protective effects of vitamin c and chitosan against cadmium-induced oxidative stress in the liver of common carp (cyprinuscarpio)

background: cadmium (cd) intoxication can cause oxidative stress and involve the antioxi-dant defense system in hepatocytes. administration of vitamin c, chitosan, or a combination of both may prevent cd-induced oxidative damage. methods:cyprinus carpio were distributed into six groups. the control group received normal feed (group i). group ii was exposed to 0.2 mg.l-1 cadmium chloride. group iii were fed 1000 mg chitosan per 1 kg feed. group iv was exposed to 0.2 mg.l-1 cadmium chloride and fed with1000 mg chitosan per 1 kg feed while group v was exposed to 0.2 mg.l-1 cadmium chlo-ride and was fed with 1000 mg vitamin c per 1 kg feed. group vi, however, was exposed to 0.2 mg.l-1 cadmium chloride and was fed with 1000 mg vitamin c combined with 1000 mg chi-tosanper 1 kg feed. after 21 days of experiment, activities of hepatic enzymes and oxidative stress biomarkers were evaluated. results:exposure to cdcl2 caused a significant increase in malondialdehyde levels and al-tered alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase activities in liver tissues. hepatic antioxidant capacity, catalase, and glucose-6-phosphate dehydrogenase activities significantly decreased in fishes exposed to cdcl2 as compared to the control group. treatment with vitamin c and vitamin c combined with chitosan significantly ameliorated these changes. conclusion:the present findings suggest that the administration of chitosan failed to restore biochemical parameters to normal levels. however, these findings demonstrate that vitamin c and vitamin c combined with chitosan protect the fish against the toxic effects of cdcl2 on the examined biochemical parameters in liver tissues.