(Dicks.) Gray (1821)
Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks. The mushroom is commonly known among English speakers as hen-of-the-woods, ram's head and sheep's head. It is typically found in late summer to early fall. In the United States' supplement market, as well as in Asian grocery stores, the mushroom is known by its Japanese name maitake (舞茸), which means "dancing mushroom". Throughout Italian American communities in the northeastern United States, it is commonly known as the signorina mushroom. G. frondosa should not be confused with Laetiporus sulphureus, another edible bracket fungus that is commonly called chicken of the woods or "sulphur shelf". Like all polypores, the fungus becomes inedible when older, because it is then too tough to eat.
The fungus is native to the northeastern part of Japan and North America, and is prized in traditional Chinese and Japanese herbology as a medicinal mushroom, an aid to balance out altered body systems to a normal level. It is widely eaten in Japan, and its popularity in western cuisine is growing, although the mushroom has been alleged to cause allergic reactions in rare cases.
|pores on hymenium|
cap is offsetor indistinct
|hymenium is decurrent|
|lacks a stipe|
|spore print is white|
|ecology is parasitic|
Like the sulphur shelf mushroom, G. frondosa is a perennial fungus that often grows in the same place for a number of years in succession. It occurs most prolifically in the northeastern regions of the United States, but has been found as far west as Idaho.
G. frondosa grows from an underground tuber-like structure known as a sclerotium, about the size of a potato. The fruiting body, occurring as large as 100 cm, is a cluster consisting of multiple grayish-brown caps which are often curled or spoon-shaped, with wavy margins and 2–7 cm broad. The undersurface of each cap bears approximately one to three pores per millimeter, with the tubes rarely deeper than 3 mm. The milky-white stipe (stalk) has a branchy structure and becomes tough as the mushroom matures.
In Japan, the Maitake can grow to more than 100 pounds (45 kilograms), earning this giant mushroom the title "King of Mushrooms". Maitake is one of the major culinary mushrooms used in Japan, the others being shiitake, shimeji and enoki. They are used in a wide variety of dishes, often being a key ingredient in nabemono or cooked in foil with butter.
The sclerotia from which hen of the woods arises have been used in traditional Chinese and Japanese medicine to enhance the immune system. Researchers have also indicated that whole maitake has the ability to regulate blood pressure, glucose, insulin, and both serum and liver lipids, such as cholesterol, triglycerides, and phospholipids, and may also be useful for weight loss.
Maitake is rich in minerals (such as potassium, calcium, and magnesium), various vitamins (B2, D2 and niacin), fibers and amino acids. One active constituent in Maitake for enhancing the immune activity was identified in the late 1980s as a protein-bound beta-glucan compound.
Medical research and use
In 2009, a phase I/II human trial, conducted by Memorial Sloan–Kettering Cancer Center, showed Maitake could stimulate the immune systems of breast cancer patients. Small experiments with human cancer patients have shown Maitake can stimulate immune system cells, like NK cells. In vitro research has also shown Maitake can stimulate immune system cells. An in vivo experiment showed that Maitake could stimulate both the innate immune system and adaptive immune system.
In vitro research has shown Maitake can induce apoptosis in various cancer cell lines as well as inhibit the growth of various types of cancer cells. Small studies with human cancer patients revealed that a portion of the Maitake mushroom, known as the "Maitake D-fraction", possesses anti-cancer activity. In vitro research demonstrated the mushroom has potential anti-metastatic properties.
Research has shown Maitake has a hypoglycemic effect, and may be beneficial for the management of diabetes. The reason Maitake lowers blood sugar is because the mushroom naturally contains an alpha glucosidase inhibitor.
Maitake contains antioxidants and may partially inhibit the enzyme cyclooxygenase. An experiment showed that an extract of Maitake inhibited angiogenesis via inhibition of the vascular endothelial growth factor (VEGF).
- McIlvaine, Charles; Robert K. Macadam; and Robert L. Shaffer. 1973. One Thousand American Fungi. Dover Publications. New York. 729 pp. (Polyporus frondosus, pp. 482-483 & Plate CXXVIII.)
- Deng G, Lin H, Seidman A, et al. (September 2009). "A phase I/II trial of a polysaccharide extract from Grifola frondosa (Maitake mushroom) in breast cancer patients: immunological effects". Journal of Cancer Research and Clinical Oncology 135 (9): 1215–21. doi:10.1007/s00432-009-0562-z. PMID 19253021.
- Kodama N, Komuta K, Nanba H (2003). "Effect of Maitake (Grifola frondosa) D-Fraction on the activation of NK cells in cancer patients". Journal of Medicinal Food 6 (4): 371–7. doi:10.1089/109662003772519949. PMID 14977447.
- Kodama N, Komuta K, Sakai N, Nanba H (December 2002). "Effects of D-Fraction, a polysaccharide from Grifola frondosa on tumor growth involve activation of NK cells". Biological & Pharmaceutical Bulletin 25 (12): 1647–50. doi:10.1248/bpb.25.1647. PMID 12499658.
- Kodama N, Asakawa A, Inui A, Masuda Y, Nanba H (March 2005). "Enhancement of cytotoxicity of NK cells by D-Fraction, a polysaccharide from Grifola frondosa". Oncology Reports 13 (3): 497–502. doi:10.3892/or.13.3.497. PMID 15706424.
- Kodama N, Murata Y, Nanba H (2004). "Administration of a polysaccharide from Grifola frondosa stimulates immune function of normal mice". Journal of Medicinal Food 7 (2): 141–5. doi:10.1089/1096620041224012. PMID 15298759.
- Ulbricht C, Weissner W, Basch E, Giese N, Hammerness P, Rusie-Seamon E, Varghese M, Woods J. (2009). "Maitake mushroom (Grifola frondosa): systematic review by the natural standard research collaboration". Journal of the Society for Integrative Oncology 7 (2): 66–72. PMID 19476741.
- Kodama N, Komuta K, Nanba H (June 2002). "Can maitake MD-fraction aid cancer patients?" (PDF). Alternative Medicine Review 7 (3): 236–9. PMID 12126464.
- Nanba H, Kubo K (December 1997). "Effect of Maitake D-fraction on cancer prevention". Annals of the New York Academy of Sciences 833 (1 Cancer): 204–7. doi:10.1111/j.1749-6632.1997.tb48611.x. PMID 9616756.
- Masuda Y, Murata Y, Hayashi M, Nanba H (June 2008). "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". Biological & Pharmaceutical Bulletin 31 (6): 1104–8. doi:10.1248/bpb.31.1104. PMID 18520039.
- Matsuur H, Asakawa C, Kurimoto M, Mizutani J (July 2002). "Alpha-glucosidase inhibitor from the seeds of balsam pear (Momordica charantia) and the fruit bodies of Grifola frondosa". Bioscience, Biotechnology, and Biochemistry 66 (7): 1576–8. doi:10.1271/bbb.66.1576. PMID 12224646.
- Zhang Y, Mills GL, Nair MG (December 2002). "Cyclooxygenase inhibitory and antioxidant compounds from the mycelia of the edible mushroom Grifola frondosa". Journal of Agricultural and Food Chemistry 50 (26): 7581–5. doi:10.1021/jf0257648. PMID 12475274.
- Lee JS, Park BC, Ko YJ, et al. (December 2008). "Grifola frondosa (maitake mushroom) water extract inhibits vascular endothelial growth factor-induced angiogenesis through inhibition of reactive oxygen species and extracellular signal-regulated kinase phosphorylation". Journal of Medicinal Food 11 (4): 643–51. doi:10.1089/jmf.2007.0629. PMID 19053855.
- Nonaka, T; Y Hashimoto; K Takio (July 1998). "Kinetic characterization of lysine-specific metalloendopeptidases from Grifola frondosa and Pleurotus ostreatus fruiting bodies". Journal of Biochemistry 124 (1): 157–162. doi:10.1093/oxfordjournals.jbchem.a022074. ISSN 0021-924X. PMID 9644258.
- Taouatas, Nadia; Madalina M Drugan; Albert J R Heck; Shabaz Mohammed (May 2008). "Straightforward ladder sequencing of peptides using a Lys-N metalloendopeptidase". Nat Meth 5 (5): 405–407. doi:10.1038/nmeth.1204. ISSN 1548-7091. PMID 18425140.
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