Abstract

The antioxidant and antimicrobial activities of polysaccharides extracted by microwave-assisted extraction (MAE) were reviewed. An ascending dose-dependent manner was found for the in vitro antioxidant (e.g., nitrite scavenging, phospho-molybdenum reduction, inhibition of lipid peroxidation (ILP), ferric reducing power, and ferrous metal ions chelating), and antiradical (against DPPH center dot, OH center dot, ABTS(center dot), NO center dot, and O-2(center dot-)) activities. There was a positive and significant correlation between ILP and erythrocyte hemolysis inhibition, showing the excellent antioxidative properties to prevent the risk of cell damage. These carbohydrate-based polymers in vivo could reduce malonaldehyde and protein carbonyls and increase stress-resistance-related enzymes such as catalase, superoxide dismutase, and glutathione peroxidase. They showed an effective bactericidal activity against a wide variety of gram-negative and gram-positive bacterial infections. The in vitro strong antifungal and antiviral activities of sulfated polysaccharides extracted by MAE were also diagnosed without any cytotoxicity effect. Therefore, these biomacromolecules might be used to develop functional foods and nutraceuticals.