Immune enhancement effects of Korean ginseng berry polysaccharides on RAW264.7 macrophages through MAPK and NF-κB signalling pathways

Ginseng, a commonly used medicinal herb, contains polysaccharide as one of the bioactive compounds. This study aimed at evaluating the immune enhancement effects of Korean ginseng berry polysaccharides (GBPs) on macrophage RAW264.7 cells and their chemical characteristics. The crude polysaccharide (GBP-C) was extracted and fractionated to different polysaccharides (GBP-F1, GBP-F2, and GBP-F3). GBPs were mainly composed of rhamnose, arabinose, mannose, glucose and galactose, with molecular weights (Mw) ranging from 16 × 103 to 328 × 103 g/mol. While all the GBPs significantly increased the NO production in a dose-dependent manner, GBP-F2 showed the highest immune-enhancing effects. GBP-F2 up-regulated the mRNA expression of iNOS, IL-1β, IL-6, IL-10, and TNF-α through activating phosphorylation of NF-κB-p65, ERK1/2, JNK, and p38 to a greater extent than the other GBPs samples. These results indicate that GBPs, and especially GBP-F2, have strong immune enhancement effects desirable for application in the food and pharmaceutical industries.