title: Comparative antioxidant status in freshwater fish Carassius auratus exposed to six current-use brominated flame retardants: a combined experimental and theoretical study.
abstract: Decabromodiphenyl ether (BDE-209) and several non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), such as tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB) and pentabromotoluene (PBT), are persistent halogenated contaminants ubiquitously detected in aquatic systems. However, data on comparative toxicological effects of these BFRs are lacking for fish. In this study, a combined experimental and theoretical approach was used to compare and analyze the effects of these BFRs on biochemical biomarkers in liver of Carassius auratus injected intraperitoneally with different doses (10 and 100mg/kg) for 7, 14 and 30 days. Oxidative stress was evoked evidently for the prolonged exposure, represented by the significantly altered indices (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response (IBR) index ranked biotoxicity as: PBT>HBB>HBCD>TBBPA>BDE-209>DBDPE. Quantum chemical calculations (electronic parameters, frontier molecular orbitals, and Wiberg bond order) were performed for theoretical analysis. Notably, some descriptors were correlated with the toxicity order, probably implying the existence of a potential structure-activity relationship when more BFRs were included. Besides, theoretical calculations also provided some valuable information regarding the molecular characteristics and metabolic pathways of these current-use BFRs, which may facilitate the understanding on their environmental behavior and fate. Overall, this study adopted a combined experimental and theoretical method for the toxicological determination and analysis of the BFRs, which may also be considered in future ecotoxicological studies.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Jiangsu, Nanjing 210046, PR China.
authors.forename: Mingbao
authors.initials: M
authors.lastname: Feng
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Qu
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Liansheng
authors.initials: L
authors.lastname: Wang
authors.forename: Zunyao
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001966:Bromine / Q000737:chemistry / Q000633:toxicity; D004789:Enzyme Activation / Q000187:drug effects; D005411:Flame Retardants / Q000633:toxicity*; D005618:Fresh Water; D006054:Goldfish / Q000502:physiology*; D008958:Models, Molecular; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000032:analysis / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D005411:Flame Retardants; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases; D001966:Bromine
keywords: Brominated flame retardant; DFT calculations; Integrated biomarker response; Oxidative stress; Toxicity order