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

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 center dot)-radical scavenging activity (IC50 = 1.25 +/- 0.10 mg/mL), 3-ethyl benzothiazoline-6-sulphonic acid (ABTS center dot+)-radical scavenging activity (IC50 = 0.41 +/- 0.05 mg/mL), and hydroxyl scavenging activity (IC50 = 3.36 +/- 0.31 mg/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 +/- 1.61 mu M TE/mg and 55630 +/- 12.83 mu M TE/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. (C) 2018 Elsevier B.V. All rights reserved.