Transcriptional, biochemical and histological alterations in adult zebrafish (Danio rerio) exposed to benzotriazole ultraviolet stabilizer-328

Abstract

The occurrence of Benzotriazole Ultraviolet Stabilizer-328 (BUV-328) in different environmental and biological matrices is of immediate environmental concern. In the present study, we evaluated the toxicity of BUV-328 in zebrafish liver tissues to understand the role of oxidative damage in hepatotoxicity. Adult zebrafish were exposed to 0.01, 0.1 and 1 mg/L of BUV-328. At the end of 14, 28 and 42 days, liver tissues were examined for the responses of antioxidant enzymes, gene expression and histopathological alterations. The results indicated that superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were elevated at concentrations of 0.1 and 1 mg/L on 14th and 28th day. Glutathione S-transferase (GST) activity and malondialdehyde (MDA) levels were elevated in all the treated groups. The transcriptional levels of genes encoding sod, cat, gpx and gst enzymes were increased at 14th day and then declined (except sod on 28th day). Moreover, transcription of cyp1a and hsp70 were up-regulated throughout the study period. Histopathological lesions such as hypertrophy, cellular and nuclear enlargement, cytoplasmic and nuclear degeneration, necrosis with pyknotic nuclei, lipid and cytoplasmic vacuolization and nuclear displacement to the periphery were found to be increased with the dose and exposure duration. In brief, our findings indicate that even a low dose of BUV-328 is toxic to induce oxidative stress and liver damage in zebrafish over a long period of exposure.