vitamin c and chitosan alleviate toxic effects of paraquat on some biochemical parameters in hepatocytes of common carp

background: paraquat is nonselective bipyridyl herbicide that induces hepatotoxicity through oxidative stress. vitamin c and chitosan have antioxidant as well as radical scavenger properties and show protective effects against reactive oxygen species (ros). in the present study, hepatoprotective effects of chitosan and vitamin c were evaluated in common carp exposed to paraquat. methods: while exposed to 0.02 mg. l-1paraquat for 21 days, common carp were fed chitosan (1000 mg. kg‑1 feed), vitamin c (1000 mg. kg-1 feed), and vitamin c combined with chitosan. at the end of the experiment, activities of hepatic enzymes and oxidative stress biomarkers were evaluated. results: paraquat induces changes in the activity of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase and lactate dehydrogenase in liver tissue of fish. however, these enzymes were restored to normal levels in fish fed with vitamin c and vitamin c combined with chitosan following exposure to paraquat. increased levels of malondialdehyde were observed in liver after exposure to paraquat, while glucose-6-phosphate dehydrogenase and catalase activities and the total antioxidant levels decreased. administration of vitamin c combined with chitosan significantly reduced malondialdehyde levels and increased the total antioxidant capacity, glucose-6-phosphate dehydrogenase and catalase activities. conclusion: administration of vitamin c is effective in reducing liver toxicity of paraquat. however, administrating both vitamin c and chitosan is more effective. in other words, chitosan and vitamin c have a synergic effect. they could be used as hepatoprotective agents against paraquat-induced hepatotoxicity in fish.