Effects of α-Lipoic Acid on Liver Oxidative Damage Induced by Hyperglycemia in GK Rats

[Objective]To investigate the protective effects of α-lipoic acid(α-LA) on sucrose-induced liver oxidative damages in Goto-Kakizaki(GK) rats.[Methods]Thirty-six eight-week-old male GK rats were randomly divided into 6 groups:1 negative control(no treatment),1 positive control(30% sucrose solution),and 4 experimental(30% sucrose solution+daily α-LA supplementation of 25,50,75,or 100mg/kg by gavage,respectively) groups.Nine weeks after the interference,changes in lipid peroxidation concentrations,antioxidases activity,and reactive oxygen species(ROS) levels in liver mitochondria were recorded.[Results]The levels of malondialdehyde(MDA) and ROS increased significantly(P0.05),and the activities of superoxidase dismutase(SOD) and glutathione peroxidase(GSH-Px) in mitochondria of liver decreased remarkably in the positive control rats compared with those of the negative control rats(P0.05),which indicated that sucrose feeding obviously enhanced oxidative stress in the liver cells of GK rats.Compared with the positive control rats,the rats treated with 25 or 50mg/kg α-LA showed significant declines in the levels of MDA and ROS and increases in the activities of GSH-Px and SOD in mitochondria of rat liver(P0.05),and the above antioxidative effects were superior to the similar indicators in the rats with 75 and 100mg/kg α-LA interference.[Conclusion]α-lipoic acid within a certain range of concentration may have a protective effect on the oxidative damage in liver cells of sucrose-induced GK rats.