Abstract

Aim: We isolated and identified RAP1, an active polypeptide in Rhizoma Alismatis, and investigated its anti-inflammatory mechanism.

Methods: Chronic colitis was induced in mice by dextran sulfate sodium (DSS). After RAP1 intervention, the life status, body weight and pathological score of mice were measured. The proportions of regulatory T cells (Treg), helper T cells 1 and 17 (Th1 and Th17) in mesenteric lymph nodes and spleen were determined by flow cytometry (FCM). Cytokine levels were detected by enzyme-linked immunosorbent assay (ELISA), and protein expressions were assayed by Western-Blotting.

Results: RAP1 improved the immune balance, increased the proportion of Tregs, while decreased the proportions of Th1 and Th7 cells. Meanwhile, it could lower the levels of inflammatory cytokines, ameliorate the chronic colitis and reduce the tissue inflammation and permeability.

Conclusions: RAP1 can inhibit tissue inflammation in chronic colitis by regulating intestinal immune balance, which is one of its mechanisms.