Phytotherapy

Running total of the number of research papers listed on PubMed from 1990-2007 containing the word "phytotherapy."^{[original research?]}

Phytotherapy is the study of the use of extracts from natural origin as medicines or health-promoting agents.

Traditional phytotherapy is often used as synonym for herbalism and regarded as "alternative medicine" by much of Western medicine, although effects of many substances found in plants have scientific evidence.

Modern phytotherapy when critically conducted, can be considered the scientific study on the effects and clinical use of herbal medicines.

Points to consider in phytotherapy

Standardization

In herbal medicine, standardization refers to providing processed plant material that meets a specified concentration of a specific marker constituent. 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 John's wort 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.^[1]

Quality

The quality of crude drugs or plant medicines depends upon a variety of factors, including the variability in the specie (or species) of plant being used; the plant's growing conditions (i.e. soil, sun, climate); and the timing of harvest, post-harvest processing, and storage conditions. The quality of some plant drugs can judged by Organoleptic factors (i.e. sensory properties such as the taste, color, odor or feel of the drug), or by administering a small dose of the drug and observing the effects.

These conditions have been noted in historical herbals such as Culpepper's Complete Herbal^[2] or The Shen Nong or Divine Farmer's Materia Medica.^[3] This was standard pharmacognosy curriculum for many years.^{[citation needed]}

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.^[4]

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.^{[citation needed]} 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.^[5]

Safety

A number of herbs are thought to be likely to cause adverse effects.^[6]

Furthermore, "adulteration, inappropriate formulation, or lack of understanding of plant and drug interactions have led to adverse reactions that are sometimes life threatening or lethal."^[7] Proper double-blind clinical trials are needed to determine the safety and efficacy of each plant before they can be recommended for medical use.^[8] Although many consumers believe that herbal medicines are safe because they are "natural", herbal medicines may interact with synthetic drugs causing toxicity to the patient, may have contamination that is a safety consideration, and herbal medicines, without proven efficacy, may be used to replace medicines that have a proven efficacy.^[9]

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.^[10]

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.^[11]

Poisonous plants which have limited medicinal effects are often not sold in material doses in the United States or are available only to trained practitioners,^{[citation needed]} these include:

• Aconite
• Arnica
• Belladonna
• Bryonia
• Datura
• Gelsemium
• Henbane
• Male Fern
• Phytolacca
• Podophyllum and
• Veratrum

Furthermore, herbs such as Lobelia, Ephedra and Eonymus that cause nausea, sweating, and vomiting, have been traditionally prized for this action.^{[citation needed]}

Plants such as Comfrey^[12][13] and Petasites have specific toxicity due to hepatotoxic pyrrolizidine alkaloid content.^[14][15] There are other plant medicines which require caution or can interact with other medications, including St. John's wort and grapefruit.^[16]

See also

• Pharmacognosy
• Herbalism
• Alternative medicine
• Phytotherapy Research

References

1. ^ Alan Tillotson Growth, Maturity, Quality
2. ^ Culpeper's Complete Herbal by Nicholas Culpeper reprinted in 2003 by Kensington Arts Press
3. ^ The Divine Farmer's Materia Medica: A Translation of the Shen Nong Ben Cao (Blue Poppy's Great Masters Series) by Yang Shou-Zhong and Bob Flaws (translator) Blue Poppy 1998
4. ^ Tillotson Institute of Natural Health - Growth, Manufacture, Quality
5. ^ Making Sense of Commission E, review by Jonathan Treasure, 1999-2000.
6. ^ Talalay P. and Talalay P., "The Importance of Using Scientific Principles in the Development of Medicinal Agents from Plants", Academic Medicine, 2001, 76, 3, p238.
7. ^ Elvin-Lewis M. (2001). "Should we be concerned about herbal remedies". Journal of Ethnopharmacology 75 (2-3): 141–164. doi:10.1016/S0378-8741(00)00394-9. PMID 11297844. 
8. ^ Vickers AJ (2007). "Which botanicals or other unconventional anticancer agents should we take to clinical trial?". J Soc Integr Oncol 5 (3): 125–9. doi:10.2310/7200.2007.011. PMC 2590766. PMID 17761132. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2590766. 
9. ^ Ernst E (2007). "Herbal medicines: balancing benefits and risks". Novartis Found. Symp. 282: 154–67; discussion 167–72, 212–8. doi:10.1002/9780470319444.ch11. PMID 17913230. 
10. ^ [Jane Brody. Taking Stock of Mysteries of Medicine]http://query.nytimes.com/gst/fullpage.html?res=9A05EEDC1F3EF936A35756C0A96E958260&sec=health&spon=&pagewanted=2
11. ^ Ephedra information from Memorial Sloan-Kettering Cancer Center. Accessed April 11, 2007.
12. ^ Hiller K, Loew D. 2009. Symphyti radix. In Teedrogen und Phytopharmaka, WichtlM (ed). Wissenschaftliche Verlagsgesellschaft mbH Stuttgart: Stuttgart; 644–646.
13. ^ Benedek, B., Ziegler, A. and Ottersbach, P. (2010), Absence of mutagenic effects of a particular Symphytum officinale L. liquid extract in the bacterial reverse mutation assay. Phytotherapy Research, 24: 466–468. doi: 10.1002/ptr.3000 - http://onlinelibrary.wiley.com/doi/10.1002/ptr.3000/abstract
14. ^ Mattocks AR 1986. Chemistry and Toxicology of Pyrrolizidine Alkaloids, Academic Press: London; 391.
15. ^ Cordell, G. A., Quinn-Beattie, M. L. and Farnsworth, N. R. (2001), The potential of alkaloids in drug discovery. Phytotherapy Research, 15: 183–205. doi: 10.1002/ptr.890 - http://onlinelibrary.wiley.com/doi/10.1002/ptr.890/abstract
16. ^ [1] Winston, David. Herbal Medicine Introduction