Effects of Selenylation Modification on Immune-Enhancing Activity of Garlic Polysaccharide

Abstract

The garlic polysaccharide was modified by HNO 3 -Na 2 SeO 3 method according to orthogonal design L 9 (3 4 ) to obtain nine selenizing garlic polysaccharides, sGPS 1 -sGPS 9 . Their effects on chicken peripheral lymphocytes proliferation in vitro were compared by MTT assay. The results showed that sGPSs could significantly promote lymphocytes proliferation, sGPS 3 , sGPS 5 and sGPS 6 presented stronger efficacy. In vivo experiment, 14-day-old chickens were injected respectively with sGPS 3 , sGPS 5 and sGPS 6 when they were vaccinated with ND vaccine taking unmodified GPS as control. The results showed that three sGPSs could significantly promote lymphocyte proliferation, enhance serum antibody titer, IFN-c and IL-2 contents. These results indicated that selenylation modification could significantly enhance the immune-enhancing activity of GPS, sGPS 6 possessed the best efficacy and could be as a candidate drug of immunoenhancer. Its optimal modification conditions were 400 mg of sodium selenite for 500 mg of GPS, reaction temperature of 70uC and reaction time of 6 h.