Protective effects of tea polyphenols on intestinal injury induced by intestinal ischemia reperfusion in rats

Objective: To investigate the protective effects of tea polyphenols(TP) on intestinal injury induced by intestinal ischemia/reperfusion(I/R) and the possible mechanism,to provide pharmacological evidence for its new clinical uses.Methods: Rats were randomly divided into six groups: the sham group,I/R injury control group,and TP groups(100,50,25 and 12.5 mg·kg-1).The intestinal I/R injury was induced by clamping superior mesenteric artery for 1 h and reperfusing for 2 h.TP was administered by sublingual vein at 20 min before ischemia.Blood samples and mid-segment intestine samples were collected 2 h after reperfusion.SOD activity,MDA and NO contents in serum and intestine were determined,and pathological changes of intestine were observed.Results: After intestinal I/R injury,activity of SOD was decreased,while the levels of MDA and NO were increased in serum and intestine.In addition,intestine was destroyed obviously.TP dose-dependently increased SOD activity,decreased MDA and NO content in both serum and intestine,and attenuated pathological changes in intestine tissue after I/R injury.Conclusion: TP can dose-dependently protect against intestinal I/R injury.This protective effect relates to its anti-oxidant action.