Characterized polysaccharides from black soybean induce granulocyte colony-stimulated factor gene expression in a phosphoinositide 3-kinase-dependent manner.

Black soybean (Glycine max L. merr.) is an edible Chinese medicine for nourishment spleen. In the present study, effects of characterized polysaccharides from black soybean (PGM) on granulocyte colony-stimulated factor (G-CSF) production in human peripheral blood mononuclear cells (PBMC) were determined and their action mechanisms were examined. The results indicated that PGM concentration-dependently enhanced G-CSF production in PBMC through modulation of mRNA expression. Data from Western blotting showed that PGM significantly induced the extracellular signal-regulated protein kinase (ERK) activation in PBMC. The nuclear factor (NF)-κB activation in PBMC was increased with PGM by modulation of IκB degradation and PKC θ activation. The levels of G-CSF mRNA in PGM-treated PBMC could be reduced by ERK inhibitor U0126 and NF-κB inhibitor pyrrolidine dithiocarbamate, respectively. Furthermore, the data showed that PGM stimulated phosphoinositide 3-kinase (PI3K)-regulated Akt phosphorylation. The PI3K inhibit...