Dietary soy isoflavone-induced increases in antioxidant and eNOS gene expression lead to improved endothelial function and reduced blood pressure in vivo

SPECIFIC AIMSThe cardiovascular risks associated with hormone replacement therapy in postmenopausal women have precipitated a search for alternative estrogen receptor modulators. Genistein, a major isoflavone in soy protein, binds to estrogen receptor β (ERβ) with much higher affinity than ERα, and plasma concentrations of genistein and daidzein range from 50 to 800 ng mL−1 in adults consuming soy-rich foods. The aim of the present study was to compare the effects of a soy protein (SP) versus a soy-deficient (SD) diet on indices of oxidative stress, endothelial function in vitro and arterial blood pressure in vivo in adult male rats. Because imbalanced maternal nutrition during pregnancy can lead to the development of cardiovascular disease in adulthood, dams were maintained on SP or SD diets for 4 months before gestation and weaning, and male offspring were then fed the same diets for up to 16 months. To assess whether impaired vascular reactivity in SD animals could be reversed, SD males were switched a...