Effects of combined acupuncture and eugenol on learning-memory ability and antioxidation system of hippocampus in Alzheimer disease rats via olfactory system stimulation

OBJECTIVE: To investigate the effects of combined acupuncture and eugenol on learning-memory ability and the antioxidation system of the hippocampus in Alzheimer disease (AD) rats. METHODS: Sixty Sprague Dawley rats, weighing (300±10) g, were randomly divided with 10 rats per group into a normal control group, AD model group, AD with cut olfactory nerve group, Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group. The AD model was established by injection of amyloid β1-40 (Aβ 1-40). Morris maze tests were conducted for evaluating the learning-memory ability. Content of malo- ndialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the hippocampus were detected. RESULTS: The average escape latency and the mean swimming distance in the normal control group, the Xiu three-needle group, the eugenol group, and the combined acupuncture and euge-nol group were significantly shorter than those in the AD model group (all P<0.01). The combined acupuncture and eugenol group had shorter escape latency and mean swimming distance than those in the Xiu three-needle group and the eugenol group. There were no significant differences between the Xiu three-needle group and the eugenol group and between the AD group and the AD with cut olfactory nerve group (P>0.05). Compared with the normal control group, the MDA content in the hippocampus significantly increased (P<0.05) and GSH-Px and SOD activities significantly decreased in the AD model group (P<0.01). Compared with the AD model group, significantly decreased (P< 0.01) and SOD and GSH-Px activities significantly increased in the Xiu three-needle group, eugenol group, and combined acupuncture and eugenol group (P<0.05). Compared with the Xiu three-needle group and eugenol group, the MDA content significantly decreased (P<0.05) and SOD and GSH-Px activities increased (P<0.05) in the combined acupuncture and eugenol group. There were no significant differences among the three indices between the Xiu three-needle group and the eugenol group and between the AD model group and the AD with cut olfactory nerve group (P>0.05). CONCLUSION: Both Xiu three-needle and eugenol can increase learning-memory ability, decrease MDA content, and increase SOD and GSH-Px activities in the hippocampus in AD rats. The combination of acupuncture with eugenol has stronger effects, and the effects depend on the olfactory pathway.