ObjectiveTo investigate the effect of diaminonium glycyrrhizinate (DG) on the activity of acetylcholinesterase (AChE) in cerebrospinal fluid of rabbits and the learning and memory ability of mice.MethodsThe injection of DG was performed on mice(20-60mg/kg iv)and rabbits (20-60 mg/kg iv) once everyday.After 2 weeks,the activity of AChE in cerebrospinal fluid of rabbits was determined.Y-maze test was designed to study the learning and memory ability of mice.Resultsthe activity of AChE of the group injected with DG was lower than that of the group injected with sodium chloride(P＜0.05);The number of electric shocks of the group injected with DG（high dosage）significantly decreased in Y-maze(P＜0.05).ConclusionThe DG has an inhibitory effect on the activity of AChE in cerebrospinal fluid and has the effects of improving learning and memory.

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