Antioxidant activity of Ilex paraguariensis and related species

It is well recognized that oxygen radicals are involved in various patholog ies, and that antioxidants could protect the body from oxygen radical-induc ed 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 a s substitutes or adulterants of I. paraguariensis. Some of these are I. the ezans C. Martis ex Reisseck; I. dumosa Reisseck var dumosa; I. argentina Li llo; 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 b y incubation (37 degrees C, 60 min) with 10 mM 2,2'-azobis-(2-amidinopropan e) hydrochloride (AAPH), in the presence or the absence of Ilex spp. extrac ts. Lipid oxidation products were measured as 2-thiobarbituric acid-reactiv e substances (TBARS). Caffeoyl-derivatives were estimated spectrophotometri cally, using chlorogenic acid as standard. Results showed that all the assa yed plants had antioxidant activity when prepared as mate. I. paraguariensi s 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 mos t 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 im prove human antioxidant defenses. (C) 2000 Elsevier Science Inc.