Phytoestrogen α-zearalanol improves vascular function in ovariectomized hyperhomocysteinemic rats.

Previous studies have showed that phytoestrogen α-zearalanol (α-ZAL) could antagonize homocysteine (Hcy) induced endothelin-1 (ET-1) expression, oxidative stress and apoptosis in human umbilical vein endothelial cells in vitro, however, its effect on vascular function in vivo remains to be determined. This study was designed to investigate the effects of α-ZAL on vascular function in ovariectomized (OVX) hyperhomocysteinemia (HHcy) rats and explore the mechanisms involved primarily. HHcy rat model was induced by diets containing 2.5% methionine (Met) for 12 weeks. Forty adult female Wistar rats were assigned randomly into five groups: (1) Con; (2) Met; (3) OVX+Met; (4) OVX+Met+α-ZAL; (5) OVX+Met+17β-E(2) (17β-estradiol). Blood was collected to analyze plasma estradiol, Hcy and ET-1. Thoracic aortas were isolated to detect its response to phenylephrine (PE) and acetylcholine (ACh) or sodium nitroprusside (SNP). Aortas eNOS expression was determined by Western blot. Thoracic aortas histological characterization was analyzed by optical microscope and scanning electron microscope (SEM). Rat plasma Hcy was significantly elevated after fed with 2.5% methionine diets, and ovariectomy aggravated this elevation. Phytoestrogen α-ZAL or 17β-E(2) could attenuate this elevation. Plasma ET-1 levels increased significantly in ovariectomized HHcy rats, and supplement with α-ZAL or 17β-E(2) could reverse these changes. In rats of OVX+Met group, PE elicited significantly greater contraction in a dose-dependent manner in endothelium-intact thoracic aortas rings; ACh elicited significantly less percentage relaxation. These effects were significantly attenuated by supplement with α-ZAL or 17β-E(2). There was no significant difference between groups in relaxation induced by SNP whether endothelium intact or not. Thoracic aortas morphology study also showed severe endothelium injury in ovariectomized HHcy rats, both α-ZAL and 17β-E(2) could attenuate this change. Aortas eNOS expression was decreased in ovariectomized HHcy rats, and supplement with α-ZAL or 17β-E(2) could reverse these changes. These findings demonstrated that α-ZAL could effectively alleviate the impairment of endothelial cells and improve vascular function in ovariectomized HHcy rats by decreasing plasma Hcy and antagonizing decreasing of aortas eNOS expression. This protective effect is somewhat similar with 17β-E(2).

Zhen PP ，Duan JH ，Zhao Q ，Hou DD ，Wang HX ，Hong N ，Zhen HX ，Wang W ... -  《-》

Genistein attenuates vascular endothelial impairment in ovariectomized hyperhomocysteinemic rats.

Zhen P ，Zhao Q ，Hou D ，Liu T ，Jiang D ，Duan J ，Lu L ，Wang W ... -  《-》

Relaxing effects of phytoestrogen alpha-zearalanol on rat thoracic aorta rings in vitro.

Wang W ，Jiang D ，Zhu Y ，Liu W ，Duan J ，Dai S ... -  《CHINESE JOURNAL OF PHYSIOLOGY》

Phytoestrogen alpha-zearalanol antagonizes homocysteine-induced imbalance of nitric oxide/endothelin-1 and apoptosis in human umbilical vein endothelial cells.

Duan J ，Dai S ，Fang CX ，Sun R ，Shavali S ，Sharma SK ，Ebadi M ，Ren J ... -  《CELL BIOCHEMISTRY AND BIOPHYSICS》

[17β-estradiol protects against injury of aortic relaxation and contraction in ovariectomized rats with insulin resistance induced by fructose].

Zhou SH ，Ling HY ，Tian SW ，Liu XQ ，Wang BX ，Hu B ... -  《-》