Immunomodulating activities of Ganoderma, a mushroom with medicinal properties

Abstract

This review highlights the recent research progress in the study of immunomodulating effects of Ganoderma, which belongs to the basidiomycotina class of fungi. The commonly used Ganoderma species include G. lucidum, G. tsugae, G. capense, and G. applanatum. Several major substances with potent immunomodulating action have been isolated from Ganoderma. These include polysaccharides (in particular β-D-glucan), proteins (e.g., Ling Zhi-8) and triterpenoids. The major immunomodulating effects of these active substances derived from Ganoderma include mitogenicity and activation of immune effector cells, such as lymphocytes, macrophages, and natural killer cells, resulting in the production of cytokines, including interleukins (ILs), tumor necrosis factor (TNF)-α, and interferons. There is evidence indicating that β-D-glucans from medicinal mushrooms induce biological response by binding to membrane complement receptor type three (CR3, αMβ2 integrin, or CD11b/CD18) on immune effector cells. The ligand-receptor complex is then internalized, intriguing a series of molecular events such as the activation of the nuclear factor NF-kB. Immunosuppressive effects by Ganoderma components have also been observed. The therapeutic effects of Ganoderma, such as anticancer and anti-inflammatory effects, have been associated with its immunomodulating effects. However, further studies are needed to determine the molecular mechanisms of the immunomodulating effects of Ganoderma mushrooms.