Abstract

Maytenus ilicifolia is an important plant with a great potential for cancer treatment and has a popular and diffused use, as tea, in Brazil and in other countries against gastric ulcers, dyspepsia and others gastric problems. In this paper, the antioxidant and anti-radical activities of this plant were compared with trolox and uric acid by their abilities as scavengers of DPPH^·, ABTS^·+, O₂^·-, HOCl and NO. In all systems, a significant correlation existed between concentration of extracts and percentage inhibition of free radicals. Moreover, these extracts could inhibit oxidation of guaiacol catalyzed by peroxidases (horseradish peroxidase and myeloperoxidase) or by their prosthetic group, the hemin. The results provide useful pharmacological information against free radicals and reactive oxygen species, which are involved in a variety of pathological events like diabetes, cancer and aging. The crude extract and the hydroalcoholic fraction were able to act efficiently over all species assayed. This ability to scavenge radicals and endogenous reactive oxygen species, as well as to act as inhibitors of the enzymes that participate in their generation, would be useful for the treatment of various diseases mediated by radical species.

Key words: Myeloperoxidase, celastraceae, oxidative damage, free radical,Maytenus ilicifolia.