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Hou R, Huang C, Rao K, Xu Y, Wang Z. Characterized in Vitro Metabolism Kinetics of Alkyl Organophosphate Esters in Fish Liver and Intestinal Microsomes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3202-3210. [PMID: 29439571 DOI: 10.1021/acs.est.7b05825] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Tris(2-butoxyethyl) phosphate (TBOEP) and tris( n-butyl) phosphate (TNBP) are the most commonly used alkyl organophosphate esters (alkyl-OPEs), and they increasingly accumulate in organisms and create potential health hazards. This study examined the metabolism of TNBP and TBOEP in Carassius carassius liver and intestinal microsomes and the production of their corresponding monohydroxylated and dealkylated metabolites. After 140 min of incubation with fish liver microsomes, the rapid depletion of TNBP and TBOEP were both best fitted to the Michaelis-Menten model (at administrated concentrations ranging from 0.5 to 200 μM), with a CLint (intrinsic clearance) of 3.1 and 3.9 μL·min-1·mg-1 protein, respectively. But no significant ( P > 0.05) biotransformation was observed for these compounds in intestinal microsomes at any administrated concentrations. In fish liver microsomes assay, bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) and bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate (3-OH-TBOEP) were the most abundant metabolites of TBOEP, and dibutyl-3-hydroxybutyl phosphate (3-OH-TNBP) was the predominant metabolite of TNBP. Similarly, the apparent Vmax values (maximum metabolic rate) of BBOEHEP and 3-OH-TNBP were also respectively highest among those of other metabolites. Further inhibition studies were conducted to identify the specific cytochrome P450 (CYP450) isozymes involved in the metabolism of TNBP and TBOEP in liver microsomes. It was confirmed that CYP3A4 and CYP1A were the significant CYP450 isoforms catalyzing the metabolism of TNBP and TBOEP in fish liver microsomes. Overall, this study emphasized the importance of hydroxylated metabolites as biomarkers for alkyl-OPEs exposure, and further research is needed to validate the in vivo formation and toxicological implications of these metabolites.
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Affiliation(s)
- Rui Hou
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Chao Huang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Kaifeng Rao
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
| | - Yiping Xu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
| | - Zijian Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
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102
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Toxicogenomics of the flame retardant tris (2-butoxyethyl) phosphate in HepG2 cells using RNA-seq. Toxicol In Vitro 2018; 46:178-188. [DOI: 10.1016/j.tiv.2017.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/10/2017] [Accepted: 10/08/2017] [Indexed: 11/20/2022]
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103
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Campo J, Lorenzo M, Cammeraat ELH, Picó Y, Andreu V. Emerging contaminants related to the occurrence of forest fires in the Spanish Mediterranean. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 603-604:330-339. [PMID: 28633110 DOI: 10.1016/j.scitotenv.2017.06.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/01/2017] [Accepted: 06/01/2017] [Indexed: 05/21/2023]
Abstract
Forest fires can be a source of contamination because, among others, of the use of chemicals to their extinction (flame retardants, FRs), or by the production of Polycyclic Aromatic Hydrocarbons (PAHs) derived from high temperature alteration of organic matter. Up to our knowledge, this study is the first to assess the direct (PAHs 16 on the USA EPA's priority list), and indirect [tri- to hepta- brominated diphenyl ethers (PBDEs), organophosphorus flame retardants (PFRs) and perfluoroalkyl substances (PFASs)] contamination related to forest fires. The abundance and distribution of these contaminants were monitored on two Mediterranean hillslopes, one burned and one unburned, near Azuébar (SE Spain). Samples were taken in the foot, middle, and top of the slope, at two depths, and in two environments (under canopy and bare soil). Sediments were collected from sediment fences after erosive rainfall events. Most of the screened compounds were found in both, burned and control hillslopes, though significant differences were found between both. In burned soil, low concentrations of PBDEs (maximum ΣPBDEs: 7.3ngg-1), PFRs (664.4ngg-1) and PFASs (56.4ngg-1) were detected in relation to PAHs (Σ16 PAHs=1255.3ngg-1). No significant influence of the hillslope position was observed for any of the contaminants but differences based on depth and vegetation presence tended to be significant, particularly for the PAHs. After the first erosive event, concentrations of PBDEs and PAHs were higher in sediment than in soil (ΣPBDEs: 17.8ngg-1 and Σ16 PAHs=3154.2ngg-1) pointing out the importance of connectivity processes, especially shortly after fire.
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Affiliation(s)
- Julian Campo
- Environmental Forensic and Landscape Chemistry Research Group, Desertification Research Centre - CIDE, (Spanish Council for Scientific Research, University of Valencia, Generalitat Valenciana), Carretera Moncada - Náquera km 4.5 (Campus IVIA), 46113 Moncada, Valencia, Spain; Department of Ecosystem and Landscape Dynamics, Institute for Biodiversity and Ecosystems Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
| | - María Lorenzo
- Food and Environmental Safety Research Group (SAMA - UV), Desertification Research Centre - CIDE, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Erik L H Cammeraat
- Department of Ecosystem and Landscape Dynamics, Institute for Biodiversity and Ecosystems Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Yolanda Picó
- Food and Environmental Safety Research Group (SAMA - UV), Desertification Research Centre - CIDE, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Vicente Andreu
- Environmental Forensic and Landscape Chemistry Research Group, Desertification Research Centre - CIDE, (Spanish Council for Scientific Research, University of Valencia, Generalitat Valenciana), Carretera Moncada - Náquera km 4.5 (Campus IVIA), 46113 Moncada, Valencia, Spain
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104
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Giraudo M, Dubé M, Lépine M, Gagnon P, Douville M, Houde M. Multigenerational effects evaluation of the flame retardant tris(2-butoxyethyl) phosphate (TBOEP) using Daphnia magna. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 190:142-149. [PMID: 28711770 DOI: 10.1016/j.aquatox.2017.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 06/07/2023]
Abstract
Tris(2-butoxyethyl) phosphate (TBOEP) is an organophosphate ester used as substitute following the phase-out of brominated flamed retardants. Because of its high production volume and its use in a broad range of applications, this chemical is now frequently detected in the environment and biota. However, limited information is available on the long-term effects of TBOEP in aquatic organisms. In this study, Daphnia magna were exposed over three 21d generations to an environmentally relevant concentration of TBOEP (10μg/L) and effects were evaluated at the gene transcription, protein, and life-history (i.e., survival, reproduction and growth) levels. Chronic exposure to TBEOP did not impact survival or reproduction of D. magna but affected the growth output. The mean number of molts was also found to be lower in daphnids exposed to the chemical compared to control for a given generation, however there were no significant differences over the three generations. Molecular responses indicated significant differences in the transcription of genes related to growth, molting, ecdysteroid and juvenile hormone signaling, proteolysis, oxidative stress, and oxygen transport within generations. Levels of mRNA were also found to be significantly different for genes known to be involved in endocrine-mediated mechanisms such as reproduction and growth between generations F0, F1, and F2, indicating effects of parental exposure on offspring. Transcription results were supported by protein analyses with the significant decreased in catalase (CAT) activity in F1 generation, following the decreased transcription of cat in the parental generation. Taken together, these multi-biological level results suggest long-term potential endocrine disruption effects of TBOEP in D. magna exposed to an environmentally relevant concentration. This study highlights the importance of using chronic and multigenerational biological evaluation to assess risks of emerging chemicals.
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Affiliation(s)
- Maeva Giraudo
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada
| | - Maxime Dubé
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada
| | - Mélanie Lépine
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada
| | - Pierre Gagnon
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada
| | - Mélanie Douville
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada
| | - Magali Houde
- Environment and Climate Change Canada, Aquatic Contaminants Research Division, Water Science and Technology Directorate,105 McGill Street, Montreal, QC, H2Y 2E7, Canada.
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105
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Altenhofen S, Nabinger DD, Wiprich MT, Pereira TCB, Bogo MR, Bonan CD. Tebuconazole alters morphological, behavioral and neurochemical parameters in larvae and adult zebrafish (Danio rerio). CHEMOSPHERE 2017; 180:483-490. [PMID: 28431386 DOI: 10.1016/j.chemosphere.2017.04.029] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/05/2017] [Accepted: 04/07/2017] [Indexed: 05/27/2023]
Abstract
In this study, we evaluated the effects of tebuconazole on morphology and exploratory larvae behavior and adult locomotion. Furthermore, we analyzed the effects of this fungicide on AChE activity and gene expression in zebrafish larvae and in the adult zebrafish brain. Tebuconazole (4 mg/L) increased the ocular distance in larvae and reduced the distance travelled, absolute turn angle, line crossing and time outside area in exposed larvae. Moreover, adult zebrafish that were exposed to this fungicide (4 and 6 mg/L) showed a decrease in distance travelled and mean speed when compared to the control group. However, tebuconazole did not alter the number of line crossings or time spent in the upper zone. Tebuconazole inhibited AChE activity at concentrations of 4 mg/L for larvae and 4 and 6 mg/L in the adult zebrafish brain. However, this fungicide did not alter AChE gene expression in the adult zebrafish brain but increased AChE mRNA transcript levels in larvae. These findings demonstrated that tebuconazole could modulate the cholinergic system by altering AChE activity and that this change may be associated with the reduced locomotion of these animals.
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Affiliation(s)
- Stefani Altenhofen
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Neuroquímica e Psicofarmacologia, Porto Alegre, RS, Brazil
| | - Débora Dreher Nabinger
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Neuroquímica e Psicofarmacologia, Porto Alegre, RS, Brazil
| | - Melissa Talita Wiprich
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Neuroquímica e Psicofarmacologia, Porto Alegre, RS, Brazil
| | - Talita Carneiro Brandão Pereira
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Biologia Genômica e Molecular, Porto Alegre, RS, Brazil
| | - Maurício Reis Bogo
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Biologia Genômica e Molecular, Porto Alegre, RS, Brazil
| | - Carla Denise Bonan
- PUCRS, Faculdade de Biociências, Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Neuroquímica e Psicofarmacologia, Porto Alegre, RS, Brazil.
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106
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Lipscomb ST, McClelland MM, MacDonald M, Cardenas A, Anderson KA, Kile ML. Cross-sectional study of social behaviors in preschool children and exposure to flame retardants. Environ Health 2017; 16:23. [PMID: 28274271 PMCID: PMC5343384 DOI: 10.1186/s12940-017-0224-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 02/22/2017] [Indexed: 05/18/2023]
Abstract
BACKGROUND Children are exposed to flame retardants from the built environment. Brominated diphenyl ethers (BDE) and organophosphate-based flame retardants (OPFRs) are associated with poorer neurocognitive functioning in children. Less is known, however, about the association between these classes of compounds and children's emotional and social behaviors. The objective of this study was to determine if flame retardant exposure was associated with measurable differences in social behaviors among children ages 3-5 years. METHODS We examined teacher-rated social behaviors measured using the Social Skills Improvement Rating Scale (SSIS) and personal exposure to flame retardants in children aged 3-5 years who attended preschool (n = 72). Silicone passive samplers worn for 7 days were used to assess personal exposure to 41 compounds using gas chromatography-mass spectrophotometer. These concentrations were then summed into total BDE and total OPFR exposure prior to natural log transformation. Separate generalized additive models were used to evaluate the relationship between seven subscales of the SSIS and lnΣBDE or lnΣOPFR adjusting for other age, sex, adverse social experiences, and family context. RESULTS All children were exposed to a mixture of flame retardant compounds. We observed a dose dependent relationship between lnΣOPFR and two subscales where children with higher exposures were rated by their preschool teachers as having less responsible behavior (p = 0.07) and more externalizing behavior problems (p = 0.03). Additionally, children with higher lnΣBDE exposure were rated by teachers as less assertive (p = 0.007). CONCLUSIONS We observed a cross-sectional association between children's exposure to flame retardant compounds and teacher-rated social behaviors among preschool-aged children. Children with higher flame retardant exposures exhibited poorer social skills in three domains that play an important role in a child's ability to succeed academically and socially.
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Affiliation(s)
| | - Megan M. McClelland
- College of Public Health and Human Sciences, Oregon State University, 15 Milam Hall, Corvallis, OR 97331 USA
| | - Megan MacDonald
- College of Public Health and Human Sciences, Oregon State University, 15 Milam Hall, Corvallis, OR 97331 USA
| | | | - Kim A. Anderson
- Oregon State University, College of Agricultural Sciences, Corvallis, OR USA
| | - Molly L. Kile
- College of Public Health and Human Sciences, Oregon State University, 15 Milam Hall, Corvallis, OR 97331 USA
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