Immunomodulatory effects of CMDB, the component of Cordyceps militaris mycelium, by the enhanced production of cytokines in macrophages (B64)

Abstract

Abstract Cordyceps militaris (CM) have been reported to modify the immune and inflammatory responses both in vivo and in vitro. Macrophages play important roles in the innate immunity through the phagocytosis of antigens. This study examined the effects of CM on the activation of murine macrophage RAW264.7 cells. The filtered components of the draff broth (DB) cultured with mycelium of CM, CMDB, CMDBW, CMDB5P, CMDB25P, were purified by propyl alcohol extraction and HP 20 column chromatography. All the components of CM produced significant amounts of nitric oxide (NO). In particular, CMDB produced much more NO in RAW264.7 cells and primary macrophages than the other fractions of CM. CMDB increased significantly the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 dose-dependently in RAW264.7 cells. To examine whether the CMDB effects on cytokine production were attributable to its influence on the expression of mRNAs, semi-quantitative RT-PCR experiments were performed for the transcripts. Examination of the gene expression level showed that the enhanced production of cytokines was correlated with the up-regulation of i-NOS expression, cycloxygenase (COX)-2 expression, IL-1β and IL-6 expression, and TNF-α gene expression. Western blot analysis also confirmed that CMDB enhances the expression level of these cytokines. These results suggest that CMDB has immunostimulatory effects on macrophages through the enhanced production of cytokines.