Wine polyphenols decrease blood pressure, improve NO vasodilatation, and induce gene expression

The effects of short-term oral administration of red wine polyphenolic comp ounds on hemodynamic parameters and on vascular reactivity were investigate d in rats. Endothelial function and vascular smooth muscle contractility we re studied in association with the induction of gene expression in the vasc ular wall. Rats were treated daily for 7 days by intragastric administratio n of either 5% glucose or red wine polyphenolic compounds (20 mg/kg). Admin istration of these compounds produced a progressive decrease in systolic bl ood pressure, which became significantly different on day 4. Aortas from ra ts treated with red wine polyphenolic compounds displayed increased endothe lium-dependent relaxation to acetylcholine that was related to increased en dothelial NO activity and involved a mechanism sensitive to superoxide anio n scavengers. However, no increase in whole-body oxidative stress has been observed in rats treated with red wine polyphenolic compounds, as shown by plasma glutathione assay. Also, in the aorta, red wine polyphenolic compoun ds increased the expression of cyclooxygenase-2 and increased the release o f endothelial thromboxane A(2), which compensated for the extraendothelial NO-induced hyporeactivity in response to norepinephrine, resulting from enh anced inducible NO synthase expression. The present study provides evidence that short-term oral administration of red wine polyphenolic compounds pro duces a decrease in blood pressure in normotensive rats. This hemodynamic e ffect was associated with an enhanced endothelium-dependent relaxation and an induction of gene expression (of inducible NO synthase and cyclooxygenas e-2) within the arterial wall, which together maintain unchanged agonist-in duced contractility. These effects of red wine polyphenolic compounds may b e a potential mechanism for preventing cardiovascular diseases.