title: Hot-water extracts from the inner bark of Norway spruce with immunomodulating activities.
abstract: The inner bark of Norway spruce (Picea abies) was sequentially extracted with hot water at 100°C, 140°C and 160°C. The hot-water extracts (IB 100°C, IB 140°C and IB 160°C) contained pectic polysaccharides and showed immunostimulating activities. Structural analyses of their carbohydrate content, including glycosidic linkage analyses, revealed the presence of pectins with a large rhamnogalacturonan RG-I domain ramified with highly-branched arabinans. IB 100°C also contained a large amount of terminal glucosyl residues, indicating the presence of highly substituted polymers. IB 160°C was mainly composed of starch. The hot-water extracts were tested for two biological activities, namely complement fixation and macrophage stimulation. IB 100°C exhibited the highest complement fixation activity, with a 1.7-times higher ICH50 than the control pectin, while IB 140°C and IB 160°C gave similar ICH50 values as the control. Macrophages were stimulated by IB 100°C and IB 140°C in a dose-dependent manner, but not by IB 160°C. IB 100°C presented the highest activity toward macrophages, comparable to the control pectin.
authors.affiliation: Division of Wood Chemistry and Pulp Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Teknikringen 56, SE-10044 Stockholm, Sweden.
authors.forename: Myriam
authors.initials: M
authors.lastname: Le Normand
authors.forename: Hugo
authors.initials: H
authors.lastname: Mélida
authors.forename: Bjarne
authors.initials: B
authors.lastname: Holmbom
authors.forename: Terje E
authors.initials: TE
authors.lastname: Michaelsen
authors.forename: Marit
authors.initials: M
authors.lastname: Inngjerdingen
authors.forename: Vincent
authors.initials: V
authors.lastname: Bulone
authors.forename: Berit Smestad
authors.initials: BS
authors.lastname: Paulsen
authors.forename: Monica
authors.initials: M
authors.lastname: Ek
mesh_terms: D000818:Animals; D002460:Cell Line; D003165:Complement System Proteins / Q000378:metabolism; D006358:Hot Temperature; D007155:Immunologic Factors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D051379:Mice; D028222:Picea / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014867:Water / Q000737:chemistry*
chemical_list: D007155:Immunologic Factors; D011134:Polysaccharides; D014867:Water; D003165:Complement System Proteins
keywords: Bark; Biorefinery; Compositional analysis; Immunomodulating activities; Pectins