基于肠道菌群优化的当归芍药散抗AD的实验研究

Experimental study of the intestinal microflora effects of Danggui Shaoyao San on mice with Alzheimer disease

目的:研究当归芍药散(DSS)对APP/PSN双转基因阿尔茨海默病(AD)小鼠认知功能的作用及对肠道菌群的影响。方法:将48只APP/PSN双转基因AD小鼠随机分为AD模型组和DSS高、中、低剂量用药组,连续灌胃给药2个月,另取12只C57BL6小鼠作为正常对照。Morris水迷宫检测小鼠的认知功能,16S rRNA基因高通量测序法检测小鼠肠道菌群的群落结构并进行差异分析,Western blot检测海马组织内Aβ1-42水平。结果:与正常对照组比,AD模型组小鼠寻找平台潜伏期延长,在目标象限逗留时间减少(P<0.01);肠道厚壁菌门、乳杆菌、毛螺菌丰度降低,拟杆菌、瘤胃菌、幽门螺杆菌丰度升高(P<0.01);海马组织中Aβ1-42表达升高(P<0.01);与AD模型组小鼠比,DSS用药组小鼠寻找平台潜伏期缩短,在目标象限逗留时间增加,差异均有统计学意义(P<0.01);肠道厚壁菌门、乳杆菌、毛螺菌丰度升高,拟杆菌、瘤胃菌、幽门螺杆菌丰度降低(P<0.01);DSS剂量依赖性地降低海马组织中Aβ1-42的表达(P<0.01)。结论:DSS可降低肠道有害菌群丰度,提高肠道益生菌群丰度,优化小鼠肠道菌群,降低海马脑区Aβ1-42的表达,改善AD小鼠的认知功能。

Objective:To investigate the effect of Danggui Shaoyao San(DSS)on the cognitive function and the intestinal microflora in APP/PSN double-transgenic Alzheimer disease(AD)model mice.Methods:Forty-eight APP/PSN double-transgenic AD mice were randomly divided into model group,DSS high,medium and low dose treatment groups.Mice in DSS treatment groups underwent continuous gavage of DSS for 2 months,and 12 C57BL6 mice were taken as normal control.Morris water maze test was performed to examine the cognitive function of the mice.High-throughput sequencing of 16S rRNA gene was used to detect the community structure of intestinal microflora,and Western blot assay was conducted to measure the level of Aβ1-42 in the hippocampus.Results:Significantly reduced escape latency,yet increased time of the mice spending in the target quadrant was seen by Morris water maze test in mice in the model group compared to the normal controls(P<0.01).The abundance of Firmicutes,Lactobacillus and Lachnospiraceae was notably decreased,and Bacteroidetes,Ruminococcaceae and Helicobacteraceae were markedly increased,as well as the Aβ1-42 expression was significantly up-regulated in hippocampus in mice in the model group(all P<0.01).As compared with the model group,DSS significantly reduced the escape latency and increased the time that mice spent in the target quadrant in Morris water maze test,enhanced the abundance of Firmicutes,Lactobacillus and Lachnospiraceae,and decreased which of Bacteroidetes,Ruminococcaceae and Helicobacteraceae,reduced the expression of Aβ1-42 in the hippocampus in a dose-dependent manner(all P<0.01).Conclusion:DSS improving the cognitive function of the AD mice is based on reducing the expression of Aβ1-42 in hippocampus,and the effect might be related to reducing the abundance of intestinal harmful bacteria,increasing the abundance of intestinal probiotics,and optimizing the intestinal microflora.