参苓白术散对伴焦虑腹泻型肠易激综合征模型小鼠的改善作用及机制

目的:研究参苓白术散对伴焦虑腹泻型肠易激综合征(IBS-D)模型小鼠的改善作用,并从肠道微生态角度初步阐明其作用机制。方法:将C57 BL/6小鼠随机分为空白对照组、模型组、参苓白术散组(3.6 g/kg),每组8只。除空白对照组外,模型组和参苓白术散组小鼠以皮下注射皮质酮联合灌胃番泻叶水煎液及慢性束缚建立伴焦虑IBS-D模型。造模成功后,空白对照组、模型组小鼠灌胃给予生理盐水,参苓白术散组灌胃给予相应药物,连续给药4周。末次给药后,检测各组小鼠的稀便率、腹泻指数、体质量、糖水偏好百分比、穿过旷场中心区域次数、最小疼痛阈值和海马组织中内源性脑神经营养因子(BDNF)及血清中5-羟色氨(5-HT)的水平;提取各组小鼠盲肠内容物进行微生物DNA提取并测序,采用Alpha、Beta多样性分析法分析肠道微生物丰度及多样性。结果:与空白对照组比较,模型组小鼠体质量、糖水偏好百分比、穿过旷场中心区域次数、最小疼痛阈值、海马组织中BDNF水平和肠道中厚壁菌门微生物的相对丰度及Lachnospiraceae_NK4A136_group属微生物的相对丰度均显著降低(P<0.05);稀便率、腹泻指数、血清中5-HT水平和疣微菌门微生物的相对丰度、艾克曼菌属微生物的相对丰度均显著升高(P<0.05);肠道微生物种类差异较大。与模型组比较,参苓白术散组小鼠体质量、糖水偏好百分比、穿中心区域次数、最小疼痛阈值、海马组织中BDNF水平和肠道中厚壁菌门微生物的相对丰度、Lachnospiraceae_NK4A136_group属微生物的相对丰度均显著升高(P<0.05或P<0.01);稀便率、腹泻指数、血清中5-HT水平、疣微菌门微生物的相对丰度、艾克曼菌属微生物的相对丰度均显著降低(P<0.05);肠道微生物种类差异较大。结论:参苓白术散可改善伴焦虑IBS-D模型小鼠的腹泻和焦虑行为,升高其海马组织中BDNF水平,降低血清中5-HT水平;其作用机制可能与降低肠道微生物疣微菌门、艾克曼菌属微生物的相对丰度,升高厚壁菌门、Lachnospiraceae_NK4A136_group属微生物的相对丰度有关。

Improvement Effect and Mechanism of Shenling Baizhu Powder on Irritable Bowel Syndrome with Diarrhea Model Mice with Anxiety

OBJECTIVE:To study the improvement effect of Shenling baizhu powder on irritable bowel syndrome with diarrhea(IBS-D)model mice with anxiety,and to elucidate its mechanism from the point of view of intestinal microecology.METHODS:C57 BL/6 mice were randomly divided into blank control group,model group,Shenling baizhu powder group(3.6 g/kg),with 8 mice in each group.Except for blank control group,IBS-D model with anxiety was established in model group and Shenling baizhu powder group by giving corticosterone subcutaneously combined with intragastric administration of Folium Sennae decoction and chronic restraint treatment.After modeling,blank control group and model group were given intragastric administration of normal saline,and Shenling baizhu powder group was given relevant medicine intragastrically,for consecutive 4 weeks.After last medication,loose stools rate,diarrhea index,body weight,sugar water preference percentage,the times of crosssing open field center area and minimum pain threshold as well as the levels of BDNF in hippocampal tissue and 5-HT in serum were detected in each group.The cecal contents of mice in each group were extracted for microbial DNA extraction and sequencing;the abundance and diversity of intestinal microorganisms were analyzed by Alpha and Beta diversity analysis.RESULTS:Compared with blank control group,body weight,sugar water preference percentage,the times of crossing open field center area and minimum pain threshold as well as the levels of BDNF in hippocampal tissue,relative abundance of Firmicutes phylum microorganism in intestine,relative abundance of Lachnospiraceae_NK4A136_group genus microorganism were decreased significantly(P<0.05);loose stools rate,diarrhea index,serum level of 5-HT,relative abundance of Verrucomicrobia phylum microorganism and relative abundance of Ackermann phylum microorganism were increased significantly(P<0.05),and there were great differences in the types of intestinal microorganisms.Compared with model group,body weight,sugar water preference percentage,the times of crossing open field center area,minimum pain threshold,BDNF level of hippocampus,relative abundance of Firmicutes phylum microorganism,relative abundance of Lachnospiraceae_NK4A136_group genus microorganism were increased significantly(P<0.05 or P<0.01);loose stools rate,diarrhea index,serum level of 5-HT,relative abundance of Verrucomicrobia phylum microorganism and relative abundance of Ackermann phylum microorganism were decreased significantly(P<0.05),and and there were great differences in the types of intestinal microorganisms.CONCLUSION:Shenling baizhu powder can improve the diarrhea and anxiety behavior of IBS-D model mice with anxiety,increase the level of BDNF in hippocampus and decrease serum level of 5-HT.Its mechanism may be related to decreasing relative abundance of Verrucomicrobia phylum microorganism and Ackermann phylum microorganism,increasing the relative abundance of Firmicutes phylum and Lachnospiraceae_NK4A136_group genus microorganism.