title: Antioxidant activity of a botanical extract preparation of Ilex paraguariensis: prevention of DNA double-strand breaks in Saccharomyces cerevisiae and human low-density lipoprotein oxidation.
abstract: We analyzed the antioxidant properties of Ilex paraguariensis infusion (Ip) popularly known as mate (mä'tā), by using two experimental models: the induction of DNA double-strand breaks (DSB) by hydrogen peroxide (H(2)O(2)) and lethality in Saccharomyces cerevisiae, as well as peroxide and lipoxygenase-induced human low-density lipoprotein (LDL) oxidation. Diploid yeast cells were exposed to different concentrations of H(2)O(2) (5-10 mmol/L) in the absence or presence of Ip infusion (10(-1) v/v) or alpha-tocopherol (10(-2) mol/L). Both mate infusion and alpha-tocopherol significantly decreased the dose dependent DSB number, and the lethality induced by H(2)O(2). Peroxynitrite and lipoxygenase-induced human LDL oxidation are inhibited by Ip extracts in a potent, dose-dependent fashion. Dilutions of 5 x 10(-3) v/v provide 50% +/- 10% inhibition. Finally, Ip extracts are potent direct quenchers of the free radical 1,1-diphenyl-2-picrylhydrazyl. Dilutions of 2 x 10(-2) v/v produced quenching of more than 30%, which was comparable to that obtained with 0.5-1 mmol/L alpha-tocopherol or the quercetin aglycone, respectively. For comparison, total polyphenol content of Ip, green, and black tea (Camelia sinensis) were 6.5 +/- 0.8; 1.8 +/- 0.5; and 1.13 +/- 0.3 mmol of quercetin equivalents per liter, respectively. Their respective free radical quenching activities at dilutions of 1 x 10(-1) v/v were 75% +/- 5%; 35% +/- 5%; and 2% +/- 5%. Ip is thus a rich source of polyphenols and has antioxidant properties comparable to those of green tea which merit further in vivo intervention and cross-sectional studies.
authors.affiliation: Laboratory de Radiobiología, Department of Biofísica, Facultad Medicina, University of the República, Montevideo, Uruguay.
authors.forename: Nelson
authors.initials: N
authors.lastname: Bracesco
authors.forename: Mercedes
authors.initials: M
authors.lastname: Dell
authors.forename: Alberto
authors.initials: A
authors.lastname: Rocha
authors.forename: Solmaz
authors.initials: S
authors.lastname: Behtash
authors.forename: Teresita
authors.initials: T
authors.lastname: Menini
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gugliucci
authors.forename: Elia
authors.initials: E
authors.lastname: Nunes
mesh_terms: D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D019457:Chromosome Breakage; D004249:DNA Damage / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D030019:Ilex paraguariensis; D008077:Lipoproteins, LDL / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000378:metabolism / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D006861:Hydrogen Peroxide