title: Antioxidant and immunomodulatory properties of polysaccharides from Allanblackia floribunda Oliv stem bark and Chromolaena odorata (L.) King and H.E. Robins leaves.
abstract: BACKGROUND
  Many plant polysaccharides have shown high antioxidant and immunostimulating properties and can be explored as novel molecules with biological properties that can potentially improve immune function. The objective of this work was to characterize soluble and cell wall polysaccharides isolated from the stem bark of Allanblackia floribunda and Chromolaena odorata leaves and to evaluate their antioxidant and immunomodulatory properties.
  
  
  METHODS
  Three polysaccharide fractions: soluble polysaccharides (PoS), pectins (Pec) and hemicelluloses (Hem) were extracted from A. floribunda stem bark and C. odorata leaves. These samples were analysed for their proteins, phenolic compounds and total sugar contents. The monosaccharide composition was determined by gas chromatography and arabinogalactan proteins content in PoS was evaluated by rocket electrophoresis. The in vitro antioxidant activities were evaluated by 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-bis-3-éthylbenzylthiazoline-6-sulphonic acid (ABTS) radical scavenging assays and ferrous ions chelating activity. Immunomodulatory activities were performed on the peripheral blood mononuclear cells (PBMCs) using proliferation and enzyme linked immunospot (ELISPOT) method to determine the production of an interferon-gamma.
  
  
  RESULTS
  The characterization of the various fractions showed varied metabolites in each plant. In PoS fractions, Ara and Gal were the major monosaccharides found, indicating that arabinogalactans are the primary macromolecules. Hem fractions contained predominantly Xyl and GalA for A. floribunda and Xyl (upto 80 %) for and C. odorata. A. floribunda Hem fraction and C. odorata PoS fraction showed significant DPPH and ABTS radical scavenging activities and immunostimulatory activity via stimulation of PBMC and production of IFN-γ in a dose-dependent manner.
  
  
  CONCLUSIONS
  The results obtained from this study support the ethnomedicinal use of the stem bark of A. floribunda and leaves of C. odorata. Further research is necessary to have supporting evidence that the antioxidative and immunomodulative activities of these fractions are really connected to the polysaccharides and not polyphenols.
authors.affiliation: Laboratory of Phytoprotection and Valorisation of Plants Resources, Biotechnology Centre-Nkolbisson, P.O. Box 3851, Messa, Yaounde, Cameroon. boudjeko@yahoo.com.|Department of Biochemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. boudjeko@yahoo.com.
authors.forename: Thaddée
authors.initials: T
authors.lastname: Boudjeko
authors.affiliation: Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. megnekor@yahoo.fr.
authors.forename: Rosette
authors.initials: R
authors.lastname: Megnekou
authors.affiliation: Department of Biochemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. woguia2002@yahoo.fr.
authors.forename: Alice Louise
authors.initials: AL
authors.lastname: Woguia
authors.affiliation: Laboratory of Phytoprotection and Valorisation of Plants Resources, Biotechnology Centre-Nkolbisson, P.O. Box 3851, Messa, Yaounde, Cameroon. Mediessefrancyn@yahoo.fr.|Department of Biochemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. Mediessefrancyn@yahoo.fr.
authors.forename: Francine Mediesse
authors.initials: FM
authors.lastname: Kegne
authors.affiliation: Laboratory of Phytoprotection and Valorisation of Plants Resources, Biotechnology Centre-Nkolbisson, P.O. Box 3851, Messa, Yaounde, Cameroon. emerykanemoto@rocketmail.com.|Department of Biochemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. emerykanemoto@rocketmail.com.
authors.forename: Judith Emery Kanemoto
authors.initials: JE
authors.lastname: Ngomoyogoli
authors.affiliation: Laboratory of Phytoprotection and Valorisation of Plants Resources, Biotechnology Centre-Nkolbisson, P.O. Box 3851, Messa, Yaounde, Cameroon. daniellenounga@yahoo.fr.|Department of Biochemistry, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. daniellenounga@yahoo.fr.
authors.forename: Christiane Danielle Nounga
authors.initials: CD
authors.lastname: Tchapoum
authors.affiliation: Laboratory of Phytoprotection and Valorisation of Plants Resources, Biotechnology Centre-Nkolbisson, P.O. Box 3851, Messa, Yaounde, Cameroon. koumolga@yahoo.fr.|Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. koumolga@yahoo.fr.
authors.forename: Olga
authors.initials: O
authors.lastname: Koum
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002849:Chromatography, Gas; D036604:Chromolaena / Q000737:chemistry*; D028084:Clusiaceae / Q000737:chemistry*; D058501:Enzyme-Linked Immunospot Assay; D016166:Free Radical Scavengers / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D007122:Immunoelectrophoresis / Q000379:methods; D007155:Immunologic Factors / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis; D007502:Iron Chelating Agents / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009005:Monosaccharides / Q000032:analysis / Q000302:isolation & purification; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D010940:Plant Proteins / Q000032:analysis / Q000302:isolation & purification; D011134:Polysaccharides / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D007155:Immunologic Factors; D007502:Iron Chelating Agents; D009005:Monosaccharides; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D010940:Plant Proteins; D011134:Polysaccharides; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D007371:Interferon-gamma; C004931:1,1-diphenyl-2-picrylhydrazyl