title: Screening and appraisal for immunological adjuvant-active fractions from Platycodon grandiflorum total saponins.
abstract: In this study, the total saponins from the root of Platycodon grandiflorum (PGS(t)) was subjected to D101 macroreticular resin column chromatography to afford four fractions (PGS₃₀, PGS₅₀, PGS₇₅ and PGS₉₅). PGS(t) and its four fractions were evaluated and compared for the haemolytic activities and adjuvant potentials on the specific cellular and humoral immune responses of ICR mice against recombinant hepatitis B surface antigen (HBsAg). PGS(t), PGS₃₀, PGS₅₀, PGS₇₅, and PGS₇₅ showed a slight haemolytic effect, with their concentration inducing 50% of the maximum haemolysis (HD₅₀) being 16.13 ± 0.81, >200, 17.53 ± 0.24, 20.16 ± 0.76, 76.31 ± 2.20 μg/mL against 0.5% rabbit red blood cell, respectively. PGS(t), PGS₅₀, and PGS₇₅ significantly not only enhanced the Con A-, lipopolysaccharide-, and HBsAg-induced splenocyte proliferation, but promoted the killing activities of natural killer (NK) cells from splenocytes in HBsAg-immunized mice (P < 0.01 or P < 0.001). HBsAg-specific IgG, IgG1, IgG2a, and IgG2b antibody levels in serum were also significantly enhanced by PGS(t), PGS₅₀, and PGS₇₅ compared with HBsAg control group (P < 0.05, P < 0.01, or P < 0.001). Moreover, the adjuvant effects of PGS₅₀ and PGS₇₅ on the cellular immune responses and HBsAg-specific IgG2a and IgG2b antibody responses were more significant than those of Alum, PGS₃₀, and PGS₉₅. The results indicated that PGS₅₀ and PGS₇₅ could improve both cellular and humoral immune responses, and elicit a balanced Th1/Th2 response to HBsAg in mice, and that PGS₇₅ may be developed as an ideal candidate adjuvant for hepatitis B vaccine.
authors.affiliation: Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, People’s Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Ouyang
authors.forename: Liqing
authors.initials: L
authors.lastname: Chen
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Sun
authors.forename: Jing
authors.initials: J
authors.lastname: Du
authors.forename: Minghua
authors.initials: M
authors.lastname: Shi
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D005260:Female; D006461:Hemolysis / Q000187:drug effects; D006514:Hepatitis B Surface Antigens / Q000494:pharmacology; D017325:Hepatitis B Vaccines / Q000494:pharmacology; D007111:Immunity, Cellular / Q000187:drug effects*; D056724:Immunity, Humoral / Q000187:drug effects*; D007074:Immunoglobulin G / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D008813:Mice, Inbred ICR; D018517:Plant Roots / Q000737:chemistry*; D031238:Platycodon / Q000737:chemistry*; D011817:Rabbits; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D007074:Immunoglobulin G; D012503:Saponins