Abstract:Objective To investigate the effects of tetrandrine(Tet) on expression of pro-inflammatory factors, including TNF-α, IL-1β and IL-6, in rat suffering from cardiac ischemia/reperfusion(I/R) injury, and the mechanism through which Tet attenuates cardiac I/R injury. Methods Totally 80 male Sprague-Dawley(SD) rats were randomly divided into 4 groups: sham group, I/R group, Tet group and simvastatin(Sim) group. The SD rats in I/R group were subjected to 30- min left anterior descending (LAD) coronary occlusion and 24-h reperfusion to make I/R injury model in vivo. The rats in sham group were not subjected to similar procedures except artery occlusion. The rats in Tet group received abdo minal injection of Tet at 20 min before I/R injury. The rats in Sim group received intragastric ad ministration of Sim (2 mg/kg) for 14 days before I/R injury. Cardiac function was assessed using two-dimensional(2-D) ultrasound, including left ventricular end-diastolic dimension(LVDd), left ventricular end-systolic dimension(LVDs), fractional shortening(FS), and left ventricular ejection fraction(LVEF). The serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) were detected. The expression levels of TNF-α, IL-1β and IL-6 in serum and myocardial tissue were detected by ELISA. The neutrophil infiltration degree in myocardium was deter mined by measuring the activity of myeloperoxidase (MPO) method. Azovan Blue/2,3,5-Tripheny-2H-Tetrazoliam Chloride (EB/TTC) dyeing method was used to measure the infraction size. Results The LDH and CK levels were significantly higher in I/R, Tet and Sim groups than in sham group (P<0.01), and were much lower in Tet and Sim groups than in I/R group (P<0.01); there was no difference between Tet and Sim groups (P>0.05). Myocardial infarction size, ratio of infarction size to left ventricular myocardial size, and ratio of infarction size to ischemia size were lower in Tet and Sim groups than in I/R group (P<0.01); there was no difference between Tet and Sim groups (P>0.05). Compared with sham group, FS, LVEF and E/A were decreased significantly in I/R, Tet and Sim groups(P<0.01), which was higher in Tet and Sim groups than in I/R group(P<0.01). The activity of MPO was significantly higher in I/R, Tet and Sim groups than in sham group (P<0.01), and in Tet group than in Sim group (P>0.05); there was no difference between Tet and Sim groups (P>0.05). The levels of TNF-α, IL-1β and IL-6 were significantly higher in in I/R, Tet and Sim groups than in sham group (P<0.01), and in Tet and Sim groups than in I/R group (P<0.01); there was no difference between Tet and Sim groups (P>0.05). Conclusion Tet can attenuate myocardial I/R injury. It achieves this pharmacologic action through reducing the levels of harmful cytokines including TNF-α, IL-6 and IL-1β.