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Moderate consumption of wine is associated with cardiovascular protection most likely by increasing the endothelial formation of nitric oxide (NO). The present study investigated whether red wine polyphenolic compounds (RWPCs) increase the formation of endothelium-derived hyperpolarizing factor (EDHF) in arteries and, if so, to characterize the underlying mechanism. Porcine coronary artery rings were suspended in organ chambers for measurement of changes in isometric tension and membrane potential in the presence of indomethacin and Nω-nitro-l-arginine. RWPCs caused pronounced endothelium-dependent relaxations and hyperpolarizations, which were reduced by the combination of charybdotoxin plus apamin (two inhibitors of EDHF-mediated responses). Both responses to RWPCs were also reduced by antioxidants, membrane permeant analogues of superoxide dismutase, and diphenylene iodonium, an inhibitor of flavin-dependent enzymes. RWPCs induced the formation of superoxide in cultured endothelial cells. These findings demonstrate that RWPCs cause EDHF-mediated relaxations of coronary arteries, which are critically dependent on a redox-sensitive mechanism involving a flavin-dependent enzyme. [Copyright &y& Elsevier]

Determines the mechanism underlying the activation of endothelial nitric oxide (NO) synthase and the subsequent formation of NO in coronary arteries in response to red wine polyphenols. Exposure of cultured porcine coronary artery endothelial cells to red wine polyphenols; Exposure of cells to wortmannin; Role of reactive oxygen species as key intracellular mediators to activate signal transduction pathways leading to numerous biological responses in vascular cells.

Consumption of polyphenol-rich foods, such as fruits and vegetables, and beverages derived from plants, such as cocoa, red wine and tea, may represent a beneficial diet in terms of cardiovascular protection. Indeed, epidemiological studies demonstrate a significant inverse correlation between polyphenol consumption and cardiovascular risk. Among the numerous plausible mechanisms by which polyphenols may confer cardiovascular protection, improvement of the endothelial function and inhibition of angiogenesis and cell migration and proliferation in blood vessels have been the focus of recent studies. These studies have indicated that, in addition to and independently from their antioxidant effects, plant polyphenols (1) enhance the production of vasodilating factors [nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF) and prostacyclin] and inhibit the synthesis of vasoconstrictor endothelin-1 in endothelial cells; and (2) inhibit the expression of two major pro-angiogenic factors, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in smooth muscle cells. The mechanisms of these effects involve: (1) in endothelial cells, increased Ca2+ level and redox-sensitive activation of the phosphoinositide 3 (PI3)-kinase/Akt pathway (leading to rapid and sustained activation of nitric oxide synthase and formation of EDHF) and enhanced expression of nitric oxide synthase; and (2) in smooth muscle cells, both redox-sensitive inhibition of the p38 mitogen-activated protein kinase (p38 MAPK) pathway activation (leading to inhibition of platelet-derived growth factor (PDGF)-induced VEGF gene expression) and redox-insensitive mechanisms (leading to inhibition of thrombin-induced MMP-2 formation). The current evidence suggests that all these mechanisms are triggered by polyphenols with specific structures, although the structural requirements may be different from one effect to the other, and that they all contribute to the vasoprotective, anti-angiogenic, anti-atherogenic, vasorelaxant and anti-hypertensive effects of acute or chronic administration of plant polyphenols found in vivo in animals and in patients. [Copyright &y& Elsevier]