Analysis on Mechanism of Baiyaojian in Treating Ulcerative Colitis Based on Intestinal Flora and Intestinal Mucosal Barrier Function / 中国实验方剂学杂志

ABSTRACT

Objective:To compare the effects of Baiyaojian before and after fermentation on intestinal flora and expression of Occludin and zonula occludens protein-1 （ZO-1） in intestinal mucosa of mice with ulcerative colitis （UC）， and to explore the mechanism of Baiyaojian and Galla Chinensis in the treatment of UC. Method:Totally 50 mice were randomly divided into 5 groups with 10 mice in each group， one group was randomly selected as blank group， and the other 4 groups were treated with dextran sodium sulfate （DSS） to induce UC model. After modeling， mice in the blank group and model group were given normal saline， and treatment groups were given Mesalazine （0.8 g·kg^-1）， Galla Chinensis decoction （1.8 g·kg^-1） and Baiyaojian decoction （2.7 g·kg^-1） by intragastric administration for 7 days. The 16S rRNA sequencing technology was used to detect the changes of intestinal flora in mouse feces. The histopathological changes of colon tissue were observed by hematoxylin-eosin （HE） staining， and the expression of Occludin and ZO-1 in colon tissue of mice were compared by immunohistochemistry. Result:Compared with the blank group， the abundance and diversity of intestinal flora in UC mice were significantly decreased， and the colonic tissue was thickened with congestion and obvious ulcers， and the expression levels of Occludin and ZO-1 were significantly decreased （<italic>P</italic><0.01）. After treatment with Galla Chinensis and Baiyaojian， the abundance and diversity of flora were improved. At the phylum level， relative abundance of Firmicutes， Proteobacteria and Actinobacteria increased significantly （<italic>P</italic><0.01）， while the relative abundance of Bacteroidetes decreased significantly （<italic>P</italic><0.01） in Galla Chinensis group. In Baiyaojian group， the relative abundance of Proteobacteria and Actinobacteria increased significantly （<italic>P</italic><0.01）， while the relative abundance of Firmicutes increased and the relative abundance of Bacteroidetes decreased， but there was no significant difference. At the genus level， the relative abundance of <italic>Bacteroides</italic>， <italic>Allobaculum </italic>and <italic>Ruminococcus</italic> decreased significantly （<italic>P</italic><0.01）， the relative abundance of <italic>Roseburia</italic>， <italic>Prevotella</italic>， <italic>Oscillospira</italic> and <italic>Paraprevotella</italic> increased significantly （<italic>P</italic><0.05， <italic>P</italic><0.01） in Galla Chinensis group. In Baiyaojian group， the relative abundance of <italic>Bacteroides</italic> and <italic>Allobaculum</italic> decreased significantly （<italic>P</italic><0.05， <italic>P</italic><0.01）， and the relative abundance of <italic>Prevotella</italic>， <italic>Oscillospira</italic>， <italic>Roseburia</italic> and <italic>Ruminococcus</italic> increased significantly （<italic>P</italic><0.01）. Compared with model group， colon tissue of Galla Chinensis group and Baiyaojian group was recovered obviously， congestion was alleviated， only scattered ulcers were seen. The expression of Occludin and ZO-1 increased， and the expression level of Baiyaojian group was higher than that of Galla Chinensis group. Conclusion:The effect of Baiyaojian is better than Galla Chinensis in the treatment of UC. The mechanism may be through regulating the abundance and diversity of intestinal flora， improving the disorder of intestinal flora and increasing the expression of ZO-1 and Occludin and protecting the intestinal mucosal barrier function for alleviating intestinal inflammation.