Purification and antioxidant activity of a polysaccharide from bulbs of Fritillaria ussuriensis Maxim.

A water-soluble polysaccharide (FUP-1) was obtained from Fritillaria ussuriensis Maxim through warm water extraction, ethanol precipitation, anion-exchange and gel-permeation chromatography. Structural analysis of this compound revealed that the average molecular weight of FUP-1 was 4.1×10(4)Da, and the major monosaccharide component was xylose, followed by glucose and galactose, at low levels. In vitro antioxidant assays showed that FUP-1 exhibited strong hydroxyl, superoxide anion and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities. During in vivo antioxidant testing, the administration of FUP-1 could largely attenuate the increase in d-gal-induced malondialdehyde (MDA) and renew the activities of superoxide dismutase (SOD) in serums as well as glutathione peroxidase (GSH-Px) and the total antioxidant capacity (T-AOC) in the livers of d-gal-treated mice. Overall, the results of the present study indicate that FUP-1 exerts antioxidant activity not only through its own radical-scavenging activity but also by boosting the enzymatic and nonenzymatic antioxidant defense system of the host.