Suppression of Th17 Cell Response in the Alleviation of Dextran Sulfate Sodium-Induced Colitis by Ganoderma lucidum Polysaccharides

Background. Ganoderma lucidum polysaccharides (GLP) has anti-inflammatory and immunomodulatory effects. Dysregulated immune responses are involved in the pathogenesis of dextran sulfate sodium (DSS)-induced colitis. The aim of this study was to assess the therapeutic potential of GLP to alleviate DSS-induced colitis. Methods. The mice were administered with GLP by intragastric gavage daily for two weeks prior to the DSS treatment. Mice were orally administered with 2.5% DSS dissolved in drinking water with GLP or water treatment for 6 days. The mice were killed on day 7 after induction of colitis. Survival rates, body weight loss, colon lengths, histological changes, and disease activity index scores (DAI) were evaluated. Results. GLP significantly improved survival rates, colon length shortening, body weight loss, histopathological score, and DAI scores in mice with DSS-induced colitis. GLP markedly suppressed the secretions of TNF-α, IL-1β, IL-6, IL-17A, and IL-4 and significantly affected populations of Th17 cells, B cells, NK cells, and NKT cells in the lamina propria lymphocytes. Conclusions. GLP prevented inflammation, maintained intestinal homeostasis, and regulated the intestinal immunological barrier functions in mice with DSS-induced colitis.