Macrophage Immunomodulatory Activity of a Purified Polysaccharide Isolated from Ganoderma atrum

The objective of this study was to evaluate the immunomodulatory effects of the purified Ganoderma atrum polysaccharide (PSG-1) on murine macrophage cell line RAW264.7. Phagocytotic assay by fluorescein isothiocyanate-dextran internalization showed that PSG-1 stimulated the phagocytosis of macrophages. G.atrum polysaccharide increased the production of NO, and the level of mRNA expression of inducible nitric oxide synthase in a doseresponse manner. G.atrum polysaccharide also dose-dependently induced the release of TNF- and interleukin-1. Generation of reactive oxygen species was promoted by PSG-1, as determined by flow cytometry. Moreover, PSG-1 induced nuclear factor-B activation by elevation of p65 nuclear translocation, suggesting that PSG-1 probably stimulated macrophage activities by activating the nuclear factor-B pathway. Copyright (c) 2012 John Wiley & Sons, Ltd.