IMMUNOMODULATING POLYSACCHARIDES FROM AQUEOUS EXTRACTS OF CETRARIA-ISLANDICA (ICELAND MOSS)

Several polysaccharide fractions, isolated from a hot aqueous extract of Cetraria islandica (L.) Ach, by ethanol fractionation and ion-excha nge chromatography, exerted significant in vitro anti-complementary ac tivity and pronounced enhancement of in vitro granulocytic phagocytosi s. Prior to aqueous extraction, low molecular weight compounds were re moved from the plant material by organic extraction. An aqueous extrac t, prepared by the traditional method of briefly boiling the lichen di rectly with water, also exhibited significant anti-complementary and e nhanced phagocytic activity. When tested for reticuloendothelial phago cytic activity in the in vivo carbon clearance test, the extract gave rise to a significant increase in the rate of colloidal carbon elimina tion. Results show, that in addition to an immunostimulating alkali-so luble galactomannan previously isolated from Iceland moss, the plant a lso contains water soluble polysaccharides, extractable by traditional methods, which exert immunomodulating effects.