Pulcherrimasaponin, from the leaves of Calliandra pulcherrima, as adjuvant for immunization in the murine model of visceral leishmaniasis.
A novel triterpenoidal saponin, called pulcherrimasaponin (CP05), isolated from the leaves of Calliandra pulcherrima Benth. shows remarkable similarities to the previously described potent adjuvant, QS21 saponin (Quillaja saponaria Molina). On the basis of chemical and physicochemical evidence, its structure was established as [3beta,16alpha,28[2E,6S[2E,6S(2E,6S)]]]-olean-12-en-28-oic acid 3-[[O-alpha-l-arabinopyranosyl-(1-->2)-O-alpha-l-arabinopyranosyl-(1-->6)-2-(acetylamino)-2-deoxy-beta-d-glucopyranosyl]oxy]-16-hydroxy-O-beta-d-glucopyranosyl-(1-->3)-O-[O-beta-d-xylopyranosyl-(1-->3)-beta-d-xylopyranosyl-(1-->4)-O-6-deoxy-alpha-l-mannopyranosyl-(1-->2)-6-O-[6-[[2-O-2,6-dimethyl-1-oxo-6-(beta-d-xylopyranosyloxy)-2,7-octadienyl]-[(6-deoxy-beta-d-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-beta-d-xylopyranosyl]oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-beta-d-glucopyranosyl ester. In vivo toxicity assays disclosed similar and transitory local swelling and loss of hair but no lethality for mice. The haemolytic index was higher for QS21 (5 microg/ml) than for CP05 (13 microg/ml). Mouse vaccination with either CP05 or QS21 in combination with the fucose-mannose ligand (FML) antigen of Leishmania donovani showed anti-FML responses, significantly enhanced over the saponin and saline controls, in IgM, IgG, IgG1, IgG2a, IgG2b and IgG3. Antibody levels were similar for both vaccines in most subtypes. However, QS21-FML vaccine showed a 1.5 to 2.1 proportional increase over the CP05-FML vaccine in IgG, IgG2a and IgG3 responses. The delayed type of hypersensitivity against leishmanial antigen was impressively increased for CP05-FML and for QS21-FML-treated animals over controls (p<0.005). Enhancement was similar for both vaccines (p<0.05). The safety analysis and the effect on humoral and cellular immune responses demonstrated that the novel Calliandra pulcherrima Benth. CP05 saponin is a potential candidate for a vaccine adjuvant.
Silva
Bernadete Pereira da
BP
Laboratório de Química de Plantas Medicinais, Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, P.O. Box 68045, CEP 21944-970 Rio de Janeiro, Brazil.
Soares
Juliana Baptista Rocha Correa
JB
Souza
Edilma Paraguai de
EP
Palatnik
Marcos
M
Sousa
Clarisa Beatriz Palatnik de
CB
Parente
José Paz
JP
D000276:Adjuvants, Immunologic / Q000302:isolation & purification / Q000627:therapeutic use*; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D006224:Cricetinae; D004195:Disease Models, Animal; D007887:Fabaceae / Q000737:chemistry / Q000276:immunology*; D005260:Female; D006801:Humans; D007114:Immunization / Q000379:methods*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D010936:Plant Extracts / Q000276:immunology / Q000302:isolation & purification / Q000627:therapeutic use; D018515:Plant Leaves; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D031990:Quillaja / Q000276:immunology; D012503:Saponins / Q000737:chemistry* / Q000276:immunology
D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D010936:Plant Extracts; D016052:Protozoan Vaccines; D012503:Saponins