Protective Effects Of α-Lipoic Acid On Mice With Oxidative Damage Caused By D-galactose

Objectiveα-lipoic acid has been a focus of medical research for years,especially its potent antioxidative power. In this months-long study, we observed its restoration of the endogenous antioxidative system, effects on DNA oxidative damage of hippocampus neurons and upgradation of nNOS expression of mice hippocampus CAI subregion, supplying scientific evidence for its application on medicine.Method50 pure Kuming female mice were weighed and assigned randomly into blank control group (?), model group (П) and threeα-lipoic acid groups (Ш,IV, V).Model group and threeα-lipoic acid groups took D-galactose by subcutaneous injection once per day for 14 weeks (100mg/kgBW) (0.1ml/10gBW),meanwhile mice of blank control group were given isotonic Na chloride(0.1ml/10gBW) .In the last 6 weeks, while the subcutaneous injection was undergoing as previous, threeα-lipoic acid groups were given different doses ofα-lipoic acid mixed in colleseed oil (pretreated by alcohol and high temperature) (0.05ml/10gBW) via intragastric administration (Ш,IV, V)( 50mg/kgBW,100mg/kgBW,200mg/kgBW),meanwhile blank control group and model group were given colleseed oil(0.05ml/10gBW)too.Results:1,Effects on the endogenous antioxidative ability1.1 Reversed D-galactose-caused decline of erythrocyte superoxide dismutase (SOD) activity: Model group was satistically significantly lower than other groups (P<0.05). Compared to model group, SOD activity of the three groups of mice administered withα-lipoic acid was higher (P<0.05).The higher the dose ofα-lipoic acid, the higher SOD activity (P<0.05). 1.2 Reduced blood serum LPO levels: LPO levels of model group were statistically significantly higher than those of blank control group (P<0.05), Feeding rats theα-lipoic acid diet reduced LPO levels markedly (P<0.05). The higher the dose ofα-lipoic acid, the lower LPO levels (P>0.05).1.3 Reduced LPO levels in livers: LPO levels of liver in model group were higher than those in blank control group (P<0.05). Between the threeα-lipoic acid group, the higher the dose ofα-lipoic acid, the lower LPO levels (P>0.05), Only high dose ofα-lipoic acid could completely reversed increase of LPO levels in liver caused by D-galactose (P<0.05).1.4 Reduced LPO levels in spleen: LPO levels of spleen in model group were markedly higher than those in blank control group (P<0.05), Only high dose ofα-lipoic c acid could completely reversed increase of LPO levels in spleen caused by D-galactose (P<0.05).1.5 Reduced brain lipofuscin levels: The LF in brain of model group was markedly higher than that of blank control group (P<0.05), which could be reversed by different doses ofα-lipoic acid (P<0.05).2,Protective effects on DNA oxidative damage of miec hippocampus. TailLength,TailMoment and OliveTailMoment of comet-like cells in hippocampus of model group were satistically significantly different from other groups( P<0.05).The D-galactose induced DNA oxidative damage was nearly restored to norm byα-lipoic acid (P<0.05).3,Improvement of nNOS expression in hippocampus CA1 subregion. Compared to model group mice, nNOS expression levels in hippocampus CA1 subregion ofα-lipoic acid groups were upgraded highly (P<0.05), Among the five groups, the contents of nNOS in model group were lowest (P<0.05).Conclusion1,α-lipoic acid could eliminate free radicals and strengthen the endogenous antioxidative system, thus relieved oxidative stress.Dose-effect association existed.2,α-lipoic acid was capable of repairing DNA oxidative damage which was induced by D-galactose. 3,D-galactose lowered expression of nNOS in mice hippocampus CA1 subregion, which was reversed byα-lipoic acid.