'''Herbalism''' is a traditional shells and certain animal parts.

Many plants synthesize substances that are useful to the maintenance of health in humans and other animals. These include aromatic substances, most of which are phenols or their oxygen-substituted derivatives such as tannins. Many are secondary metabolites, of which at least 12,000 have been isolated &mdash; a number estimated to be less than 10% of the total. In many cases, these substances (particularly the alkaloids) serve as plant defense mechanisms against predation by microorganisms, insects, and herbivores.  Many of the herbs and spices used by humans to season food yield useful medicinal compounds.<ref>{{cite journal
 | quotes = 
 | author =  Lai PK
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 | title = Antimicrobial and chemopreventive properties of herbs and spices
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 | author = Tapsell LC
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 | year =  2006
 | month =  Aug
 | title = Health benefits of herbs and spices: the past, the present, the future
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==Anthropology of herbalism==
right|thumb|Mint from Project Gutenberg EBook of Culinary Herbs: Their Cultivation Harvesting Curing and Uses, by M. G. Kains

People on all continents have used hundreds to thousands of indigenous plants for treatment of ailments since prehistoric times.<ref>{{cite The first generally accepted use of plants as healing agents was depicted in the cave paintings discovered in the Ice man," whose body was frozen in the Swiss Alps for more than 5,300 years, which appear to have been used to treat the parasites found in his intestines.[http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9851424 ''5300 years ago, the Ice Man used natural laxatives and antibiotics''], Capasso L., Lancet. 1998;352:1864, PMID 9851424.</ref> 

Anthropologists theorize that animals evolved a tendency to seek out bitter plant parts in response to illness.<ref></ref> This behavior arose because bitterness is an indicator of secondary metabolites.  The risk benefit ratio favored animals and protohumans that were inclined to experiment in times of sickness. Over time, and with insight, instinct, and trial-and-error, a base of knowledge would have been acquired within early tribal communities.<ref></ref> As this knowledge base expanded over the generations, the specialized role of the herbalist emerged. The process would likely have occurred in varying manners within a wide diversity of cultures.

[[Image:Basil.png|left|thumb|Basil from Project Gutenberg EBook of Culinary Herbs: Their Cultivation
Harvesting Curing and Uses, by M. G. Kains]]

Indigenous healers often claim to have learned by observing that sick animals change their food preferences to nibble at bitter herbs they would normally reject.<ref>{{cite journal
 | quotes = 
 | author =  Huffman MA
 | date = 
 | year =  2003
 | month =  May
 | title = Animal self-medication and ethno-medicine: exploration and exploitation of the medicinal properties of plants
 | journal = Proc Nutr Soc
 | volume =  62
 | issue =  2
 | pages =  371–81
 | pmid = 14506884
  
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}}</ref>  Field biologists have provided corroborating evidence based on observation of diverse species, such as butterflies. Lowland gorillas take 90% of their diet from the fruits of ''Aframomum melegueta'', a relative of the ginger plant, that is a potent antimicrobial and apparently keeps shigellosis and similar infections at bay.<ref name=engel2002>''Wild Health: How Animals Keep Themselves Well and What We Can Learn From Them, '' Cindy Engel, Houghton Mifflin, 2002</ref> 

Researchers from Ohio Wesleyan University found that some birds select nesting material rich in antimicrobial agents which protect their young from harmful bacteria.<ref>Jann Ichida, Proceedings of the 104th General Meeting of the American Society for Microbiology. reported in [http://www.scienceblog.com/cms/node/2776 ''Birds use herbs to protect their nests''], BJS, Science Blog, Wed, 2004-05-26</ref> 

Sick animals tend to forage plants rich in secondary metabolites, such as tannins and alkaloids.<ref>{{cite journal
 | quotes = 
 | author =  Hutchings MR, Athanasiadou S, Kyriazakis I, Gordon IJ
 | date = 
 | year =  2003
 | month =  May
 | title = Can animals use foraging behavior to combat parasites?
 | journal = Proc Nutr Soc.
 | volume =  62
 | issue =  2
 | pages =  361
 | pmid = 14506883
  
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}}</ref> Since these phytochemicals often have antiviral, antibacterial, antifungal and antihelminthic properties, a plausible case can be made for self-medication by animals in the wild.<ref name=engel2002 />

Some animals have digestive systems especially adapted to cope with certain plant toxins. For example, the koala can live on the leaves and shoots of the eucalyptus, a plant that is dangerous to most animals.<ref>{{cite web|url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Phascolarctos_cinereus.html
|title=Phascolarctos cinereus}}</ref>A plant that is harmless to a particular animal may not be safe for humans to ingest.<ref></ref> A reasonable conjecture is that these discoveries were traditionally collected by the medicine people of indigenous tribes, who then passed on safety information and cautions.

The use of herbs and spices in cuisine developed in part as a response to the threat of food-born pathogens. Studies show that in tropical climes where pathogens are the most abundant recipes are the most highly spiced.  Further, the spices with the most potent antimicrobial activity tend to be selected.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Billing J, Sherman PW.
  | coauthors = 
  | title = Antimicrobial functions of spices: why some like it hot
  | journal = Q Rev Biol.
  | volume = 73
  | issue = 1
  | pages =3–49
  | date = 1998 Mar
  | url =
  | doi =
  | pmid = : 9586227
  | accessdate =  }}</ref>In all cultures vegetables are spiced less than meat, presumably because they are more resistant to spoilage.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Sherman PW, Hash GA.
  | coauthors = 
  | title = Why vegetable recipes are not very spicy
  | journal = Evol Hum Behav.
  | volume = 22
  | issue = 3
  | pages = 147–163
  | date = 2001 May
  | url =
  | doi =
  | pmid = : 11384883
  | accessdate =  }}</ref>

==Herbs in history==
[[Image:Borage.png|right|thumb|Borage from Project Gutenberg EBook of Culinary Herbs: Their Cultivation
Harvesting Curing and Uses, by M. G. Kains]]

In the written record, the study of herbs dates back over 5,000 years to the Sumerians, who described well-established medicinal uses for such plants as laurel, caraway, and thyme.  The Egyptians of 1000 B.C. are known to have used garlic, opium, castor oil, coriander, mint, indigo, and other herbs for medicine and the Old Testament also mentions herb use and cultivation, including mandrake, vetch, caraway, wheat, barley, and rye.

The first Chinese herb book (or herbal), dating from about 2700 B.C., lists 365 medicinal plants and their uses - including ma-Huang, the shrub that introduced the drug ephedrine to modern medicine.

The ancient Greeks and Romans made medicinal use  of plants. Greek and Roman medicinal practices, as preserved in the writings of Hippocrates and - especially - Galen, provided the patterns for later western medicine. Hippocrates advocated the use of a few simple herbal drugs - along with fresh air, rest, and proper diet. Galen, on the other had, recommended large doses of drug mixtures - including plant, animal, and mineral ingredients. The Greek physician compiled the first European treatise on the properties and uses of medicinal plants, ''De Materia Medica''. In the first century AD, Dioscorides wrote a compendium of more that 500 plants that remained an authoritative reference into the 17th century. Similarly important for herbalists and botanists of later centuries was the Greek book that founded the science of botany, Theophrastus’ ''Historia Plantarum'', written in the fourth century B.C. 

[[Image:Thyme.png|left|thumb|Thyme from Project Gutenberg EBook of Culinary Herbs: Their Cultivation
Harvesting Curing and Uses, by M. G. Kains]]
The uses of plants for medicine and other purposes changed little during the Middle Ages. Many Greek and Roman writings on medicine, as on other subjects, were preserved by diligent hand copying of manuscripts in monasteries. The monasteries thus tended to become local centers of medical knowledge, and their herb gardens provided the raw materials for simple treatment of common disorders. At the same time, folk medicine in the home and village continues uninterrupted, supporting numerous wandering and settled herbalists. Among these were the “wise-women,” who prescribed herbal remedies often along with spells and enchantments. It was not until the later Middle Ages that women who were knowledgeable in herb lore became the targets of the witch hysteria. One of the most famous women in the herbal tradition was Hildegard of Bingen.  A twelfth century Benedictine nun, she wrote a medical text called ''Causes and Cures''.

Medical schools began to return in the eleventh century, teaching Galen’s system. At the time, the Arabic world was more advanced in science than Europe. As a trading culture, the Arabs had access to plant material from distant places such as China and India. Herbals, medical texts and translations of the classics of antiquity filtered in from east to west.<ref></ref> Alongside the university system, folk medicine continued to thrive. The continuing importance of herbs for the centuries following the Middle Ages is indicated by the hundreds of herbals published after the invention of printing in the fifteenth century. Theophrastus’ ''Historia Plantarum'' was one of the first books to be printed, and Dioscorides’ ''De Materia Medica'' was not far behind.

[[Image:Marjoram.png|right|thumb|Marjoram from Project Gutenberg EBook of Culinary Herbs: Their Cultivation
Harvesting Curing and Uses, by M. G. Kains]]
The fifteenth, sixteenth, and seventeenth centuries were the great age of herbals, many of them available for the first time in English and other languages rather than Latin or Greek.
The first herbal to be published in English was the anonymous ''Grete Herball'' of 1526. The two best-known herbals in English were ''The Herball or General History of Plants'' (1597) by Dodoens and his illustrations came from a German botanical work. The original edition contained many errors due to faulty matching of the two parts. Culpeper’s blend of traditional medicine with astrology, magic, and folklore was ridiculed by the physicians of his day  yet his book - like Gerard’s and other herbals - enjoyed phenomenal popularity.  The Age of Exploration and the Columbian Exchange introduced new medicinal plants to Europe. The ''Badianus Manuscript'' was an illustrated Aztec herbal translated into Latin in the 16th century.

The second millennium, however, also saw the beginning of a slow erosion of the pre-eminent position held by plants as sources of therapeutic effects. This began with the introduction of the mercury, and chemical medicine - as the orthodox system of the twentieth century.

==Role of herbal medicine in modern human society==
right|333px|right|thumb|[[Botánicals, such as this one in Jamaica Plain, lucky bamboo, and other items.]]
The use of herbs to treat disease is almost universal among non-industrialized societies.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Edgar J. DaSilva, Elias Baydoun, Adnan Badran
  | coauthors = 
  | title = Biotechnology and the developing world
  | journal =  Electronic Journal of Biotechnology 
  | volume =
  | issue =
  | pages =
  | date = 2002
  | url =
  | doi =
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  | accessdate =  }}</ref> A number of traditions came to dominate the practice of herbal medicine at the end of the twentieth century:
* The herbal medicine system, based on Greek and Roman sources
* The Siddha and Ayurvedic medicine systems from India
* Chinese herbal medicine (Chinese herbology)
* Unani-Tibb medicine 
* Shamanic Herbalism

Many of the Native American medicine. 
 
The use of, and search for, drugs and dietary supplements derived from plants have accelerated in recent years. Pharmacologists, microbiologists, botanists, and natural-products chemists are combing the Earth for phytochemicals and leads that could be developed for treatment of various diseases. In fact, according to the World Health Organisation, approximately 25% of modern drugs used in the United States have been derived from plants.<ref></ref><blockquote> 
*Three quarters of plants that provide active ingredients for prescription drugs came to the attention of researchers because of their use in traditional medicine.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Farnsworth NR.
  | coauthors = 
  | title = The role of ethnopharmacology in drug development
  | journal =  Ciba Found Symp.
  | volume = 154
  | issue =
  | pages = 2–11
  | date = 1990
  | url =
  | doi =
  | pmid = : 2086037 
  | accessdate =  }}</ref>

*Among the 120 active compounds currently isolated from the higher plants and widely used in modern medicine today, 80 percent show a positive correlation between their modern therapeutic use and the traditional use of the plants from which they are derived.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Daniel S. Fabricant, Norman R. Farnsworth
  | coauthors = 
  | title = The Value of Plants Used in Traditional Medicine for Drug Discovery
  | journal = Environmental Health Perspectives, Vol., Supplement 1: Reviews in Environmental Health, 2001 (), pp. 
  | volume = 109
  | issue = 1
  | pages = 69–75
  | date = Mar., 2001
  | url =
  | doi = 10.2307/3434847
  | id = 
  | accessdate =    | author = Fabricant, Daniel S.
}}</ref>
*More than two thirds of the world's plant species - at least 35,000 of which are estimated to have medicinal value - come from the developing countries.

*At least 7,000 medical compounds in the modern pharmacopoeia are derived from plants<ref>{{ Citation
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==Biological background==
right|thumb|The anthocyanins in [[Viola odorata|sweet violets produce deep red, violet and blue shades.]]
right|thumb|The carotenoids in [[primrose produce bright red, yellow and orange shades.]]

All plants produce chemical compounds as part of their normal metabolic activities. These include primary metabolites, such as sugars and fats, found in all plants, and secondary metabolites found in a smaller range of plants, some useful ones found only in a particular genus or species. Pigments harvest light, protect the organism from radiation and display colors to attract pollinators.  Many common weeds have medicinal properties.<ref>{{cite journal
  | last =
  | first =
  | authorlink = John R Stepp
  | coauthors = 
  | title = The role of weeds as sources of pharmaceuticals
  | journal = Journal of Ethnopharmacology
  | volume = 92
  | issue = 2-3
  | pages = 163–166
  | date = June 2004
  | url =
  | doi = 10.1016/j.jep.2004.03.002 
  | id = 
  | accessdate =
  | author =Stepp, J  }}</ref><ref>{{cite journal
  | last =
  | first =
  | authorlink = John R. Stepp, Daniel E. Moerman
  | coauthors = 
  | title = The importance of weeds in ethnopharmacology
  | journal = Journal of Ethnopharmacology 
  | volume = 75
  | issue = 1
  | pages = 19–23
  | date = April 2001
  | url =
  | doi = 10.1016/S0378-8741(00)00385-8 
  | accessdate =
  | author =Stepp, J  }}</ref> 

The functions of secondary metabolites are varied. For example, some secondary metabolites are deter predation, and others are pheromones used to attract insects for pollination. Phytoalexins protect against bacterial and fungal attacks. Allelochemicals inhibit rival plants that are competing for soil and light.

Plants upregulate and downregulate their biochemical paths in response to the local mix of herbivores, pollinators and microorganisms.<ref>
</ref> The chemical profile of a single plant may vary over time as it reacts to changing conditions. It is the secondary metabolites and pigments that can have therapeutic actions in humans and which can be refined to produce drugs.

Plants synthesize a bewildering variety of phytochemicals but most are derivatives of a few biochemical motifs.

*Alkaloids contain a ring with nitrogen.  Many alkaloids have dramatic effects on the central nervous system. Caffeine is an alkaloid that provides a mild lift but the alkaloids in datura cause severe intoxication and even death.

*Phenolics contain phenol rings.  The anthocyanins that give grapes their purple color, the isoflavones, the phytoestrogens from soy and the tannins that give tea its astringency are phenolics.

*Turpenoids are built up from terpene building blocks. Each terpene consists of two paired isoprenes. The names monoterpenes, sesquiterpenes, diterpenes and triterpenes are based on the number of isoprene units.  The fragrance of rose and lavender is due to monoterpenes. The carotenoids  produce the reds, yellows and oranges of pumpkin, corn and tomatoes.

*Glycosides consist of a glucose moiety attached to an aglycone.  The aglycone is a molecule that is bioactive in its free form but inert until the glycoside bond is broken by water or enzymes. This mechanism allows the plant to defer the availability of the molecule to an appropriate time, similar to a safety lock on a gun. An example is the cyanoglycosides in cherry pits that release toxins only when bitten by a herbivore.

The word drug itself comes from the Swedish word "druug", which means 'dried plant'.  Some examples are foxglove. 

The active ingredient in willow bark, once prescribed by Hippocrates, is salicin, or salicylic acid.  The discovery of salicylic acid, also known as "acetylsalicylic acid", would eventually lead to the development of "aspirin" when it was isolated from a plant known as meadowsweet.  The word ''aspirin'' comes from an abbreviation of meadowsweet's Latin genus ''Spiraea'', with an additional "A" at the beginning to acknowledge acetylation, and "in" was added at the end for easier pronunciation.<ref></ref>  "Aspirin" was originally a brand name, and is still a protected trademark in some countries. This medication was patented by Bayer AG.

==Herbal philosophy==
left|thumb|[[Rosemary]]
Since herbalism is such a diverse field few generalizations apply universally.  Nevertheless a rough consensus can be inferred.

Most herbalists concede that pharmaceuticals are more effective in emergency situations where time is of the essence.  An example would be where a patient had elevated blood pressure that posed imminent danger.  However they claim that over the long term herbs can help the patient resist disease and in addition provide nutritional and immunological support that pharmaceuticals lack. They view their goal as prevention as well as cure.

Herbalists tend to use extracts from parts of plants, such as the roots or leaves but not isolate particular phytochemicals.<ref>{{cite journal
 | quotes = 
 | author = Andrew Vickers,  Catherine Zollman
 | date=  16
 | year = 1999
 | month = Oct 
 | title = ABC of complementary medicine: Herbal medicine - Clinical review
 | journal = British Medical Journal
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 }}</ref> Pharmaceutical medicine prefers single ingredients on the grounds that dosage can be more easily quantified.  Herbalists reject the notion of a single active ingredient.  They argue that the different phytochemicals present in  many herbs will interact to enhance the therapeutic effects of the herb and dilute toxicity.<ref></ref>Furthermore, they argue that a single ingredient may contribute to multiple effects. Herbalists deny that herbal synergism can be duplicated with synthetic chemicals. They argue that phytochemical interactions and trace components may alter the drug response in ways that cannot currently be replicated with a combination of a few putative active ingredients.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Jack Challem
  | coauthors = 
  | title = The Problem With Herbs
  | journal = Natural Health  
  | volume =
  | issue =
  | pages =
  | date = Jan, 1999
  | url =
  | doi =
  | id = 
  | accessdate =  }}</ref><ref>{{cite journal
  | last =
  | first =
  | authorlink = E.M. Williamson
  | coauthors = 
  | title = Synergy and other interactions in phytomedicines
  | journal = Phytomedicine
  | volume =  8
  | issue =  5
  | pages = 401–409
  | date = 2001
  | url =
  | doi =
  | pmid = : 11695885
  | accessdate =  }}</ref> Pharmaceutical researchers recognize the concept of  drug synergism but note that clinical trials may be used to investigate the efficacy of a particular herbal preparation, provided the formulation of that herb is consistent.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Peter Goldman
  | coauthors = 
  | title = Herbal Medicines Today and the Roots of Modern Pharmacology
  | journal = Annals of internal medicine 
  | volume =
  | issue =
  | pages = 594–600
  | date = 2001
  | url = http://annals.highwire.org/cgi/reprint/135/8_Part_1/594.pdf
  | doi =
  | id = 
  | accessdate =  }}</ref> 
right|thumb|Thai chili [[peppers contain capsaicin ]]

In specific cases the claims of synergy<ref>{{cite journal
  | last =
  | first =
  | authorlink = E.M. Williamson
  | coauthors = 
  | title = Synergy and other interactions in phytomedicines
  | journal = Phytomedicine
  | volume =  8
  | issue =  5
  | pages = 401–409
  | date = 2001
  | url =
  | doi =
  | id = 
  | accessdate =  }}</ref> and multifunctionality<ref>{{cite journal
  | last =
  | first =
  | authorlink = Ido Izhaki
  | coauthors = 
  | title = Emodin – a secondary metabolite with multiple ecological functions in higher plants
  | journal = New Phytologist 
  | volume = 155
  | issue = 2
  | pages =  205–217
  | date = August 2002  
  | url =
  | doi =
  | id = 
  | accessdate =  }}</ref> have been supported by science. The open question is how widely both can be generalized. Herbalists would argue that cases of synergy can be widely generalized, on the basis of their interpretation of evolutionary history, not necessarily shared by the pharmaceutical community. Plants are subject to similar selection pressures as humans and therefore they must develop resistance to threats such as radiation, reactive oxygen species and microbial attack in order to survive.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Johanna Grassmann, Susanne Hippeli and Erich F. Elstner
  | coauthors = 
  | title = Plant’s defence and its benefits for animals and medicine: role of phenolics and terpenoids in avoiding oxygen stress 
  | journal = Plant Physiology and Biochemistry 
  | volume = 40
  | issue = 6-8
  | pages = 471–478
  | date = June-August 2002
  | url =
  | doi = 10.1016/S0981-9428(02)01395-5 
  | id = 
  | accessdate =    | author = Grassmann, J
}}</ref>  Optimal chemical defenses have been selected for and have thus developed over millions of years.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Donald P. Briskin
  | coauthors = 
  | title = Medicinal Plants and Phytomedicines. Linking Plant Biochemistry and Physiology to Human Health
  | journal = Plant Physiol,
  | volume = 124
  | issue =
  | pages = 507–514
  | date = October 2000
  | doi =
  | id = 
  | accessdate =  }}</ref>Human diseases are multifactorial and may be treated by consuming the chemical defences that they believe to be present in herbs. Bacteria, inflammation, nutrition and ROS (reactive oxygen species) may all play a role in arterial disease.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Mallika V, Goswami B, Rajappa M.
  | coauthors = 
  | title = Atherosclerosis pathophysiology and the role of novel risk factors: a clinicobiochemical perspective
  | journal = Angiology.
  | volume = 58
  | issue = 5
  | pages = 513–22
  | date = 2007 Oct-Nov
  | url =
  | doi =
  | pmid = : 18024933
  | accessdate =  }}</ref> Herbalists claim a single herb may simultaneously address several of these factors. Likewise a  factor such as ROS may underly more than one condition.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Govindarajan R, Vijayakumar M, Pushpangadan P.
  | coauthors = 
  | title = Antioxidant approach to disease management and the role of 'Rasayana' herbs of Ayurveda
  | journal = J Ethnopharmacol. 
  | volume = 99
  | issue = 2
  | pages =  165–78
  | date = 2005 Jun 3 Epub 2005 Apr 26
  | url =
  | doi =
  | pmid = : 15894123
  | accessdate =  }}</ref>  In short herbalists  view their field as the study of a web of relationships rather than a quest for single cause and a single cure for a single condition.

In selecting herbal treatments herbalists may use forms of information that are not applicable to pharmacists. Because herbs can moonlight as vegetables, teas or spices they have a huge consumer base and large-scale epidemiological studies become feasible.  Ethnobotanical studies are another source of information. <ref>{{cite book
  | last = 
  | first = 
  | authorlink = L.J.Slikkerveer
  | coauthors = 
  | title = Medicinal and Aromatic Plants
  | publisher = Springer
  | date = 2006
  | location = 
  | pages = 
  | url=http://library.wur.nl/ojs/index.php/frontis/article/viewFile/1220/792
  | doi = 
  | id = 
  | isbn = }}</ref>  For example, when indigenous peoples from geographically dispersed areas use closely related herbs for the same purpose that is taken as supporting evidence for its efficacy. Herbalists contend that historical medical records and herbals are underutilized resources.<ref>{{cite journal
  | last =
  | first =
  | authorlink = Riddle JM.
  | coauthors = 
  | title = History as a tool in identifying "new" old drugs
  | journal = Adv Exp Med Biol.
  | volume =
  | issue = 505
  | pages = 89–94
  | date = 2002
  | url =
  | doi =
  | pmid = : 12083469 
  | accessdate =  }}</ref> They favor the use of convergent information in assessing the medical value of plants.  An example would be when in-vitro activity is consistent with traditional use.

Certain strains of herbalism rely on sources that would be widely considered unreliable and would not be accepted in a scientifically oriented herbal journal.  These include astrology, the Bible, intuition, dreams, “plant spirits”, etc.

==Popularity==
A survey released in May 2004 by the complementary and alternative medicines (CAM), what was used, and why it was used. The survey was limited to adults, aged 18 years and over during 2002, living in the United States. 

According to this survey, herbal therapy, or use of natural products other than vitamins and minerals, was the most commonly used CAM therapy (18.9%) when all use of prayer was excluded.<ref> (See table 1 on page 8).</ref><ref>[http://nccam.nih.gov/news/2004/052704.htm More Than One-Third of U.S. Adults Use Complementary and Alternative Medicine] Press release, May 27, 2004. National Center for Complementary and Alternative Medicine</ref>

Herbal remedies are very common in Europe. In Germany, herbal medications are dispensed by apothecaries (e.g., Apotheke). Prescription drugs are sold alongside essential oils, herbal extracts, or herbal teas. Herbal remedies are seen by some as a treatment to be preferred to chemical medications which have been industrially produced.<ref>{{cite journal
 | quotes = 
 | author = James A. Duke
 | date =:23,24,.
 | year =  2000
 | month =  Dec/Jan
 | title = Returning to our Medicinal Roots
 | journal = Mother Earth News
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In the United Kingdom, the training of medical herbalists is done by state funded Universities. For example, Bachelor of Science degrees in herbal medicine are offered at Universities such as University of East London, Middlesex University, University of Central Lancashire, University of Westminster, University of Lincoln and Napier University in Edinburgh at the present.

==Types of herbal medicine systems==
thumb|350px|'''[[Dioscorides’ Materia Medica''', c. 1334 copy in Arabic, describes medicinal features of cumin and dill.]]
Use of medicinal plants can be as informal as, for example, culinary use or consumption of an herbal tea or supplement, although the sale of some herbs considered dangerous is often restricted to the public. Sometimes such herbs are provided to professional herbalists by specialist companies. Many herbalists, both professional and amateur, often grow or "wildcraft" their own herbs.

thumb|300px|Séchage de plantes médicinales dans un centre de [[médecine tibétaine traditionnelle (Jarkot, Nepal). Elles seront ensuite broyées en poudre fine et utilisées en tisane]]

La '''phytothérapie''', étymologiquement le traitement  par les plantes médicinales. 

On peut distinguer deux types de phytothérapie :

* Une pratique traditionnelle, parfois très ancienne basée sur l'utilisation de plantes selon les vertus découvertes empiriquement. Selon l'OMS, cette phytothérapie est considérée comme une médecine traditionnelle et encore massivement employée dans certains pays dont les pays en voie de développement. C'est une médecine parallèle du fait de l'absence d'étude clinique.

* Une pratique basée sur les avancées scientifiques qui recherche des extraits actifs des plantes. Les extraits actifs identifiés sont standardisés. Cette pratique conduit aux phytomédicaments et selon la réglementation en vigueur dans le pays, la circulation des phytomédicaments est soumise à l'autorisation de mise sur le marché (AMM). On parle alors de pharmacognosie ou de biologie pharmaceutique.

== Histoire ==
thumb|300px|Description de l'usage du cumin et de l'aneth - La matière médicale de [[Dioscoride, copie en arabe de 1334]]

Le premier texte connu sur la médecine par les plantes est gravé sur une tablette d'3000 ans av. J.-C.; Ils utilisaient des plantes telles le myrte, le chanvre, le thym, le saule en décoctions filtrées.

Le Papyrus Ebers, du  est le premier recueil connu consacré aux plantes médicinales. De loin le plus volumineux connu de l'Égypte ancienne avec « 110 pages », il fait référence à de plus anciens documents citant des dizaines de plantes accompagné d'un mode d'utilisation<ref>  [http://www.fpharm.uniba.sk/Kfgb/Pedagogika/Ucebne_Texty/History%20of%20Pharmacognosy.pdf] et [http://www.indiana.edu/~ancmed/egypt.HTM].</ref>.

Les Grecs et les Romains utilisaient également de nombreuses plantes. On en retrouve des références, entre autres, dans l'œuvre de Dioscoride (médecin grec du ) (cf. illustration).

En Europe, les plantes représentent l'essentiel de la pharmacopée jusqu'à la fin du  et l'avènement de la chimie moderne. Encore largement utilisées après la Seconde Guerre mondiale, elles furent ensuite supplantées par les médicaments de synthèse plus simple d'emploi.

En gouvernement de Vichy. De  herboristes en 1941, ils sont désormais une dizaine tandis qu'en Allemagne ou en Italie, on compte plusieurs milliers d'herboristes.

<!-- demande de référence : 
Depuis le début des années 1990, l'utilisation de plantes au lieu de préparations de synthèse retrouve un regain de popularité sous le terme « phytothérapie ».
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== Méthodes : utilisation et fabrication ==

En phytothérapie traditionnelle les plantes peuvent être utilisées fraîches, ce qui n'est pas toujours possible, ou séchées, entrant ensuite éventuellement dans des préparations diverses afin de conserver les principes actifs des plantes et éviter toute décomposition. 
On les administre sous forme de teintures alcooliques, macérats, tisanes, compresses, baumes... (remarque : la tisane ne permet d'extraire que les principes actifs de la plante solubles dans l'eau).

Un procédé plus récent permet d'obtenir l'ensemble des principes actifs par broyage (cryobroyage par exemple) fin de la plante après séchage. La poudre est macérée dans un mélange eau/alcool. Après purification des éléments inertes comme la cellulose, la solution sera séchée jusqu'à obtention d'une poudre. Cette poudre peut être ensuite présentée sous forme de comprimés, gélules, sachets, etc.

En Europe, certaines plantes sont reconnues comme plantes médicinales, et soumises comme les médicaments à une autorisation de mise sur le marché. De ce fait, les produits extraits de certaines plantes ne sont vendus que dans les pharmacies et parfois sur ordonnance.

== Précautions d'emploi de la phytothérapie ==