Influences of Vit-E on the mtDNA damage and Ca2+ homostasis of hippocampus and antioxidative ability in brain of aging mice induced by D-galactose

AIM: To study the influences of vitamin E (Vit-E) on the mtDNA damage and Ca²⁺ homeostasis in hippocampus and antioxidative ability in aging brain induced by D-galactose.METHODS: D-galactose (1 000 mg·k^-1·d^-1 ) was injected into mice hypodermically for 8 weeks to induce aging animal model, and Vit-E (100 mg·kg^-1; 250 mg·kg^-1) was administered for 6 weeks by ig at the 3rd week of making model. After Vit-E treatment for 8 weeks, water maze test was used to determine the ability of mice’s learning and memory. The activities of glutathione peroxidase (GSH-Px) and succinate dehydrogenase (SDH), the content of nitric oxide (NO) and activity of nitric oxide synthase (NOS) in the brain tissue were detected separately. Fura-2/AM, double-wave-length fluorospectrophotometer and PCR method were used to measure the concentration of calcium ion and mtDNA mutation in the hippocampus cells.RESULTS: Administration of Vit-E improved significantly the ability of learning and memory in model mice, inhibited the activity of NOS and decreased the amount of NO, and increased the activities of GSH-Px and SDH respectively in brain tissues, decreased the concentration of calcium ion (P<0.01, P<0.05), and prevented the damage of mtDNA in hippocampus.CONCLUSION: Vit-E can enhance the antioxidative ability, regulate the homeostasis of Ca²⁺ and inhibit the damage of mtDNA caused by oxidative stress in aging brain, and improve the ability of learning and memory in aging mice.