Neurotoxicological Effects of 4‐Bromodiphenyl Ether in Adult Zebrafish: DNA Damage, Oxidative Stress, Histology and Biomolecular Alterations

Polybrominated diphenyl ethers (PBDEs) have emerged as a major environmental pollutant and are widely employed in different industrial and consumer products. The 4-bromodipehnyl ether (BDE-3) is the most common and fundamental mono-BDE which is being used as a flame retardant in different products. The present investigation was conducted to evaluate the neurotoxicological effects of BDE-3 via. DNA damage, oxidative stress biomarkers, apoptotic, histopathological and ATR-FTIR analysis in brain of adult zebrafish. The 96 h LC₅₀ was determined for zebrafish adult and further zebrafish were exposed to sublethal concentrations that is 0.48 mg/L (¼ LC₅₀) and 0.97 mg/L (½ LC₅₀) of BDE-3 for 96 h. The DNA damage in terms of tail length (TL), tail intensity (TI), tail moment (TM) and olive tail moment (OTM) was found to be significantly elevated in a concentration and duration dependant manner. A significantly increased MDA content, GST and AChE activity was reported in the brain tissue after BDE-3 exposure whereas a depleted SOD activity was observed. The histological analysis revealed the different types of alterations in brain tissue. The viable cell frequency was found to be decreased whereas apoptotic and necrotic cell frequency were found to be significantly increased in BDE-3 exposed groups. The structural alterations in different biomolecules were assessed via ATR-FTIR in brain tissue. The results of the present study inflict the accelerated lipid peroxidation, altered enzymatic activity, enhanced DNA damage, disrupted histology, cell viability and biomolecular alterations in brain of zebrafish even at sub-lethal concentrations, indicating the neurotoxic nature of BDE-3.