The effect of lipoic acid on antioxidant status and lipid peroxidation in rats exposed to chronic restraint stress.

This study was designed to investigate effect of alpha-lipoic acid (LA) on lipid peroxidation, nitric oxide production and antioxidant systems in rats exposed to chronic restraint stress. Twenty four male Wistar rats, aged three months, were divided into four groups: control (C), the group treated with LA (L), the group exposed to restraint stress (S) and the group exposed to stress and treated with LA (LS). Restraint stress was applied for 21 days (1 h/day) and LA (100 mg/kg/day) was injected intraperitonally to the L and LS groups for the same period. Restraint stress significantly decreased brain copper/zinc superoxide dismutase (Cu,Zn-SOD) and brain and retina glutathione peroxidase (GSH-Px) and catalase (CAT) activities compared with the control group. Thiobarbituric acid reactive substances (TBARS), nitrite and nitrate levels were significantly increased in the tissues of the S group compared with the C group. LA produced a significant decrease in brain and retina TBARS, nitrite and nitrate levels of the L and LS groups compared to their corresponding control groups. LA increased all enzyme activities in the tissues of the LS group compared to the S group. Our study indicated that LA is an ideal antioxidant candidate for the prevention of stress-induced lipid peroxidation.