还脑益聪方提取物对阿尔茨海默病模型小鼠脑组织Aβ、APP及相关分泌酶表达的影响

Effect of Extracts from Huannao Yicong Prescription on Expression of Cerebral Amyloid Beta,Amyloid Precursor Protein and Secretases in Alzheimer's Disease Mouse Model

目的观察由补肾益气、活血解毒中药组成的还脑益聪方提取物对β-淀粉样前体蛋白(APP)转基因造成的阿尔茨海默病(AD)模型小鼠脑组织β淀粉样蛋白(Aβ)生成的影响,并初步探讨其作用机制。方法将3月龄AD模型小鼠随机分为模型组、还脑益聪方提取物大、小剂量组(2.8,1.4 g.kg-1)和盐酸多奈哌齐组(0.65×10-3 g.kg-)1,每组15只;同月龄相同遗传背景的C57BL/6J小鼠15只作为正常对照组。所试药物稀释相同体积灌胃给药,对照组和模型组给以等体积蒸馏水灌胃,每日1次,连续灌胃6个月。采用免疫组织化学法结合彩色图像分析法观察各组小鼠脑组织APP、Aβ、β位点剪切酶(BACE)和早老蛋白1(PS-1)的表达;采用刚果红染色观察各组小鼠脑组织淀粉样沉积的变化。结果与正常对照组相比,模型组小鼠海马CA1区APP、Aβ、BACE和PS-1表达显著增多(P<0.01),刚果红染色示橘红色染色增多;与模型组相比,还脑益聪方组小鼠海马CA1区APP、Aβ、BACE和PS-1表达显著减少(P<0.05或P<0.01),橘红色染色较少。结论还脑益聪方提取物可通过减少脑组织的APP含量及抑制β-和γ-分泌酶,从而减少AD模型小鼠脑组织Aβ的生成及淀粉样沉积的形成,这也是其改善AD模型小鼠学习记忆能力的机制之一。

Objective To investigate the effect of extracts from Huannao Yicong Prescription（HYP）,a Chinese herbal recipe with the actions of tonifying kidney and strengthening Qi,activation blood and removing toxicity,on cerebral amyloid beta protein（Aβ） expression in amyloid precursor protein（APP） transgenic AD mice models,and to explore their therapeutic mechanism.Methods Three-month aged APP transgenic AD mice were randomly divided into model group,large-dose HYP extracts group（2.8 g·kg-1·d-1）,small-dose HYP extracts group（1.4 g·kg-1·d-1） and donepezil group（0.65×10-3 g·kg-1·d-1）,15 mice in each group.Fifteen C57BL/6J mice with the same age and background were used as the normal control.The animals were administered intragastrically once a day with the corresponding drug or water for 6 months.The expression of APP,Aβ,β-site APP cleaving enzyme（BACE） and presenilin 1（PS-1） in mice hippocampal CA1 region was observed by immunohistochemistry and with image analysis.Amyloid deposition was observed with congo red staining.Results Compared to the normal control group,the expression levels of APP,Aβ,BACE and PS-1 in hippocampal CA1 region of mice in the model group increased obviously（P 0.01）,and the results of congo red staining showed more orange staining in the model group.Compared to the model group,the expression levels of APP,Aβ,BACE and PS-1 in hippocampal CA1 region of mice decreased obviously in the HYP groups（P 0.05 or P 0.01）,and less orange staining was presented.Conclusion HYP extracts can reduce the production and accumulation of Aβ in the brain of APP transgenic mice by decreasing the expression of APP,β-secretase and γ-secretase,which may be one of the mechanisms of HYP in improving the learning and memory ability of AD animal model.