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观察天麻素对5×FAD阿尔茨海默病(Alzheimer’s disease,AD)模型小鼠脑内Aβ纤维斑块的影响,并利用117模型细胞(过表达Aβ和β-分泌酶)研究其可能的作用机制。5×FAD小鼠随机分为天麻素(gastrodin,GAS)高剂量(200 mg·kg~(-1)·d~(-1))、中剂量(100 mg·kg~(-1)·d~(-1))及低剂量(50 mg·kg~(-1)·d~(-1)),并设置5×FAD阳性小鼠对照组及5×FAD阴性小鼠对照组。用药3个月后,用Morris水迷宫检测小鼠行为学变化,ELISA法检测小鼠脑匀浆中Aβ含量,免疫组化观察5×FAD小鼠脑内海马区及皮层区Aβ斑块。天麻素以不同的浓度(10~100μmol·L~(-1))作用于117细胞,分别检测细胞内外Aβ含量变化,分析细胞内β-分泌酶转录水平和蛋白水平的变化,以及细胞凋亡、细胞活力的变化情况。结果显示:与5×FAD阳性对照组相比,天麻素高剂量组(GAS-H)平台寻找时间缩短50.60%,在目标象限逗留时间延长2.25倍;脑匀浆中Aβ含量下降55.74%;脑内Aβ斑块在海马区减少93.28%,在皮质区减少88.88%;117细胞实验结果表明,天麻素在100μmol·L~(-1)时细胞内外Aβ含量分别降低63.1%和49.1%,且降低的效果呈浓度依赖性;天麻素在100μmol·L~(-1)时细胞β-分泌酶转录水平降低32.9%;50μmol·L~(-1)时细胞β-分泌酶蛋白表达水平降低47.9%。结果提示:天麻素可抑制5×FAD鼠脑内Aβ纤维斑块,同时可明显改善其学习记忆及认知能力。初步研究其机制,发现可能与抑制β-分泌酶的表达进而抑制Aβ及其纤维斑块的形成有关。
To investigate the effects of gastrodin on Aβ fibrotic plaques in brain of 5 × FAD Alzheimer’s disease (AD) model mice and to explore its possible role by using 117 model cells (overexpressing Aβ and β-secretase) mechanism. The 5 × FAD mice were randomly divided into three groups: high dose (200 mg · kg -1 · d -1) of gastrodin (GAS), middle dose (100 mg · kg -1) · d ~ (-1)) and low dose (50 mg · kg ~ (-1) · d ~ (-1)), and the control group of 5 × FAD positive mice and the control group of 5 × FAD negative mice were set up. After 3 months of treatment, the behavioral changes of mice were detected by Morris water maze, the content of Aβ in brain homogenate of mice was detected by ELISA, and the Aβ plaques of hippocampus and cortex in 5 × FAD mice were observed by immunohistochemistry. Gastrodin was applied to 117 cells at different concentrations (10 ~ 100μmol·L -1), the changes of intracellular and extracellular Aβ levels were detected, and the changes of intracellular β-secretase transcription and protein levels and the changes of apoptosis , Changes in cell viability. The results showed that compared with 5 × FAD positive control group, GAS-H platform reduced the search time by 50.60%, and stayed in the target quadrant for a 2.25-fold longer time. The content of Aβ in brain homogenate decreased by 55.74% The internal Aβ plaque in the hippocampus decreased by 93.28% and in the cortex decreased by 88.88%. The results of 117 cells showed that the content of Aβ decreased by 63.1% and 49.1% at 100μmol·L -1, In a dose-dependent manner. The transcript level of β-secretase in gastrodin decreased by 32.9% at 100 μmol·L -1 and decreased by 47.9% at 50 μmol·L -1, . The results suggest that gastrodin can inhibit Aβ fiber plaques in 5 × FAD mice brain, and can significantly improve learning and memory and cognitive abilities. Preliminary study of its mechanism, found that may inhibit the expression of β-secretase and thus inhibit the formation of Aβ and its fibrous plaque.