Ganoderma lucidum has been rated the top medicinal herb in traditional Chinese medicine for over 2,000 years and so highly treasured that it was traded for its own weight in gold and was available only to emperors. The results of many hundreds of scientific and medical studies support traditional health claims. Reishi contains over 200 active ingredients and unique compounds that are the most biologically active obtainable from any plant source. In order to obtain maximum benefit, reishi is best taken as an extract because it is a very tough, woody mushroom and the raw biomass is very difficult to digest.
Ganoderrna lucidum (Lingzhi or Reishi) has a long history of use for promoting health and longevity in China, Japan, and other Asian countries. It is a large, dark mushroom with a glossy exterior and a woody texture. The Latin word lucidus means "shiny" or "brilliant" and refers to the varnished appearance of the surface of the mushroom. In China, G. lucidum is called lingzhi, whereas in Japan the name for the Ganodermataceae family is reishi or mannentake.
The name lingzhi, in Chinese, represents a combination of spiritual potency and essence of immortality, and is regarded as the "herb of spiritual potency," symbolizing success, well-being, divine power, and longevity. Among cultivated mushrooms, Ganoderma lucidum is unique in that its pharmaceutical rather than nutritional value is paramount.
The specific applications and attributed health benefits of lingzhi include control of blood glucose levels, modulation of the immune system, hepatoprotection, bacteriostasis, and more. Lingzhi has been recognized as a medicinal mushroom for over 2000 years, and its powerful effects have been documented in ancient scripts (Wasser 2005). According to the State Pharmacopoeia of the People's Republic of China (2000), Ganoderma lucidum acts to replenish Qi, ease the mind, and relieve cough and asthma, and it is recommended for dizziness, insomnia, palpitation, and shortness of breath. Wild lingzhi is rare, and in the years before it was cultivated, only the nobility could afford it. It was believed that the sacred fungus grew in the home of the immortals on the "three aisles of the blest" off the coast of China (McMeekin 2005). However, its reputation as a panacea may have been earned more by virtue of its irregular distribution, rarity, and use by the rich and privileged members of Chinese society than by its actual effects.
The family Ganodermataceae describes polypore basidiomycetous fungi having a double-walled basidiospore (Donk 1964). In all, 219 species within the family have been assigned to the genus Ganoderma, of which Ganoderma lucidum (JV. Curt.: Fr.) P. Karsten is the species type (Moncalvo 2000). Basidiocarps of this genus have a laccate (shiny) surface that is associated with the presence of thickwalled pilocystidia embedded in an extracellular melanin matrix (Moncalvo 2000). Ganoderma species are found all over the world, and different characteristics, such as shape and color (red, black, blue/green, white, yellow, and purple) of the fruit body, host specificity, and geographical origin, are used to identify individual members of the species (Zhao and Zhang 1994; Woo et al. 1999; Upton 2000).
In manufacturing terms other products are prepared with materials (e.g., polysaccharides, triterpenes} extracted, usually with hot water or ethanol, from fruiting bodies or mycelia harvested from submerged liquid cultures and then evaporated to dryness and tabulated/encapsulated either separately or integrated together in designated proportions.
Most mushrooms are composed of around 90% of water by weight. The remaining 10% consists of 10--40% protein, 2- 8% fat, 3-28% carbohydrate, 3-32% fiber, 8-10% ash, and some vitamins and minerals, with potassium, calcium, phosphorus, magnesium, selenium, iron, zinc, and copper accounting for most of the mineral content (Borchers et al. 1999}. Ina study of the nonvolatile components of G. lucidum, it was found that the mushroom contains 1.8% ash, 26--28% carbohydrate, 3-5% crude fat, 59% crude fiber, and 7-8% crude protein. In addition to these, mushrooms contain a wide variety of bioactive molecules, such as terpenoids, steroids, phenols, nucleotides and their derivatives, glycoproteins, and polysaccharides.
Mushroom proteins contain all the essential amino acids and are especially rich in lysine and leucine. The low total fat content and high proportion of polyunsaturated fatty acids relative to the total fatty acids of mushrooms are considered significant contributors to the health value of mushrooms (Chang and Buswe111996; Borchers et al. 1999; Sanodiya et al. 2009). Polysaccharides, peptidoglycans, and triterpenes are three major physiologically active constituents in Ganoderma lucidum
Fungi are remarkable for the variety of high-molecular-weight polysaccharide structures that they produce, and bioactive polyglycans are found in all parts of the mushroom. Polysaccharides represent structurally diverse biological macromolecules with wide-ranging physiochemical properties. Various polysaccharides have been extracted from the fruit body, spores, and mycelia oflingzhi; they are produced by fungal mycelia cultured in fermenters and can differ in their sugar and peptide compositions and molecular weight (e.g., ganoderans A, B, and C). Ganoderma lucidum polysaccharides (GL-PSs) are reported to exhibit a broad range of bioactivities, including anti inflammatory, hypoglycemic, antiulcer, antitumorigenic, and immunostimulating effects (Miyazaki and Nishijima 1981; Hikino et al. 1985; Tomoda et al. 1986; Bao et al. 2001; Wachtel-Galor, Buswell et al. 2004). Polysaccharides are normally obtained from the mushroom by extraction with hot water followed by precipitation with ethanol or methanol, but they can also be extracted with water and alkali. Structural analyses of GL-PSs indicate that glucose is their major sugar component (Bao et al. 2001; Wang et al. 2002).
In Ganoderma lucidum, the chemical structure of the triterpenes is based on lanostane, which is a metabolite of lanosterol, the biosynthesis of which is based on cyclization of squalene (Haralampidis, Trojanowska, and Osbourn 2002).
Extraction oftriterpenes is usually done by means of methanol, ethanol, acetone, chloroform, ether, or a mixture of these solvents. More than 100 triterpenes with known chemical compositions and molecular configurations have been reported to occur in Ganoderma lucidum. Among them, more than 50 were found to be new and unique to this fungus. Ganoderma lucidum is clearly rich in triterpenes, and it is this class of compounds that gives the herb its bitter taste and, it is believed, confers on it various health benefits, such as lipid-lowering and antioxidant effects. However, the triterpene content is different in different parts and growing stages of the mushroom. The profile of the different triterpenes in Ganoderma lucidum contains some other compounds that may contribute to its reported medicinal effect, such as proteins and lectins. The protein content of dried Ganoderma lucidum was found to be around 7-8%, which is lower than that of many other mushrooms (Chang and Buswel11996; Mau, Lin, and Chen 2001). The carbohydrate and crude fiber content of the dried mushroom was examined and found to be 26--28% and 59%, respectively (Mau, Lin, and Chen 2001). Lectins were also isolated from the fruit body and mycelium of the mushroom (Kawagishi et al. 1997)
Agents that enhance the functioning of the host immune system could be expected to enhance health in terms of improved resistance and, thus, removal of malignant or premalignant cells. There is considerable evidence to support the immunostimulating activities of Ganoderma lucidum via induction of cytokines and enhancement of immunological effector (Wang et al. 1997; Zhu and Lin 2006).
Antioxidants protect cellular components from oxidative damage, which is likely to decrease risk of mutations and carcinogenesis and also protect immune cells, allowing them to maintain immune surveillance and response. Various components of Ganoderma lucidum, in particular polysaccharides and triterpenoids, show antioxidant activity in vitro (Lee et al. 2001; Mau, Lin, and Chen 2002; Shi et al. 2002; Wachtel-Galor, Choi, and Benzie 2005; Yuen and Gohel2008; Saltarelli et al. 2009; Wu and Wang 2009). Antioxidants from lingzhi were found to be absorbed quickly after ingestion, resulting in an increase in the plasma total antioxidant activity of human subjects (Wachtel-Galor, Szeto et al. 2004).