Tuesday, March 6, 2012
Herbs in Medical history - Willow bark & Aspirin
On March 6th 1899, aspirin was patented by Felix Hoffman of the German company, Bayer. The word was coined from a- for acetylsalicylic and -spirin for Spirea, the original genus name of the herb meadowsweet where the main compound was extracted.
Here is a general history of how aspirin came to be. Some of this history was obtained from Aspirin: The Remarkable Story of a Wonder Drug.
Aspirin or acetylsalicylic acid, is a derivative of salicylic acid that is a mild, nonnarcotic analgesic useful in the relief of headache and muscle and joint aches. The drug works by inhibiting the production of prostaglandins, body chemicals that are necessary for blood clotting and which also sensitize nerve endings to pain.
The father of modern medicine was Hippocrates, who lived sometime between 460 B.C and 377 B.C. Hippocrates left historical records of pain relief treatments, including the use of powder made from the bark and leaves of the willow tree to help heal headaches, pains and fevers. Willow bark has been used as a treatment for pain and fever in China since 500 BC. In Europe, it was primarily used for altogether different purposes, such as stopping vomiting, removing warts, and suppressing sexual desire. However, in 1828, European chemists made a discovery that would bring together some of these different uses. They extracted the substance salicin from white willow, which was soon purified to salicylic acid. Salicylic acid is an effective treatment for pain and fever, but it is also sufficiently irritating to do a good job of burning off warts.
In 1828, Johann Buchner, professor of pharmacy at the University of Munich, isolated a tiny amount of bitter tasting yellow, needle-like crystals, which he called salicin. Two Italians, Brugnatelli and Fontana, had in fact already obtained salicin in 1826, but in a highly impure form. By 1829, [French chemist] Henri Leroux had improved the extraction procedure to obtain about 30g from 1.5kg of bark. In 1838, Raffaele Piria [an Italian chemist] then working at the Sorbonne in Paris, split salicin into a sugar and an aromatic component (salicylaldehyde) and converted the latter, by hydrolysis and oxidation, to an acid of crystallized colorless needles, which he named salicylic acid.
The problem was that salicylic acid was tough on stomachs and a means of 'buffering' the compound was searched for. The first person to do so was a French chemist named Charles Frederic Gerhardt. In 1853, Gerhardt neutralized salicylic acid by buffering it with sodium (sodium salicylate) and acetyl chloride, creating acetylsalicylic acid. Gerhardt's product worked but he had no desire to market it and abandoned his discovery. Chemists later modified salicylic acid (this time from the herb meadowsweet) to create acetylsalicylic acid, or aspirin.
As interest in natural medicine has grown, many people have begun to turn back to white willow as an alternative to aspirin. One double-blind, placebo-controlled trial found it effective for back pain, and another found it helpful for osteoarthritis. It is also used for such conditions as bursitis, dysmenorrhea, tension headaches, migraine headaches, rheumatoid arthritis, and tendonitis. However, two recent studies failed to find it effective for rheumatoid arthritis or osteoarthritis.
Aspirin and related anti-inflammatory drugs are notorious for irritating or damaging the stomach. However, when taken in typical doses, willow does not appear to produce this side effect to the same extent. This may be partly due to the fact that most of the salicylic acid provided by white willow comes from salicin and other chemicals that are only converted to salicylic acid after absorption into the body. Other evidence suggests that standard doses of willow bark are the equivalent of one baby aspirin daily rather than a full dose.
This latter finding raises an interesting question: If willow provides only a small amount of salicylic acid, how can it work? The most likely answer seems to be that other constituents besides salicin play a role. Another possibility may be that the studies finding benefit were flawed, and that it actually does not work.
Since herbs taken as medicine in traditional infusion and tincture forms vary in potency and effectiveness due to the way they are made and the body chemistry of the recipient, my feeling is not enough research has been done to eliminate willow bark, so perhaps one can try it (with a doctor’s permission of course since it is a blood thinner) to see if it is effective for you.