title: Multiple mechanisms of soy isoflavones against oxidative stress-induced endothelium injury.
abstract: Diabetic vascular complications are related to a combination of oxidative stress and hyperglycemia. Here we investigate the effect and mechanism of soy isoflavones on oxidative stress-induced endothelial cell injury. Oxidative stress was modeled in primary cultured human umbilical vein endothelial cells by incubation with H(2)O(2) and high glucose. Genistein and daidzein protected the cells against H(2)O(2)-induced apoptosis and their protective actions were abolished by ICI 182780, an estrogen receptor antagonist. The inhibition of cell proliferation by oxidative stress was prevented by genistein and daidzein under normal glucose conditions, but they were less effective at high glucose levels. Genistein and daidzein upregulated the estrogen receptor ERbeta and increased Bcl-2 expression. Silencing of Bcl-2 with siRNA abolished the protection of genistein. Moreover, inhibition of the PI3K and Rho A/Rho kinase pathways by wortmannin and Y-27632 altered the effects of genistein and daidzein on cell survival. We conclude that oxidative stress-induced apoptosis and cell proliferation inhibition can be prevented by soy isoflavones via the regulation of ERbeta and Bcl-2/Bax expression and modulation of cell survival signaling, such as the PI3K pathway. These findings imply that multiple mechanisms are involved in the beneficial effects of soy isoflavone supplements for diabetic endothelial injury.
authors.affiliation: Endocrinology, Diabetes and Metabolism, Hull York Medical School, University of Hull, Hull HU6 7RX, UK. s.xu@hull.ac.uk
authors.forename: Shang-Zhong
authors.initials: SZ
authors.lastname: Xu
authors.forename: Wenwen
authors.initials: W
authors.lastname: Zhong
authors.forename: Maryam
authors.initials: M
authors.lastname: Ghavideldarestani
authors.forename: Rahul
authors.initials: R
authors.lastname: Saurabh
authors.forename: Steve W
authors.initials: SW
authors.lastname: Lindow
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Atkin
mesh_terms: D017209:Apoptosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D047629:Estrogen Receptor beta / Q000037:antagonists & inhibitors / Q000378:metabolism; D000077267:Fulvestrant; D019833:Genistein / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007529:Isoflavones / Q000494:pharmacology*; D018384:Oxidative Stress / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry*; D014471:Umbilical Veins / Q000166:cytology; D054460:rho-Associated Kinases / Q000502:physiology; D020742:rhoA GTP-Binding Protein / Q000502:physiology
chemical_list: D047629:Estrogen Receptor beta; D007529:Isoflavones; D019253:Proto-Oncogene Proteins c-bcl-2; D000077267:Fulvestrant; D004958:Estradiol; C004742:daidzein; D006861:Hydrogen Peroxide; D019833:Genistein; D019869:Phosphatidylinositol 3-Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D005947:Glucose