Abstract:Objective: To study the effect of Banxia Xiexin Tang on intestinal immune function in fluorouracil-induced diarrhea mice, and to reveal the therapeutic mechanism on chemotherapy-induced diarrhea. Method: The fluorouracil(40 mg· kg-1) was intraperitoneal injected for 6 days to establish the diarrhea mice model. Sixty ICR mice were randomized into 6 groups:normal group, model group,montmorillonite powder group(1.17 g·kg-1), Banxia Xiexin Tang(2.5,1.25,0.625 g· kg-1) group, administrated by oral gavage for 2 day before modeling, the intervention period lasted 11 days. Then we observed the changes of daily activity status, food intake, body weight, diarrhea, measured the quality of the thymus and spleen, observed the pathological changes of ileal tissue, measured the expression of intestinal immunoglobulin A (IgA), vasoactive intestinal peptide (VIP), interleukin-15(IL-15)by ELISA method. Result: Compared to normal group, the diarrhea of model group mice was aggravated and the weight, thymus and spleen index were decreased, the levels of IgA and VIP were decreased, whereas the IL-15 was increased.Compared to model group,Banxia Xiexin Tang could significantly inhibit body weight loss, diarrhea and spleen, thymus reduction induced by fluorouracil in mice. Banxia Xiexin Tang could increase the levels of IgA and VIP and decrease IL-15 expression (P<0.05, P<0.01). Conclusion: Banxia Xiexin Tang could prevent the fluorouracil induced diarrhea by up-regulating the expression of IgA, VIP and down-regulating the expression of IL-15, thereby generating immune protection.