EFFECTS OF NATURAL ANTIOXIDANT GINKGO-BILOBA EXTRACT (EGB-761) ON MYOCARDIAL ISCHEMIA-REPERFUSION INJURY

Recently, it was reported that Ginkgo biloba extract (EGb 761), which is known to have antioxidant properties, also has antiarrhythmic effects on cardiac reperfusion-induced arrhythmias. In the present study, effects of EGb 761 on cardiac ischemia-reperfusion injury were investigated from the point of view of recovery of mechanical function as well as the endogenous antioxidant status of ascorbate. Isolated rat hearts were perfused using the Langendorff technique, and 40 min of global ischemia were followed by 20 min of reperfusion. EGb 761 improved cardiac mechanical recovery and suppressed the leakage of lactate dehydrogenase (LDH) during reperfusion. Furthermore, EGb 761 diminished the decrease of myocardial ascorbate content after 40 min of ischemia and 20 min of reperfusion. Interestingly, EGb 761 also suppressed the increase of dehydroascorbate. These results indicate that EGb 761 protects against cardiac ischemia-reperfusion injury and suggest that the protective effects of EGb 761 depend on its antioxidant properties.