Chinese herbology

Chinese pharmacopoeia

Chinese herbs have been used for centuries. Among the earliest literature are lists of prescriptions for specific ailments, exemplified by the manuscript Recipes for 52 Ailments, found in the Mawangdui which were sealed in 168 BCE.

The first traditionally recognized herbalist is Shénnóng (神农, lit. 'Divine Farmer'), a mythical god-like figure, who is said to have lived around 2800 BCE.[7] He allegedly tasted hundreds of herbs and imparted his knowledge of medicinal and poisonous plants to farmers. His Shénnóng Běn Cǎo Jīng (神农本草经, Shennong's Materia Medica) is considered as the oldest book on Chinese herbal medicine. It classifies 365 species of roots, grass, woods, furs, animals and stones into three categories of herbal medicine:[8]

1. The "superior" category, which includes herbs effective for multiple diseases and are mostly responsible for maintaining and restoring the body balance. They have almost no unfavorable side-effects.[8]
2. A category comprising tonics and boosters, whose consumption must not be prolonged.[8]
3. A category of substances which must usually be taken in small doses, and for the treatment of specific diseases only.[8]

The original text of Shennong's Materia Medica has been lost; however, there are extant translations.[9] The true date of origin is believed to fall into the late Western Han dynasty[7] (i.e., the first century BCE).

The Treatise on Cold Damage Disorders and Miscellaneous Illnesses was collated by Zhang Zhongjing, also sometime at the end of the Han dynasty, between 196 and 220 CE. Focusing on drug prescriptions,[10] it was the first medical work to combine Yinyang and the Five Phases with drug therapy.[11] This formulary was also the earliest Chinese medical text to group symptoms into clinically useful "patterns" (zheng, 證) that could serve as targets for therapy. Having gone through numerous changes over time, it now circulates as two distinct books: the Treatise on Cold Damage Disorders and the Essential Prescriptions of the Golden Casket, which were edited separately in the eleventh century, under the Song dynasty.[12]

Succeeding generations augmented these works, as in the Yaoxing Lun (药性论; 藥性論; 'Treatise on the Nature of Medicinal Herbs'), a 7th-century Tang dynasty Chinese treatise on herbal medicine.

There was a shift in emphasis in treatment over several centuries. A section of the Neijing Suwen including Chapter 74 was added by Wang Bing in his 765 edition. In which it says: 主病之謂君，佐君之謂臣，應臣之謂使，非上下三品之謂也。 "Ruler of disease it called Sovereign, aid to Sovereign it called Minister, comply with Minister it called Envoy (Assistant), not upper lower three classes (qualities) it called." The last part is interpreted as stating that these three rulers are not the three classes of Shénnóng mentioned previously. This chapter in particular outlines a more forceful approach. Later on Zhang Zihe (a.k.a. Zhang Cong-zhen, 1156–1228) is credited with founding the 'Attacking School' which criticized the overuse of tonics.

Arguably the most important of these later works is the Compendium of Materia Medica (Bencao Gangmu, 本草綱目) compiled during the Ming dynasty by Li Shizhen, which is still used today for consultation and reference.

The use of Chinese herbs was popular during the medieval age in western Asian and Islamic countries. They were traded through the Silk Road from the East to the West. Cinnamon, ginger, rhubarb, nutmeg and cubeb are mentioned as Chinese herbs by medieval Islamic medical scholars Such as Rhazes (854–925 CE), Haly Abbas (930–994 CE) and Avicenna (980–1037 CE). There were also multiple similarities between the clinical uses of these herbs in Chinese and Islamic medicine.[13]

There are roughly 13,000 medicinals used in China and over 100,000 medicinal recipes recorded in the ancient literature.[14] Plant elements and extracts are by far the most common elements used.[15] In the classic Handbook of Traditional Drugs from 1941, 517 drugs were listed – out of these, only 45 were animal parts, and 30 were minerals.[15] For many plants used as medicinals, detailed instructions have been handed down not only regarding the locations and areas where they grow best, but also regarding the best timing of planting and harvesting them.[16]

Some animal parts used as medicinals can be considered rather strange such as cows' gallstones.[17]

Furthermore, the classic materia medica Bencao Gangmu describes the use of 35 traditional Chinese medicines derived from the human body, including bones, fingernail, hairs, dandruff, earwax, impurities on the teeth, feces, urine, sweat, and organs, but most are no longer in use.[18][19][20]

There are several different methods to classify traditional Chinese medicinals:

• The Four Natures (四气; 四氣; sìqì)
• The Five Flavors (五味; wǔwèi)
• The meridians (经络; 經絡; jīngluò)
• The specific function.

Five Flavors

The Five Phases, which correspond to the Five Flavors

The Five Flavors, sometimes also translated as Five Tastes, are: acrid/pungent (辛), sweet (甘), bitter (苦), sour (酸), and salty (咸; 鹹).[25] Substances may also have more than one flavor, or none (i.e., a bland (淡) flavor).[25] Each of the Five Flavors corresponds to one of the zàng organs, which in turn corresponds to one of the Five Phases:[26] A flavor implies certain properties and presumed therapeutic "actions" of a substance: saltiness "drains downward and softens hard masses";[25] sweetness is "supplementing, harmonizing, and moistening";[25] pungent substances are thought to induce sweat and act on qi and blood; sourness tends to be astringent (涩; 澀) in nature; bitterness "drains heat, purges the bowels, and eliminates dampness".

Many herbs earn their names from their unique physical appearance. Examples of such names include Niu Xi (Radix cyathulae seu achyranthis), 'cow's knees,' which has big joints that might look like cow knees; Bai Mu Er (Fructificatio tremellae fuciformis), 'white wood ear', which is white and resembles an ear; Gou Ji (Rhizoma cibotii), 'dog spine,' which resembles the spine of a dog.[30]

From the earliest records regarding the use of medicinals to today, the toxicity of certain substances has been described in all Chinese materia medica.[31] Since TCM has become more popular in the Western world, there are increasing concerns about the potential toxicity of many traditional Chinese medicinals including plants, animal parts and minerals.[6] For most medicinals, efficacy and toxicity testing are based on traditional knowledge rather than laboratory analysis.[6] The toxicity in some cases could be confirmed by modern research (i.e., in scorpion); in some cases it could not (i.e., in Curculigo).[32] Further, ingredients may have different names in different locales or in historical texts, and different preparations may have similar names for the same reason, which can create inconsistencies and confusion in the creation of medicinals,[33] with the possible danger of poisoning.[34][35][36] Edzard Ernst "concluded that adverse effects of herbal medicines are an important albeit neglected subject in dermatology, which deserves further systematic investigation."[37] Research suggests that the toxic heavy metals and undeclared drugs found in Chinese herbal medicines might be a serious health issue.[38]

Substances known to be potentially dangerous include aconite,[32] secretions from the Asiatic toad,[39] powdered centipede,[40] the Chinese beetle (Mylabris phalerata, Ban mao),[41] and certain fungi.[42] There are health problems associated with Aristolochia.[6] Toxic effects are also frequent with Aconitum.[6] To avoid its toxic adverse effects Xanthium sibiricum must be processed.[6] Hepatotoxicity has been reported with products containing Reynoutria multiflora (synonym Polygonum multiflorum), glycyrrhizin, Senecio and Symphytum.[6] The evidence suggests that hepatotoxic herbs also include Dictamnus dasycarpus, Astragalus membranaceus, and Paeonia lactiflora; although there is no evidence that they cause liver damage.[6] Contrary to popular belief, Ganoderma lucidum mushroom extract, as an adjuvant for cancer immunotherapy, appears to have the potential for toxicity.[43]

Also, adulteration of some herbal medicine preparations with conventional drugs which may cause serious adverse effects, such as corticosteroids, phenylbutazone, phenytoin, and glibenclamide, has been reported.[44][45]

However, many adverse reactions are due to misuse or abuse of Chinese medicine.[6] For example, the misuse of the dietary supplement Ephedra (containing ephedrine) can lead to adverse events including gastrointestinal problems as well as sudden death from cardiomyopathy.[6] Products adulterated with pharmaceuticals for weight loss or erectile dysfunction are one of the main concerns.[6] Chinese herbal medicine has been a major cause of acute liver failure in China.[46]

Most Chinese herbs are safe but some have shown not to be. Reports have shown products being contaminated with drugs, toxins, or false reporting of ingredients. Some herbs used in TCM may also react with drugs, have side effects, or be dangerous to people with certain medical conditions.[47]

Only a few trials exist that are considered to have adequate methodology by scientific standards. Proof of effectiveness is poorly documented or absent.[4] A 2016 Cochrane review found "insufficient evidence that Chinese Herbal Medicines were any more or less effective than placebo or hormonal therapy" for the relief of menopause related symptoms.[48] A 2012 Cochrane review found no difference in decreased mortality for SARS patients when Chinese herbs were used alongside Western medicine versus Western medicine exclusively.[49] A 2010 Cochrane review found there is not enough robust evidence to support the effectiveness of traditional Chinese medicine herbs to stop the bleeding from haemorrhoids.[50] A 2008 Cochrane review found promising evidence for the use of Chinese herbal medicine in relieving painful menstruation, compared to conventional medicine such as NSAIDs and the oral contraceptive pill, but the findings are of low methodological quality.[51] A 2012 Cochrane review found weak evidence suggesting that some Chinese medicinal herbs have a similar effect at preventing and treating influenza as antiviral medication.[52] Due to the poor quality of these medical studies, there is insufficient evidence to support or dismiss the use of Chinese medicinal herbs for the treatment of influenza.[52] There is a need for larger and higher quality randomized clinical trials to determine how effective Chinese herbal medicine is for treating people with influenza.[52] A 2005 Cochrane review found that although the evidence was weak for the use of any single herb, there was low quality evidence that some Chinese medicinal herbs may be effective for the treatment of acute pancreatitis.[53]

Successful results have been scarce: artemisinin is one of few examples, as effective treatment for malaria derived from Artemisia annua, which is traditionally used to treat fever.[1] Chinese herbology is largely pseudoscience, with no valid mechanism of action for the majority of its treatments.[1]

Dried seahorses like these are extensively used in traditional medicine in China and elsewhere.

The traditional practice of using now-endangered species is controversial within TCM. Modern Materia Medicas such as Bensky, Clavey and Stoger's comprehensive Chinese herbal text discuss substances derived from endangered species in an appendix, emphasizing alternatives.[54]

Parts of endangered species used as TCM drugs include tiger bones[55] and rhinoceros horn.[56] Poachers supply the black market with such substances,[57][58] and the black market in rhinoceros horn, for example, has reduced the world's rhino population by more than 90 percent over the past 40 years.[59] Concerns have also arisen over the use of turtle plastron[60] and seahorses.[61]

TCM recognizes bear bile as a medicinal. In 1988, the Chinese Ministry of Health started controlling bile production, which previously used bears killed before winter. Now bears are fitted with a sort of permanent catheter, which is more profitable than killing the bears.[62] More than 12,000 asiatic black bears are held in "bear farms", where they suffer cruel conditions while being held in tiny cages. The catheter leads through a permanent hole in the abdomen directly to the gall bladder, which can cause severe pain. Increased international attention has mostly stopped the use of bile outside of China; gallbladders from butchered cattle (牛胆; 牛膽; niú dǎn) are recommended as a substitute for this ingredient.

Collecting American ginseng to assist the Asian traditional medicine trade has made ginseng the most harvested wild plant in North America for the last two centuries, which eventually led to a listing on CITES Appendix II.[63]

Chinese herbology is a pseudoscientific practice with potentially unreliable product quality, safety hazards or misleading health advice.[64][65][66] There are regulatory bodies, such as China GMP (Good Manufacturing Process) of herbal products.[67] However, there have been notable cases of an absence of quality control during herbal product preparation.[68] There is a lack of high-quality scientific research on herbology practices and product effectiveness for anti-disease activity.[64][65] In the herbal sources listed below, there is little or no evidence for efficacy or proof of safety across consumer age groups and disease conditions for which they are intended.[64][65]

There are over 300 herbs in common use. Some of the most commonly used herbs are Ginseng (人参; 人參; rénshēn), wolfberry (枸杞子; gǒuqǐzǐ), dong quai (Angelica sinensis, 当归; 當歸; dāngguī), astragalus (黄耆; 黃耆; huángqí), atractylodes (白术; 白朮; báizhú), bupleurum (柴胡; cháihú), cinnamon (cinnamon twigs (桂枝; guìzhī) and cinnamon bark (肉桂; ròuguì)), coptis (黄连; 黃連; huánglián), ginger (姜; 薑; jiāng), hoelen (茯苓; fúlíng), licorice (甘草; gāncǎo), ephedra sinica (麻黄; 麻黃; máhuáng), peony (white: 白芍; báisháo and reddish: 赤芍; chìsháo), rehmannia (地黄; 地黃; dìhuáng), rhubarb (大黄; 大黃; dàhuáng), and salvia (丹参; 丹參; dānshēn).

In Chinese herbology, there are 50 "fundamental" herbs, as given in the reference text,[69] although these herbs are not universally recognized as such in other texts. The herbs are:

In addition to the above, many other Chinese herbs and other substances are in common use, and these include:

• Chen, John K.; Chen, Tina T. (2004). Chinese Medical Herbology and Pharmacology. Art of Medicine Press. ISBN 0-9740635-0-9.
• Chen, John K.; Chen, Tina T. (2009). Pocket Atlas of Chinese Medicine. Art of Medicine Press. ISBN 978-0-9740635-7-7.
• Ergil, M.; et al. (2009). Pocket Atlas of Chinese Medicine. Thieme. ISBN 978-3-13-141611-7.
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• Kiessler, Malte (2005). Traditionelle Chinesische Innere Medizin (in German). Elsevier, Urban & Fischer. ISBN 978-3-437-57220-3.
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• Unschuld, Paul U. (1985). Medicine in China: A History of Ideas. Berkeley: University of California Press. ISBN 978-0-520-05023-5.
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• Quotations related to Traditional Chinese medicine at Wikiquote