Antioxidant activity of Ilex paraguariensis and related species

It is well recognized that oxygen radicals are involved in various pathologies, and that antioxidants could protect the body from oxygen radical-induced damage. Ilex paraguariensis St. Hilaire ("mate" or "yerba mate") is the most commercialized plant of South America, and it is used to prepare a tea-like beverage, the mate. Some related species of the genus Ilex are used as substitutes or adulterants of I. paraguariensis. Some of these are I. theezans C. Martis ex Reisseck; I. dumosa Reisseck var dumosa; I. argentina Lillo; I. brevicuspis Reisseck; I. pseudobuxus Reisseck. In the present work, the antioxidant activity of a group of Ilex (Ilex spp.) was examined, and related to their content of caffeoyl-derivatives. Liposomes were oxidized by incubation (37 degrees C, 60 min) with 10 mM 2,2'-azobis-(2-amidinopropane) hydrochloride (AAPH), in the presence or the absence of Ilex spp. extracts. Lipid oxidation products were measured as 2-thiobarbituric acid-reactive substances (TBARS). Caffeoyl-derivatives were estimated spectrophotometrically, using chlorogenic acid as standard. Results showed that all the assayed plants had antioxidant activity when prepared as mate. I. paraguariensis had the highest antioxidant activity. Its content of caffeoyl derivatives was 10.71 +/- 0.40 g chlorogenic acid/100 g dry plant material. A positive and significant correlation was observed between the antioxidant activity and the content of caffeoyl-derivatives of the assayed extracts (r = 0.94, p = 0.0005). The present results suggest that I. paraguariensis and the most widely consumed Southamerican Ilex spp., have antioxidant properties that they conserve when are prepared as mate. It is possible to speculate that the regular consumption of this beverage may significantly contribute to improve human antioxidant defenses. (C) 2000 Elsevier Science Inc.