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Phytotherapy is the study of the use of extracts from natural origin as medicines of health-promoting agents. Even though phytotherapy is usually regarded as "alternative medicine" in the Western countries, it is as well, when critically carried out, an essential part of modern pharmacognosy.
Additional recommended knowledge
Points to consider in phytotherapy
In herbal medicine standardization refers to providing processed plant material that meets a specified concentration of a specific marker constituent. However plant constituents have synergy and even active constituent concentrations may be misleading measures of potency if cofactors are not present. A further problem is that the important constituent is often unknown. For instance St. Johnswort is often standardized to the antiviral constituent hypericin which is now known to be the "active ingredient" for antidepressant use. Other companies standardize to hyperforin or both, although there may be some 24 known possible constituents. Only a minority of chemicals used as standardization markers are known to be active constituents. Standardization has not been standardized yet: different companies use different markers, or different levels of the same markers, or different methods of testing for marker compounds. Herbalist and manufacturer David Winston points out that whenever different compounds are chosen as "active ingredients" for different herbs, there is a chance that suppliers will get a substandard batch (low on the chemical markers) and mix it with a batch higher in the desired marker to compensate for the difference.
Quality in the use of crude drugs or plant medicines depends upon a variety of factors: genetically strong seed, correct species, maturity of the plant at harvest, good soils, air quality, climate, organoleptic factors such as intensity of color, flavor and odor, processing after harvest and a variety of other factors. These conditions have been noted in historical herbals such as Culpepper's Complete Herbal  or the The Shen Nong or Divine Farmer's Materia Medica This was standard pharmacognosy curriculum for many years. Storage after collection is a factor worthy of study: Researchers in Nara, Japan have stored samples of ginseng root (Panax ginseng), licorice root (Glycyrrhiza glabra) and rhubarb root (Rheum emodi) that have been shown to retain their active properties for over 1,200 years. 
In modern times the foregoing aspects are no less important, but have been neglected with the advent of laboratory testing, although it generally is true that only certain constituents are identified and measured. Processes like HPLC (High performance liquid chromatography), GC (gas chromatography), UV/VIS (Ultraviolet/Visible spectrophotometry) or AA (Atomic Absorption spectroscopy)are used to identify species, measure bacteriological contamination, assess potency and eventually creating Certificates of Analysis for the material.
Quality should be overseen by either authorities ensuring Good Manufacturing Practices or regulatory agencies by the US FDA. In the United States one frequently sees comments that herbal medicine is unregulated, but this is not correct since the FDA and GMP regulations are in place. In Germany, the Commission E has produced a book of German legal-medical regulations which includes quality standards . 
The political issues around the safety of crude drugs vary from considering natural remedies "safe" regardless of potential dangers to considering them a dangerous unknown.
Ephedra has been known to have numerous side effects, including severe skin reactions, irritability, nervousness, dizziness, trembling, headache, insomnia, profuse perspiration, dehydration, itchy scalp and skin, vomiting, hyperthermia, irregular heartbeat, seizures, heart attack, stroke, or death.Poisonous plants which have limited medicinal are often not sold in material doses in the United States or are available only to trained practitioners. These include Aconite, Arnica, Belladonna, Bryonia, Datura, Gelsemium, Henbane, Male Fern, Phytolacca, Podophyllum, and Veratrum. Secondly, are herbs like Lobelia, Ephedra and Eonymus that cause nausea, sweating vomiting, that were traditionally prized for this action. Third are plants with specific toxicity like hepatotoxic pyrrolizidine alkaloids like Comfrey or Petasites. There are other plant medicines which require caution or can interact with medications including St. Johnswort or grapefruit. [
Recommended Standards for Random Clinical Trials
The Consolidated Standards of Reporting Trials (CONSORT) group came up with standards for random clinical trials (RTC) of herbs in 1996, revised in 2002. This statement comprises a 22-item checklist and flow diagram to guide authors, peer reviewers, editors, and readers on the essential information required in reports of two-group parallel RCTs of natural products. The CONSORT statement is endorsed by leading medical journals, editorial groups, professional societies, and funding bodies.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Phytotherapy". A list of authors is available in Wikipedia.|