Many pharmaceuticals were originally derived from plants, including:
In addition, about 25 percent of all pharmaceutical drugs still include some plant-derived constituents.
So it is not surprising that botanical medicines often work in the body in ways that are similar to pharmaceutical drugs.
Like pharmaceutical drugs, botanical medicines adhere to principles of pharmacodynamics and pharmacokinetics. These are the scientific words for the study of how drugs interact with bodily systems.
So, as with pharmaceuticals, scientists study how the active components in a particular botanical is absorbed, distributed, and metabolized in the body and then excreted. They also study the pharmacological activity-the effect the botanical has in the body. All this helps scientists understand the mechanism of action-where the drug goes in the body, what it does, and how that impacts the individual's health.
Like many pharmaceutical drugs, there are botanical medicines for which the mechanism of action is unknown.
Here is an example of a botanical with a known or postulated mechanism of action:
Many botanicals are comprised of multiple active ingredients that act together (synergistically) to produce a response (Williamson, 2001). Thus, there may not be one active ingredient that accounts for all the observed effects.
This concept of synergy underlines much of the modern clinical use of botanical medicines, and there is an increasing body of evidence in support of its validity.
While botanicals are like pharmaceuticals in many ways, there are important differences.
|Botanical Medicines||Pharmaceutical Drugs |
|Wide margin of safety||Narrow margin of safety and greater potential for adverse effects with overuse|
|Active ingredients are diluted||Active ingredients are highly purified (potency is greater)|
|Dozens to hundreds of related compounds (also contain non-active ingredients)||Usually a single active chemical or a well-defined mixture of active chemicals|
|Often have a synergistic action||Usually a well-defined, specific activity|
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Williamson, E.M. (2001). Synergy and other interactions in phytomedicines. Phytomedicine, 8, 401-409.
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Wilt, T., Ishani, A., Mac Donald, R. (2002). Serenoa repens for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews, 3, CD001423.