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

Water-soluble polysaccharides were isolated from the brown alga Hizikia fusiformis and separated using hydrophobic chromatography on an ME-1 resin column. Three major polysaccharide fractions, FG, GM-1 and GM-2, were analyzed by high-performance liquid chromatography, Fourier-transform infrared and (13)C nuclear magnetic resonance spectroscopy. These three fractions showed free radical scavenging activity against hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl radical in vitro. Among these three fractions, GM-2 had the best free radical scavenging activity. Thus, only GM-2 was used in the acute oxidative stress experiments in the CCl₄-induced liver injury model. GM-2 also protected against oxidative injury induced by CCl₄in vivo.