The neuroprotective activities and antioxidant activities of the polysaccharides from Saccharina japonica.

The crude polysaccharide (W) was extracted by water from Saccharina japonica and five fractions were separated by anion-exchange chromatography. And their chemical constituents, neuroprotective activities and antioxidant activities were studied. It showed that W had the neuroprotective activity while its fractions did not. In addition, the fractions displayed higher activities on hydroxyl-radical scavenging effects and reducing power than these of W. Moreover, it was speculated that the neuroprotective activities of samples were related to the hydroxyl-radical scavenging effect and reducing power while did not relate to superoxide-radical scavenging effect. Finally, it was concluded that some fractions could be good candidate antioxidants in food chemistry owing to the high antioxidant activities and their non-toxic characteristics.