RESUMO
OBJECTIVE To investigate the improvement effects of Runchang granules on the constipation in mice and its potential mechanism. METHODS The mice were randomly divided into normal control group， model group， Runchang granules low-dose and high-dose groups （5， 10 g/kg）， mosapride group （0.003 g/kg， positive control）， with 6 mice in each group. The latter 4 groups were given loperamide intragastrically （0.004 g/kg）， twice a day， for 3 consecutive days. Normal control group and model group were given purified water intragastrically， and administration groups were given relevant medicine intragastrically for 7 consecutive days. After the last medication， fecal moisture content and intestinal motility of mice were determined， while the structures of colon and ileum， and the secretion of colonic mucus were observed. Protein expressions of tyrosine kinase receptor （c-kit）， mucin 2 （MUC2） and stem cell factor （SCF） were determined in colon； meanwhile， the mRNA expression levels of inflammatory factors [tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， IL-1β， inducible nitric oxide synthase （iNOS）] as well as factors related to promoting intestinal motility [neuronal nitric oxide synthase （nNOS）， smooth muscle myosin light chain kinase （smMLCK）， 5-hydroxytryptamine 4 receptor （5-HT4R）， MUC2， SCF， c-kit] were determined. RESULTS Compared with model group， the fecal water content， intestinal propulsion rate， protein expression of c-kit in colon， relative expressions of MUC2 and SCF protein， and mRNA expressions of factors related to promoting intestinal motility （except for nNOS and SCF in Runchang granules low-dose group） were all increased significantly in Runchang granules low-dose and high-dose groups， and mosapride group （P＜0.05 or P＜0.01）. mRNA expression levels of inflammatory factors were decreased significantly（P＜0.05 or P＜0.01）. Both colon and ileum injuries improved， and the secretion of colon mucus was increased significantly in Runchang granules high-dose group （P＜0.01）. CONCLUSIONS Runchang granules have laxative effect and can improve constipation in mice， and its mechanism may be related to the promotion of the secretion of colon mucus and MUC2 expression， and the activation of SCF/c-kit signaling pathway.