Evaluation of antioxidant activities of water-soluble polysaccharides from brown alga Hizikia fusiformis

► Three fractions FG, GM-1 and GM-2 of water-soluble polysaccharides were separated and isolated from Hizikia fusiformis using resin ME-1. ► Fraction FG was heteropolysaccharide in which fucose, galactose and mannose were the major monosaccharide units. ► Two fractions GM-1 and GM-2 were heteropolysaccharides in which galactose and mannose were the major monosaccharide units. ► GM-2 had the best free radical scavenging activity and protected against oxidative injury induced by CCl4in vivo.