Effect of Oxymatrine Mediated by RhoA/ROCK Signaling Pathway on Expression of E-cadherin and TGF-β in Ulcerative Colitis / 中国实验方剂学杂志

ABSTRACT

Objective:To investigate the mechanism of Oxymatrine on epithelial-mesenchymal transition mediated by RhoA/Rho-associated kinase(ROCK) signaling pathway to prevent and treat ulcerative colitis(UC) and its related canceration by detecting the changes of ROCK, E-cadherin and transforming growth factor-β(TGF-β)in colon tissues of mice. Method:Totally 48 male Balb/c mice were randomly divided into normal control group, model group, low, medium and high-dose Oxymatrine groups (25,50,100 mg·kg-1)and Y-27632 group(10 mg·kg-1), with 8 mice in each group. Mice in control group received distilled water, while all the other mice were treated with 3% dextra sulfate sodium for 7 days to induce the ulcerative colitis model. Since the first day of modeling,Y-27632(10 mg·kg-1)and different doses of Oxymatrine(25, 50, 100 mg·kg-1) were intraperitoneally injectedfor 7 days, and equal volume of PBS was intraperitoneally injected in normal group and model group. Body weight loss, stool consistency and fecal blood loss were observed on a daily basis. On the 8thday, mice were put to death,colon was collected and its length was measured; the scores of disease activity index (DAI) were evaluated; part of the colons were fixed and stained with hematoxylin and eosin (HE) for a histopathological analysis; the ultrastructural changes of mucosa tissue in ulcerative colitis were observed by transmission electron microscope. The expression levels of TGF-β in tissue mucosa were tested by enzyme-linked immunosorbentassay(ELISA). The expression levels of Rho-associated kinase-1, Rho-associated kinase-2, E-cadherin and TGF-β in colon were measured by Western blot and Real-time PCR. Result:Compared with normal group, model group showed the infiltration of a large number of inflammatory cells in mucosa and submucosa, disordered gland arrangement, varying degrees of intestinal mucosal defect and even ulcer formation. Under electron microscopy, microvilli were sparse on the surface of intestinal epithelial cells, the gap between cell junctions was widened, goblet cells were reduced and organelles were swollen. The disease activity index,and the expression levels of ROCK-1 and ROCK-2 proteins in the colonic mucosa of model group were increased(Pβ were decreased(PPPβ were increased(PPPβ and E-cadherin protein and mRNA levels were significantly decreased(PConclusion:Oxymatrine may alleviate ulcerative colitis by down-regulating the expression of Rho kinase,up-regulating the expressions of E-cadherin and TGF-β, inducing the apoptosis of intestinal epithelial cells, and mediating epithelial-mesenchymal transition.