When aspirin was ‘invented’ in the late 1800’s, it heralded a new era in modern medicine. Touted as a wonder drug, it could take away the pain of aching joints, relieve inflammation and reduce fevers. Truly a remarkable feat of modern science! But was it?
The active ingredients in most modern synthetic drugs have their origins in plant chemicals. Indeed some modern drugs like morphine are still produced from plants. The plant versions of these modern drugs invariably have a long history of medicinal use in many cultures around the world. From the Assyrians and Babylonians some 4000 years before Christ was born to ancient Chinese and Native Americans, ancient writings contain ample evidence of their use.
Acetylsalicylic Acid – An Aspirin By Any Other Name
One such modern synthetic plant based drug is the humble aspirin. The active ingredient in aspirin is manufactured acetylsalicylic acid, a compound that was originally derived from salicylic acid. Salicylic acid itself is an oxidized derivative of salicyl alcohol, the natural compound found in the bark and leaves of the willow tree. It is a very powerful anti-inflammatory and analgesic.
The most commonly used willow is Salix alba, the white willow, but the black, purple and violet willow species also have salicin. The bark of these willow trees was traditionally chewed to release the salicin in it or brewed into a tea. It was used to relieve inflammation and pain, and help reduce fever. Whilst there are records of Hippocrates using it circa 400 BC for these purposes, including helping women through childbirth, its known use actually dates back much further.
History Of Willow Use As An Anti-Inflammatory And Antipyretic Drug
In 4000 BC the Assyrians used an extract from the leaves of the willow tree to relieve musculoskeletal joint pain and as an antipyretic drug to reduce fever. Five hundred years later, in 3500 BC we find descriptions of willow leaves being used to treat fever in Sumerian culture. By 1300 BC willow leaves were known to have been used by the Egyptians for joint pain, antipyretic purposes and as an anti-inflammatory for treating wounds. The Babylonians are recorded to have been using it around 605 BC for treating pain, inflammation and fever. In 500 BC Chinese medicine was using it and the Greek physician Hippocrates was prescribing it for fever and childbirth pain around 400 BC.
Interestingly however it seems that it wasn’t until the mid 1700’s that willow bark’s use became commonplace in England. That was when Oxfordshire Reverend Edward Stone chewed on a twig of willow and found it relieved his joint pain. He further noted that its bitter taste was similar to that of the bark from the Cinchona tree (Peruvian bark) used to treat ague and fevers caused by malaria, and rheumatism. We now know the active compound in Peruvian bark is quinine, a highly effective anti-malarial drug.
This similarity in taste led the Reverend to wonder if perhaps willow bark contained the same, or similar, compounds to Peruvian bark. Up until that point, no one really knew why or how it worked. They just knew it did! So in 1763 Reverend Stone conducted what would become the first known clinical trial on willow bark. Over a 5-year period, he prepared and used the bark of the white willow (Salix alba) to treat malarial fever and agues. At the end of the 5 years, he was able to conclude that the therapeutic characteristics of Salix alba were comparable to those of Peruvian bark for the treatment of similar ailments.
How Does Willow Work – The Race Is On To Find Out
Over the ensuing decades, scientists in Europe were able to identify and extract salicin, the active ingredient in willow bark. They learnt how to purify it and ultimately identified its chemical structure as a glucosidic salicyl alcohol. Significantly, when this salicyl alcohol was oxidized, it produced salicylic acid. In 1853, a professor at Montpellier University further identified the chemical structure of salicylic acid and was able to develop a slightly modified version called acetylsalicylic acid but more on this later….
…..because in 1860 in parallel developments, the chemical structure of salicyl alcohol was unraveled and a synthetic version of salicylic acid developed.
This led to the establishment of a commercial facility in 1874 to produce synthetic salicylic acid in industrial quantities. A development that effectively ended the widespread therapeutical use of willow bark in Europe as the drug of choice for treating inflammation, fever and pain.
Unfortunately, salicylic acid has an undesirable side effect. It can cause irritation to the stomach, resulting in bleeding. This prompted Felix Hoffman, whose father suffered from this side effect when taking salicylic acid for his arthritis, to take another look at the acetylsalicylic acid developed some 40 years early by the Montpellier University professor.
In 1893, he duly came up with a synthetic version of acetylsalicylic acid that was safer to use than salicylic acid. Tests proved that it provided the same therapeutical benefits as salicylic acid minus the undesirable side effects. And so the modern wonder drug aspirin was born!
An Aspirin A Day….!
However, it wasn’t until nearly a century later, towards the end of the 1900’s, that other benefits of aspirin surfaced. In 1971, a British pharmacologist proved that acetylsalicylic acid was also a powerful anticoagulant and suggested that it could effectively lessen the risk of cardiovascular disease. This finding subsequently had important implications for the use of aspirin as a preventative for certain types of cardiac conditions.
Today white willow bark natural remedies are readily available across the counter as teas, tinctures, capsules and powder. It is still very popular in alternative medicine for treating joint pain, fever and inflammation. However, users need to bear in mind that unlike aspirin, white willow bark still contains the active ingredient that can cause upper gastrointestinal tract bleeding. This compound was identified in salicylic acid and removed in the synthetic version of acetylsalicylic acid that ultimately went into mass production as modern aspirin.
Other Plant Based Sources Of Salicylic Acid
Another interesting piece of information is that willows are not the only plant with salicylic alcohol. Meadow sweet flowers (Filipendula ulmaria, syn. Spiraea ulmaria) were also used as an anti-inflammatory and analgesic throughout the middle ages. The active ingredient in these was identified as salicylic aldehyde in 1835. When oxidized, salicylic aldehyde and salicylic alcohol yield an identical salicylic acid.