Do you know where your drugs come from? Most of the drugs we use today came from plants originally.
Plant chemicals (phytochemicals) are responsible for some of the most important medical advancements of our time.
Some examples include:
- Antibiotics
- Chemotherapy
- Pain management
- Hallucinogenics
Here are some of the most common drugs that were derived from, or inspired by compounds found in plants.
1. Aspirin (Salicylic Acid)
Aspirin is a popular treatment for pain, inflammation, and fever. It works by inhibiting an enzyme known as cyclooxygenase (COX).
The COX-1 enzyme converts arachidonic acid to thromboxanes and prostaglandins which are responsible for sustaining inflammation and blood clotting.
The compound was first synthesized in 1890 by a man named Felix Hoffmann.
Aspirin is modelled after the naturally occurring polyphenol salicylic acid — a compound found in a handful of plants including Salix alba (white willow), Spirea spp. (wintergreens), and Betula spp. (birch).
All of these plants were traditionally used for conditions involving injury, pain, and inflammation.
The difference Aspirin has to its naturally occurring counterpart is the addition of an acetyl chemical group, which gives Aspirin its antifibrinolytic effects and improved bioavailability.
2. Quinine (Qualaquin)
Quinine is used as a malaria and babesiosis medication. It remains one of the primary treatments for malaria to this day under the brand name Quinalaquin, and the generic name Quinine.
It’s an alkaloid taken from the Cinchona calisaya tree from South America. It was a popular herb used by the local Quechua tribes of the Amazon rainforest, which eventually caught the attention of the Jesuits who brought it to Europe.
Although the drug can be synthesised, the most economically viable method of production is to extract it from the cinchona tree. Unfortunately, there are many side effects to this medication, including permanent kidney damage.
3. Opiates (Oxycontin, Morphine, Codeine)
Opiates are a class of chemicals that target the opioid receptors in the human body that regulate pain and temperature control.
Most opiates are classified as benzylisoquinoline alkaloids which can be either naturally occurring, or synthetic.
These alkaloids were discovered from the Opium poppy (Papaveraceae somniferum), starting with codeine and morphine. In 1874, a chemist named C.R Alder Wright synthesised a similar compound called diamorphine, more commonly referred to as heroin.
For the first 23 years of this discovery, nothing was done.
It wasn’t until Felix Hoffmann (the creator of aspirin), re-synthesised it that it caught the attention of Bayer Pharmaceuticals, where it was commercialised as a pain management drug.
Heroin has since been banned in most countries due to high addiction rates and drug abuse, however, opiates in general are still widely used in modern medicine. Morphine, codeine, methadone, and Fentanyl are all used to provide varying potencies of pain management.
4. Myriocin
Myriocin (aka ISP-1 or thermozymocidin), is an antibiotic and immunosuppressant derived from the sterile (non-spore-producing) fungus Mycelia sterilia and entomopathogenic (bug-eating) fungus Isaria sinclairii.
Scientists modified myriocin to produce a compound known as fingolimod (compound FTY720), which is used to treat autoimmune conditions like multiple sclerosis.
5. Penicillin
Penicillin was the very first class of antibiotics ever discovered. It’s made from a mould known as Penicillium chrysogenum. It was known for years that this mould was able to kill off bacteria, including Streptococcus and Staphylococcus strains that were responsible for substantial loss of human life around that time. A Scottish scientist named Alexander Fleming finally isolated the active constituent in 1928.
Unfortunately, Alexander was a poor communicator, and couldn’t attract any serious attention from the media or his peers on his finding. It wasn’t until 1940 that penicillin was mass produced and incorporated into conventional medicine.
Although there are many penicillins, they’re all classified as beta-lactam antibiotics. They work by blocking a key process during cell division (peptidoglycan cross-link formation), causing the cell to eject its insides, effectively killing the bacteria. This is most effective in gram-positive bacteria.
6. Digoxin
Digoxin is a heart medication used for heart failure, and cardiac arrhythmias (such as atrial flutter, or atrial fibrillation). It was isolated from the foxglove plant (Digitalis lanata) in 1930, however, the first mention of foxglove derivatives for cardiac related conditions goes all the way back to 1785. It was used to treat a condition known as dropsy, which is an accumulation of fluid under the skin, often as a result of chronic heart failure.
The use of digoxin changed how we treated cardiovascular disease for many years, but has since fallen out of favour due to some of its more dangerous side effects. In fact, in 2003 a nurse named Charles Cullen killed 40 of his patients with overdoses of digoxin and other heart medications.
Digoxin works by inhibiting sodium, potassium, ATP channels in the heart. This causes sodium levels to build up inside the cells of the heart, which then causes calcium to increase inside the cell as well. This heightened calcium allows stronger contraction of the heart, while expending less energy. It also has an effect on the vagus nerve, which is used to control the heart rhythm.
7. Paclitaxel (Taxol)
Paclitaxel is a chemotherapeutic agent derived from the bark of the Pacific Yew (Taxus brevifolia).When making the medicine, the yew tree was killed. As demand for the drug increased, the drug became involved in an ecological controversy. The need for the medication was scrutinised in light of the extensive damage it was causing to yew populations in North America. Researchers began seeking more sustainable ways to obtain this compound.
The drug is now made using semisynthetic methods obtained from liquid plant cultures. Although the plant tissue is still needed to make the medicine, it poses no threat to wild yew populations because manufactures now rely on sterile lab-grown cultures of the plant.
Paclitaxel works by inhibiting a compound called tubulin inside the cells.
Tubulin is needed during cell division, by inhibiting this compound, Paclitaxel is able to prevent cell division in the body.
Since cancer often involves rapidly dividing cells, the drug is used to target these rapidly dividing cells more specifically, slowing the growth of cancer.
Unfortunately, there are also a wide range of side effects, mostly as a result of the inhibition of rapidly dividing cells.
Side-effects include:
- Hair loss
- Stomach ulcers
- Nausea
- Eczema
8. Vincristine & Vinblastine
Vincristine and vinblastine are alkaloids taken from the Madagascar periwinkle plant (Catharanthus roseus).
Both are intravenous chemotherapeutic agents used for cancers like Hodgkin’s disease and neuroblastoma. Vinblastine was isolated first in 1958, with vincristine to follow in 1961.
Similarly to Paclitaxel, these alkaloids work by preventing cells from dividing by blocking tubulin. This has a marked effect on cancers, which are often characteristic in how rapidly they divide. As a result of this action, both have fairly strong side effects including hair loss, constipation, nausea & vomiting, neutropenia (low white blood cells), and lung damage.
9. Lysergic Acid Diethylamide (LSD)
Lysergic acid was made in 1938 by a man named Albert Hofmann in Switzerland.
It’s made from a naturally occurring alkaloid called ergotamine found in the fungus called ergot (Claviceps purpurea). It can now be manufactured synthetically.
Hofmann didn’t identify the psychoactivity of the extract for another 5 years. Soon after his discovery, it was picked up by psychologists a treatment for psychiatric illnesses, and by the United States government in an attempt to use mind control (for which it was unsuccessful).
LSD works by stimulating various types of serotonin receptors (5HT2A, and 5HT2B), as well as the dopamine D2 receptors in the brain.
