Lingzhi mushroom

The lingzhi mushroom or reishi mushroom encompasses several fungal species of the genus Ganoderma, and most commonly refers to the closely related species, Ganoderma lucidum, Ganoderma tsugae and Ganoderma sichuanense. G. sichuanense enjoys special veneration in East Asia, where it has been used as a medicinal mushroom in traditional Chinese medicine for more than 2,000 years, making it one of the oldest mushrooms known to have been used medicinally. Lingzhi is listed in the American Herbal Pharmacopoeia and Therapeutic Compendium.

Taxonomy and naming
Names for the lingzhi fungus have a two thousand year history. The Chinese term lingzhi 灵芝 was first recorded in the Eastern Han Dynasty (25–220 CE). Petter Adolf Karsten named the genus Ganoderma in 1881.

Botanical names
The lingzhi's botanical names have Greek and Latin roots. The generic name Ganoderma derives from the Greek ganos γανος "brightness; sheen", hence "shining" and derma δερμα "skin". The specific epithet Lucidum is Latin for "shining" and tsugae for "hemlock" (from Japanese tsuga 栂).

There are multiple species of Lingzhi, scientifically known to be within the Ganoderma lucidum species complex and mycologists are still researching the differences among species within this complex.

Chinese names
In the Chinese language, lingzhi compounds ling 灵 "spirit, spiritual; soul; miraculous; sacred; divine; mysterious; efficacious; effective" (cf. Lingyan Temple) and zhi 芝 "(traditional) plant of longevity; fungus; seed; branch; mushroom; excrescence". Fabrizio Pregadio explains, "The term zhi, which has no equivalent in Western languages, refers to a variety of supermundane substances often described as plants, fungi, or "excresences"." Zhi occurs in other Chinese plant names such as zhima 芝麻 "sesame" or "seed", and was anciently used a phonetic loan character for zhi 芷 "Angelica iris". Chinese differentiates Ganoderma species between chizhi 赤芝 "red mushroom" G. lucidum and zizhi 紫芝 "purple mushroom" G. japonicum.

Lingzhi 灵芝has several synonyms. Ruicao 瑞草 "auspicious plant" (with rui 瑞 "auspicious; felicitous omen" and the suffix cao "plant; herb") is the oldest; the (ca. 3rd century BCE) Erya dictionary defines qiu 苬 (interpreted as a miscopy of jun 菌 "mushroom") as zhi 芝 "mushroom" and the commentary of Guo Pu (276–324) says, "The [zhi] flowers three times in one year. It is a [ruicao] felicitous plant." Other Chinese names for Ganoderma include ruizhi 瑞芝 "auspicious mushroom", shenzhi 神芝 "divine mushroom" (with shen "spirit; god' supernatural; divine"), mulingzhi 木灵芝 (with "tree; wood"), xiancao 仙草 "immortality plant" (with xian "(Daoism) transcendent; immortal; wizard"), and lingzhicao 灵芝草 or zhicao 芝草 "mushroom plant".

Since both Chinese Ling and Zhi have multiple meanings, Lingzhi has diverse English translations. Renditions include "[zhi] possessed of soul power", "Herb of Spiritual Potency" or "Mushroom of Immortality", "Numinous Mushroom", "divine mushroom", "divine fungus", "Magic Fungus", and "Marvelous Fungus".

Japanese names
Japanese language Reishi 霊芝 is a Sino-Japanese loan word from Lingzhi. This modern Japanese kanji 霊 is the shinjitai "new character form" for the kyūjitai "old character form" 霊.

Reishi synonyms divide between Sino-Japanese borrowings and native Japanese coinages. Sinitic loanwords include literary terms such as zuisō 瑞草 (from ruicao) "Auspicious Plant" and sensō 仙草 (from xiaocao) "Immortality Plant". A common native Japanese name is mannentake 万年茸 "10,000 year mushroom". The Japanese writing system uses shi or shiba 芝 for "grass; lawn; turf" and take or kinoko 茸 for "mushroom" (e.g., shiitake). Other Japanese terms for Reishi include kadodetake 門出茸 "Departure Mushroom", hijiridake 聖茸 "Sage Mushroom", and magoshakushi 孫杓子 "grandchild ladle".

Korean names
Korean language Yeong Ji or Yung Gee (영지,灵芝) is a word from hanja of lingzhi. It is also called Seon-cho (선초,仙草), Gil-sang-beo-seot (길상버섯,吉祥茸), Yeong ji cho (영지초,灵芝草) or Jeok ji (적지,赤芝). It can be classified by its color such as Ja-ji (자지,紫芝) for purple one, Heuk-ji (흑지,黑芝) for black, Cheong-ji (청지,靑芝) for blue or green, Baek-ji (백지,白芝) for white, Hwang-ji (황지,黃芝) for yellow.

Vietnamese names
Vietnamese language linh chi is a word from tiếng Việt. It is often used with (nấm Linh Chi) which is the equivalent of Ganoderma Lucidum or Reishi Mushroom.

English names
English Lingzhi or ling chih (sometimes misspelled "ling chi" from French EFEO Chinese transcription) is a Chinese loanword. The Oxford English Dictionary gives Chinese "líng divine + zhī fungus" as the origin of ling chih or Lingzhi, and defines, "The fungus Ganoderma lucidum, believed in China to confer longevity and used as a symbol of this on Chinese ceramic ware." The OED notes the earliest recorded usage of the Wade-Giles romanization ling chih in 1904, and of the Pinyin lingzhi in 1980. In addition to the transliterated loanword, English names include "Glossy Ganoderma" and "shiny polyporus".

Description
Lingzhi is a polypore mushroom that is soft (when fresh), corky, and flat, with a conspicuous red-varnished, kidney-shaped cap and, depending on specimen age, white to dull brown pores underneath. It lacks gills on its underside and releases its spores through fine pores, leading to its morphological classification as a polypore.

Varieties
Ganoderma lucidum generally occurs in two growth forms, one, found in North America, is sessile and rather large with only a small or no stalk, while the other is smaller and has a long, narrow stalk, and is found mainly in the tropics. However, many growth forms exist that are intermediate to the two types, or even exhibit very unusual morphologies, raising the possibility that they are separate species. Environmental conditions also play a substantial role in the different morphological characteristics Lingzhi can exhibit. For example, elevated carbon dioxide levels result in stem elongation in Lingzhi. Other forms show antlers, without a cap and these may be affected by carbon dioxide levels as well. The species can also be differentiated by their colors in which the red reishi is the most researched kind. The three main factors that are greatly influencing the shape it takes are light, temperature, and humidity (although less significant water and air quality can have an impact).

Biochemistry
Ganoderma lucidum produces a group of triterpenes, called ganoderic acids, which have a molecular structure similar to steroid hormones. It also contains other compounds often found in fungal materials, including polysaccharides (such as beta-glucan), coumarin, mannitol, and alkaloids. Sterols isolated from the mushroom include, ganoderol, ganoderenic acid, ganoderiol, ganodermanontriol, lucidadiol, and ganodermadiol.

Habitat
Ganoderma lucidum, and its close relative Ganoderma tsugae, grow in the northern Eastern Hemlock forests. These two species of bracket fungus have a worldwide distribution in both tropical and temperate geographical regions, growing as a parasite or saprotroph on a wide variety of trees. Similar species of Ganoderma have been found growing in the Amazon. In nature, Lingzhi grows at the base and stumps of deciduous trees, especially maple. Only two or three out of 10,000 such aged trees will have Lingzhi growth, and therefore its wild form is extremely rare. Today, Lingzhi is effectively cultivated both indoors under sterile conditions and outdoors on either logs or woodchip beds.

History
The Chinese classics first used zhi during the Warring States period (475–221 BCE) and lingzhi during the Han Dynasty (206 BCE-220 CE).

The word zhi 芝 occurs approximately 100 times in classical texts. Occurrences in early Chinese histories, such as the (91 BCE) Shiji "Records of the Grand Historian" and (82 CE) Hanshu "Book of Han", predominantly refer to the "Mushroom of Immortality; elixir of life". They record that fangshi "masters of esoterica; alchemists; magicians", supposedly followers of Zou Yan (305–240 BCE), claimed to know secret locations like Mount Penglai where the magic zhi mushroom grew. Some sinologists propose that the mythical zhi 芝 derived from Indian legends about soma that reached China around the 3rd century BCE. Fangshi courtiers convinced Qin and Han emperors, most notably Qin Shi Huang (r. 221–210 BCE) and Emperor Wu of Han (r. 141–87 BCE), to dispatch large expeditions (e.g., Xu Fu in 219 BCE) seeking the zhi Plant of Immortality, but none produced tangible results. Zhi occurrences in other classical texts often refer to an edible fungi. The Liji "Record of Ritual" lists zhi "lichens" as a type of condiment. The Chuci "Song of the South" metaphorically mentions, "The holy herb is weeded out". The Huainanzi "Philosophers of Huainan" records a zizhi 紫芝 "Purple Mushroom" Aphorism, "The zhi fungus grows on mountains, but it cannot grow on barren boulders."

The word lingzhi 靈芝 was first recorded in a fu 賦 "rhapsody; prose-poem" by the Han dynasty polymath Zhang Heng (CE 78–139). His Xijing fu 西京賦 "Western Metropolis Rhapsody" description of Emperor Wu of Han's (104 BCE) Jianzhang Palace parallels lingzhi with shijun 石菌 "Rock Mushroom": "Raising huge breakers, lifting waves, That drenched the stone mushrooms on the high bank, And soaked the magic fungus on vermeil boughs." The commentary by Xue Zong (d. 237) notes these fungi were eaten as drugs of immortality.

The (ca. 1st–2nd century CE) Shennong bencao jing "Divine Farmer's Classic of Pharmaceutics" classifies zhi into six color categories, each of which is believed to benefit the qi "Life Force" in a different part of the body: qingzhi 青芝 "Green Mushroom" for Liver, chizhi 赤芝 "Red Mushroom" for heart, huangzhi 黃芝 "Yellow Mushroom" for spleen, baizhi 白芝 "White Mushroom" for Lung, heizhi "Black Mushroom" 黑芝 for kidney, and zizhi 紫芝 "Purple Mushroom" for Essence. Commentators identify this red chizhi (or danzhi 丹芝 "cinnabar mushroom") as the lingzhi. "Chi Zhi (Ganoderma rubra) is bitter and balanced. It mainly treats binding in the chest, boosts the heart qi, supplements the center, sharpens the wits, and [causes people] not to forget [i.e., improves the memory]. Protracted taking may make the body light, prevent senility, and prolong life so as to make one an immortal. Its other name is Dan Zhi (Cinnabar Ganoderma). It grows in mountains and valleys." While Chinese texts have recorded medicinal uses of lingzhi for more than 2,000 years, a few sources erroneously claim more than 4,000 years. Modern scholarship neither accepts the historicity of Shennong "Divine Farmer" (legendary inventor of agriculture, traditionally r. 2737–2697 BCE) nor that he wrote the Shennong bencao jing.

The (ca. 320 CE) Baopuzi, written by the Jin Dynasty Daoist scholar Ge Hong, has the first classical discussion of Zhi. Based upon no-longer extant texts, Ge distinguishes five categories of zhi, each with 120 varieties: Shizhi 石芝 "stone Zhi", Muzhi 木芝 "wood Zhi", Caozhi 草芝 "Plant Zhi", Rouzhi 肉芝 "flesh zhi", and junzhi 菌芝 "mushroom zhi. For example, the "mushroom zhi". "Tiny excresences. These grow deep in the mountains, at the base of large trees or beside springs. They may resemble buildings, palanquins and horses, dragon and tigers, human beings, or flying birds. They may be any of the five colors. They too number 120 for which there exist illustrations. All are to be sought and gathered while using Yu's Pace [a Daoist ritual walk], and they are to be cut with a bone knife. When dried in the shade, powdered, and taken by the inch-square spoonful, they produce geniehood. Those of the intermediate class confer several thousands of years, and those of the lowest type a thousand years of life." Pregadio concludes, "While there may be no better term than "mushrooms" or "excresences" to refer to them, and even though Ge Hong states that they "are not different from natural mushrooms (ziran zhi 自然芝) (Baopuzi 16.287)", the Zhi pertain to an intermediate dimension between mundane and transcendent reality."

The (1596) Bencao Gangmu ("Compendium of Materia Medica") has a zhi 芝 category that includes six types of Zhi (calling the green, red, yellow, white, black, and purple ones from the Shennong bencao jing the liuzhi 六芝 "six mushrooms") and sixteen other fungi, mushrooms, and lichens (e.g., mu'er 木耳 "wood ear" "Cloud ear fungus; Auricularia auricula-judae"). The author Li Shizhen classified these six differently colored Zhi as Xiancao 仙草 "immortality herbs", and described the effects of Chizhi "red mushroom": "It positively affects the life-energy, or Qi of the heart, repairing the chest area and benefiting those with a knotted and tight chest. Taken over a long period of time, agility of the body will not cease, and the years are lengthened to those of the Immortal Fairies." Stuart and Smith's classical study of Chinese herbology describes the zhi. "芝 (Chih) is defined in the classics as the plant of immortality, and it is therefore always considered to be a felicitous one. It is said to absorb the earthy vapors and to leave a heavenly atmosphere. For this reason it is called 靈芝 (Ling-chih.) It is large and of a branched form, and probably represents Clavaria or Sparassis. Its form is likened to that of coral."

The Bencao Gangmu does not list lingzhi as a variety of zhi, but as an alternate name for the shi'er 石耳 "stone ear" "Umbilicaria esculenta" lichen. According to Stuart and Smith, "[The 石耳 Shih-erh is] edible, and has all of the good qualities of the 芝 (Chih), being also used in the treatment of gravel, and said to benefit virility. It is specially used in hemorrhage from the bowels and prolapse of the rectum. While the name of this would indicate that it was one of the Auriculariales, the fact that the name 靈芝 (Ling-chih) is also given to it might place it among the Clavariaceae."

Chinese pharmaceutical handbooks on Zhi mushrooms were the first illustrated publications in the history of mycology. The historian of Chinese science Joseph Needham discussed a no-longer extant Liang Dynasty (502–587) illustrated text called Zhong Shenzhi 種神芝 "On the Planting and Cultivation of Magic Mushrooms". "The pictures of mushrooms in particular must have been an extremely early landmark in the history of mycology, which was a late-developing science in the West. The title of [this book] shows that fungi of some kind were being regularly cultivated – hardly as food, with that special designation, more probably medicinal, conceivably hallucinogenic.'" The (1444) Ming Dynasty edition Daozang "Daoist canon" contains the Taishang lingbao zhicao pin 太上靈寶芝草品 "Classifications of the Most High Divine Treasure Mushroom Plant", which categorizes 127 varieties of Zhi. A (1598) Ming reprint includes woodblock pictures.

In Chinese art, the lingzhi symbolizes great health and longevity, as depicted in the imperial Forbidden City and Summer Palace. It was a talisman for luck in the traditional culture of China, and the goddess of healing Guanyin is sometimes depicted holding a reishi mushroom.

Research and therapeutic usage
Lingzhi possesses anti-tumor, anti-cancer, immunomodulatory and immunotherapeutic qualities, supported by studies on polysaccharides, terpenes, and other bioactive compounds isolated from fruiting bodies and mycelia of this fungus (reviewed by R. R. Paterson and Lindequist et al. ). It has also been found to inhibit platelet aggregation, and to lower blood pressure (via inhibition of angiotensin-converting enzyme ), cholesterol, and blood sugar.

Laboratory studies have shown anti-neoplastic effects of fungal extracts or isolated compounds against some types of cancer, including epithelial ovarian cancer. In an animal model, Ganoderma has been reported to prevent cancer metastasis, with potency comparable to Lentinan from Shiitake mushrooms.

The mechanisms by which Ganoderma lucidum may affect cancer are unknown and they may target different stages of cancer development: inhibition of angiogenesis (formation of new, tumor-induced blood vessels, created to supply nutrients to the tumor) mediated by cytokines, cytoxicity, inhibiting migration of the cancer cells and metastasis, and inducing and enhancing apoptosis of tumor cells. Nevertheless, Ganoderma lucidum extracts are already used in commercial pharmaceuticals such as MC-S for suppressing cancer cell proliferation and migration.

Additional studies indicate that ganoderic acid  has some protective effects against liver injury by viruses and other toxic agents in mice, suggesting a potential benefit of this compound in the treatment of liver diseases in humans, and Ganoderma-derived sterols inhibit lanosterol 14α-demethylase activity in the biosynthesis of cholesterol. Ganoderma lucidum compounds inhibit 5-alpha reductase activity in the biosynthesis of dihydrotestosterone.

Besides effects on mammalian physiology, Ganoderma lucidum is reported to have anti-bacterial and anti-viral activities. Ganoderma lucidum is reported to exhibit direct anti-viral with the following viruses; HSV-1, HSV-2, influenza virus, vesicular stomatitis. Ganoderma lucidum mushrooms are reported to exhibit direct anti-microbial properties with the following organisms; Aspergillus niger, Bacillus cereus, Candida albicans, and Escherichia coli. Other benefits were studied such as the effect of lowering hypertension, cholesterol, and anti-inflammatory benefits through the ganoderic acid properties.

Its genome, with about 12,600 genes on 13 chromosomes, was sequenced in 2012.

Preparation
Due to its bitter taste, Lingzhi is traditionally prepared as a hot water extract product. Thinly sliced or pulverized lingzhi (either fresh or dried) is added to a pot of boiling water, the water is then brought to a simmer, and the pot is covered; the lingzhi is then simmered for two hours. The resulting liquid is fairly bitter in taste and dark, with the more active red lingzhi more bitter than the black. The process is sometimes repeated for additional concentration. Alternatively, it can be used as an ingredient in a formula decoction or used to make an extract (in liquid, capsule, or powder form). The more active red forms of lingzhi are far too bitter to be consumed in a soup. While hot water extraction seems to be effective to target the polysaccharides, alcohol extraction is another method used to extract the triterpenes element of the Reishi.