Immunoenhancing Effects of Polysaccharides Isolated from Barley Sprout Through MAPK and NF-κB Signaling Pathways in RAW264.7 Cells
This research investigated the immunoenhancing effect through the intracellular MAPKs and NF-B signaling pathways in macrophages activated by crude polysaccharides (YBP) of barley sprouts. YBP extracted from barley sprouts is composed of xylose (25.8%), arabinose (24.1%), galactose (23.4%), and galacturonic acid (11.7%). YBP did not affect the cytotoxicity and showed superior secretion of nitric oxide (NO), interleukin (IL)-6, and tumor necrosis factor (TNF)- by RAW264.7 cells. Also, YBP dose dependently increased IL-6, TNF-, and inducible nitric oxide synthase (iNOS) mRNA gene expression. In the western blot, YBP strongly induced the phosphorylation of the p38, JNK, ERK, and IB pathways in RAW 264.7 cells. In the anti-pattern recognition receptor (anti-PRRs) assay, the effect of YBP on NO secretion strongly decreased toll-like receptor (TLR) 4 and Dectin1 antibodies, whereas IL-6 and TNF- secretion by YBP mainly decreased SR and CD14. Therefore, we concluded that YBPinduced NO, IL-6, and TNF- were secreted via the MAPKs, while NF-B pathways through TLR4, Dectin1, SR, and CD14 receptors existed in a macrophage surface and were involved in the immunoenhancing effect.