EGCG decreases myocardial infarction in both I/R and MIRI rats through reducing intracellular Ca2+ and increasing TnT levels in cardiomyocytes

Abstract

Background. Myocardial ischemia/reperfusion injury (MIRI) usually induces serious health problems.Objectives. This study attempted to explore protective effects of (−)-epigallocatechin-3-gallate (EGCG) on MIRI and the associated mechanism. Materials and methods.Ischemia/reperfusion of an isolated rat heart (I/R model) and the MIRI model were used in this study. Myocardial infarction was measured with staining with 2,3,5-triphenyltetrazolium chloride (TTC). Ca 2+ and troponin T (TnT) concentrations in coronary perfusion fluid were evaluated using the chromatometry method. Ca 2+ concentration in cardiomyocytes was determined with detecting Ca 2+ fluorescence intensity. The ultrastructure of cardiomyocytes was observed using transmission electron microscopy (TEM). β-nicotinamide adenine dinucleotide (NAD + ) of cardiomyocytes was also determined. Results.The EGCG (I/R+EGCG) significantly reduced myocardial infarction size of isolated rat heart compared to I/R rats (p < 0.05), remarkably increased Ca 2+ and decreased TnT concentrations in coronary perfusion fluid of I/R rats compared to the I/R model (p < 0.05), as well as markedly decreased intracellular Ca 2+ concentration and promoted NAD + concentration in cardiomyocytes compared to I/R rats (p < 0.05). It also obviously maintained the mitochondrial structure in cardiomyocytes of I/R rats and improved the ultrastructure of cardiomyocytes of MIRI rats. Lonidamine (LND) treatment (I/R+EGCG+LND group) significantly blocked the effects of EGCG on I/R injury compared to the I/R+EGCG group (p < 0.05). The EGCG (MIRI+EGCG) significantly decreased myocardial infarction size compared to MIRI rats (p < 0.05) and remarkably enhanced Ca 2+ and reduced TnT concentrations in the pulmonary artery compared to that of MIRI rats (p < 0.05). Conclusions.The EGCG decreased myocardial infarction size in both I/R models and MIRI models by reducing intracellular Ca 2+ concentration, increasing TnT concentration, promoting NAD + concentration, and improving the ultrastructure of cardiomyocytes.

Cardioprotective Effect of Epigallocatechin Gallate in Myocardial Ischemia/Reperfusion injury and Myocardial Infarction: a Meta-analysis in Preclinical Animal Studies

“…A meta-analysis of 15 studies, involving 231 animals 16, [19][20][21]23,25,26,[28][29][30][31][32][33]35,36 , showed that the EGCG treatment signi cantly reduced the myocardial infarct size (IS) compared to controls (SMD=-4.06; 95% CI: -5.17, -2.94; P < 0.01; I 2 = 77%) (Fig. 2a).…”

“…The effects of EGCG on serum biomarkers of myocardial injury were evaluated by creatine kinase (CK), creatine kinase isoenzyme (CK-MB), lactic dehydrogenase (LDH), and troponin T (TnT). Four publications involved 64 animals utilizing CK 13,14,18,26 , 6 publications involved 112 animals utilizing CK-MB 13,22,24,32,33,37 , 8 publications involved 132 animals utilizing LDH 13,18,[24][25][26]31,33,37 , and 2 publications involved 24 animals utilizing TnT 24,30 , as the outcome measure. Compared to controls, EGCG signi cantly reduces serum CK (SMD=-4.66; 95% CI: -6.72, -2.59; P < 0.01; I 2 = 73%; Fig.…”