Objective: To investigate the effect of Erxian Yikun decoction on the ability of learning and memory of perimenopausal female mice. Method: The female mice was ovariectomized to simulate perimenopausal status and then randomly divided into model group

diethylstilbestrol group (DES

0.1 mg· kg-1)

and Erxian Yikun decoction high

middle land low dose groups(30

15

7.5 g· kg-1). The sham operation group was also established as the control group. The mice were given corresponding drugs for 5 weeks. The effect on the ability of learning and memory in the different groups was investigated by using step down test and Morris water-maze test. The superoxide dismutase(SOD) and malondialdehyde(MDA) level in serum

lipid peroxidase(LPO)

nitric oxide(NO) and acetyl choline(ACh) level in brain tissue

as well as the activity of SOD

nitric oxide synthase(NOS) and acetyl choline esterase(AChE) were also detected. Fluorescence quantitative PCR was used to detect Bcl-2 Assaciated x protein(Bax) and B cell lymphoma/lewkmia-2(Bcl-2) mRNA expressions in the hippocampus. Result: Compared with model group

the ability of learning and memory was significantly improved

the SOD activity in serum was increased

and the SOD activity and MDA level was decreased in the different treatment groups (P<0.05

P<0.01). Meanwhile

the ACh level in brain tissue was increased

the AChE activity and LPO level and NO level were also decreased in the treatment groups

and Erxian Yikun decoction activated the Bcl-2 and lowered expressions of Bax (P<0.05

P<0.01). Conclusion: Erxian Yikun decoction has the effect in improving the ability of learning and memory

this mechanism may relate to scavenging free radicals

anti-oxidization and regulating neurotransmitter level and influencing the effect of Bcl-2 and Bax expression.