A novel polysaccharide from plant fermentation extracts and its immunomodulatory activity in macrophage RAW264.7 cells

Abstract

Plant fermentation extracts (PFEs) produced from fermenting various fruits and vegetables by microorganisms have traditionally been consumed as healthy beverages in Asia. Herein, the immunomodulatory activities of a novel polysaccharide (AP) isolated from PFE were examined in RAW264.7 cells. The results showed that AP was composed of Rha, Xyl, Man and Glu in a molar ratio of 9.7:27.6:8.81:53.85 and the average molecular weight was 4.81 × 105 Da. Our data showed that AP could significantly enhance the phagocytic activity of RAW264.7 cells and their ability to release NO, TNF-α, IL-6 and IL-10. Furthermore, AP could significantly up-regulate the mRNA expression of iNOS, cytokines (TNF-α, IL-6, IL-10) and pattern recognition receptors (TLR2, MR, GR, CR3 and SR). Western blotting demonstrated that the regulation of NO and TNF-α were mediated through the NF-κB and MAPK signalling pathways. These findings helped to elucidate the immunomodulatory properties of the polysaccharide AP and PFE.

Keywords

• plant fermentation extracts
• polysaccharide
• immunomodulatory activity
• mapk
• nf-κb