Toxic Effects of 4-Bromodiphenyl Ether (BDE-3) on Antioxidant Enzymes, Cell Viability, Histology and Biomolecules in Zebrafish Embryo-Larvae.

Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants that are being used widely in industrial and consumers products such as plastics, electronics, furniture, textiles and so forth. They can undergo debromination process to form less brominated diphenyl ethers, which are bioaccumulative, more volatile and more toxic in nature. The current study was conducted to reveal the biochemical, apoptotic, histopathological, ultrastructural and biomolecular (ATR-FTIR) toxicity of 4-bromodiphenyl ether (BDE-3) in zebrafish larvae. After the 96-h LC₅₀ determination, the zebrafish embryos were exposed to sublethal concentrations of BDE-3, that is, 0.79 and 1.59 mg/L. The MDA content was found to be significantly increased in BDE-3 exposed larvae whereas the FRAP activity was found to be decreased. The catalase (CAT), glutathione-S-transferase (GST) and acetylcholinesterase (AChE) activity were observed to be significantly increased, and a decreased superoxide dismutase (SOD) activity was reported after the BDE-3 exposure in zebrafish larvae. The cell viability was reported to be decreased in zebrafish larvae after BDE-3 exposure. Histopathological and ultrastructural alterations were also observed in the BDE-3 exposed zebrafish larvae. The changes in the biomolecules such as DNA and protein were also revealed via ATR-FTIR analysis. The present investigation will help to understand the toxic nature of less brominated diphenyl ethers and could be utilised to assess environmental risk.