Abstract:Objective To investigate the mechanism of water-soluble propolis (WSP) in relieving dextran sulfate sodium (DSS)-induced intestinal inflammation in ulcerative colitis (UC) rats. Methods SD rats were randomly divided into 5 groups:CON, DSS, L-WSP, M-WSP, H-WSP. By measuring disease activity index (DAI) score, colon length, small intestinal mucosa permeability and histological score (HS) of rats, the degree of intestinal inflammation injury in each group was evaluated. ELISA was used to detect the level of IL-6, IL-9 and TNF-α in colon homogenate of rats. Results Compared with CON group, DSS group experienced severe weight loss, loose stools, and bloody stools, shortened colon length, and increased HS(P<0.05). While compared with DSS group, M-WSP group and H-WSP group were significantly improved (P<0.01,P<0.05). Compared with CON group, the content of proinflammatory cytokines IL-6, IL-9 and TNF-α in colon tissue homogenate in DSS group increased significantly(P<0.05), while decreased significantly in M-WSP group and H-WSP group compared with CON group(P<0.01,P<0.05). Conclusion WSP can improve the intestinal mucosal barrier function and reduce intestinal inflammation by reducing the levels of proinflammatory cytokines IL-6, IL-9 and TNF-α.