title: Red wine antioxidants bind to human lipoproteins and protect them from metal ion-dependent and -independent oxidation.
abstract: Plant-derived polyphenols may exert beneficial effects on atherosclerosis and cardiovascular diseases, in part, because of their antioxidant properties. In this study we compared the effects of unbound (free) and lipoprotein-associated red wine components on in vitro antioxidant protection of human low-density lipoprotein (LDL). Preincubation of LDL (1 mg protein/mL) with 0-2.5% (v/v) red wine for 3 h at 37 degrees C followed by gel filtration to remove unbound red wine components resulted in a dose-dependent, up to 4-fold increase in LDL-associated antioxidant capacity (measured as Trolox equivalents). Similar results were obtained with high-density lipoprotein (HDL) and bovine serum albumin (BSA). Furthermore, LDL was subjected to oxidation by copper and aqueous peroxyl radicals (2,2'-azobis[2-amidinopropane] dihydrochloride, AAPH). Under both types of oxidative stress, LDL-associated and free red wine components significantly decreased oxidation of the lipoprotein's protein moiety (assessed by tryptophan fluorescence) and lipid moiety (assessed by thiobarbituric acid-reactive substances and conjugated dienes). Similar protective effects of red wine components were observed against HDL oxidation. In contrast, red wine exerted a pro-oxidant effect on copper-induced oxidation of BSA tryptophan residues, while protecting them from AAPH-induced oxidation. Ascorbate strongly enhanced the protective effect of red wine against copper-induced LDL oxidation, and had an additive effect against AAPH-induced oxidation. Our data indicate that red wine components bind to LDL and HDL and protect these lipoproteins from metal ion-dependent and -independent protein and lipid oxidation.
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, Oregon 97331.
authors.forename: V
authors.initials: V
authors.lastname: Ivanov
authors.forename: A C
authors.initials: AC
authors.lastname: Carr
authors.forename: B
authors.initials: B
authors.lastname: Frei
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002850:Chromatography, Gel; D003300:Copper / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids; D006801:Humans; D066298:In Vitro Techniques; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010636:Phenols / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D059808:Polyphenols; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013997:Time Factors; D014920:Wine / Q000032:analysis
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D012710:Serum Albumin, Bovine; D003300:Copper