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Uses many references from “The Efficacy, History, And Politics Of Medicinal Plants” by Frank J. Lipp, Ph.D. in Alternative Therapies in Health and Medicine (1996;2(4):36-41), now a subscription only website.
Herbalism is an ancestor to which we owe many thanks in homeopathy. As a system, it is the oldest and most widely used form of medicine in the world today. Yet as science marches on, some medicinal herbs have lost their importance and are seen as nothing but placebos.
As sources of remedies and herbs, nature has proven to be the best. But herbalists and scientific research have sometimes been at odds about the healing that nature can handle.
A drug (§-methoxypsoralen) produced from bishop's weed (Ammi majus) to treat psoriasis and other skin disorders, as well as T-cell lymphoma was used by ancient Egyptians to treat vitiligo, a skin condition characterized by a loss of pigment.
Pokeroot (Phytolacca decandra) was thought to be effective against cancer in the 18th century, and in studies has been shown to kill cancer in mice. Hale introduced the remedy to homeopathy. Clarke records several cancer cases cured by it and notes uses for a flu epidemic. But modern science has passed on it.
One quarter of all medical prescriptions are somehow based on plants or plant-derived synthetic analogs. That doesn’t seem like a lot but that’s only 20% of the world’s population that uses those. The other 80%, primarily in developing countries, rely 100% on plant-derived medicines for their healthcare.
Just since 1960, at least a dozen flowering plants have provided modern drugs including:
Three major sources for anti-cancer drugs were derived from North American plants used medicinally by Native Americans because of random events.
Why hasn’t modern science taken a look at some of the homeopathic provings which have been on the books for almost a century? Besides being on the edge, there is the economic side to realize. It costs a lot to research. But certainly, there is some bias.
Research investment in plant-derived drugs by pharmaceutical companies has been dwindling for much of the 20th century, and almost stopped by the end of the 1970s. One reason is that after a 20-year, multimillion-dollar plant screening effort by researchers for the National Cancer Institute, not a single agent of general use in the treatment of human cancer was identified using a screen of one of about 200 types of cancer. Recent improvements in screening allow for testing of many more plant extracts on a variety of diseases.
Drug companies once again are actively collecting plants and other natural products. Two results of this chemical prospecting are alkaloids from a Cameroonian rain forest vine and an Australian chestnut tree showing activity against the AIDS virus.
Pharmaceutical companies are asking whether the plants should be collected randomly or on the basis of local ethnobotanical knowledge. If you take a plant from Brazil, can you legally protect the drug, do you owe the people who told you about it any money? Other drug discovery methods are available and sometimes look good in light of these questions.
The chemical components of plants, even if published, cannot be patented and therefore generate profit. No profit incentive means drug companies will be unwilling to investigate and develop plant-based drugs. They also know that the imitations they can legally protect do not always work the same as the original plant substance..
Some $6 billion is spent annually on herbal medicines in Europe which attracts pharmaceutical companies without an interest in alternative medicine. They have been aggressively buying up smaller herbal medicine companies.
The prevailing scientific theory of drug discovery is that all disease starts at the molecular level. Molecules that go bad cause disease. Cholesterol molecules gang up and block the blood vessels causing heart disease.
All drug discovery procedures look for a particular molecule that stimulates or blocks the activity of cell receptor molecules by fitting into them, like a lock and key. In contrast, medicinal plants work on a higher, physiological level. A plant that increases the secretion of urine can be used to treat kidney and bladder ailments or to eliminate body poisons. Tannins can bind with proteins in the skin and mucous membranes to convert them into insoluble and resistant tissues. Hence, plants high in tannins such as bilberry and oak bark are used for a number of ailments including diarrhea, wounds, inflamed gums, hemorrhoids, and frostbite.
When herbal medicines were first used, certain parts or the whole plant was prepared. But as chemistry got better, scientists extracted less and less of the plant which was thought to be a good idea until they found that the parts they had discarded helped the body to manage the toxicity of the extracts.
The other components also affected how the extract was assimilated in the body, the stability, or increase the positive effects. For example, polysaccharides in chamomile increase the anti-inflammatory activity of apigenin, luteolin, and other flavones.
Combinations of chemicals occurring naturally in one plant are synergistic. Herbalists have found combining several plants create a synergy of healing also. Traditional Chinese medicine uses combinations to minimize or eliminate side effects, inhibit the action of one drug, direct healing to a site, or many other variations.
In what manner and how often the herbal preparation is given affects the outcome. For example, a hot tea made from boneset will cause sweating, a cold infusion is a mild laxative, and in large doses boneset will cause vomiting and act as a purgative like castor oil.
Dosage is important and therefore standardization of the substance used is important as we know from the standards set forth in the HPUS. Herbal medicines do not have this kind of supervision to protect the consumer.
Herbal literature can exaggerate the uses of the botanic substances which has given scientists a bad feeling about accuracy. For example, one popular herb book averages 23 different medicinal uses for each plant. There are many different symptoms that have been recorded in homeopathic materia medicas for each remedy which is one of the difficulties of making a good choice of remedies.
But herbs have a long recorded history of medicinal use and they commonly exhibit a wide range of pharmacological activities. Nut grass (Cyperus rotundus), for example, shows hypotensive, antihistamine, antiemetic, smooth muscle relaxant, antipyretic, and anti-inflammatory activities in experimental animal studies. Gingkolide B inhibits the platelet activating factor, an important inflammatory mediator, and has potential in treating illnesses including psoriasis, lupus, broncho-asthma, allergic inflammations, anaphylaxis, graft rejection, Alzheimer's disease, and immunocomplex disorders like toxic shock. Gingko tree herbal preparations are quite popular.
A proper dose of anything is important. Prune juice taken as a laxative can produce diarrhea. Licorice root is good for gastric ulcers but in large doses causes heart failure. Castor oil (Ricinus communis) seeds yield a strong laxative but are highly toxic. Several common medicinal plants including chamomile, marigold, and yarrow can produce minor allergic reactions. Mistletoe, sassafras bark, comfrey, coltsfoot, and calamus contain carcinogenic chemicals.
As with any type of subjective study, there are those who want you to believe it’s good and minimize potential dangers. Then there are those who are the conservatives in another camp that magnify tales of error and call for caution. Cases of adverse reactions to herbal medicines are rare and often due to misidentified or incorrect plant admixtures, adverse interaction of the herbal medicine with a prescription drug, inadequate evaluation and quality control, and over-consumption or prolonged use of an herbal remedy. Compared with the dangerous side effects and errors of well-meaning handlers of drugs and pesticides, the risks of herbal medicines seem quite low.
Four cases of herbal poisoning in two years can be understood considering that tons of most every kind of herb have been consumed over the years. In contrast, there are three million severe pesticide poisonings each year, with 220,000 deaths worldwide. Interestingly, no clinical trials are set to determine the safety of the billions of tons of more than 100,000 foreign chemicals released into the environment annually.
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Traditions in Western Herbal Medicine from The Medicinal HerbFAQ.
