[Effect of Gengnianchun Recipe on learning memory function and hippocampal cholinergic system in ovariectomized rats].

Objective: To evaluate the effect of Gengnianchun Recipe (GNC) on learning memory function and its regulatory effect on hippocampal cholinergic system in ovariectomized rats.

Methods: Female rats 10-12 months old were randomized into 5 groups, the sham-operation group, the model group treated with normal saline, the positive control group treated with Nilestriol, and the two GNC groups treated with high and low dose GNC respectively. A little fat around ovary was cut in the sham-operation group. The treatment lasted for 12 weeks after ovariectomy. Changes of learning memory function were tested by Morris water maze; serum level of estradiol (E2) was measured by chemical fluorescent method; hippocampal acetylcholinesterase (AChE) mRNA was determined with Real-time PCR; and the activities of acetylcholine (ACh), AChE and choline acetyltransferase (ChAT) in hippocampus were detected by immunohistochemistry respectively.

Results: Twelve weeks after ovariectomy, serum E2 and learning memory function markedly decreased in the ovariectomized rats (P < 0.01, P < 0.05). Nilestriol and high dose GNC showed an effect in improving the symptoms of learning memory functional deprivation and elevating the activities of hippocampal ACh, AChE and ChAT (all P < 0.05).

Conclusion: GNC can improve learning memory function of ovariectomized rats, and its mechanism might be realized by regulating the cholinergic system in hippocampus.