Plants have been used since antiquity to treat a large number of medical conditions. They still serve a vital role in many parts of the world where people either do not have access to modern medical care, or cannot afford it. Proponents of the use of plant products as medicinals feel that their effectiveness has been proven by their long use, or they would have been discontinued long ago.
The western medical community, however, has been schooled in the scientific method, and has treated these traditional methods with skepticism. The purported cures may be due to reasons other than the plant medicinals, and in many instances the patient does not improve with these treatments.
Due to the growing popularity of "alternative" medicine (outside the mainstream or conventional Western medicine), in 1998 Congress established the National Center for Complimentary and Alternative Medicine within the National Institutes of Health. The primary mission of the Center is to support and conduct research into alternative medicine. In terms of plant medicinals, this research would normally involve laboratory studies to determine the active molecules, animal studies to study its mode of action, and finally clinical studies to determine safety and effectiveness in humans. In so doing, the Center will be better able to inform the public on the use of alternative therapies.
This article focuses on the use of plant products in the treatment of cancer. Normally, the part of the plant that contains the active principle is selected, and may be extracted to further concentrate the active principle. I will provide a few examples of plant medicinals that are proven effective, are promising, or are ineffective and even dangerous.
Effective plant medicinals
Taxol is the trade name for paclitaxel, which is sold by Bristol-Myers Squibb. 5This taxoid drug was originally isolated from the bark of the Pacific yew tree in the late 1960's. However, logging this tree is difficult, and since it takes the bark from about six trees to treat each patient, people worried about the depletion of this relatively rare tree. Hence, Taxol is a semisynthetic compound derived from the needles of this tree. Docetaxel is a related taxoid drug that is marketed as Taxotere by Rhone-Poulenc Rorer. This is also a semi-synthetic drug derived from the needles of the English yew tree. The drugs are effective against a variety of cancers, including ovarian, breast, non-small cell lung, and Karposi's sarcoma.
