[Effect of Madecassoside on Intestinal Mucosal Immunity in Collagen-Induced Arthritis Rats]

To explore the changes of intestinal mucosal immunity in collagen-induced arthritis rats and the impact of madecassoside on these changes.

Collagen-induced arthritis was established in female Wistar rats. Treatment group was orally administrated madecassoside once daily for consecutive 21 days, while blank control and model groups were orally administered saline at the same volume. The concentrations of sIgA in small intestine content and IFN-γ in small intestinal tissue homogenate were determined by ELISA. The proportions of CD4+ T and CD8+ T in the epithelium and laminar propria of small intestine were detected by flow cytometry, and the ratios of CD4+/CD8+ were calculated. The relative expressions of CD80, CD86, IL-6, IL-12 and Foxp3 mRNA in the small intestine were determined by real-time PCR.

Compared with blank control rats, the concentrations of sIgA in small intestine content and IFN-γ in small intestinal tissue homogenate from model rats were increased, the ratios of CD4+/CD8+ in the epithelium and laminar propria of small intestine were higher and the relative expressions of CD80, CD86, IL-6 and IL-12 mRNA in the small intestine were increased. Madecassoside treatment decreased the concentrations of sIgA in small intestine content and IFN-γ in small intestinal tissue, downregulated the ratios of CD4+/CD8+ in the epithelium and laminar propria and decreased the relative expressions of CD80, CD86, IL-6 and IL-12 mRNA, while upregulated the relative expression of Foxp3 mRNA in the small intestine.

The intestinal mucosal immune response is enhanced in collagen-induced arthritis rats, the antigen presenting cells are activated abnormally and the immune tolerance is disturbed. Madecassoside treatment can downregulate the intestinal mucosal immune response and benefit for the induction and maintenance of intestinal immune tolerance.