ABSTRACT
ObjectiveTo investigate the therapeutic effect and the possible mechanism of Mankuining decoction on dextran sulfate sodium （DSS）-induced ulcerative colitis （UC） in mice. MethodA total of 90 male SPF C57BL/6 mice were randomly classified into normal group， model group， mesalazine group （0.266 g·kg-1）， and high-， and medium-， low-dose （20， 10， 5 g·kg-1） Mankuining decoction groups， with 15 rats in each group. Mice， except the normal group， drank 3% DSS solution for 7 days to induce UC， and administration （ig） started on the day of modeling. The model group and the normal group were given equivalent amount of 0.9% normal saline once a day for 7 days. The general conditions of mice were recorded every day and the disease activity index （DAI） was calculated. On the 8th day， mice were killed by cervical dislocation. All the colons and feces were collected. The length of colon was recorded， and the histopathological changes of colon were observed based on hematoxylin-eosin （HE） staining. The content of inflammatory factors in colon was detected by enzyme-linked immunosorbent assay （ELISA）， and the changes of intestinal flora in mouse feces were determined based on 16SrRNA sequencing. ResultCompared with the normal group， the model group had severe colon damage， reduction in colon length （P<0.01）， increase in DAI （P<0.01）， decrease in interleukin-10 （IL-10） and transforming growth factor-β1 （TGF-β1） in colon（P<0.01）， rise of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， interleukin-17α （IL-17α）， and tumor necrosis factor-α （TNF-α） in colon （P<0.05， P<0.01）， and decrease in abundance and diversity of intestinal flora. Compared with the model group， mesalazine and high-， medium-， low-dose Mankuining decoction alleviated the colon injury， recovered the length of colon （P<0.01）， decreased DAI （P<0.01）， increased IL-10 and TGF-β1 in colon （P<0.01）， and decreased IL-1β， IL-6， IL-17α， and TNF-α in colon （P<0.01）. Moreover， they raised the abundance and diversity of intestinal flora compared with the model group， as manifested by the increase in the abundance of Firmicutes， Akkermansia， Dubosiella， and Blautia and the decrease in the abundance of Bacteroidetes， Muribaculaceae， Clostridia_UCG-014， and Alistipes. ConclusionMankuining decoction has definite effect in treating UC mice， and the effect is positively correlated with the concentration. In addition， different concentration has different influence on the structure of flora. The mechanism is the likelihood that it alleviates the disorder of intestinal flora to restore intestinal immune balance and further promote the recovery of colonic mucosa.