Medicinal mushrooms are used to treat and prevent a wide array of illnesses through their use as immune stimulants, immune modulators, adaptogens and antioxidants.
Over thirty species are commonly used as medicinals in the form of mycelium or mushroom fruiting-body.
The most well known and researched of these are reishi, maitake, cordyceps, blazei, split-gill, turkey tail and shiitake.
However, many other mushrooms are currently being used medicinally and have shown positive clinical results including mesima, chaga, oyster, tinder polypore and enoki, among others.
These various mushrooms contain numerous constituents that have a variety of physiological effects and are also rich in "essential sugars".
As immune stimulants, mushrooms can be used to help treat cancer and fight infections by initiating an immune response which results in higher levels of white blood cells, cytokines, antibodies and complement proteins. The cell walls of these mushrooms contain large polysaccharides called 1,3 ß-D-glucans linked to the chitin framework. These polysaccharides can also have smaller branching chains called 1,6 ß-D-glucans. Each mushroom has a different arrangement and degree of branching, which results in a different immune response. In addition, some mushrooms have 1,6 ß-D-glucans with 1,3 ß-D-glucan branching. A fragment of a mushroom ß-glucan serves as an antigen which a macrophage will display on its surface and present to T-helper cells. These T-helper cells will in turn release a variety of immune stimulating substances, cytokines, which will result in a cascade of immune responses. Cytokines released by both the macrophage and T-helper cells will cause a proliferation of T cells and B cells and stimulate production of complement proteins. Certain mushrooms, especially reishi, maitake and multi-mushroom blends, also dramatically increase the activity of natural killer cells and facilitate apoptosis of cancer cells resulting in the reduction of tumors. Macrophages and neutrophils will increase their levels of antimicrobial substances. These substances include antimicrobial enzymes and toxins, such as superoxide radical, hydrogen peroxide, hydroxyl radical, hydrochloruous acid and nitric oxide. These substances are produced in membrane-bound sacs, lysosomes, so they do not enter the cytoplasm of the white blood cell. When a macrophage or neutrophil envelopes a bacterium or virus, the microbe is enveloped within another membrane bound sac, a phagosome, which separates it from the cytoplasm of the phagocyte. Once a lysosome and phagosome merge, the toxins are released onto the microbe and destroy it (Delves 2006). The ß-glucan fragments thus serve to charge the immune system into an activated state making response to disease and infection much swifter and more effective.
Arabinoxylanes, from mycelium grown on brown rice, also serve as an antigen to stimulate the immune system and result in similar immunological responses. After the rice bran has been enzymatically treated by the mycelium, the bran breaks down into fragments, some of which are the arabinoxylane polysaccharides composed of a xylose main chain with arabinose side chains. Arabinoxylanes cause an increase in cytokine levels, including tumor necrosis factor, and an increase in natural killer activity (Ghoneum 1998). Arabinoxylanes also stimulate a proliferation of T cells and B cells thereby increasing white blood cell counts. In addition, arabinoxylanes have also shown anti-HIV activity in vitro and appear to have anti-viral activity (Ghoneum 1998). The mycelium of many medicinal mushrooms produce arabinoxylanes when grown on brown rice. When the mycelium/ brown rice biomass is dried and powdered, the resulting arabinoxylane levels are typically at least 8% of the total weight (Stamets 2003).
In addition to stimulating the immune system, mushrooms make the immune system more effective by providing some of the "essential sugars"(also referred to as glyconutrients) that many people with compromised systems are deficient in ( Mondoa 2001). Many of these sugars are part of the communication system members of the immune system use to exchange information about invading microbes and to distinguish between self and non-self. Cell membranes are studded with proteins, glycoproteins and glycolipids that serve in recognition and communication. The sugar component of a membrane glycoprotein is frequently composed of N-acetylglucosamine, fucose, glucose, galactose, N-acetylneuraminate, N-acetylgalactosamine, xylose and mannose (Stryer 1988). Two of these sugars, fucose and N-acetylneuraminate, are both made from mannose, which is found in abundance in some mushrooms, such as cordyceps, along with xylose, galactose and N-acetylglucosamine. A deficiency of these sugars results in a smaller amount of glycoproteins being present resulting in poorer communication between the cells. Furthermore, antibodies are also composed of both protein and sugars and range between 3% -10% in total carbohydrate content. Antibodies are one of the immune systems most effective tools for fighting microbes. Antibodies inactivate toxins and microbes directly and also tag them, opsonization, for destruction by phagocytes. The presence of these tagging antibodies greatly improves the ability of a phagocyte to recognize and bind foreign invaders for phagocytosis (10 - 1,000x more effective in combination with complement protein). As opposed to an antibiotic to which a microbe can develop resistance, different B cells produce different antibodies to the same microbe creating an environment more difficult for the microbe to adapt to. In fact, the human body is capable of producing up to 100 billion different types of antibodies (Prescott et al. 2005). A deficiency in glyconutrients also limits the volume of antibodies the immune system is capable of producing. In essence, mushrooms both stimulate the immune system and also provide some of the raw materials ( "essential sugars") needed for its optimal performance.
Reishi, Ganoderma lucidum, is a hard woody conk with a shiny reddish upper surface belonging to the polypore family. The mycelium or mushroom is most commonly used as a tea or as a powder sprinkled on food or encapsulated. Reishi's most recognized traits are its ability to help the body fight cancer, stimulate the immune system and increase vitality. The constituents of reishi that have received the most attention are 1,3 ß-D-glucans and triterpenes; however, it also contains other polysaccharides, ergosterol, polyphenols and adenosine (Willard 1990). When reishi mycelium is grown on brown rice, the mycelium/ brown rice biomass also contains arabinoxylanes. The majority of the 119 triterpenes that have been isolated from reishi have a lanosterol-like skeleton and thus are referred to as lanostanoid triterpenes (Kim and Kim 1999). Some of these triterpenes, such as ganoderic acid C, inhibit the release of histamine and give relief from both asthma and allergies (Kohda et al. 1985). The triterpenes of reishi have also been found to inhibit cholesterol synthesis, reduce hypertension, protect the liver and have antioxidant properties (Zhu et al. 1999, Gao et al. 2004). Having a steroid skeleton appears to allow triterpenes to be enzymatically converted into hormones thus giving reishi adaptogenic traits to help the body handle stress. Several other Ganoderma spp. have also been found to have medicinal properties including G. tsugae (hemlock reishi), G. oregonense (Oregon reishi), G. applanatum (artist conk) and G. sinense (black reishi).
Cordyceps, Cordyceps sinensis, is a very unusual mushroom that parasitizes caterpillar larvae of moths, found in the mountains of Tibet and China, and then sends a long, club-like mushroom up above ground level. The mycelium is more commonly used than the mushroom due to the growing scarcity of the mushroom in the wild. In addition to polysaccharides, cordyceps also contains high levels of cordycepic acid and nucleosides, such as cordycepin and adenosine (Li et al. 2006). Cordycepin is present in mycelium grown on a solid substrate but is virtually absent in mycelium grown in liquid culture (Masuda et al. 2006). The mycelium of cordyceps is particularly good at producing arabinoxylanes when grown on brown rice (Stamets 2003). Cordyceps has a wide-range of uses including immune system stimulation, reducing cholesterol levels and the treatment of asthma, arrhythmia and cancer (Zhu et al. 1998). Cordyceps has become very popular in sports nutrition due to its ability to increase physical endurance and its use by Olympic athletes. The high adenosine content in cordyceps also helps to prevent blood platelet aggregation.
Maitake, Grifola frondosa, is a medicinal polypore that is also a choice edible being composed of a bracket of soft, over-lapping, fan-shaped fronds. It is best known for its anti-tumor and immune-stimulating properties due to the high levels of ß-glucans found in this mushroom. Maitake has also been found to help regulate blood glucose levels and cholesterol levels (Hobbs 1995). Several products have been produced that contain certain fractions of the polysaccharide content, most famous of which is the D-fraction. The D-fraction is composed mostly of 1,6 ß-D-glucans with 1,3 ß-D-glucan side chains, but it also contains 1,3 ß-D-glucans with 1,6 ß-D-glucan side chains and proteins. This D-fraction contains the most highly branched ß-glucan polysaccharides that have been found in mushrooms and is thought to be one of the reasons why maitake is such a potent immune stimulator. In addition to the D-fraction ß-glucans, maitake also contains other polysaccharides, arabinoxylanes on rice-grown mycelium and ergothioneine, a strong antioxidant.
Shiitake, Lentinula edodes, is not only a medicinal mushroom but is also an excellent gourmet edible. Both the mycelium and the mushroom are commonly used medicinally. The main constituents of shiitake are polysaccharides, but it also contains ergosterol and ergothioneine (Dubost 2006). Shiitake is used for cancer, immune stimulation, cholesterol reduction and the treatment of HIV. A hot-water mycelial extract, called LEM, and a ß-D-glucan, lentinan, have been used extensively as medicinals in Japan (Hobbs 1995).
Turkey Tail, Coriolus versicolor, is a small polypore composed of overlapping thin, fibrous bracket mushrooms that can be found covering large areas of logs. Polysaccharide based products derived from the mycelium and mycelium biomass products are the most commonly used form of this mushroom. The two most well researched turkey tail products are PSP and PSK (Krestin), which are similar glycoproteins. The main chains of PSK and PSP are a 1,3 ß-D-glucan with polypeptide side chains. Turkey tail has been extensively researched in cancer studies having very positive results for several types of cancer including lung, breast, cervical, stomach, liver, and prostate(Hobbs 2004). When used in conjunction with chemotherapy, turkey tail has been shown to significantly reduce side effects (Halpern 2002).
Blazei, Agaricus blazei, is another choice edible with significant medicinal properties and a high ß-glucan content containing smaller molecular weight 1,3 ß-D-glucans, 1,6 ß-D-glucans and 1,4 ß-D-glucans. Blazei has been found to stimulate the immune system causing activation of the complement system, macrophages and an increase in cytokine levels, notably tumor necrosis factors and interleukins (Shimizu et al. 2002, Mizuno et al. 2006). In addition to the ß-glucans, researchers have also found a 1,4 ß-glucan with 1,6 ß-glucan side chains that was shown to have strong antitumor properties (Fujimiya et al. 1999). Blazei has been shown to be active against breast, cervical and colorectal cancers (Mizuno 2002, Stamets 2002).
The impressively wide variety of medicinal properties mushrooms possess are mostly due to their affect on the immune system, whether it be antitumor, antiviral, anti-inflammatory, etc. All these different benefits are usually obtained by the consumption of just 4 - 8 g. of mycelium or mushroom per day. The presence of vitamin C has been show to increase the absorption of the polysaccharide constituents, so it is frequently recommended to take 500 mg. to 1 g. of vitamin C along with the mushrooms.
Though many mushrooms do have similar traits, they also have species specific properties. The following is an outline of some of the most common medicinal uses of mushrooms (Hobbs 1995, Halpern 2002, Stamets 2002) and the mushrooms that have been shown to be particularly effective.
Cancer - Reishi, cordyceps, enoki, maitake, lion's mane, shiitake, mesima, turkey tail, split-gill and chaga. Cholesterol Reduction - Shiitake, blazei, reishi, enoki, cordyceps, maitake, mesima and oyster. Immune Stimulation - Reishi, cordyceps, blazei, maitake, lion's mane, chaga, shiitake and turkey tail. Antioxidant - Reishi, cordyceps, turkey tail, shiitake and maitake. Stress - Reishi, cordyceps, shiitake and maitake. Memory Improvement - Lion's Mane Insomnia - Reishi Physical Endurance - Cordyceps Sexual Performance - Cordyceps Asthma and Allergies - Reishi, cordyceps, chaga and lion's mane. High Blood Pressure - Shiitake, maitake, cordyceps, and reishi. Liver Protector - Reishi, cordyceps, chaga, shiitake, and turkey tail. Diabetes - Reishi, maitake, turkey tail and shiitake. References Delves P.J., Martin S.J., Burton D.R., and Roitt I.M. 2006. Roitt's essential immunology 11th ed. Blackwell Publishing, Oxford, U.K. Dubost N.J., Beelman R.B., Peterson, D., and Royse, D.J. 2006. Identification and quantification of ergothioneine in cultivated mushrooms by liquid chromatography-mass spectroscopy. Int J Med Mushr, 8, 215-222. Fujimiya Y., Suzuki Y., Katahura R., and Ebina T. 1999. Tumor-specific cytocidal and immunopotentiating effects of relatively low molecular weight products derived from the basidiomycete, Agaricus blazei Murrill. Anticaner Research 19: 113-118. Gao Y., Chan E., and Zhou S. 2004. Immunomodulating activities of Ganoderma, a mushroom with medicinal properties. Food Reviews International 20 (2), 123-161. Ghoneum M. 1998. Anti-HIV activity in-vitro of MGN-3, an activated arabinoxylane from rice bran. Biochem Biophys Res Commun 243, 25-29. Ghoneum, M. 1998. Enhancement of human natural killer cell activity by modified arabinoxylane from rice bran (MGN-3). International Journal of Immunotherapy XIV (I), 89-99. Halpern G.M. 2002. Medicinal mushrooms: ancient remedies for modern ailments. M. Evans & Co., New York. Hobbs, C.R. 1995. Medicinal mushrooms: an exploration of tradition, healing and culture. Botanica Press, Santa Cruz, CA. Hobbs C.R. 2004. Medicinal Value of Turkey Tail Fungus Trametes versicolor (L.:Fr.) Pilát (Aphyllophoromycetideae). A Literature Review. Int J Med Mushr, 6, 195-218. Kim H.W. and Kim B.K. 1999. Biomedical triterpenoids of Ganoderma lucidum (curt.:fr.) P. Karst. (Aphyllophoromycetideae). Int J Med Mushr, 1, 121-138. Kohda H., Tokumoto W., Sakamoto K., Fuji H., Hirai P., Yamasaki K., Nakamura H., Isihara S., and Uchida M. 1985. The biologically active constituents of Ganoderma lucidum, histamine release inhibitory triterpenes. Chem Pharm Bull, 33 (4), 1367-1374. Li S.P., Yang F.Q., and Tsim K.W.K. 2006. Quality control of Cordyceps sinensis, a valued traditional Chinese medicine. Journal of Pharmaceutical and Biomedical Analysis. 41, 1571-1584. Masuda M., Urabe E., Sakurai A., and Sakakibara, M. 2006. Production of cordycepin by surface culture using the medicinal mushroom Cordyceps militaris. Enzyme and Microbial Technology 39, 641-646. Mizuno M. and Kawakami S. 2006. An immunomodulating polysaccharide in Agaricus braziliensis S. Wasser et al. (Agaricomycetideae) activates macrophages through toll-like receptor 4. Int J Med Mushr, 8, 223 - 230. Mizuno T. 2002. Medicinal properties and clinical effects of culinary-medicinal mushroom Agaricus blazei Murrill. (Agaricomycetidae) (Review). Int J Med Mushr, 4, 299-312. Mondoa E.I. and Kitei M. 2001. Sugars that heal: the new healing science of glyconutrients. Ballantine Books, New York. Prescott L.M., Harley J.P., and Klein D.A. 2005. Microbiology 6th ed. McGraw Hill, New York. Shimizu S., Kitada H., and Yokota H. 2002. Activation of the alternative complement pathway by Agaricus blazei Murill. Phytomedicine 9: 536-45. Stamets P. 2002. Mycomedicinals: An Informational Treatise on Mushrooms. Mycomedia Productions, Olympia, WA. Stamets P. 2003. Potentiation of cell-mediated host defense using fruitbodies and mycelia of medicinal mushrooms. Int J Med Mushr, 5, 179-191. Stryer L. 1988. Biochemistry 3rd ed. W. H. Freeman & Co., New York. Willard T. 1990. Reishi mushroom: herb of spiritual potency and medical wonder. Sylvan Press, Issaquah, WA. Zhu J., Halpern G.M., Jones K. 1998. The scientific rediscovery of an ancient Chinese herbal medicine: Cordyceps sinensis Part I. The Journal of Alternative and Complementary Medicine, 4 (3), 289-303. Zhu M., Chang Q., Wong, L.K., Chong F.S., and Li R.C. 1999. Triterperne antioxidants from Ganoderma lucidum. Phytother Res 13, 529-531.