Kaur_2015_Comp.Biochem.Physiol.C.Toxicol.Pharmacol_167_108

The aim of the present study was to evaluate effect of a highly toxic azo dye, acid black (AB) (CI: 20470, 96h LC50=10mg/L) on the biochemical responses of Labeo rohita. Antioxidant/detoxification enzymes such as glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), acid phosphatase (AcP), alkaline phosphatase (AKP), alanine transaminase (ALT) and aspartate transaminase (AST) were determined in liver, kidney, gill, muscle and brain of L. rohita after 96h exposure to 6mg/L (LC10), 8mg/L (LC30) and 10mg/L (LC50) of dye with an aim to find out the target tissue and biomarker enzyme for AB. The fish were then kept for a recovery period of 90days, and activity of the selected enzymes was determined at the end of this period. Present dye altered the activities of all these enzymes in the selected tissues of the experimental fish in a dose-dependent manner. SOD was the maximally affected enzyme, and liver was the most affected tissue. The results indicate that AB is very toxic to L. rohita as there was a significant effect of even 6mg/L dose of the dye and the toxicity prolonged for a long time because the fish was not able to recover from the stress even 90days after the exposure. The study suggests that SOD can be used as a biomarker enzyme and liver is the target tissue for AB.