【摘要】 目的研究黄芪提取物对阿尔茨海默病(AD)大鼠海马组织中诱导型一氧化氮合酶(i NOS)的表达和NO含量的影响及其作用机制。方法 SD大鼠海马内注射Aβ25-35制备AD大鼠模型,实验分4组:假手术组、模型组、黄芪组和西药治疗组。黄芪组和西药治疗组分别用黄芪提取物和脑复康灌胃,假手术组和模型组用等剂量生理盐水灌胃。用Morris水迷宫测定各组大鼠的学习记忆能力;Western blot测定各组大鼠海马组织中i NOS蛋白的表达;硝酸还原酶法检测各组大鼠海马组织中NO含量。结果模型组的逃避潜伏期延长,单位时间内跨越原平台次数减少,海马组织中i NOS的表达水平及NO含量均升高,与假手术组比较,差异均有统计学意义(P<0.05);黄芪组逃避潜伏期均缩短,单位时间内跨越原平台次数均增多;i NOS表达水平及NO含量下降,与模型组比较,差异均有统计学意义(P<0.05),其作用效果与西药治疗组相当(P>0.05)。结论黄芪提取物对Aβ25-35所致AD模型大鼠学习记忆障碍具有明显的改善作用,其机制可能是黄芪提取物通过抑制i NOS的表达和NO的生成,减轻Aβ25-35毒性作用所致脑组织神经元损伤,从而改善AD的学习记忆障碍。更多还原

【Abstract】 [ Objective] To investigate the effect of astragalus extract on the expression of inducible nitric oxide synthase(i NOS)and the content of NO in the hippocampus of rats with Alzheimer disease(AD), analyze the mechanisms.[ Methods] AD model rats were established by injecting Aβ 25-35 into hippocampuses, and were divided into 4 groups, including control group, model group, astragalus group and western medicine treatment group. The rats of astragalus group and western medicine treatment group were treated with astragalus extract and Naofukang by intragastric administration respectively, while the rats of control group and model group were treated with isodose normal saline. The ability of learning and memory was detected by Morris water maze, the expression level of i NOS in the hippocampus of rats was detected by western blot, and the content of NO in the hippocampus of rats was detected by nitrate reductase method.[ Results] In model group rats, the escape latency lengthened, the frequency of passing through platform decreased, the expression level of i NOS and the content of NO in the hippocampus increased, and the differences were statistically significant between model group and control group(P <0.05). In astragalus group rats, the escape latency shortened, the frequency of passing through platform increased, the expression level of i NOS and the content of NO decreased, and the differences were statistically significant between astragalus group and model group( P <0.05). The effect of astragalus group was similar with western medicine treatment group(P >0.05).[ Conclusion] The astragalus extract has obvious improvement effect on learning and memory disorder of AD model rats induced by Aβ25-35. The possible mechanism is astragalus extract can relieve the brain neuronal damage caused by Aβ25-35 through inhibiting the expression of i NOS and produce of NO,so as to improve the learning and memory disorder of AD.更多还原