AimExploration of the protective effects of Guanxinshutong (GXST)against Oxidative Stress(OS) injury following ischemia/reperfusion.MethodsThirty male Sprague Dawley rats were randomized into three groups: non-MI/R group (Sham, n=10), MI/R group treated with vehicle (Model, n=10) and MI/R group treated with GXST (Drug, n=10).MI/R was induced by ligation of the left anterior descending coronary artery (LAD) for 30 min, followed by 3 h reperfusion in the model and Drug groups.In the Sham group, the LAD was exposed without occlusion.GXST powder (in the Drug group) or saline (in the Model and Sham groups) were administered via direct gastric gavage from 5 days prior to surgery.Blood samples were collected from the carotid artery after 3 h of reperfusion, to determine the levels of CK-MB, LDH, Tn-T, MDA, SOD, TNOS, iNOS and NO.ResultsGXST significantly decreased levels of CK-MB, LDH, Tn-T, MDA and iNOS; increased levels of SOD, TNOS and NO compared with the model group (all p<0.05).ConclusionsGXST is effective in protecting the myocardium against MI/R injury in rats.Its possible cardioprotective mechanism involves inhibition of the OS injury following MI/R.