Study on the regulation of brain–gut peptide by Shenling Baizhu San in functional diarrhea rats

Abstract Objective To explore the therapeutic mechanism of Shenling Baizhu San (SLBZS) on functional diarrhea (FDr) by studying the brain–gut axis and related neuropeptides. Methods Sixty male Wistar rats were randomly divided into the control group, model group, SLBZS-treated group and Montmorillonite Powder-treated group (MP-treated group) (n = 15/group). Rats received gavage after the establishment of functional diarrhea. An equal volume of SLBZS solution and Montmorillonite Powder (MP) solution was administered to the SLBZS-treated group and MP-treated group, respectively, and an equal volume of distilled water was administered to the control group and the model group. The chemical components and targets related to SLBZS were identified from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and Traditional Chinese Medicine Integrated Database (TCMID). The effective chemical components were screened based on oral bioavailability (OB) and drug like-index (DL), and their biological functions were analyzed by GlueGO. Based on this screening, the expression of Cholecystokinin (CCK) and Ghrelin in the hypothalamus of rats was detected by real-time PCR (RT-PCR) and western blotting. Results In this study, 72 effective components and 190 core targets of SLBZS were screened. SLBZS may regulate smooth muscle contraction, energy metabolism and other biological processes. The results of RT-PCR showed that in the model group, the expression of CCK mRNA ( P  = .001) and Ghrelin mRNA ( P  = .000) increased significantly. Compared with the model group, CCK mRNA ( P  = .007) and Ghrelin mRNA ( P  = .001) levels in SLBZS-treated rats were decreased significantly. The results of western blotting showed that in the model group, the protein expression of CCK ( P  = .001) and Ghrelin ( P  = .000) increased significantly. The protein levels of CCK ( P  = .001) and Ghrelin ( P  = .005) in the SLBZS-treated group were decreased significantly compared with the model group. Conclusion SLBZS improved functional diarrhea by regulating the brain–gut axis. Changes in the expressions of brain–gut peptide, CCK and Ghrelin might explain the pathogenesis of functional diarrhea related to brain–gut peptide and gastrointestinal hormone.