Integrating 16srRNA sequencing, non-targeted metabolomics, and transcriptome sequencing to explore the mechanism of Total glucosides of paeony alleviating ulcerative colitis.

Total glucosides of paeony (TGP), an active ingredient extracted from the dried root of Paeonia lactiflora Pall., has been approved in China for the treatment of various autoimmune diseases. However, the role and mechanism of TGP in UC have yet to be fully elucidated. This study aims to investigate the regulatory effects and underlying mechanisms of TGP on intestinal homeostasis disruption and immune imbalance in a mouse model of dextran sulfate sodium (DSS)-induced colitis. The results showed that TGP alleviated DSS induced body weight loss, colonic shortening and histopathological changes in mice, and also enhanced the integrity of the intestinal barrier by up-regulating the expression of ZO-1, Occludin and tight junction protein in the colon. The results of 16S and antibiotic cocktail (ABX) experiments showed that TGP alleviated colitis by inhibiting Th17 cell differentiation by correcting intestinal microbial imbalance in UC mice. Mechanism studies showed that TGP inhibited the activation of JAK2/STAT3 signaling pathway in UC mice, and decreased the levels of inflammatory factors in colon supernatant and serum. Importantly, TGP regulates JAK2/STAT3 to inhibit Th17 cell differentiation depending on gut flora. In addition, TGP can also improve the metabolic imbalance in UC mice, especially purine metabolism. In conclusion, TGP promotes the normalization of purine metabolism and relies on gut microbiota to regulate JAK2/STAT3 pathway, inhibit Th17 cell differentiation, and alleviate colitis. Our findings highlight TGP as a promising treatment candidate for ulcerative colitis.