Characterization and immunostimulating effects on murine peritoneal macrophages of oligosaccharide isolated from Panax ginseng C.A. Meyer

Ethnopharmacological relevance: Panax ginseng C.A. Meyer has been the most precious and renowned Chinese herb used in Asian countries for the treatment of various medical disorders.

Aim of the study: The aim of this work was to investigate the activation effect on murine peritoneal macrophages of oligosaccharide from the roots of P. ginseng.

Materials and methods: In this work, the water-extracted oligosaccharide of P. ginseng was (WGOS) isolated and purified from the roots of P. ginseng by hot water extraction, ultrafiltration and gel-permeation chromatography. The monosaccharide composition and degree of polymerization (DP) of WGOS were determined by a combination of acid hydrolysis, high performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Phagocytosis of macrophages was measured by uptake of the neutral red by macrophages, nitric oxide (NO) was determined by the Griess method, inducible NO synthase (iNOS) activity was determined by colorimetric method using a reagent kit, and tumor necrosis factor-α (TNF-α) was analyzed by enzyme linked immunosorbent assay (ELISA). The reactive species detection kit was used to measure the reactive oxygen species (ROS) level.

Results: WGOS was composed of glucose and the DP was ranging from 2 to 14. Immunological tests showed that treatment of WGOS significantly increased phagocytosis of macrophages, and promoted NO, TNF-α and ROS production. Furthermore, WGOS dose-dependently stimulated NO formation through the up-regulation of iNOS activity.

Conclusions: Taken together, WGOS possessed high immunopotentiating activity and could be developed as a novel immnunostimulant.