Effect of chronic restraint stress and alpha-lipoic acid on lipid peroxidation and antioxidant enzyme activities in rat peripheral organs.

OBJECTIVES: The aim of this study was to evaluate the effect of chronic restraint stress and alpha-lipoic acid (LA) administration on lipid peroxidation and antioxidant enzyme activities in rat peripheral organs. METHODS: Forty male wistar rats, aged 3 months were randomized to one of the following groups: control, restraint stress, LA treated and restraint stress+LA treated. Chronic restraint stress was applied for 21 days (1h/day) and LA (100 mg/kg/day) was administered intraperitoneally for the same period. RESULTS: Restraint stress had no statistically significant effect on lipid peroxidation, copper/zinc superoxide dismutase (Cu/Zn SOD), catalase (CAT) and glutathione peroxidase (GPx) activity in rat liver and heart, when compared to the control group. Lipid peroxidation, determined by measuring malondialdehyde (MDA) levels, was found to be increased in the kidney of restraint stress treated rats, compared to controls. Restraint stress-induced lipid peroxidation in the kidney was significantly decreased via LA treatment. Administration of LA also enhanced GPx and decreased Cu/Zn SOD activity in rat kidney, liver and heart, compared to the control group. CONCLUSIONS: The presented data shows that LA is a protective agent against restraint stress--the inducer of lipid peroxidation in the kidney. These findings also suggest that LA-induced changes in antioxidant enzyme activities in rat peripheral organs may contribute to their versatile effects observed in vivo.