淫羊藿苷对SAMP8小鼠皮层β淀粉样蛋白代谢途径相关蛋白的影响

摘要

目的 观察淫羊藿苷(ICA)对SAMP8小鼠皮层β淀粉样蛋白代谢途径中Aβ、APP及BACE1、PS1蛋白的影响.方法 8月龄雄性SAMP8小鼠随机分为模型、ICA低剂量组(20 mg/kg)、ICA中剂量组(40 mg/kg)、ICA高剂量组(80 mg/kg),同月龄雄性SAMR1小鼠作为空白对照组,每组12只,5月龄开始灌胃,1次/d,连续给药3个月,模型SAMP8组和正常对照SAMR1组给予同等体积的蒸馏水.HE和尼氏染色观察皮层神经元形态学变化,Western blot检测各组小鼠皮层Aβ1 42、APP、PS1、BACE1蛋白水平.结果 与同月龄的SAMR1小鼠相比,8月龄的SAMP8小鼠皮层正常神经元数量减少;Western blot检测到Aβ1-42、PS1蛋白在8月龄的SAMP8小鼠皮层中表达升高(P＜0.05),APP、BACE1蛋白表达上升无明显差异,给予ICA后4种蛋白水平均降低.结论 淫羊藿苷能够减轻神经元损伤,降低皮层Aβ1-42、APP、PS1、BACE1蛋白表达.%Objective The aim of this study is to investigate the effects of Icariin (ICA) on the expression of Aβ1-42 ,APP ,BACE1 and PSI in the Aβ metabolic pathway of SAMP8 mouse cortex. Methods 8 - month -old male SAMP8 mice were administered with different doses of ICA ( 20 ,40 ,80 mg/kg) for 3 months,while SAMRI mice of the same age were used as the normal group,12 mice in each group. Model of SAMP8 and normal of SAMRI mice were given equal volume of distilled water. The morphological change of cortex neurons were observed by H&E and Nissl staining, Western blot was used to detect the protein expression of Aβ1-42 , APP, PS1 and BACEI in mouse brain. Results Compared with SAMRl mice , the numbers of neurons in the 8-month -old SAMP8 mice were decreased. The abnormal neuron cells were reduced after administration of ICA. The protein expression of Aβ1-42 , PS1 in 8-month-old SAMP8 mice cortex were increased( P＜0. 05 ) , but the expression of APP and BACE1 showed no signiricant difference ,while the expression were decreased after administration with ICA. Conclusion This study demonstrated that ICA could reduce the damage of neurons and down-regulates the protein levels of Aβ1-42 , APP, BACEI and PSI.