also shown the toxic potential of this substance. In search of a better and less toxic BFR, tetrabromobisphenol S (TBBPS) has been developed in order to replace TBBPA in the industry. There is a lack of data on the toxic effects of TBBPS, while no study has explored apoptotic mechanism of action of TBBPA and TBBPS in human leukocytes. Methods: The cells were separated from leucocyte-platelet buffy coat and were incubated with studied compounds in concentrations ranging from 0.01 to 50 µg/mL for 24 h. In order to explore the apoptotic mechanism of action of tested BFRs, phosphatidylserine externalization at cellular membrane (the number of apoptotic cells), cytosolic calcium ion and transmembrane mitochondrial potential levels, caspase-8, -9 and -3 activation, as well as PARP-1 cleavage, DNA fragmentation and chromatin condensation in PBMCs were determined. Results: TBBPA and TBBPS triggered apoptosis in human PBMCs as they changed all tested parameters in the incubated cells. It was also observed that the mitochondrial pathway was mainly involved in the apoptotic action of studied compounds. Conclusions: It was found that TBBPS, and more strongly TBBPA, triggered apoptosis in human PBMCs. Generally, the mitochondrial pathway was involved in the apoptotic action of tested compounds; nevertheless, TBBPS more strongly than TBBPA caused intrinsic pathway activation.
Collapse
|
6
|
Hou X, Wei L, Tang Y, Kong W, Liu J, Schnoor JL, Jiang G. Two Typical Glycosylated Metabolites of Tetrabromobisphenol A Formed in Plants: Excretion and Deglycosylation in Plant Root Zones. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2021; 8:313-319. [PMID: 34805424 PMCID: PMC8603600 DOI: 10.1021/acs.estlett.1c00084] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The glycosylation process was investigated for the common brominated flame retardant tetrabromobisphenol A (TBBPA) in hydroponic exposure systems with pumpkin seedlings. Two typical glycosylation metabolites of TBBPA formed in pumpkin seedlings, TBBPA mono-β-d-glucopyranoside (TBBPA MG) and TBBPA di-β-d-glucopyranoside (TBBPA DG), increasing their mass early in the exposure (reaching maximum masses of 608 ± 53 and 3806 ± 1570 pmol at 12 h, respectively) and then falling throughout exposure. These two metabolites were released from roots to rhizosphere solutions, where they also exhibited initial increases followed by decreasing trends (reaching maximum masses of 595 ± 272 pmol at 3 h and 77.1 ± 36.0 pmol at 6 h, respectively). However, a (pseudo)zero-order deglycosylation of TBBPA MG and TBBPA DG (during the first 1.5 h) back to TBBPA was unexpectedly detected in the hydroponic solutions containing pumpkin exudates and microorganisms. The function of microorganisms in the solutions was further investigated, revealing that the microorganisms were main contributors to deglycosylation. Plant detoxification through glycosylation and excretion, followed by deglycosylation of metabolites back to the toxic parent compound (TBBPA) in hydroponic solutions, provides new insight into the uptake, transformation, and environmental fate of TBBPA and its glycosylated metabolites in plant/microbial systems.
Collapse
Affiliation(s)
- Xingwang Hou
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Linfeng Wei
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yinyin Tang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenqian Kong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiyan Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment and Institute of Environment and Health, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jerald L Schnoor
- Department of Civil and Environmental Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment and Institute of Environment and Health, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
7
|
Zhang W, Li A, Pan Y, Wang F, Li M, Liang Y, Yao X, Song J, Song M, Jiang G. Tetrabromobisphenol A induces THR β-mediated inflammation and uterine injury in mice at environmentally relevant exposure concentrations. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124859. [PMID: 33360189 DOI: 10.1016/j.jhazmat.2020.124859] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/19/2020] [Accepted: 12/12/2020] [Indexed: 06/12/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is a widely used flame retardant, but the adverse outcomes induced by TBBPA has not been fully elucidated. In this study, TBBPA was detected in 54.9% of 102 female Chinese volunteers with an average serum concentration of 0.34 ng/mL. To investigate whether TBBPA induces adverse outcomes at environmentally relevant exposure doses, the mice were exposed to TBBPA for 14 and 28 days. The internal doses of TBBPA in mice serum were nearly the internal doses in volunteers. TBBPA significantly increased the secretion of some pro-inflammatory cytokines and suppressed immune responses in mice under such serum concentrations after 14- and 28-days exposure. Interestingly, uterine edema was observed in TBBPA-treated mice. In primary uterine cells model, the results showed TBBPA exposure suppressed THRβ expression, leading to the activation of the inflammatory PI3K/NF-κB signaling pathway. Our findings indicated that the uterus is the susceptible target organ of TBBPA and TBBPA exposure might increase risk of uterine cancer through deregulating inflammation pathways.
Collapse
Affiliation(s)
- Wenjuan Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, Hubei, PR China
| | - Aijing Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Yu Pan
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, Hubei, PR China
| | - Fengbang Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Ming Li
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, Hubei, PR China
| | - Yong Liang
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, Hubei, PR China
| | - Xinglei Yao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Jinghai Song
- Department of General Surgery, Beijing Hospital, National Center of Gerontology, Beijing 1000730, PR China
| | - Maoyong Song
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| |
Collapse
|
8
|
Castro L, Liu J, Yu L, Burwell AD, Saddler TO, Santiago LA, Xue W, Foley JF, Staup M, Flagler ND, Shi M, Birnbaum LS, Darlene D. Differential Receptor Tyrosine Kinase Phosphorylation in the Uterus of Rats Following Developmental Exposure to Tetrabromobisphenol A. TOXICOLOGY RESEARCH AND APPLICATION 2021; 5. [PMID: 35071781 DOI: 10.1177/23978473211047164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Tetrabromobisphenol A (TBBPA) is a brominated flame retardant that induces endometrial adenocarcinoma and other uterine tumors in Wistar Han rats; however, early molecular events or biomarkers of TBBPA exposure remain unknown. We investigated the effects of TBBPA on growth factor receptor activation (phospho-RTK) in uteri of rats following early-life exposures. Pregnant Wistar Han rats were exposed to TBBPA (0, 0.1, 25, 250 mg/kg/day) via oral gavage on gestation day 6 through weaning of pups (PND 21). Pups were exposed in utero, through lactation, and by daily gavage from PND 22 to PND 90. Uterine horns were collected (at PND 21, PND 33, PND 90) and formalin-fixed or frozen for histologic, immunohistochemical, phospho-RTK arrays, or western blot analysis. At PND 21, the phosphor-RTKs, FGFR2, FGFR3, TRKC and EPHA1 were significantly increased at different treatment concentrations. Several phospho-RTKs were also significantly overexpressed at PND 33 which included epithelial growth factor receptor (EGFR), Fibroblast Growth Factor Receptor 3-4 (FGFR2, FGFR3, FGFR4), insulin-like growth factor receptor 1 (IGF1R), INSR, AXL, MERTK, PDGFRa and b, RET, Tyrosine Kinase with Immunoglobulin Like and EGF Like Domains 1 and 2 (TIE1; TIE2), TRKA, VEGFR2 and 3, and EPHA1 at different dose treatments. EGFR, an RTK overexpressed in endometrial cancer in women, remained significantly increased for all treatment groups at PND 90. Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2) and IGF1R were overexpressed at PND 33 and remained increased through PND 90, although ERBB2 was statistically significant at PND 90. The phospho-RTKs, FGFR3, AXL, DTK, HGFR, TRKC, VEGFR1 and EPHB2 and 4 were also statistically significant at PND 90 at different dose treatments. The downstream effector, phospho-MAPK44/42 was also increased in uteri of treated rats. Our findings show RTKs are dysregulated following early life TBBPA exposures and their sustained activation may contribute to TBBPA-induced uterine tumors observed in rats later in life.
Collapse
Affiliation(s)
- Lysandra Castro
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Jingli Liu
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Linda Yu
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Alanna D Burwell
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Trey O Saddler
- Office of Data Science, DNTP, NIEHS, 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Lindsay A Santiago
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - William Xue
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Julie F Foley
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Michael Staup
- Charles River Laboratories, Inc., Durham, NC 27703, USA
| | - Norris D Flagler
- Cellular and Molecular Pathogenesis Branch, DNTP, NIEHS, 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Min Shi
- Biostatistics and Computational Biology Branch, Division of the Intramural Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, USA
| | - Linda S Birnbaum
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Dixon Darlene
- Mechanistic Toxicology Branch, Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA
| |
Collapse
|
9
|
Zhou H, Yin N, Faiola F. Tetrabromobisphenol A (TBBPA): A controversial environmental pollutant. J Environ Sci (China) 2020; 97:54-66. [PMID: 32933740 DOI: 10.1016/j.jes.2020.04.039] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 06/11/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and is extensively used in electronic equipment, furniture, plastics, and textiles. It is frequently detected in water, soil, air, and organisms, including humans, and has raised concerns in the scientific community regarding its potential adverse health effects. Human exposure to TBBPA is mainly via diet, respiration, and skin contact. Various in vivo and in vitro studies based on animal and cell models have demonstrated that TBBPA can induce multifaceted effects in cells and animals, and potentially exert hepatic, renal, neural, cardiac, and reproductive toxicities. Nevertheless, other reports have claimed that TBBPA might be a safe chemical. In this review, we re-evaluated most of the published TBBPA toxicological assessments with the goal of reaching a conclusion about its potential toxicity. We concluded that, although low TBBPA exposure levels and rapid metabolism in humans may signify that TBBPA is a safe chemical for the general population, particular attention should be paid to the potential effects of TBBPA on early developmental stages.
Collapse
Affiliation(s)
- Hui Zhou
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nuoya Yin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Francesco Faiola
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
10
|
|
11
|
Rock KD, Gillera SEA, Devarasetty P, Horman B, Knudsen G, Birnbaum LS, Fenton SE, Patisaul HB. Sex-specific behavioral effects following developmental exposure to tetrabromobisphenol A (TBBPA) in Wistar rats. Neurotoxicology 2019; 75:136-147. [PMID: 31541695 PMCID: PMC6935469 DOI: 10.1016/j.neuro.2019.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/07/2019] [Accepted: 09/02/2019] [Indexed: 12/25/2022]
Abstract
Tetrabromobisphenol A (TBBPA) has become a ubiquitous indoor contaminant due to its widespread use as an additive flame retardant in consumer products. Reported evidence of endocrine disruption and accumulation of TBBPA in brain tissue has raised concerns regarding its potential effects on neurodevelopment and behavior. The goal of the present study was to examine the impact of developmental TBBPA exposure, across a wide range of doses, on sexually dimorphic non-reproductive behaviors in male and female Wistar rats. We first ran a pilot study using a single TBBPA dose hypothesized to produce behavioral effects. Wistar rat dams were orally exposed using cookie treats to 0 or 0.1 mg TBBPA/kg bw daily from gestational day (GD) 9 to postnatal day (PND) 21 to assess offspring (both sexes) activity and anxiety-related behaviors. Significant effects were evident in females, with exposure increasing activity levels. Thus, this dose was used as the lowest TBBPA dose in a subsequent, larger study conducted as part of a comprehensive assessment of TBBPA toxicity. Animals were exposed to 0, 0.1, 25, or 250 mg TBBPA/kg bw daily by oral gavage starting on GD 6 through PND 90 (dosed dams GD 6 - PND 21, dosed offspring PND 22 - PND 90). Significant behavioral findings were observed for male offspring, with increased anxiety-like behavior as the primary phenotype. These findings demonstrate that exposure to environmental contaminants, like TBBPA, can have sex-specific effects on behavior highlighting the vulnerability of the developing brain.
Collapse
Affiliation(s)
- Kylie D Rock
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Sagi Enicole A Gillera
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA; National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Pratyush Devarasetty
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Brian Horman
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Gabriel Knudsen
- Laboratory of Toxicokinetics, National Cancer Institute, Research Triangle Park, NC, 27709, USA
| | - Linda S Birnbaum
- Laboratory of Toxicokinetics, National Cancer Institute, Research Triangle Park, NC, 27709, USA
| | - Suzanne E Fenton
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
| |
Collapse
|
12
|
Yu Y, Yu Z, Chen H, Han Y, Xiang M, Chen X, Ma R, Wang Z. Tetrabromobisphenol A: Disposition, kinetics and toxicity in animals and humans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:909-917. [PMID: 31351299 DOI: 10.1016/j.envpol.2019.07.067] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/29/2019] [Accepted: 07/13/2019] [Indexed: 06/10/2023]
Abstract
Tetrabromobisphenol A (TBBPA) is a nonregulated brominated flame retardant with a high production volume, and it is applied in a wide variety of consumer products. TBBPA is ubiquitous in abiotic matrices, wildlife and humans around the world. This paper critically reviews the published scientific data concerning the disposition, metabolism or kinetics and toxicity of TBBPA in animals and humans. TBBPA is rapidly absorbed and widely distributed among tissues, and is excreted primarily in the feces. In rats, TBBPA and its metabolites have limited systemic bioavailability. TBBPA has been detected in human milk in the general population. It is available to both the developing fetus and the nursing pups following maternal exposure. It has been suggested that TBBPA causes acute toxicity, endocrine disruptor activity, immunotoxicity, neurotoxicity, nephrotoxicity, and hepatotoxicity in animals. Cell-based assays have shown that TBBPA can induce reactive oxygen species in a concentration-dependent manner, and it promotes the production of inflammatory factors such as TNF α, IL-6, and IL-8. Cells exposed to high levels of TBBPA exhibit seriously injured mitochondria and a dilated smooth endoplasmic reticulum. This review will enhance the understanding of the potential risks of TBBPA exposure to ecological and human health.
Collapse
Affiliation(s)
- Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China.
| | - Ziling Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Haibo Chen
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Yajing Han
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Mingdeng Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Xichao Chen
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Ruixue Ma
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Zhengdong Wang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| |
Collapse
|
13
|
Coulter SJ. Mitigation of the effect of variability in digital PCR assays through use of duplexed reference assays for normalization. Biotechniques 2019; 65:86-91. [PMID: 30091389 DOI: 10.2144/btn-2018-0058] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Digital PCR has been promoted as a technique for obtaining absolute measures of the amount of nucleic acid target sequence in a sample, but still lacks standardization in data reporting. The initial method of representing data as copies per microliter produced inconsistent results and made inter-assay comparisons difficult. Normalizing copies to amount of nucleic acid gives more uniform results, but factors influencing the effective concentration of nucleic acid in the final digital PCR assay must be considered. Using droplet digital PCR and previously validated reference genes duplexed with target genes, a method of normalization was developed to estimate the amount of input nucleic acid in individual assays, subsequently reporting the number of copies of target gene relative to this amount. Correcting for the actual amount of amplifiable nucleic acid present demonstrated a higher correlation between various dilutions of sample mRNA and allowed more accurate comparisons of digital PCR results.
Collapse
Affiliation(s)
- Sherry J Coulter
- National Cancer Institute at the National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| |
Collapse
|
14
|
Cannon RE, Trexler AW, Knudsen GA, Evans RA, Birnbaum LS. Tetrabromobisphenol A (TBBPA) Alters ABC Transport at the Blood-Brain Barrier. Toxicol Sci 2019; 169:475-484. [PMID: 30830211 PMCID: PMC6542337 DOI: 10.1093/toxsci/kfz059] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Tetrabromobisphenol A (TBBPA, CAS No. 79-94-7) is a brominated flame retardant used in 90% of epoxy coated circuit boards. Exposures to TBBPA can induce neurotoxicity and disrupt MAPK, estrogen, thyroid, and PPAR-associated signaling pathways. Because these pathways also regulate transporters of the central nervous system barriers, we sought to determine the effect of TBBPA on the expression and activity of 3 ATP binding cassette (ABC) transporters of the blood-brain barrier (BBB). Using a confocal based assay, we measured the ex vivo and in vivo effects of TBBPA on P-glycoprotein (P-gp), breast cancer resistant protein (BCRP), and multidrug resistance-associated protein 2 (MRP2) transport activity in rat brain capillaries. Our rationale for using a rat model was based on tissue availability, ease of handling, and availability of historical TBBPA toxicokinetic data. We found that TBBPA (1-1000 nM) exposure had no significant effect on multidrug resistance-associated protein 2 transport activity in either sex, suggesting TBBPA does not compromise the physical integrity of the BBB. However, low concentrations of TBBPA (1-100 nM) significantly decreased breast cancer resistant protein transport activity in both sexes. Additionally, TBBPA exposures (1-100 nM), elicited a sex-dependent response in P-gp transport: increasing transport activity in males and decreasing transport activity in females. All TBBPA dependent changes in transport activity were dose- and time-dependent. Inhibitors of either transcription or translation abolished the TBBPA dependent increases in male P-gp transport activity. Western blot and immunofluorescent assays confirmed the TBBPA dependent P-gp increases expression in males and decreases in females. Antagonizing PPAR-γ abolished the TBBPA dependent increases in males but not the decreases in females. However, the decreases in female P-gp transport were blocked by an ER-α antagonist. This work indicates that environmentally relevant concentrations of TBBPA (1-100 nM) alter ABC transporter function at the BBB. Moreover, permeability changes in the BBB can alter brain homeostasis, hinder central nervous system drug delivery, and increase the brain's exposure to harmful xenobiotic toxicants.
Collapse
Affiliation(s)
- Ronald E Cannon
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Andrew W Trexler
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Gabriel A Knudsen
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Rebecca A Evans
- University of North Carolina School of Medicine, Chapel Hill, North Carolina 27516
| | - Linda S Birnbaum
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute, National Institutes of Health, Research Triangle Park, North Carolina 27709
| |
Collapse
|
15
|
Kacew S, Hayes AW. Comment on "TBBPA and Its Alternatives Disturb the Early Stages of Neural Development by Interfering with the NOTCH and WNT Pathways". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13657-13659. [PMID: 30376301 DOI: 10.1021/acs.est.8b05091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Sam Kacew
- Mclaughlin Centre for Population Health Risk Assessment , University of Ottawa , Ottawa , Ontario Canada
- University of South Florida College of Public Health and Institute for Integrative Toxicology, Michigan State University , Tampa , Florida United States
| | - A Wallace Hayes
- University of South Florida College of Public Health and Institute for Integrative Toxicology, Michigan State University , Tampa , Florida United States
| |
Collapse
|
16
|
Yu Y, Ma R, Yu L, Cai Z, Li H, Zuo Y, Wang Z, Li H. Combined effects of cadmium and tetrabromobisphenol a (TBBPA) on development, antioxidant enzymes activity and thyroid hormones in female rats. Chem Biol Interact 2018; 289:23-31. [DOI: 10.1016/j.cbi.2018.04.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/08/2018] [Accepted: 04/23/2018] [Indexed: 12/12/2022]
|
17
|
Pecquet AM, Martinez JM, Vincent M, Erraguntla N, Dourson M. Derivation of a no-significant-risk-level for tetrabromobisphenol A based on a threshold non-mutagenic cancer mode of action. J Appl Toxicol 2018; 38:862-878. [PMID: 29441599 PMCID: PMC6099322 DOI: 10.1002/jat.3594] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 12/16/2022]
Abstract
A no‐significant‐risk‐level of 20 mg day–1 was derived for tetrabromobisphenol A (TBBPA). Uterine tumors (adenomas, adenocarcinomas, and malignant mixed Müllerian) observed in female Wistar Han rats from a National Toxicology Program 2‐year cancer bioassay were identified as the critical effect. Studies suggest that TBBPA is acting through a non‐mutagenic mode of action. Thus, the most appropriate approach to derivation of a cancer risk value based on US Environmental Protection Agency guidelines is a threshold approach, akin to a cancer safe dose (RfDcancer). Using the National Toxicology Program data, we utilized Benchmark dose software to derive a benchmark dose lower limit (BMDL10) as the point of departure (POD) of 103 mg kg–1 day–1. The POD was adjusted to a human equivalent dose of 25.6 mg kg–1 day–1 using allometric scaling. We applied a composite adjustment factor of 100 to the POD to derive an RfDcancer of 0.26 mg kg–1 day–1. Based on a human body weight of 70 kg, the RfDcancer was adjusted to a no‐significant‐risk‐level of 20 mg day–1. This was compared to other available non‐cancer and cancer risk values, and aligns well with our understanding of the underlying biology based on the toxicology data. Overall, the weight of evidence from animal studies indicates that TBBPA has low toxicity and suggests that high doses over long exposure durations are needed to induce uterine tumor formation. Future research needs include a thorough and detailed vetting of the proposed adverse outcome pathway, including further support for key events leading to uterine tumor formation and a quantitative weight of evidence analysis. A non‐mutagenic threshold mode of action for tetrabromobisphenol A was utilized to derive a no‐significant‐risk‐level of 20 mg day–1 for uterine tumors (adenomas, adenocarcinomas, and malignant mixed Müllerian combined) observed in female Wistar Han rats from a National Toxicology Program 2‐year bioassay. The most recent available techniques were utilized, including literature review, benchmark dose software, mode of action analysis, and threshold extrapolation. The derived no‐significant‐risk‐level aligns well with other available non‐cancer and cancer risk values based on the biology of these tumors.
Collapse
Affiliation(s)
- Alison M Pecquet
- Risk Science Center, Department of Environmental Health, College of Medicine, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45213, USA
| | - Jeanelle M Martinez
- Risk Science Center, Department of Environmental Health, College of Medicine, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45213, USA
| | - Melissa Vincent
- Risk Science Center, Department of Environmental Health, College of Medicine, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45213, USA
| | | | - Michael Dourson
- Risk Science Center, Department of Environmental Health, College of Medicine, University of Cincinnati, 160 Panzeca Way, Cincinnati, OH, 45213, USA
| |
Collapse
|
18
|
Pollock T, Weaver RE, Ghasemi R, deCatanzaro D. A mixture of five endocrine-disrupting chemicals modulates concentrations of bisphenol A and estradiol in mice. CHEMOSPHERE 2018; 193:321-328. [PMID: 29145094 DOI: 10.1016/j.chemosphere.2017.11.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/05/2017] [Accepted: 11/07/2017] [Indexed: 06/07/2023]
Abstract
Most people in developed countries are exposed to multiple endocrine-disrupting synthetic chemicals. We previously showed that a single dose of triclosan, tetrabromobisphenol A (TBBPA), butyl paraben, propyl paraben, or di(2-ethylhexyl) phthalate elevated concentrations of bisphenol A (BPA) in mice. Here we investigated whether concurrent exposure to lower doses of these five chemicals could modulate concentrations of bisphenol A (BPA) or the natural estrogen, 17β-estradiol (E2). CF1 mice were injected subcutaneously with 0.1 or 0.5 mg of one chemical, or a 0.5 mg mixture containing 0.1 mg of each of all five chemicals, then given dietary 50 μg kg-114C-BPA. The mixture elevated 14C-BPA concentrations in the lungs, muscle, uterus, ovaries, kidney, and blood serum of female mice. When administered alone, triclosan and TBBPA elevated 14C-BPA concentrations in the uterus, ovaries, and blood serum. In another experiment, CF1 mice were injected subcutaneously with the 0.5 mg mixture containing 0.1 mg of all five chemicals, then E2 was measured in urine 2-12 h later. The mixture elevated E2 at 8 h after injection in female mice. No treatments significantly altered concentrations of 14C-BPA or E2 in male mice. These data show that these endocrine-disrupting chemicals interact in vivo, magnifying one another's effects, consistent with inhibition of enzymes that are critical for estrogen metabolism. These findings highlight the importance of considering exposure to multiple chemicals when assessing health outcomes and determining regulatory exposure limits.
Collapse
Affiliation(s)
- Tyler Pollock
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
| | - Rachel E Weaver
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Ramtin Ghasemi
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
19
|
Knudsen GA, Hall SM, Richards AC, Birnbaum LS. TBBPA disposition and kinetics in pregnant and nursing Wistar Han IGS rats. CHEMOSPHERE 2018; 192:5-13. [PMID: 29091796 PMCID: PMC5696050 DOI: 10.1016/j.chemosphere.2017.10.122] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/16/2017] [Accepted: 10/23/2017] [Indexed: 06/07/2023]
Abstract
Tetrabromobisphenol-A (TBBPA) is a brominated flame retardant (BFR) commonly used in electronics to meet fire safety standards and has the largest worldwide production of any BFR. TBBPA has been detected in human breast milk and maternal/cord serum, indicating exposure to mothers, fetuses, and breastfeeding newborns although exposure to fetuses and newborns is poorly understood. Pregnant or nursing Wistar Han IGS rats were administered [14C]-TBBPA in a single dose (25 mg/kg, 2.5 μCi/kg) and euthanized between 0.5&24 h post dose to determine disposition in pregnant and nursing rats and their pups. Systemic exposure was largely unchanged between 1&8 h post dose in pregnant rats; [14C]-radioactivity in blood varied only slightly between 0.5&8 h (2.6 ± 0.6 → 2.6 ± 0.8 nmol-eq/mL) but was below the limit of detection at 24 h with an absorption half-life of 16min and elimination half-life of 17 h. Cmax was observed at 30min in lactating rats and concentrations fell steadily through 8 h. Plasma from pregnant rats contained a mixture of TBBPA and TBBPA-conjugates at 30min but only metabolites in subsequent samples. TBBPA was not detected in lactating dam plasma in this study. Placental concentrations increased through 8 h while whole-fetus Cmax occurred at 2 h post dose. In lactating animals, liver, uterus, and mammary time-concentration curves lagged slightly behind blood-concentration curves. It was clear from these studies that TBBPA is available to both the developing fetus and nursing pup following maternal exposure, and nursing pups are continuously exposed via contaminated milk produced by their mother. This research was supported in part by the Intramural Research Program of NIH/NCI.
Collapse
Affiliation(s)
- Gabriel A Knudsen
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, NC, USA.
| | - Samantha M Hall
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, NC, USA
| | - Alicia C Richards
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, NC, USA
| | - Linda S Birnbaum
- NCI Laboratory of Toxicology and Toxicokinetics, Research Triangle Park, NC, USA
| |
Collapse
|
20
|
Yu Y, Li L, Li H, Yu X, Zhang Y, Wang Q, Zhou Z, Gao D, Ye H, Lin B, Ma R. In vivo assessment of dermal adhesion, penetration, and bioavailability of tetrabromobisphenol A. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 228:305-310. [PMID: 28550799 DOI: 10.1016/j.envpol.2017.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Individuals are exposed to brominated flame retardants (BFRs), including tetrabromobisphenol A (TBBPA), on a daily basis because of their widespread usage. These compounds may have adverse effects on human health. In the present study, dermal absorption experiments were conducted in vivo to predict the adhesion, penetration, and bioavailability of TBBPA. TBBPA was administered to Wistar rats for 6 h by repeated dermal exposure at doses of 20, 60, 200, and 600 mg of TBBPA per kg of body weight (bw). The skin adhesion coefficient (AC) was calculated using a difference-value method and ranged from 0.12 to 3.25 mg/cm2 and 0.1 to 2.56 mg/cm2 for the male and female rats, respectively. The adhesion rate was 70.92%. According to Fick's first law of diffusion, the diffusion constant (D) was 1.4 × 10-4 cm2/h and the permeation coefficient (Kp) was 1.26 × 10-5 cm/h for TBBPA. TBBPA levels in the blood, urine, and feces of the male rats were significantly higher than those in the female rats. The dermal bioavailability of TBBPA was 24.71% for male rats and 20.05% for female rats 24 h after exposure.
Collapse
Affiliation(s)
- Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China.
| | - Liangzhong Li
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China
| | - Hongyan Li
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China
| | - Xiaowei Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China
| | - Yanping Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qiong Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Environmental Health and Related Product Safety, China CDC, Beijing 100021, China
| | - Zhixiang Zhou
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Dandan Gao
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hao Ye
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Bigui Lin
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China
| | - Ruixue Ma
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, China
| |
Collapse
|
21
|
Pollock T, Mantella L, Reali V, deCatanzaro D. Influence of Tetrabromobisphenol A, with or without Concurrent Triclosan, upon Bisphenol A and Estradiol Concentrations in Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:087014. [PMID: 28886593 PMCID: PMC5783675 DOI: 10.1289/ehp1329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND Humans are commonly exposed to multiple environmental chemicals, including tetrabromobisphenol A (TBBPA; a flame retardant), triclosan (an antimicrobial agent), and bisphenol A (BPA; polycarbonate plastics). These chemicals are readily absorbed and may interact with each other. OBJECTIVES We sought to determine whether TBBPA, given alone or in combination with triclosan, can modulate the concentrations of BPA and 17β-estradiol (E2). METHODS Female and male CF-1 mice were each given a subcutaneous injection of 0-27mg TBBPA, with or without concurrent 0.33mg triclosan, followed by dietary administration of 50μg/kg body weight 14C-BPA. Radioactivity was measured in blood serum and tissues through liquid scintillation counting. In subsequent experiments, female and male CF-1 mice were each given a subcutaneous injection of 0 or 1mg TBBPA and E2 was measured in urine 2-12 h after injection. RESULTS Doses as low as 1mg TBBPA significantly elevated 14C-BPA concentrations in the uterus and ovaries of females; in the testes, epididymides, vesicular-coagulating glands, and preputial glands of males; and in blood serum, heart, lungs, and kidneys of both sexes; urinary E2 concentrations were also elevated. Lower doses of TBBPA or triclosan that had no effects on their own elevated 14C-BPA concentrations when the two substances were given concurrently. CONCLUSION These data indicate that TBBPA, triclosan, and BPA interact in vivo, consistent with evidence that TBBPA and triclosan inhibit enzymes that are critical for BPA and E2 metabolism. https://doi.org/10.1289/EHP1329.
Collapse
Affiliation(s)
- Tyler Pollock
- Department of Psychology, Neuroscience & Behaviour, McMaster University , Hamilton, Ontario, Canada
| | - Leanna Mantella
- Department of Psychology, Neuroscience & Behaviour, McMaster University , Hamilton, Ontario, Canada
| | - Vanessa Reali
- Department of Psychology, Neuroscience & Behaviour, McMaster University , Hamilton, Ontario, Canada
| | - Denys deCatanzaro
- Department of Psychology, Neuroscience & Behaviour, McMaster University , Hamilton, Ontario, Canada
| |
Collapse
|
22
|
Hall SM, Coulter SJ, Knudsen GA, Sanders JM, Birnbaum LS. Gene expression changes in immune response pathways following oral administration of tetrabromobisphenol A (TBBPA) in female Wistar Han rats. Toxicol Lett 2017; 272:68-74. [PMID: 28300664 DOI: 10.1016/j.toxlet.2017.03.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 02/08/2017] [Accepted: 03/10/2017] [Indexed: 11/19/2022]
Abstract
Tetrabromobisphenol A (TBBPA) is a brominated flame retardant used globally at high volumes, primarily in the epoxy resin of circuit boards. It has been detected in the environment and in humans. The National Toxicology Program found that chronic oral TBBPA treatment of 250mg/kg and higher caused an increased incidence of uterine lesions in female Wistar Han rats. The present laboratory has previously reported changes in gene expression associated with estrogen homeostasis in liver and uterine tissue of adult female Wistar Han rats after five days of gavage with 250mg/kg of TBBPA. Microarray analysis of tissue from these same TBBPA-treated rats was performed to detect additional pathways perturbed by TBBPA. Microarray analysis of uterine tissue detected downregulation of genes in pathways of the immune response following TBBPA treatment. These results, along with validation of associated gene expression changes using droplet digital PCR, are reported here. Our findings suggest mechanisms that may be related to estrogen-mediated immunosuppression.
Collapse
Affiliation(s)
- Samantha M Hall
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, United States
| | - Sherry J Coulter
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, United States
| | - Gabriel A Knudsen
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, United States.
| | - J Michael Sanders
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, United States
| | - Linda S Birnbaum
- Laboratory of Toxicology and Toxicokinetics, National Cancer Institute at the National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC 27709, United States
| |
Collapse
|
23
|
Dunnick JK, Morgan DL, Elmore SA, Gerrish K, Pandiri A, Ton TV, Shockley KR, Merrick BA. Tetrabromobisphenol A activates the hepatic interferon pathway in rats. Toxicol Lett 2017; 266:32-41. [PMID: 27914987 PMCID: PMC5791538 DOI: 10.1016/j.toxlet.2016.11.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/11/2016] [Accepted: 11/25/2016] [Indexed: 11/25/2022]
Abstract
Tetrabromobisphenol A (TBBPA) is a widely used flame retardant in printed circuit boards, paper, and textiles. In a two-year study, TBBPA showed evidence of uterine tumors in female Wistar-Han rats and liver and colon tumors in B6C3F1 mice. In order to gain further insight into early gene and pathway changes leading to cancer, we exposed female Wistar Han rats to TBBPA at 0, 25, 250, or 1000mg/kg (oral gavage in corn oil, 5×/week) for 13 weeks. Because at the end of the TBBPA exposure period, there were no treatment-related effects on body weights, liver or uterus lesions, and liver and uterine organ weights were within 10% of controls, only the high dose animals were analyzed. Analysis of the hepatic and uterine transcriptomes showed TBBPA-induced changes primarily in the liver (1000mg/kg), with 159 transcripts corresponding to 132 genes differentially expressed compared to controls (FDR=0.05). Pathway analysis showed activation of interferon (IFN) and metabolic networks. TBBPA induced few molecular changes in the uterus. Activation of the interferon pathway in the liver occurred after 13-weeks of TBBPA exposure, and with longer term TBBPA exposure this may lead to immunomodulatory changes that contribute to carcinogenic processes.
Collapse
Affiliation(s)
- J K Dunnick
- Toxicology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - D L Morgan
- NTP Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - S A Elmore
- Cellular and Molecular Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - K Gerrish
- Molecular Genomics Core, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - A Pandiri
- Cellular and Molecular Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - T V Ton
- Cellular and Molecular Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - K R Shockley
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - B A Merrick
- Biomolecular Screening Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| |
Collapse
|
24
|
Tetrabromobisphenol-A induces apoptotic death of auditory cells and hearing loss. Biochem Biophys Res Commun 2016; 478:1667-73. [DOI: 10.1016/j.bbrc.2016.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/01/2016] [Indexed: 01/22/2023]
|
25
|
Knudsen GA, Hughes MF, McIntosh KL, Sanders JM, Birnbaum LS. Estimation of tetrabromobisphenol A (TBBPA) percutaneous uptake in humans using the parallelogram method. Toxicol Appl Pharmacol 2015; 289:323-9. [PMID: 26387765 DOI: 10.1016/j.taap.2015.09.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/08/2015] [Accepted: 09/15/2015] [Indexed: 11/19/2022]
Abstract
Tetrabromobisphenol A (TBBPA) is currently the world's highest production volume brominated flame retardant. Humans are frequently exposed to TBBPA by the dermal route. In the present study, a parallelogram approach was used to make predictions of internal dose in exposed humans. Human and rat skin samples received 100 nmol of TBBPA/cm(2) skin and absorption and penetrance were determined using a flow-through in vitro system. TBBPA-derived [(14)C]-radioactivity was determined at 6h intervals in the media and at 24h post-dosing in the skin. The human skin and media contained an average of 3.4% and 0.2% of the total dose at the terminal time point, respectively, while the rat skin and media contained 9.3% and 3.5%, respectively. In the intact rat, 14% of a dermally-administered dose of ~100 nmol/cm(2) remained in the skin at the dosing site, with an additional 8% reaching systemic circulation by 24h post-dosing. Relative absorption and penetrance were less (10% total) at 24h following dermal administration of a ten-fold higher dose (~1000 nmol/cm(2)) to rats. However, by 72 h, 70% of this dose was either absorbed into the dosing-site skin or had reached systemic circulation. It is clear from these results that TBBPA can be absorbed by the skin and dermal contact with TBBPA may represent a small but important route of exposure. Together, these in vitro data in human and rat skin and in vivo data from rats may be used to predict TBBPA absorption in humans following dermal exposure. Based on this parallelogram calculation, up to 6% of dermally applied TBBPA may be bioavailable to humans exposed to TBBPA.
Collapse
Affiliation(s)
- Gabriel A Knudsen
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA.
| | - Michael F Hughes
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | | | - J Michael Sanders
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA
| | - Linda S Birnbaum
- NCI at NIEHS, 111 T W Alexander Dr., Research Triangle Park, NC, USA
| |
Collapse
|