Modulation of antioxidant and detoxification responses mediated by lipoic acid in the fish Corydoras paleatus (Callychthyidae)

Abstract

Lipoic acid (LA) has been reported as a potential therapeutic agent due its antioxidants proprieties. It was considered its effect in different organs (gills, brain, muscle and liver) of the fish Corydoras paleatus(Callychthyidae). LA (70 mg/kg of body mass) was added to a commercial fish diet, organisms being fed daily (1% body weight). Sixty animals (mean mass: 2.37±0.09 g) were placed randomly in aquariums and received (+LA) or not (−LA) lipoic acid enriched diet during four weeks. After, fish were killed and the brain, muscle, gills and liver were dissected. LA treatment reduced significantly (pb0.05) reactive oxygen species concentration in brain and increased (pb0.05) glutamate-cysteine ligase activity in brain and liver of the same experimental group. LA fed organisms showed higher (pb0.05) brain glutathione-S-transferase activity, indicating that LA improves the detoxification and antioxidant capacity face components that waste glutathione in phase II reactions. A conspicuous reduction of protein oxidationwas observed inmuscle and liver of +LA organisms, indicating that the treatment was also effective in reducing oxidative stress parameters.