Antioxidant effects of an aqueous extract of Ilex paraguariensis

In this work we investigate the antioxidant properties of an aqueous extract prepared from an infusion of Ilex paraguariensis (Aquifoliaceae) using free radical-generating systems. The extract inhibited the enzymatic and nonenzymatic lipid peroxidation in rat liver microsomes in a concentration-dependent fashion, with IC50 values of 18 mu g/ml and 28 mu g/ml, respectively. The extract also inhibited the H2O2-induced peroxidation of red blood cell membranes with an IC50 of 100 mu g/ml and exhibited radical scavenging properties toward superoxide anion (IC50 = 15 mu g/ml) and 2,2-diphenyl-1-picrylhydrazyl radical. In the range of concentrations used, the extract was not a scavenger of the hydroxyl radical. Our results suggest that ingestion of extracts of Ilex paraguariensis could contribute to increase the antioxidant defense of an organism against free radicals attack. (C) 2000 Academic Press.