Abstract
The purpose of this study was to examine the effects of antioxidants, including vitamin C, chitosan or a combination of both, on oxidative stress markers in muscles, as edible tissues of fish, exposed to paraquat. Fish exposed to 0.02 mg/L paraquat for 21 days were fed different diets: a normal diet, a diet containing chitosan (1000 mg/kg diet), a diet with vitamin C (1000 mg/kg diet) or both vitamin C and chitosan. Oxidative stress markers, including the activity of catalase, total antioxidant and malondialdehyde (MDA), as well as biochemical parameters including the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase (CPK), lactate dehydrogenase (LDH) and acetylcholinesterase (AChE), were measured in muscles. Fish exposure to paraquat increased LDH, CPK, catalase and MDA activity significantly, while it significantly decreased AST, ALT and AChE activity and total antioxidant capacity in muscles. Administration of vitamin C, combined with chitosan, to fish exposed to paraquat was effective in regulating AChE, AST, ALT, LDH, CPK and catalase activity. A significant increase in the total antioxidant status and a significant decrease in MDA levels were observed in fish fed chitosan-vitamin C complex. In conclusion, it is suggested that combined supplementation with vitamin C and chitosan may improve the detoxification system in the muscles of fish and protect common carp from paraquat toxicity.