Effects of Pueraria Isoflavone on Learning and Memory and Changing of Neurons Morphology in Hippocampi of Aging Rats

Objective:To study the effects of pueraria isoflavone on learning and memory and changing of neurons morphology in Hippocampi of aging rats induced by D-galactose.Methods:Rats were randomly divided into 5 groups:control group,model group,drug(low、middle、high)groups.The model of aging rats was set up by subcutaneous injecting with 1% D-galactose 100mg/kg into nape for 6 weeks.Drug(low、middle、high)groups were then intragastricly administrated with Pueraria isoflavone(40mg/kg,80 mg/kg,120 mg/kg)for 8 weeks.The learning and memory ability of rats were tested by Morris Water Maze.Then the rats were sacrificed after experiment.The hippocampi were obtained to observing the structure through microscope with HE staining.Results:The escaping latency period in model group was significantly longer than that of pueraria isoflavone(middle、high)groups.The percentage of distance in the platform quadrant in model group obviously decreased compared with the Pueraria isoflavone(middle、high)groups;Comparing with Control group the CA1 pyramidal cell layers of model group were arranged sparse,almost disappeared,the cells nucleus volume was significantly diminished;the structute of hippocampi were not clear.Comparing with Model group,the changes of pueraria isoflavone(middle、high)groups weren't obvious.Conclusion:Pueraria isoflavone could promote the learning and memory ability of aging rats,relieve the damage of neuron and protect the cell.