Shiitake - Lentinus edodes
Shiitake mushroom, the common Japanese name for Lentinus edodes (Fig. 1), derives from the mushroom associated with the shii tree (Castanopsis cuspidate Schottky) and take, the Japanese word for mushroom Because Japan is the world leader in production of this type of mushroom, the mushroom is now widely known by this name. These mushrooms are renowned in Far East countries (e.g., Japan, China, Korea) as a food and medicine for thousands of years. In the year 1999 A.D., Kyusuyu, a native tribe of Japan, offered the Japanese Emperor Chuai a shiitake mushroom. Even older documents record its use in ancient China, where it was referred to as ‘‘ko-ko’’or ‘‘hoang-mo.’’
The cultivation of this mushroom has been practiced for a thousand years, with its cultivation originating in China during the Sung Dynasty(960–1127). Both history and legend credit Wu San Kwung as the originator of shiitake cultivation.Almost every mushroom-growing village in China has a temple in his honor.[2] In 1313, Chinese authorWang Cheng recorded shiitake-growing techniques in his Book of Agriculture. He described how to select a uitable site, choose appropriate tools, and cut down the trees on which one could cultivate the mushrooms. He outlined the basic methods as follows: Cut the bark with a hatchet and cover the logs with soil. After 1yr, top the soil and water frequently. Beat the logs with a wooden club to induce mushroom production. The mushrooms will appear after a rain.[2,3] Shiitake mushroom cultivation techniques were probably introduced to Japanese farmers by the Chinese between 1500 and 1600 A.D.[4]
At present, shiitake is one of the five most cultivated edible mushrooms in the world. Its production (2 million tons) is second only to button mushroom Agaricus bisporus. Grown mainly in East Asia, shiitake is now arousing interest worldwide. Increasing markets have been spawned, partly by the exotic and well appreciated taste of shiitake, and partly by advances
in research that has demonstrated its significant medicinal properties.
Shiitake mushroom is becoming Popular in nutritional and medicinal products throughout Asia, Europe, and North America.
Shiitake are traditionally well-known edible mush-rooms of high nutritious value. Raw or dried forms,
used in Chinese curative powers of shiitake mushroom,are legendary. It was stated in Ri Youg Ben Cao, Vol. 3(1620), written by Wu-Rui of the Ming Dynasty, ‘‘shii-take accelerates vital energy, wards off hunger, cure scolds, and defeats body fluid energy.’’ In later years,it was found that the mushroom contained various important nutrients. Moreover, recent scientific investigations have isolated many compounds and have found evidence of their health promotion activities.
Shitake mushrooms have excellent nutritional value. Their raw fruit bodies include 88–92%water,protein, lipids, carbohydrates as well as vitamins and minerals. It should be noted that amounts of nutrients and biologically active compounds differ in various strains and are affected by substrate, fruiting conditions, and methods of cultivation. On a dry weight basis, they have a relatively high nutritional value when compared to commonly consumed vegetables.Dried shiitake mushrooms are rich in carbohydrates and protein.
They contain 58–60%carbohydrates,20–23%protein (digestibility of 80–87%), 9–10%fiber, 3–4%lipids, and 4–5%ash. The mushroom is a good source of vitamins, especially pro vitamin D2 Solomon P.
Wasseris at the University of Haifa, Mount Carmel,Haifa, Israel.Encyclopedia of Dietary Supplements
(ergosterol), 325mg%, which under ultraviolet (UV)light and heat yields calciferol (vitamin D2).
It also contains B vitamins, including:
B1(thiamine), B2(riboflavin), B12(niacin), and pantothenic acid.
Minerals found include Fe, Mn, K, Ca, Mg, Cd, Cu,P, and Zn. Analysis of dried cultured shiitake mycelium gives the following mineral concentrations (in mg=g of dry weight): K, 15.1; Ca, 22; Mg, 44–78;Mn, 1.2; Cd, 0.96; Fe, 2.36; Ni, 52.5; Cu, 89.1; P,281; Zn, 282; Ge, 3; Br, 11.4; and Sr, 164.
Water-soluble polysaccharides amount to 1–5%of the dry weight of the shiitake mushroom.
In addition to glycogen-like polysaccharides, (1-4)-,(1-6)-a-D-glucans and anti tumor polysaccharides, lentinan, (1-3)-,(1-6)-b-bonded heteroglucans, heterogalactans, hetero-mannans, xyloglucans, etc., have been identified.
The mushrooms’ indigestible polysaccharides, which serve as dietary fiber, include heteroglycan, polyuronide,b-glucan as well as chitin. Among the free sugars present are trehalose, glycerol, mannitol, arabitol, mannose, and arabinose..
In shiitake mushrooms, dietary fiber consists of water-soluble materials such as b-glucan and protein and water-insoluble substances extractable only with salts, acids, and alkalies such as polyuronide (acidic -polysaccharide), hemicellulose, b-glucan with hetero-saccharide chains, lignin, and chitin present as cell wall constituents.
The fatty acids account for 3.38%of the totallipids. Their composition is as follows:
linoleic acid(18:2), 72.8%; palmitic acid (16:0), 14.7%; oleic acid(18:1), 3.0%; tetradecenoic acid (14:1), 1.6%; stearic acid (18:0), 0.9%; and myristic acid (14:0), 0.1%. The aroma components include alcohols, ketones, sulfides, alkanes, fatty acids, etc.
The major volatile flavor contributors are matsu takeol (octen-1-ol-3) and ethyl-n-amyl ketone.
The characteristic aroma of shiitake mushrooms was identified as 1,2,3,5,6-pentathiepane.
According to Mizuno, the components responsible for the delicious flavor are monosodiumglutamate, 50-nucleotides, free amino acids, lower molecular weight peptides, organic acids, and sugars.
Their relative ratios are responsible for the variation in flavor naturally seen in this mushroom. Organic acids contributing to the flavor of shiitake mushroom include malic acid, fumaric acid, a-keto-glutaric acid, oxalic acid, lactic acid, acetic acid, formic acid, and glycolic acid.
KS-2-a-Mannan Peptide Polysaccharide KS-2 (MW 6–9.5104[a]Dþ62;C¼0.5, water)
was obtained by extraction of cultured mycelia of shiitake mushroom (strain KSLE007) with hot water, followed by precipitation with ethanol.[9,16,29]The product is anamannan peptide containing the amino acids serine, threonine, alanin, and proline (as well as residual amounts of the other amino acids).
The polysaccharide was shown]to be effective on Sarcoma 180 and Ehrlich’s carcinoma, either i.p. or p.o., and to act via interferon-inducing activity. The acute LC50or KS-2 was found to be extremely low in mice, more than 12,500mg=kg when administered orally.The mechanism of action of KS-2 is not yet clear,but the results showed no direct KS-2 cytocidal effect against the tumor cells in vitro.
Its antitumor activity was observed to be higher at the lower in oculum size of tumor cells, regardless of the routes of KS-2 administration (60% survival rate at 5103 tumor cells=mouse, 10%survival at 1106 tumor cells=mouse).
The results also showed that the antitumor activity ofKS-2 in mice was always accompanied by the induction of interferon in the sera. Furthermore, preliminary findings indicated that macrophages obtained fromKS-2 treated mice exhibited tumoricidal activity,and it was reported that macrophage activation became tumoricidal when incubated in vitro with interferon.
Considering these findings, the antitumor activity of KS-2 may be explained by macrophage activation with or without interferon induced by KS-2.Immune-Modulating Effects
As was stated earlier, lentinan and other polysaccharides from shiitake mushrooms do not attack cancer cells directly, but produce their antitumor effects by activating different immune responses in the host. Lentinan, for example, appears to act as an HDP, which is able to restore or augment the responsiveness of host cells to lymphocytokines, hormones, and other biologically active substances by stimulating maturation, differentiation, or proliferation of cells involved in host defense mechanisms..
Host defense potenttiators are functionally different from biological response modifiers. Thus, lentinan is able to increase host resistance against various kinds of cancer and infectious diseases, including acquired immuno deficiency syndrome (AIDS)
used in Chinese curative powers of shiitake mushroom,are legendary. It was stated in Ri Youg Ben Cao, Vol. 3(1620), written by Wu-Rui of the Ming Dynasty, ‘‘shii-take accelerates vital energy, wards off hunger, cure scolds, and defeats body fluid energy.’’ In later years,it was found that the mushroom contained various important nutrients. Moreover, recent scientific investigations have isolated many compounds and have found evidence of their health promotion activities.
Shitake mushrooms have excellent nutritional value. Their raw fruit bodies include 88–92%water,protein, lipids, carbohydrates as well as vitamins and minerals. It should be noted that amounts of nutrients and biologically active compounds differ in various strains and are affected by substrate, fruiting conditions, and methods of cultivation. On a dry weight basis, they have a relatively high nutritional value when compared to commonly consumed vegetables.Dried shiitake mushrooms are rich in carbohydrates and protein.
They contain 58–60%carbohydrates,20–23%protein (digestibility of 80–87%), 9–10%fiber, 3–4%lipids, and 4–5%ash. The mushroom is a good source of vitamins, especially pro vitamin D2 Solomon P.
Wasseris at the University of Haifa, Mount Carmel,Haifa, Israel.Encyclopedia of Dietary Supplements
(ergosterol), 325mg%, which under ultraviolet (UV)light and heat yields calciferol (vitamin D2).
It also contains B vitamins, including:
B1(thiamine), B2(riboflavin), B12(niacin), and pantothenic acid.
Minerals found include Fe, Mn, K, Ca, Mg, Cd, Cu,P, and Zn. Analysis of dried cultured shiitake mycelium gives the following mineral concentrations (in mg=g of dry weight): K, 15.1; Ca, 22; Mg, 44–78;Mn, 1.2; Cd, 0.96; Fe, 2.36; Ni, 52.5; Cu, 89.1; P,281; Zn, 282; Ge, 3; Br, 11.4; and Sr, 164.
Water-soluble polysaccharides amount to 1–5%of the dry weight of the shiitake mushroom.
In addition to glycogen-like polysaccharides, (1-4)-,(1-6)-a-D-glucans and anti tumor polysaccharides, lentinan, (1-3)-,(1-6)-b-bonded heteroglucans, heterogalactans, hetero-mannans, xyloglucans, etc., have been identified.
The mushrooms’ indigestible polysaccharides, which serve as dietary fiber, include heteroglycan, polyuronide,b-glucan as well as chitin. Among the free sugars present are trehalose, glycerol, mannitol, arabitol, mannose, and arabinose..
In shiitake mushrooms, dietary fiber consists of water-soluble materials such as b-glucan and protein and water-insoluble substances extractable only with salts, acids, and alkalies such as polyuronide (acidic -polysaccharide), hemicellulose, b-glucan with hetero-saccharide chains, lignin, and chitin present as cell wall constituents.
The fatty acids account for 3.38%of the totallipids. Their composition is as follows:
linoleic acid(18:2), 72.8%; palmitic acid (16:0), 14.7%; oleic acid(18:1), 3.0%; tetradecenoic acid (14:1), 1.6%; stearic acid (18:0), 0.9%; and myristic acid (14:0), 0.1%. The aroma components include alcohols, ketones, sulfides, alkanes, fatty acids, etc.
The major volatile flavor contributors are matsu takeol (octen-1-ol-3) and ethyl-n-amyl ketone.
The characteristic aroma of shiitake mushrooms was identified as 1,2,3,5,6-pentathiepane.
According to Mizuno, the components responsible for the delicious flavor are monosodiumglutamate, 50-nucleotides, free amino acids, lower molecular weight peptides, organic acids, and sugars.
Their relative ratios are responsible for the variation in flavor naturally seen in this mushroom. Organic acids contributing to the flavor of shiitake mushroom include malic acid, fumaric acid, a-keto-glutaric acid, oxalic acid, lactic acid, acetic acid, formic acid, and glycolic acid.
KS-2-a-Mannan Peptide Polysaccharide KS-2 (MW 6–9.5104[a]Dþ62;C¼0.5, water)
was obtained by extraction of cultured mycelia of shiitake mushroom (strain KSLE007) with hot water, followed by precipitation with ethanol.[9,16,29]The product is anamannan peptide containing the amino acids serine, threonine, alanin, and proline (as well as residual amounts of the other amino acids).
The polysaccharide was shown]to be effective on Sarcoma 180 and Ehrlich’s carcinoma, either i.p. or p.o., and to act via interferon-inducing activity. The acute LC50or KS-2 was found to be extremely low in mice, more than 12,500mg=kg when administered orally.The mechanism of action of KS-2 is not yet clear,but the results showed no direct KS-2 cytocidal effect against the tumor cells in vitro.
Its antitumor activity was observed to be higher at the lower in oculum size of tumor cells, regardless of the routes of KS-2 administration (60% survival rate at 5103 tumor cells=mouse, 10%survival at 1106 tumor cells=mouse).
The results also showed that the antitumor activity ofKS-2 in mice was always accompanied by the induction of interferon in the sera. Furthermore, preliminary findings indicated that macrophages obtained fromKS-2 treated mice exhibited tumoricidal activity,and it was reported that macrophage activation became tumoricidal when incubated in vitro with interferon.
Considering these findings, the antitumor activity of KS-2 may be explained by macrophage activation with or without interferon induced by KS-2.Immune-Modulating Effects
As was stated earlier, lentinan and other polysaccharides from shiitake mushrooms do not attack cancer cells directly, but produce their antitumor effects by activating different immune responses in the host. Lentinan, for example, appears to act as an HDP, which is able to restore or augment the responsiveness of host cells to lymphocytokines, hormones, and other biologically active substances by stimulating maturation, differentiation, or proliferation of cells involved in host defense mechanisms..
Host defense potenttiators are functionally different from biological response modifiers. Thus, lentinan is able to increase host resistance against various kinds of cancer and infectious diseases, including acquired immuno deficiency syndrome (AIDS)