Extract of Sporoderm-Broken Germinating Spores of Ganoderma lucidum Activates Human Polymorphonuclear Neutrophils via the P38 Mitogen-activated Protein Kinase Pathway

Background: Ganoderma lucidum (G. lucidum) has been used in traditional Chinese medicine for thousands of years because of its immunomodulatory properties. It isbelieved that G. lucidum enhances the human immune response by improving the function of human polymorphonuclear neutrophils (PMNs); nevertheless, the actual mechanism by which G. lucidum acts on human PMNsremains unknown. In this study, we investigated the molecular pathwaysthrough which G. lucidum activates human PMNs.Methods: The phagocytic activity of PMNs was evaluated with and without treatmentwith the extract of sporoderm-broken germinating spores of G. lucidum. Thesame activity was measured after G. lucidum treatment with or without p38mitogen-activated protein kinase (p38 MAPK) inhibitor. The activation ofp38 MAPK was also evaluated with or without treatment with the extract ofsporoderm-broken germinating spores of G. lucidum.Results: In this study, we found that the extract of G. lucidum enhanced the phagocytic activity of PMNs in a dose-dependent manner, but this response was attenuated by treatment with SB203580, a p38 MAPK inhibitor. The extract of G.lucidum also enhanced activation of p38 MAPK in a dose-dependent manner.Conclusion: These results clearly show that the extract of G. lucidum can modulatehuman immunity by activating human PMNs via the p38 MAPK pathway.These results may be of clinical importance to doctors of traditional Chinesemedicine.