6533b826fe1ef96bd1283c8e

RESEARCH PRODUCT

Phytoestrogens increase the capacity of serum to stimulate prostacyclin release in human endothelial cells

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Both the estrogen receptor (ER) alpha and beta isoforms are expressed in the endothelium. The ER beta has been assigned a crucial role in normal vascular wall function. Prostacyclin has been ascribed a beneficial effect on vessel wall physiology. Isoflavones bind with higher affinity to ER beta. We investigated the hypothesis that their administration to postmenopausal women can promote endothelial prostacyclin production.Twenty-five healthy postmenopausal women with mild climacteric symptoms received capsules containing 55 mg/day isoflavones derived from soy and red clover for 6 months. Cultured human umbilical vein endothelial cells (HUVECs) were exposed for 24 h to serum collected before the initiation of therapy and then after 3 and 6 months of continuous therapy. Prostaglandin production was measured in culture medium.In the presence of serum obtained after isoflavone treatment, the prostacyclin production increased significantly from 2.7 +/- 0.5 ng/mg protein at baseline to 3.4 +/- 0.7 ng/mg protein at 3 months (por = 0.05), and to 3.8 +/- 0.7 ng/mg protein at 6 months (por = 0.05 vs. baseline and 3 months' treatment).Serum obtained from postmenopausal women treated with isoflavones stimulates the capacity to produce prostacyclin by HUVECs in culture, an effect that could contribute to a beneficial cardiovascular effect of phytoestrogens.