Ganoderma lucidum mycelia enhance innate immunity by activating NF-κB

Ganoderma lucidum is a popular medicinal mushroom in China and Japan for its immunomodulatory and antitumor effects. The goal of this research is to investigate the effect of dried mycelia of Ganoderma lucidum produced by submerged cultivation on the enhancement of innate immune response. We found that Ganoderma lucidum mycelia (0.2–1.6 mg/ml) stimulated TNF-α and IL-6 production after 8 h treatment in human whole blood. IFN-γ release from human whole blood was also enhanced after 3 day-culture with Ganoderma lucidum mycelia (0.2–1.0 mg/ml). However, Ganoderma lucidum mycelia did not potentiate nitric oxide production in RAW264.7 cells. To better understand the possible immuno-enhancement mechanisms involved, we focused on nuclear factor (NF)-κB activation. Electrophoretic mobility shift assay revealed that the Ganoderma lucidum mycelia (1.6 mg/ml) activated κB DNA binding activity in RAW264.7 cells. These results provide supporting evidences for the immunomodulatory effect of Ganoderma lucidum mycelia.