Effects of soybean isoflavones on learning and memory ability impairment and ChAT expression of hippocampus in rats induced by β-amyloidpeptide

Objective To investigate the effects of soybean isoflavones(SIF) on learning and memory ability impairment in rats induced by β-amyloidpeptide and probalble mechanism.Methods Thirty healthy male SD rats were randomly divided into control group,model group and SIF group,respectively,and each group 10 rats.The regulated dose of medicine was given to the SIF group by intragastric administration daily for 14 days before Aβ injection,while control group and model group were given equivalent of 0.5% CMC-Na.The learning and memory abilities of rats were assessed through Morris Water Maze behavioral test on 7d after Aβ injection and the expression of ChAT was detected by immunohistochemistry.Results Compared with the control rats,the abilities of learning and memory were lowered significantly(P0.01),and the expression of ChAT positive cells was decreased greatly in the model rats(P0.01).In the rats of SIF group,it was found that their learning and memory abilities were improved significantly(P0.05) and that the expression of ChAT positive cells was increased obviously(P0.05),as compared with the model rats.Conclusion SIF can improve the learning and memory ability impairment of rats induced by β-amyloidpeptide,possibly by improving ChAT expression.