Polyphenol (-)-epigallocatechin gallate targeting myocardial reperfusion limits infarct size and improves cardiac function.
BACKGROUND
This experiment was performed to determine the effect of polyphenolic (-)-epigallocatechin (EGCG), the most abundant catechin of green tea, given at reperfusion period.


METHODS
Isolated rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Green tea extract (GT) was perfused with the following concentrations; 0, 0.5, and 1 microM (GT-O, GT-0.5, and GT-1, respectively). In a next experiment, hearts were assigned randomly to one of the following groups; Control, EGCG-1 (1 microM of EGCG), and EGCG-10 (10 microM of EGCG). GT and EGCG were perfused for a period of 5 min before and 30 min after reperfusion. For comparison of cardioprotection among groups, morphometric measurement was performed by 2,3,5-triphenyltetrazolium chloride staning.


RESULTS
GT 1 microM (10.3 +/- 2.1%, P < 0.05) significantly reduced infarct volume as a percentage of ischemic volume compared to untreated hearts (27.4 +/- 1.1%). EGCG 10 microM (13.2 +/- 4.0%) significantly reduced myocardial infarction compared to control hearts (27.2 +/- 1.4%, P = 0.002). After 2 h of reperfusion, cardiodynamic variables, including left ventricular developed pressure, rate-pressure produce, +dP/dt(max), and -dP/dt(min) were significantly improved by 10 microM of EGCG compared to control hearts (P = 0.01, 0.016, 0.009, and 0.019, respectively).


CONCLUSIONS
EGCG treatment at an early reperfusion period reduces myocardial infarction and improves cardiodynamics in isolated rat hearts.
Kim
Chan Jin
CJ
Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea.
Kim
Jin Mo
JM
Lee
Seung Ryong
SR
Jang
Young Ho
YH
Kim
June Hong
JH
Chun
Kook Jin
KJ