Selenylation Modification of Atractylodes macrocephala Polysaccharide and Evaluation of Antioxidant Activity

The Atractylodes macrocephala polysaccharide (AMP) was extracted by water extracting-alcohol precipitating method and further purified by DEAE column. After that, the polysaccharides were modified by nitric acid-sodium selenite method, and nine kinds of selenizing AMPs (sAMPs) were obtained, namely, from sAMP1 to sAMP9. AMP and sAMP were characterized using FTIR spectrometry. Then their antioxidant activities in vitro were measured by free radical-scavenging test. Among these, sAMP6 presented the strongest antioxidant effect. For the test in vivo, the chickens at day 14 vaccinated with ND vaccine were repeatedly vaccinated at day 28. The chickens in sAMP and AMP were injected respectively with 1 mg of sAMP6 and AMP and, in vaccination control (VC) and BC groups, injected with equal volume of normal saline. Respectively, after the first vaccine, on days 7, 14, 21, and 28, the serum GSH-Px and SOD activities and MDA content were determined. The results suggested that sAMP6 could significantly promote GSH-Px and SOD activities and decrease MDA content. All these results indicated that selenylation modification could significantly enhance the antioxidant activity of AMP.