Immunostimulatory Effects of Gamisoyosan on Macrophages via TLR4-Mediated Signaling Pathways.

BACKGROUND

This study aimed to analyze the immunostimulatory activity of gamisoyosan (GSS) on the activation of macrophages in RAW 264.7 cells and its underlying mechanisms.

METHODS

The effects of GSS on the secretion of nitric oxide (NO), immunomodulatory mediators, cytokines and mRNAs, and related proteins were assessed using the Griess assay, Western blotting, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and H2DCFDA, respectively. The level of phagocytosis was determined by the neutral red method while the immune function of GSS was determined using adhesion and wound-healing assays.

RESULTS

GSS-treated macrophages significantly increased the production of NO, immunomodulatory enzymes, cytokines, and intracellular reactive oxygen species without causing cytotoxicity. GSS effectively improved macrophage immune function by increasing their phagocytic level, adhesion function, and migration activity. Mechanistic studies via Western blotting revealed that GSS notably induced the activation of the Toll-like receptor (TLR) 4-mediated mitogen-activated protein kinase, nuclear factor-κB, and protein kinase B signaling pathways.

CONCLUSIONS

Overall, our results indicated that GSS could activate macrophages through the secretion of immune-mediated transporters via TLR4-dependent signaling pathways. Thus, GSS has potential value as an immunity-enhancing agent.