Protective effect of epigallocatechin-3-gallate against myocardial ischemia and reperfusion injury in rats

Objective To investigate the protective effect and mechanism of epigallocatechin-3-gallate against myocardial ischemia and reperfusion injury in rats.Methods The Sprague-Dawley rats underwent 30min of left anterior descending(LAD)coronary occlusion and 6 hours reperfusion to make ischemia/repefusion(I/R)injury model in vivo.Sixty male rats were randomly divided into 3 groups:sham group,I/R group,epigallocatechin-3-gallate group.Creatine kianse isoenzyme-MB(CK-MB)and the activity of Caspase-3 and the apoptotie index(AI)by TUNEL staining were measured in each group,I/R and EGCG group were measured the infarcted size(IS/AAR%).In addition,pathologic changes of myoeardial tissue were observed under electron microscopy.Results Compared with I/Rgroup,EGCG group markedly decreasedthe activity of CK-MB in serum[(951.57±123.71)vs(1826.38±205.32),P＜0.01]and the activity of Caspase-3 in myocardiaI tissue[(0.56±0.17)vs(0.81±0.20),P＜0.01],the value of IS/AAR% in EGCG group was lower than that in I/R group[(26.73±5.22)vs(41.56±6.81),P＜0.01].AI were significantly decreased in EGCG group compared with I/R group[(7.39±2.43)vs(15.62±4.28),P＜0.01].The electron microscopic examination showed that pathologic changes of myocardiocytes in the EGCG group were significantly milder than that of the I/R group.Conclusion Epigallocatechin-3-gallate has protective effect against myocardial ischemia and reperfusion injury in rats,and the protective mechanism may be related to decreasing the cardiomyocytes apoptosis by inhibition the activity of Caspase-3. Key words: Epigallocatechin-3-gallate; Apoptosis; Isehemia and reperfusion; Caspase-3