[Antithrombotic Action of Resveratrol: Particularly Regarding Inhibition of Platelet Aggregation]

Resveratrol is a representative polyphenol compound contained in red wine that shows a preventive effect on ischemic heart disease and was originally reported to explain the cause of the French paradox. Alcoholic beverages, including red wine, have been shown to prevent ischemic heart disease when consumed in small amounts. Red wine, which contains alcohol (ethanol) as well as polyphenols, was reportedly more effective than other alcoholic beverages for reducing the incidence of ischemic heart disease. Resveratrol is known to inhibit the functions of platelets, which play a crucial role in atherosclerosis. In an in vitro study, resveratrol inhibited platelet Ca²⁺ influx and subsequent aggregation in a concentration-dependent manner. When administered simultaneously with ethanol, resveratrol at concentrations that did not affect platelet aggregation alone inhibited platelet aggregation more potently than did ethanol alone. Thus, resveratrol and ethanol show an additive inhibitory effect on platelet aggregation. A major mechanism by which resveratrol inhibits platelet aggregation is its antioxidant action that scavenges reactive oxygen species, which cause platelet adhesion and aggregation. In addition, resveratrol inhibits capacitative Ca²⁺ influx, a G protein-coupled pathway, which is crucial for platelet activation. Resveratrol also has direct inhibitory effects on cycloxygenase-1 and phospholipase A₂, resulting in decreased production of thromboxane A₂, a potent intrinsic activator of platelets. In addition to suppression of platelet function, resveratrol retards progression of atherosclerosis through inhibiting oxidation of low-density lipoprotein (LDL) cholesterol and preventing diabetes and obesity. Thus, resveratrol possesses multiple actions against atherosclerosis and thrombosis.