Effect of Acupuncture on Free Radical System and Cholinergic System in the Brain of Alzheimer's Disease Rats

Objective: To study the effects of acupuncture on antioxidative ability and cholinergic nervous system activity of the cerebral cortex and hippocampus in experimental Alzheimer's disease(AD)rats. Methods: 53 SD rats were randomized into control (n=15), model (n=13), electroacupuncture (EA, n=13) and rehabilitation (n=12) groups. AD model was established by intraperitoneal injection of AlCl 3 (49.4 mg/kg/day, continuously for 30 days). EA (dense sparse waves, 30 Hz) was applied to “Baihui(GV 20), “Dazhui(GV 14), “Shenshu(BL 23) and “Xinshu(BL 15) for 10 min, once every other day, continuously for 40 days. Rats of rehabilitation group were fed with Piracetum (0.32 g/kg), once daily. AD rats' learning memory ability was tested with maze method, and cerebral malondaldehyde (MDA) content, superoxide dismutase (SOD) and glutathione (GSH) Px activity were detected with biochemical methods, hippocampal AChE and ChAT activities were assayed with immunohistochemical technique. Results: The AD rats' learning memory ability in acupuncture group was significantly better than that of model group and rehabilitation group(P0.01, 0.05). Compared with control group, cerebral MDA level of model group increased significantly, cerebral GSH Px and SOD activities, and hippocampal AChE and ChAT activities of model group lowered considerably (P0.01); while in comparison with model group, cerebral MDA activity of rehabilitation and EA groups decreased significantly (P0.05, 0.01) and the effect of EA was significantly superior to that of Piracetum (P0.05). Compared with model group, GSH Px, SOD, AChE and ChAT activities raised remarkably and the effect of EA was also significantly superior to that of Piracetum (P0.05, 0.01). Conclusion: Acupuncture can increase the antioxidative ability and reduce free radical mediated neuronal damage in the brain, which may contribute to its action in improving AD rats' learning memory ability.