RESUMEN
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 CK-MB, 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 TFEB-treated 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.