Cadmium induced lipid peroxidation and effects on glutathione dependent enzymes in tissues of Labeo rohita

Abstract

The present study is aimed to assess the oxidative stress biomarker in kidney and liver of Labeo rohita exposed to the sub-lethal concentrations of cadmium chloride. The fishes were exposed to 33.6, 67.1 and 100.6 mg L−1 concentrations of cadmium chloride up to 96 h duration and the oxidative stress was monitored through the levels of lipid peroxidation (LPO), reduced glutathione and activities of antioxidant enzymes, viz. glutathione peroxidase (GPx) and glutathione-S-transferase (GST). The malondialdehyde content, level of reduced glutathione and activities of antioxidant enzymes were significantly (p < 0.05) elevated in treated groups with the increasing concentration and exposure duration. Regression analysis showed a significant positive correlation between elevated levels of LPO and reduced glutathione (r2 = 0.999 and 0.991 in liver and kidney, respectively) as well as glutathione and its dependent enzymes (r2 = 0.999 and 0.996 with GPx and GST, respectively) at 96 h post-exposure in both the tissues of L. rohita. Further, the increased level of reduced glutathione and activity of glutathione dependent enzymes were not effective in reducing the cadmium induced oxidative stress in the fish. These assays may be employed to monitor oxidative stress mediated macro-molecular damage in aquatic organisms due to heavy metal exposure.