RED WINE AND FRACTIONATED PHENOLIC-COMPOUNDS PREPARED FROM RED WINE INHIBIT LOW-DENSITY-LIPOPROTEIN OXIDATION IN-VITRO

The oxidative modification of low density lipoproteins (LDL) has been implicated in the development of atherosclerosis. This study examined the effect of red wine, ethanol and red wine stripped of phenols on co pper-mediated and ate-initiated LDL oxidation. Red wine containing phe nolic compounds (0.025-20 mg/l gallic acid equivalents) increased the lag time of conjugated diene formation, inhibited the generation of th iobarbituric acid reactive substances (TEARS) and decreased the relati ve electrophoretic mobility of LDL in a concentration-dependent manner . These changes were not apparent in LDL incubated with ethanol or red wine stripped of phenols. In other experiments, red wine (75 mg/l gal lic acid equivalents) was incubated with plasma at 37 degrees C for 3 h. The LDL isolated from this plasma displayed a 60% increase in lag t ime following copper-mediated oxidation. Uptake of this LDL by culture d J774 macrophages was three-fold lower than control LDL. Red wine was fractionated into phenolic acids (fraction I), catechins and monomeri c anthocyanidins (fraction 2), flavonols (fraction 3) and polymeric an thocyanidins (fraction 4). All red wine fractions prolonged the time b efore LDL oxidation. Fraction 2 displayed a significantly greater anti oxidant activity than fractions 3 and 4 (but not fraction 1) in at lea st one pro-oxidant model. In conclusion we have shown that antioxidant compounds in red wine can associate with LDL particles following an i ncubation in whole plasma, can exert an antioxidant effect and, in so doing, can inhibit the uptake of the lipoprotein by macrophages. This antioxidant effect of red wine was apparent ill most of the phenolic f ractions separated from wine, particularly catechins, monomeric anthoc yanidins and phenolic acids. (C) 1997 Elsevier Science Ireland Ltd.