Phytotherapy

Phytotherapy is the study of the use of extracts from natural origin as medicines or health-promoting agents. Although regarded as "alternative medicine" by much of Western medicine, phytotherapy, when critically carried out, is an important field of pharmacognosy.

Contents 1 Points to consider in phytotherapy 1.1 Standardization 1.2 Quality 1.3 Safety 2 Recommended standards for random clinical trials 3 Studies performed without proper identification of assay of plant materials 4 See also 5 References

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:

• Variability in the specie (or species) of plant being used;
• The plant's growing conditions (i.e. soil, sun, climate);
• 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

The safety and effectiveness of alternative medicines have not be been scientifically proven^[6] and remains largely unknown^[7]. 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^[8]." Proper double-blind clinical trials are needed to determine the safety and efficacy of each plant before they can be recommended for medical use.^[9] 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.^[10]

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.^[11]

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.^[12]

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 and Petasites have specific toxicity due to hepatotoxic pyrrolizidine alkaloid content^{[citation needed]}. There are other plant medicines which require caution or can interact with other medications, including St. John's wort and grapefruit^[13].

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.^[14]

• The title and/or abstract should include the Latin binomial for the plant species from which the herbal medicine(s) originated, the part(s) of the plant used in the preparation, and the type of preparation (e.g., dried crude herb, ethanolic extract). The background ...should include a statement explaining the rationale for investigation of the specific herbal medicinal product and whether the indication for which it is being tested is new or is based on traditional use. Participant eligibility criteria ...in a trial testing a traditional indication (e.g., in traditional Chinese herbal medicine, a trial may test the effects of an herbal medicine intervention for liver chi (Qi) deficiency) should describe the theories and concepts underlying this indication.

• The description of the intervention ...must include the herbal medicinal product name, manufacturer, plant part used, type of preparation, source and authentication of the herbal material, pharmaceutical quality (e.g., herbal drug-to-extract ratio, type and concentration of the extraction solvent, quantity of known active constituents per unit dose), and dosage regimen and qualitative testing (purity). Also, reporting of the rationale for the control/placebo used in the trial is recommended. For studies involving herbal medicine practitioners as part of the intervention, details of practitioners (e.g., training, registration status) should be reported. Not all recommendations are relevant for all types of herbal medicine interventions. Therefore, we begin this section with the words "where applicable." For example, a report of an RCT of an herbal medicinal product comprising crude herbal material (e.g., leaves, stems, root) prepared as a tea or decoction does not require reporting of the "type and concentration of solvent used and the plant to plant extract ratio"... In addition, herbal interventions made by the investigators specifically for the study will not have a finished product or extract name or manufacturer ...For such products, all methods used in preparing and formulating the product must be reported. Similarly, allegiance is only relevant for studies in which the practitioner is a part of the intervention. In other studies, the practitioner may serve a more neutral role and thus their characteristics need not be reported. With these exceptions, all information outlined in these recommendations are suggested to be reported for all herbal medicine interventions.

• Also, outcome measures ...should reflect the intervention and indications tested while considering their underlying theories and concepts. For the results section, it is recommended that in addition to other baseline data..., RCTs of herbal medicine interventions report any concomitant medication, herbal medicinal product, or other CAM use. It is recommended that when interpreting the results ... there be consideration of the specific herbal product and dosage regimen tested. This includes an overview of evidence on this particular herbal medicinal product. When considering generalizability ...), it is suggested that authors report how the product used in the trial generalizes to products used in self-care and/or in clinical practice.

Studies performed without proper identification of assay of plant materials

With the decline in pharmacognosy education in the United States^{[citation needed]}, it has been common for herbal research to be done on plants that have not been botanically identified, which have not been assayed for strength and which do not allow for proper understanding of the herb named in the research.

For instance, Eleutherococcus senticosus is frequently identified as "ginseng" although it is not part of the Panax genus and has significantly different medicinal characteristics^{[citation needed]}. As Jonathan Treasure, NIMH, has written:

"Inaccurate spelling of herb names is not uncommon in medical literature as all herbalists can attest, but more frequently there is a complete failure to use proper scientific nomenclature for botanicals."

This is not a trivial issue, because without a validated description of a herb by its binomial name (and preferably the naming authority) the identity of the herb cannot be established."^[15]

See also

• Pharmacognosy
• Herbalism
• Alternative medicine

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. ^ ^{a b} 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. ^ Eisenberg DM, Annals of Internal Medicine 127 (1997) Number 1 p61 - http://www.annals.org/content/127/1/61.full.pdf
8. ^ Elvin-Lewis M., "Should we be concerned about herbal remedies,"Journal of Ethnopharmacology 75 (2001) 141-164.
9. ^ 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. PMID 17761132. 
10. ^ 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. 
11. ^ [Jane Brody. Taking Stock of Mysteries of Medicine]http://query.nytimes.com/gst/fullpage.html?res=9A05EEDC1F3EF936A35756C0A96E958260&sec=health&spon=&pagewanted=2
12. ^ Ephedra information from Memorial Sloan-Kettering Cancer Center. Accessed April 11, 2007.
13. ^ [1] Winston, David. Herbal Medicine Introduction
14. ^ Moher D, Altman DG, Schulz KF, Elbourne DR, for the CONSORT Group. Opportunities and challenges for improving the quality of reporting clinical research: CONSORT and beyond. Canadian Medical Association Journal 2004;171:349-350.
15. ^ http://www.herbological.com/images/downloads/HH2.pdf

www.interscience.wiley.com/journal/ptr Phytotherapy Research