RESUMO
Objective To observe the effects of Banxia Xiexin Decoction on intestinal microbes and 5-HT in ulcerative colitis(UC)model mice induced by drinking sodium dextran sulfate(DSS),and to analyze the mechanism of Banxia Xiexin Decoction in treating UC from the perspective of brain-gut axis.Methods 40 male C57BL6/J mice were randomly divided into control group,model group,positive drug(mesalazine)group and Banxia Xiexin decoction group.All mice except control group were induced by 2.5%DSS solution for 7 days to establish UC model.From the 8th day,mice in the above groups were given intragastric administration of sterilized water,mesalazine aqueous solution and Banxia Xiexin decoction aqueous solution.HE staining was used to observe histopathological changes of colon,ELISA to detect 5-HT content in serum,colon and brain tissues,and 16S rRNA sequencing to further detect the changes of fecal flora in model mice.Results Compared with model group,DAI index of experimental mice model group was significantly decreased after Banxia Xiexin Decoction intervention(P<0.05);IL-2,IL-4 and IFN-γ were significantly recovered(P<0.05).The histopathological score of proximal and distal colon was significantly decreased(P<0.01).Moreover,the peripheral 5-HT level was significantly decreased(P<0.05),but the central had an increasing trend.Results of intestinal flora showed that the relative abundance of Clostridium_sensu_stricto_1,unclassified_p__Firmicutes increased(P<0.05),while Lachnospiraceae_NK4A136_group,Lachnoclostridium,norank_f__Oscillospiraceae and Eubacterium_xylanophilum_group decreased(P<0.05).It was also found that there were significant correlations between intestinal microflora and peripheral and central 5-HT levels.Conclusion Banxia Xiexin Decoction could play a role in treating ulcerative colitis by improving the intestinal microbial composition structure of UC mice to reduce peripheral 5-HT levels and increase central 5-HT levels,thereby improving intestinal inflammatory response and relieving anxiety.