Effect of Tripterygium Glycosides on Differentiation and Balancing of Th17/Treg Cells in Rats With Experimental Colitis / 胃肠病学

ABSTRACT

Background: Immune factors play an important role in the pathogenesis of inflammatory bowel disease (IBD). Clinical studies have shown that tripterygium glycosides is effective for the treatment of IBD. Aims: To investigate the effect of tripterygium glycosides on differentiation and balancing of Th17/Treg cells in rats with experimental colitis. Methods: Experimental colitis was induced by TNBS-ethanol method in rats to evaluate the therapeutic effect of tripterygium glycosides. After intragastrically administered with normal saline (model group), tripterygium glycosides or mesalazine, respectively once a day for two weeks, the disease activity index (DAI) was assessed, and the colonic mucosal injury was examined macro- and microscopically. Mononuclear cells of mesenteric lymph nodes were extracted, and the levels of Th17/Treg-related cytokines in the supernatant were detected by ELISA method. The expression of proinflammatory cytokines in colon tissues was detected by immunohistochemistry. Results: The symptoms of experimental colitis were more severe in model group. DAI, gross morphological and histopathological score of colonic mucosal injury were significantly higher in model group than in tripterygium glycosides and mesalazine groups (P0.05). Compared with the model group, the levels of IL-23 and TNF-α in the supernatant of mesenteric lymph nodes mononuclear cells in mesalazine group, and the levels of IL-23, TNF-α and IL-6 in tripterygium glycosides group were significantly reduced (P0.05). In rats treated with mesalazine, the expression of IL-6 in colon tissues was down-regulated significantly (P<0.05). Conclusions: Tripterygium glycosides have the potential to inhibit the differentiation of Th17 cells and promote the differentiation of Treg cells in IBD. Regulating the imbalance of Th17/Treg cells might be one of the mechanisms of its therapeutic effect on IBD.