Protection of Ginkgo biloba extract on cardiomyocyte after acute myocardial infarction in rats

Objective: To study the protective effect of Ginkgo biloba extract (EGb761) on cardiomyocyte after acute myocardial infarction (AMI) in rats.Methods: Thirty male Sprague-Dawley rats were randomly divided into sham group (group A),AMI group (group B),EGb761 group (group C),ten in each group.In group C,EGb 761 (20 mg/kg) was injected intraperitoneally,in group A and group B,normal saline (20 mg/kg) was injected intraperitoneally.All the liquid was injected once a day for 3 days.The animal model was established by ligating left anterior descending coronary artery on the third day.The operation in group A was similar to group B except for ligating the left anterior descending coronary artery.At the end of experiment,the levels of the superoxide dismutase (SOD),malondialdehyde (MDA),apoptotic index (AI),mitochondrial membrane potential and the expression of Cyt-c and caspase-9 were measured.Results: Compared with group B,the contents of MDA,AI,caspase-9 and cytoplasmic Cyt-c were significantly lower in group C (P<0.01).The level of SOD,the expression of mitochondrial Cyt-c and mitochondrial membrane potential were significantly higher in group C (P<0.01).Conclusions: EGb 761 can decrease apoptosis in ischemic myocardium after acute myocardial infarction.The mechanism is possibly that EGb 761 can decrease oxidative stress,protect mitochondrial functions and reduce the release of Cyt-c from mitochondria to cytoplasma.