Total flavones from Elsholtzia blanda reduce infarct size and improve heart function during acute myocardial infarction by inhibiting myocardial apoptosis in canines

Abstract

Objective — The current study tests the hypothesis that inhibition of apoptotic cell death with total flavones from Elsholtzia blanda(TFEB), a traditional Chinese medicine, reduces infarct size and improves heart function during myocardial ischaemia induced by coronary occlusion in canines.Methods and results — Myocardial apoptosis was detected by the TdT-mediated dUTP nick end labelling (TUNEL) method and DNA laddering. Infarct size of the left ventricle, serum level of CKMB, haemodynamic parameters including rate of rise and decline of left ventricular pressure (± dp/dtmax), left ventricular systolic pressure (LVSP), main arterial pressure (MAP), coronary blood flow (CBF), coronary vascular resistance (CVR) were measured in this study. TUNEL positive cells were markedly reduced from 27.83 ± 8.15 % in the control dogs to 7.74 ± 3.50 % in the TFEBtreated ones (P < 0.01), consistent with the absence of DNA laddering. TFEB significantly reduced infarct size from 19.30 ± 6.66 % in the control dogs to 8.87 ± 1.66 % (P < 0.01), confirmed by lower serum CK-MB activity. TFEB significantly reduced MAP and CVR.The decrease in ± dp/dtmax, LVSP and CBF also tended to be much smaller in the TFEB treated group.Conclusion — These data suggest that the inhibitory effect of TFEB on apoptosis during coronary occlusion is associated with reduction in infarct size and improvement in heart function.