MMP2 and colitis: In this study, the colitis rats with Hcy injection simultaneously showed increased EB content and MMP-2, MMP-9 levels as compared with the colitis control group, suggesting that Hcy can increase intestinal mucosal permeability, the underlying mechanisms of which may be attributed to its effects of promoting inflammatory injury and expression of MMP-2 and MMP-9, leading to injury of the intestinal barrier.