Immunologic enhancement of Astragalus polysaccharide (APS) on the humoral immunity of chicken.

Different doses of Astragalus polysaccharide(APS) were mixed into the oil adjuvant vaccine and inoculated to chickens,taking the same vaccine of free adjuvant and oil adjuvant as controls.At 7,14,21,28,35 and 42 days after vaccination,10 chickens were sampled randomly from each group for determination of serum antibody titers by hemagglutination inhibition.At five concentrations of APS on promoting splenic lymphocyte proliferation were determined by MTT method in chicken.The results showed that oil adjuvant vaccine with APS had significantly to improve the antibody titers at some time points,and the middle dose had the best effect.The antibody titers of the oil adjuvant vaccine with APS(0.375 mg/chicken) and half antigen quantity were similar to that of the oil adjuvant vaccine.In addition,in vitro,APS(300 μg/mL) could stimulate significantly splenic lymphocyte proliferation.Thus,APS could be expected as immunopotentiator on the humoral immunity.