Improving effect of Perilla frutescens extract on learning and memory impairment in subacute senile mice induced by D-galactose

AIM To study the improving effect of Perilla frutescens extract(PE),extracted by ethyl acetate,on learning and memory impairment in subacute senile mice induced by D-galactose.METHODS Ninety mice were randomly divided into normal control group(NC),model group,positive control group(pairacetam,500 mg/kg),treated groups with PE(150,300,600 mg/kg),and treated groups with rosmarinic acid(55,110,220 mg/kg) according to their body weights.Except NC group,all the other groups were subcutaneously injected with 1 g/(kg·d) D-galactose for 6 w,whereas NC group with normal saline.At the same time,the other groups were adminstered with corresponding drugs for successive 42 d.Then the learning and memory ability of mice were measured by step down test,Y-maze test and Morris water maze test.The activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondiadehyde(MDA),nitric oxide(NO),NO synthase(NOS) and acetylcholinesterase(AchE) in brain were detected.Morphology of hippocampal nerve cells were investigated.RESULTS Compared with the model group,PE and rosmarinic acid significantly improved aging sign and spontaneous activity,reduced error numbers,increased latent period and reduced training times(P0.05,P0.01),decreased escape latency,increased swimming time and swimming distance in platform quadrant and times of crossing platform(P0.05,P0.01).PE and rosmarinic acid could also increase the activities of SOD and GSH-Px(P0.05),reduce AchE,NOS activity and MDA,NO level(P0.05,P0.01) with dose-dependent tendency,and prevent hippocampal nerve cells from damaging obviously.CONCLUSION PE and rosmarinic acid can significantly improve learning and memory ability in subacute senile mice induced by D-galactose.The mechanism may be related to scavenging free radicals,inhibiting activity of AchE,reducing hydrolysis of acetylcholine and decreasing toxicity of NO on nerve cells.