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.

We analyzed the antioxidant properties of Ilex paraguariensis infusion (Ip) popularly known as mate (mä'ta), 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.

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

We analyzed the antioxidant properties of Ilex paraguariensis infusion (Ip) popularly known as mate (ma ta), by using two experimental models : the induction of DNA double-strand breaks (DSB) by hydrogen peroxide (H2O2) 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 H2O2 (5-10mmol/L) in the absence or presence of Ip infusion (10 -1 v/v) or a-tocopherol (10 -2 mol/L). Both mate infusion and a-tocopherol significantly decreased the dose dependent DSB number, and the lethality induced by H2O2. Peroxynitrite and lipoxygenase-induced human LDL oxidation are inhibited by Ip extract in a potent, dose-dependent fashion. Dilutions of 5 x 10-3 v/v provide 50 percent+- 10 percent 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 percent, which was comparable to that obtained with 0.5-1mmol/La-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 quecetin equivalents per liter, respectively. Their respective free radical quenching activities at dilutions of 1 x 10 -1 v/v were 75 percent+-5 percent; 53 percent+- 5 percent; and 2 percent +- 5 percent. 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