title: Commercial dietary antioxidant supplements assayed for their antioxidant activity by different methodologies.
abstract: Seven commercial dietary antioxidant supplements were evaluated for their in vitro antioxidant capacity by different methodologies: antiradical activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH.), inhibition of methyl linoleate (MeLo) autoxidation, and resistance to ion-dependent oxidation of human low-density lipoprotein (LDL). Great variability in antioxidant activity was seen among the supplements, as well as different patterns of antioxidant capacity depending on the method used. The same orders of activity were found for the MeLo autoxidation and LDL-induced oxidation methods, but the differences recorded by the former were wider. "Food/compound intake equivalents" of the doses recommended by the manufacturers were calculated in terms of quercetin, strawberries, and red wine for each of the supplements studied. Food/compound intake equivalents varied between 7.9 and 190 mg of quercetin according to the DPPH. scavenging method, between 0.20 and 98 mg according to the MeLo autoxidation method, and between 3.4 and 83 mg according to LDL-induced oxidation. In equivalent terms of red wine, the food/compound intake equivalents varied between 7 and 159 mL, between 3 and 1354 mL, and between 4 and 89 mL for the same three methods. In terms of equivalents of strawberry, they varied between 14 and 343 mg according to the DPPH. scavenging method and between 57 g and 26 kg according to the MeLo autoxidation method. These results show the need to standardize dietary supplements in terms of their antioxidant capacity to match required doses to the oxidative status of consumers.
authors.affiliation: Instituto de Fermentaciones Industriales, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Dávalos
authors.forename: Carmen
authors.initials: C
authors.lastname: Gómez-Cordovés
authors.forename: Begoña
authors.initials: B
authors.lastname: Bartolomé
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001713:Biphenyl Compounds; D019587:Dietary Supplements / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D031985:Fragaria / Q000737:chemistry; D016166:Free Radical Scavengers; D006801:Humans; D008041:Linoleic Acids / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000737:chemistry; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry; D014920:Wine / Q000032:analysis
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D008041:Linoleic Acids; D008077:Lipoproteins, LDL; D010851:Picrates; C005575:methyl linoleate; D011794:Quercetin; C004931:1,1-diphenyl-2-picrylhydrazyl