Flower extract of Caragana sinica. ameliorates Dss-induced ulcerative colitis by affecting TLR۴/NF-κB and TLR۴/MAPK signaling pathway in a mouse model

Objective(s): This study aimed to find out the protective effects and preliminary mechanisms of the flower extract of Caragana sinica (FEC) on dextran sulfate sodium salt (DSS)-induced colitis.Materials and Methods: The ulcerative colitis models of mice induced by ۳% DSS were established and treated with FEC. Body weight changes, disease activity index (DAI), colon histopathological score, anti-oxidant ability, and the level of inflammatory cytokines were determined. The expression of Toll-like receptor ۴ (TLR۴) and myeloid differentiation factor ۸۸ (MyD۸۸) were assessed in colonic tissue by immunohistochemical staining. Western blot was used to analyze the expression of TLR۴/ nuclear factor kappa-B (NF-κB) and TLR۴/ mitogen-activated protein kinase (MAPK) signaling pathway-related proteins. Results: FEC significantly prevented body weight loss and colonic shortening and reduced the disease activity index and histopathological score (p <۰.۰۵). Moreover, FEC treatment remarkably down-regulated the levels of myeloperoxidase (MPO), interleukin-۱beta (IL-۱β), tumor necrosis factor-alpha (TNF-α), and interleukin ۶ (IL-۶) and up-regulated the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and interleukin ۱۰ (IL-۱۰) in the colon of DSS mice (p <۰.۰۵). Furthermore, the expression of TLR۴/NF-κB and TLR۴/MAPK pathway-related proteins was inhibited by FEC (p <۰.۰۵). Conclusion: Our findings demonstrated that FEC could serve as a potential therapeutic agent for treatment of ulcerative colitis.