Abstract: AIM: To investigate the roles of Bcl-2, Bax and NF-κB in the anti-apoptosis effect of allitridum. METHODS: Sodium pentobarbital-anesthetized Sprague Dawley (SD) rats underwent 30 min of left anterior descending (LAD) coronary occlusion followed by 120 min of reperfusion. Forty-eight rats were randomly divided into three groups: control (CON, n=12), ischemia/reperfusion (I/R, n=18) group and allitridum pretreatment (AP, n=18) group. Twenty-four h before operation, allitridum was given to the AP group and saline was administered to the other groups. CON group underwent only sham operation, whereas the other two groups underwent I/R operation. Infarct size ［IS/AAR(%)］ was measured in the I/R group and AP group, and creatine kinase isoenzyme-MB (CK-MB), superoxide dismutase (SOD) and apoptosis index (AI) by TUNEL staining were measured in each group. DNA fragmentation agarose gel electrophoresis was conducted on isolated DNA and the expression of Bcl-2 and Bax protein and the activity of NF-κB were measured, respectively, by immunohistochemistry and electrophoretic mobility assay (EMSA) in each group. RESULTS: Allitridum pretreatment decreased the infarct size compared with that in I/R group ［(21.8±1.5)% vs.(44.6±4.6)%, P<0.01］, CK-MB ［(16.4±1.6)U/L vs. (34.1±1.8)U/L, P<0.01］. However, SOD levels in AP group were higher than those in I/R group ［(2 337±215) U/mg pro vs. (1 219±187) U/mg pro, P<0.01］. AI in I/R group was higher than in AP group ［(4.0±3.0)% vs. (7.0±1.2)%, P<0.01］, which was consistent with the result of DNA fragmentation agarose gel electrophoresis. No immunoreactivity of Bcl-2 was observed in CON group. Bcl-2 immunoreactivity was weakly expressed in the I/R group and strongly expressed in the peri-necrosis zone in the AP group. The expression of Bax significantly increased in I/R group but was weaker in the AP group. NF-κB binding activity was present at low levels in CON group but significantly increased in the I/R group. Allitridum markedly inhibited NF-κB binding in the I/R group. CONCLUSION: Allitridum has an obvious effect of protecting myocardium against I/R injury and decreasing infarcted zone. The protective effect is probably achieved through decreasing myocardium apoptosis in I/R injury and modulating the expression of Bcl-2 and Bax and the binding activity of NF-κB.