Antioxidant and moisture-retention activities of the polysaccharide from Nostoc commune

The main supporting matrix of the edible Nostoc commune colony is polysaccharide, which plays important roles in protecting the cyanobacterium itself from extreme desiccation and high radiation. To explore biomedical potential from the inherent nature of the polysaccharide, we investigated antioxidant and moisture-retention capacities of the polymer. We report here that the polysaccharide is capable of scavenging both superoxide anion and hydroxyl radicals in vitro. Using the model animal Caenorhabditis elegans. we further show that the polysaccharide can increase antioxidant enzyme activity, decrease lipid peroxidation level, and reduce paraquat-induced oxidative damage. We also reveal that the polysaccharide has strong in vitro moisture-absorption and -retention capacities as compared to chitosan and urea, and is able to improve water retention in mouse stratum corneum under dry conditions. Together, these data demonstrate the potent in vitro as well as in vivo antioxidant activities and strong moisture-retention capacities of the polysaccharide from N. commune. (C) 2010 Elsevier Ltd. All rights reserved.