Hot-water extracts from the inner bark of Norway spruce with immunomodulating activities

Myriam Le Normand, Hugo Mélida, Bjarne Holmbom, Terje E. Michaelsen, Marit Inngjerdingen, Vincent Bulone, Berit Smestad Paulsen, Ek Monica

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    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 large rhamnogalacturonen RG-1 domain ramified with highly-branched arabinans. IB 100 °C also contained a large amount of terminal glycosyl 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 compliment fixation activity, with a 1.7-times higher ICH 50 than the control pectin, while IB 140 °C and IB 160 °C gave similar ICH 50 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 towards macrophages, comparable to the control pectin.
    Original languageUndefined/Unknown
    Pages (from-to)699–704
    JournalCarbohydrate Polymers
    Publication statusPublished - 2014
    MoE publication typeA1 Journal article-refereed


    • Bark
    • Biorefinery
    • Immunomodulating activities
    • Compositional analysis
    • Pectins

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