Antioxidant and antimicrobial activities of a purified polysaccharide from yerba mate (Ilex paraguariensis)

Abstract

This study investigated the antioxidant, antimicrobial and cytotoxic properties of a purified yerba mate polysaccharide. The yerba mate polysaccharide showed a prominent antioxidant activity as evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity (IC50=1.25±0.10mg/mL), 3-ethyl benzothiazoline-6-sulphonic acid (ABTS+)-radical scavenging activity (IC50=0.41±0.05mg/mL), and hydroxyl scavenging activity (IC50=3.36±0.31mg/mL). The antioxidant activity evaluated as the ferric ion reduction power (FRAP) and oxygen radical absorbance radical assay (ORAC), expressed as trolox equivalents, were 20.84±1.61μMTE/mg and 556.30±12.83μMTE/mg, respectively. The purified yerba mate polysaccharide presented high antimicrobial activity against several bacterial and fungal strains; however, no cytotoxicity against all four tumor human cell lines assessed.