蒙古黄芪皂苷对发育期大鼠低铅暴露致海马神经元损伤的保护作用

Protective effect of Mongolian astragaloside on hippocampal neurons injury induced by low-level lead exposure in puberty rats

目的探讨蒙古黄芪皂苷对发育期大鼠低铅暴露致海马损伤的作用。方法将40只4周龄SD大鼠随机分为模型组、正常对照组及蒙古黄芪皂苷高、中、低剂量组,正常对照组给予纯净水,其余组给予0.2 mg/mL醋酸铅溶液复制模型,造模的同时给予蒙古黄芪皂苷各剂量组150、75、37.5 mg/kg蒙古黄芪皂苷,模型组、正常对照组给予生理盐水。Morris水迷宫实验检测平均潜伏期、目标象限停留时间比率、游程比率,TUNEL法检测海马神经元损伤情况,RT-qPCR和Western blot检测calcyon、IP3、CaM基因和蛋白表达。结果与正常对照组比较,模型组平均潜伏期延长,停留时间比率和游程比率降低(P<0.05),海马神经元出现明显损伤,calcyon、IP3和CaM表达异常升高(P<0.05);与模型组比较,蒙古黄芪皂苷高、中剂量组平均潜伏期缩短(P<0.05),蒙古黄芪皂苷高剂量组停留时间比率、游程比率升高(P<0.05),蒙古黄芪皂苷各剂量组海马神经元损伤减轻(P<0.05),calcyon、IP3和CaM表达降低(P<0.05),并存在剂量依赖性。结论蒙古黄芪皂苷可预防低铅暴露致发育期大鼠学习记忆力减退、减轻海马神经元损伤,其作用机制可能与下调calcyon、IP3、CaM表达有关。

AIM To investigate the effect of Mongolian astragaloside on hippocampal injury induced by low-level lead exposure in puberty rats.METHODS Forty four-week-old SD rats were randomly divided into model group,normal control group and Mongolian astragaloside groups for high dose,medium dose and low dose interventions.Unlike the normal control group given pure water,the rest groups given 0.2 mg/mL lead acetate solution were developed into the injury models for simultaneous.At the same time,dosing of 150,75,37.5 mg/kg Mongolian astragaloside(each dose group of Mongolian astragaloside),and normal saline(the model group and control group).Subsequently,the rats were subjected to determinations of average latency,target quadrant residence time ratio and run length ratio by Morris water maze test,the damage of hippocampal neurons by TUNEL,the expressions of calcyon,IP3 and CaM by RT-qPCR and Western blot.RESULTS Compared with the normal control group,the model group displayed prolonged average latency,decreased residence time ratio and the run length ratio(P<0.05),significantly damaged hippocampal neurons,and abnormally increased expressions of calcyon,IP3 and CaM(P<0.05).Compared with the model group,groups intervened with high and medium dose Mongolian astragaloside shared shortened average latency(P<0.05);high-dose Mongolian astragaloside group shared increased residence time ratio and run length ratio(P<0.05);all groups intervened with Mongolian astragaloside were observed with alleviated hippocampal neurons damage(P<0.05),down regulated expressions of calcyon,IP3 and CaM(P<0.05)in a dose-dependent manner.CONCLUSION Mongolian astragaloside can prevent the learning and memory impairment induced by low-level lead exposure and reduce the damage of hippocampal neurons.The mechanism may contribute to the down regulation of the expressions of calcyon,IP3 and CaM.