Mercuric Chloride Toxicity and Its Influence on Enzymatic Antioxidants – A Study on Zebra Fish Model (Danio rerio)

Enzymatic antioxidant was determined to establish a possible environmental impact on toxic metal in fish Danio rerio. Alterations in the antioxidant cellular systems have often been proposed as biomarkers of pollutant-mediated toxicity. This prompted us to investigate the activities of catalase, superoxide dismutase, Reduce Glutathione in the liver of mercuric chloride treated zebra fish. The fishes were exposed to Mercuric chloride for a period of 96 hours. The LC50 value was obtained by using probit software based on 50% of fish that died at each concentration. Mortality was recorded at 24th, 48th, 72nd and 96th hours. Various concentrations of Mercuric chloride (70µg/ml and 250µg/ml as 1st stage, 20mg/ml, 30mg/ml, 50mg/ml and 60mg/ml as 2nd stage, and 5mg/ml, 2.5mg/ml, 2mg/ml, 1mg/ml and 0.5mg/ml as 3rd stage) were injected into the tanks containing the fishes for 96 hours with a photoperiod of 12hours. After the 96 hours, Liver of the fishes was collected in an Eppendorf and stored at -20ºC for further analysis. In the present study, increase in SOD activity as well as Catalase activity and a decrease in glutathione activity were registered.