Objective: This study aims to observe the effect of Qihuang decoction on small intestinal mucosal barrier after gastrectomy in rats.
Materials and methods: A total of 80 Wistar rats were randomly divided into normal group, sham operation group, enteral nutrition group (EN) and Qihuang decoction group (EN+QH), there were 20 rats in each group. Both the EN group and the EN+QH group underwent gastrectomy. Instillation of enteral nutrition in the small intestine was performed after operation in the EN group. Instillation of enteral nutrition and Qihuang decoction in the small intestine was performed after operation in the EN+QH group. Only the abdominal incision and closing was performed in the sham operation group without drug and nutritional intervention. The expression levels of tight junction proteins in intestinal epithelial cells were determined by western blotting method. The sIgA content in different anatomic sites of intestinal mucosa was determined by double antibody-PEG radioimmunoassay technique. The number of IgA+B cells in different anatomic sites of intestinal mucosa was determined by immunohistochemical method.
Results: The sIgA content in the sham operated group was significantly lower than that of normal group (P<0.05). The sIgA content and the number of IgA+B cells in Peyer's patches and lamina propria lym-phocytes in the EN+QH group were significantly higher than that of EN group (P<0.01, P<0.05). The expression levels of RhoA, Rac1 and Cdc42 increased in the EN group, and the phosphorylation levels of occludin, claudin-1, claudin-5, ZO-1 and ZO-2 also increased in the EN group, while the expression levels of non-phosphorylated occluding, claudin-1, claudin-5, ZO-1 and ZO-2 proteins decreased in the EN group (P<0.01, P<0.05). After treatment of Qihuang decoction for 7 days, compared with EN group, the expression levels of RhoA, Rac1 and Cdc42, and the phosphorylation levels of occludin, claudin-1, claudin-5, ZO-1 and ZO-2 significantly decreased in the EN+QH group, while the expression levels of non-phosphorylated occluding, claudin-1, claudin-5, ZO-1 and ZO-2 proteins significantly increased in the EN+QH group (P<0.01, P<0.05).
Conclusions: Qihuang decoction can promote the proliferation and differentiation of IgA+B lymphocytes and increase the sIgA content in intestinal mucosal immune barrier after gastrectomy in rats, it also can promote the expression of tight junction proteins to improve the permeability of intestinal mucosa and promote the recovery of intestinal immune barrier dysfunction in rats after gastrectomy by inhibiting the tight junction associated proteins' phosphorylation induced by Rho/ROCK signaling pathway.
Keywords: Qihuang decoction; ZO-1 protein; claudin1 protein; immune barrier; occludin protein; tight junction.