Effects of Selenylation Modification on Antioxidative Activities of Schisandra chinensis Polysaccharide

The selenylation modification of Schisandra chinensis polysaccharide (SCP) was conducted by the HNO(3)–Na(2)SeO(3) method respectively under nine conditions according to L(9)(3(4)) orthogonal design. Nine selenizing SCPs, sSCP(1)–sSCP(9), were obtained, and their antioxidant activities were compared. In vitro test, the free radical-scavenging rates of nine sSCPs were determined for DPPH., .OH and ABTS(+). sSCP(1) presented the most significant effect, and could inhibit the nonenzymatic protein glycation. In vivo test, 14-day-old chickens were injected respectively with sSCP(1) and SCP, the serum contents of CAT, SOD and MDA were determined. The result showed that as compared with the SCP group, the SOD and CAT activities were significantly or numerically raised and MDA content was significantly or numerically lowered in the sSCP(1) group. These results indicate that selenylation modification can significantly enhance the antioxidant and antiglycative activity of SCP in vitro or in vivo. sSCP(1) possesses the best efficacy and its modification conditions can be as optimal modification conditions that were 200 mg of Na(2)SeO(3) for 500 mg of SCP, reaction temperature of 50°C and reaction time of 6 h.