Methanol extract of Cassia mimosoides var. nomame attenuates myocardial injury by inhibition of apoptosis in a rat model of ischemia-reperfusion.

摘要

Interruption of blood flow through coronary arteries and its subsequent restoration triggers the generation of a burst of reactive oxygen species (ROS), leading to myocardial cell death. Effects of a methanol extract of Cassia mimosoides var. nomame (used to prepare herbal tea in Asia) on myocardial ischaemia-reperfusion injury were determined. When radical scavenging activity of the extract was measured in vitro using its alpha, alpha-diphenyl- beta-picrylhydrazyl (DPPH) radical quenching ability, it had activity slightly lower than that of ascorbic acid. 3 days after oral administration of the extract (400 mg/kg/day) to rats, myocardial ischaemia/reperfusion injury was generated by 30 min of ligation of the left anterior descending coronary artery (LAD), followed by 3 h reperfusion. Compared with the control group, administration of the extract markedly reduced infarct size (IS) (ratio of infarct area to area at risk) by 28.3%. Reduction in cellular injury was mediated by attenuation of Bax/Bcl-2 ratio by 33.3%, inhibition of caspase-3 activation from procaspase-3 by 40%, and subsequent reduction in the number of apoptotic cells by 66.3%. Results suggest that the extract attenuates myocardial injury in a rat model of ischaemia-reperfusion by scavenging ROS, including free radicals, and consequently blocking apoptotic cascades. Intake of C. mimosoides var. nomame may prevent ischaemic myocardial injury.