Soy Isoflavone Protects Myocardial IschemiaReperfusion Injury through Increasing Endothelial Nitric Oxide Synthase and Decreasing Oxidative Stress in Ovariectomized Rats

الملخص EN

There is a special role for estrogens in preventing and curing cardiovascular disease in women.

Soy isoflavone (SI), a soy-derived phytoestrogen, has similar chemical structure to endogenous estrogen-estradiol.

We investigate to elucidate the protective mechanism of SI on myocardial ischemia/reperfusion (MI/R) injury.

Female SD rats underwent bilateral ovariectomy.

One week later, rats were randomly divided into several groups, sham ovariectomy (control group), ovariectomy with MI/R, or ovariectomy with sham MI/R.

Other ovariectomy rats were given different doses of SI or 17β-estradiol (E2).

Four weeks later, they were exposed to 30 minutes of left coronary artery occlusion followed by 6 or 24 hours of reperfusion.

SI administration significantly reduced myocardial infarct size and improved left ventricle function and restored endothelium-dependent relaxation function of thoracic aortas after MI/R in ovariectomized rats.

SI also decreased serum creatine kinase and lactate dehydrogenase activity, reduced plasma malonaldehyde, and attenuated oxidative stress in the myocardium.

Meanwhile, SI increased phosphatidylinositol 3 kinase (PI3K)/Akt/endothelial nitric oxide synthase (eNOS) signal pathway.

SI failed to decrease infarct size of hearts with I/R in ovariectomized rats if PI3K was inhibited.

Overall, these results indicated that SI protects myocardial ischemia/reperfusion injury in ovariectomized rats through increasing PI3K/Akt/eNOS signal pathway and decreasing oxidative stress.