Effect of the liver-regulating and spleen-strengthening method on the expression of Toll-like receptor 4 and occludin in the intestinal mucosa of rats with nonalcoholic fatty liver disease

Objective To investigate the effect of the liver-regulating and spleen-strengthening method on the expression of Toll-like receptor 4(TLR4) and occludin in the intestinal mucosal barrier of rats with nonalcoholic fatty liver disease(NAFLD) induced by high-fat and high-sugar diet. Methods A total of 50 male Sprague-Dawley rats were randomly divided into normal group,model group,liver-regulating and spleen-strengthening group,liver-regulating group,and spleen-strengthening group. A rat model of nonalcoholic steatohepatitis was established by high-fat and high-sugar diet for four weeks. The five groups were observed in terms of the degree of hepatic steatosis,the change in liver function,and the expression of the tight junction protein occludin in the intestinal mucosa and TLR4 in the intestinal epithelium. A one-way analysis of variance was used for comparison between multiple groups,and the least significant difference t-test was used for further comparison between two groups. Results Compared with the normal group,the model group showed hepatic steatosis and had significant increases in the serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST)(P<0. 05),as well as a reduction in the expression of the tight junction protein occludin in intestinal epithelial cells and an increase in the expression of TLR4 in the intestinal epithelium. Compared with the model group,the three treatment groups had a significant reduction in the degree of steatosis,a significant increase in the expression of occludin,and a significant reduction in the expression of TLR4 in the intestinal epithelium. Among the three treatment groups,the liver-regulating and spleen-strengthening group had the lowest degree of steatosis and significantly greater reductions in the serum levels of ALT and AST than the model group(P < 0. 05),as well as significantly greater changes in the expression of occludin and TLR4. Conclusion The liver-regulating and spleen-strengthening method can improve intestinal mucosal barrier function by increasing the expression of the tight junction protein occludin in intestinal epithelial cells and reducing the expressionof TLR4 in the intestine,with a better clinical effect than the liver-regulating method or the spleen-strengthening method alone.