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. In this study, we determined whether a
methanol extract of Cassia mimosoides var. nomame Makino could prevent
myocardial ischemia-
reperfusion injury. When radical scavenging activity of the extract was measured in vitro using its α,α-
diphenyl-β-picrylhydrazyl (DPPH) radical quenching ability, the extract showed an activity slightly lower than that of
ascorbic acid. Three days after
oral administration of the extract (400 mg/kg/day) to rats,
myocardial ischemia/
reperfusion injury was generated by 30 min of
ligation of the left anterior descending coronary artery (LAD), followed by 3 hr reperfusion. Compared with the vehicle-treated group, administration of the extract significantly reduced
infarct size (IS) (ratio of
infarct area to area at risk) in the extract-treated group by 28.3%. Reduction in the cellular injury was mediated by attenuation of Bax/Bcl-2 ratio by 33.3%, inhibition of
caspase-3 activation from procas-pase-3 by 40%, and subsequent reduction in the number of apoptotic cells by 66.3%. These results suggest that the extract attenuates myocardial injury in a rat model of
ischemia-reperfusion by scavenging ROS, including
free radicals, and consequently blocking apoptotic cascades. Therefore, intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic myocardial injury.