Kangfuxin alleviates ulcerative colitis in rats by inhibiting NF-κB p65 activation and regulating T lymphocyte subsets.

Objectives: Ulcerative colitis (UC) remains an enduring, idiopathic inflammatory bowel disease marked by persistent mucosal inflammation initiating from the rectum and extending in a proximal direction. An ethanol extract of Materials and Methods: We established the UC model by TNBS/ethanol method. Then, the rats were subject to KFX (50, 100, 200 mg/kg/day) for 2 weeks by intragastric gavage. The body weight, disease activity index (DAI), colonic mucosal injury index (CMDI), and histopathological score were evaluated. The colonic tissue interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), IL-10, transforming growth factor-1 (TGF-β1), and epidermal growth factor (EGF) were determined by Elisa. To study T-lymphocyte subsets, flow cytometry was performed. In addition, the expression level of NF-κB p65 was evaluated by immunohistochemistry and western blot analysis. Results: Compared with the TNBS-triggered colitis rats, the treatment of rats with KFX significantly increased the body weight, and decreased DAI, CMDI, and histopathological score. Also, KFX elicited a reduction in the secretion of colonic pro-inflammatory cytokines, namely IL-1β, IL-6, and TNF-α, concomitant with up-regulation of IL-10, TGF-β1, and EGF levels. Upon KFX treatment, the CD3+CD4+/CD3+CD8+ ratio in the spleen decreased, while the CD3+CD8+ subset and the CD3+CD4+CD25+/CD3+CD4+ ratio demonstrated an increase. In addition, the expression of NF-κB p65 in the colon was decreased. Conclusion: KFX effectively suppresses TNBS-induced colitis by inhibiting the activation of NF-κB p65 and regulating the ratio of CD4+/CD8+.