The activation of RAW264.7 murine macrophage and natural killer cells by glucomannogalactan polysaccharides from Tornabea scutellifera

摘要

A water-soluble polysaccharide was isolated from Tornabea scutellifera and fractionated using a DAEA Sepharose FF column to evaluate its capacity to stimulate natural killer (NK) cells and macrophages. Neutral sugars (71.8-93.5%) constituted the major part of crude polysaccharides and fractions (TSF1 and TSF2) with relatively lower levels of proteins (0.4-20.3%) and uronic acids (0.8-4.9%). The weight average molecular weights (M-w) of 152.7-537.3 x 10(3) g/mol were measured for isolated polysaccharides. The polysaccharides were composed of glucose (14.4-44.0%), galactose (23.2-43.2%), mannose (28.5-34.2%) and rhamnose (2.6-13.9%) units connected through (1 -> 2)-Galp, (1 -> 2,6)-Galp, (1 -> 4)-Glcp, (1 -> 6)-Glcp, (1 -> 3)-Rhap, (1 -> 2)-Rhap and (1 -> 4)Manp residues. TSF2 polysaccharide effectively induced RAW264.7 murine macrophages to release nitric oxide, TNF-alpha, IL-beta and IL-6, and activated NK cells to produce TNF-alpha, INF-gamma, granzyme-B, perforin, NKG2D and FasL through NF-kappa B and MAPKs signaling pathways. Overall results suggested that polysaccharides from T. scutellifera could be potent immunostimulatory compounds inducing both macrophages and NK cells.