Grifola frondosa

Maitake beta- glucan extract obtained from the fruiting bodies of maitake mushroom, or Grifola frondosa, is widely used in Asia as a cancer treatment, typically adjunctively. Research to determine the mechanisms that underlie maitake’s anticancer effects is ongoing, as detailed at http://www.mskcc.org/AboutHerbs.

Maitake mushroom is an edible perennial fungus that grows in clusters at the foot of large trees, especially oak. The whole mushroom, which can grow as large as 60 cm, can be fried or boiled. Extracts and supplements are sold as immune stimulants for patients with HIV or cancer.

Beta-1,6-glucan, a protein-bound polysaccharide, is the active component of the maitake mushroom. This compound has been shown to exert anticancer effects in vitro by stimulating various subsets of the immune system. A small study of maitake extract in cancer patients found the substance to be beneficial. Additional investigations are underway to determine optimal dosing and to fully assess maitake’s anticancer potential.

Adverse effects are rare from medicinal mushrooms. However, because maitake may interfere with immunosuppressants and may also have hypoglycemic effects, patients should use caution and consult their physicians before taking maitake supplements.

SCIENTIFIC NAME: Grifola frondosa

ALSO KNOWN AS: Maitake, hen of the woods, dancing mushroom

USES: Maitake is a medicinal mushroom used to treat diabetes and hypertension, as an immunostimulant, and to treat and prevent cancer.

BACKGROUND: Maitake is an edible mushroom of the class Basidiomycetes. It is consumed as food in Asia and also used medicinally as an immunostimulant in Japan and elsewhere in Asia. Maitake extracts are commercially available as dietary supplements. Along with other medicinal mushroom supplements, they are used to “enhance immune function” and to treat HIV and cancer. The active constituent is thought to be a protein-bound beta-glucan.

RESEARCH: In vitro studies show that the beta-1,6-glucan fraction extracted from maitake enhances bone marrow colony formation, reduces doxorubicin toxicity,[1] induces hematopoietic stem cell proliferation[2] and inhibits tumor metastasis.[3] It is thought to exert these effects by activating various effector cells, such as macrophages, natural killer cells, T cells, interleukin-1, and superoxide anions.[4]

In a small noncontrolled human study, tumor regression or significant symptom improvement was observed in half of the subjects using maitake extract.[5]

Maitake also demonstrated hypoglycemic activity in mice[6] and in patients with type 2 diabetes .[7]

References:

REFERENCES

1. Lin H, Shi YH, Cassileth BR, et al: Maitake beta-glucan MD-fraction enhances bone marrow colony formation and reduces doxorubicin toxicity in vitro. Int Immunopharmacol 4:91-99, 2004.
2. Lin H, Cheung SW, Nesin M, et al: Enhancement of umbilical cord blood cell hematopoiesis by maitake beta-glucan is mediated by granulocyte colony-stimulating factor production. Clin Vaccine Immunol 14:21-27, 2007.
3. Masuda Y, Murata Y, Hayashi M, et al: Inhibitory effect of MD-Fraction on tumor metastasis: Involvement of NK cell activation and suppression of intercellular adhesion molecule (ICAM)-1 expression in lung vascular endothelial cells. Biol Pharm Bull 31:1104-1108, 2008.
4. Adachi K, Nanba H, Kuroda H: Potentiation of host-mediated antitumor activity in mice by beta glucan obtained from Grifola frondosa (maitake). Chem Pharm Bull 35:262-270, 1987.
5. Kodama N, Komuta K, Nanba H: Can maitake MD-fraction aid cancer patients? Altern Med Rev 7:236-239, 2002.
6. Hong L, Xun M, Wutong W: Anti-diabetic effect of an alpha-glucan from fruit body of maitake (Grifola frondosa) on KK-Ay mice. Pharm Pharmacol 59:575-582, 2007.
7. Konno S, Tortorelis DG, Fullerton SA, et al: A possible hypoglycaemic effect of maitake mushroom on type 2 diabetic patients. Diabet Med 18:1010, 2001.