Maca (Lepidium meyenii) is a plant from the Andes of Peru. Maca is used as a food for its nutritional value and ethnomedicinal properties linked to fertility and vitality. The purpose of this study was to evaluate the antioxidant activity of Maca. For all experiments an aqueous extract of Maca was used. The antioxidant activity of Maca was assessed by the inhibition of peroxynitrite, 1,1-diphenyl-2-picrylhydrazyl (DPPH), peroxyls and deoxyribose degradation. The cytoprotection capacity of Maca was assessed using macrophages (RAW 264.7) treated with peroxynitrite or hydrogen peroxide (H2O2). Catechins were quantified by reversedphase HPLC. Addition of Maca extract (0.3–1 mg/ml) to peroxynitrite (300 mM) decreased peroxynitrite concentration by 15 and 41%, respectively (P
