Although herbal medicine is often criticized as being unserious, more than a third of modern medicines come directly or indirectly from natural products such as plants, microorganisms, or animals. For thousands of years, humans have exploited the healing qualities of plants.
Now, researchers at the Scripps Research Institute, in California, in the United States, have discovered that the bark of the Galbulimima belgraveana tree contains a psychoactive substance that can, for example, treat depression and anxiety states.
This tree only grows in the remote bushes of Papua New Guinea and northern Australia, where the bark has long been used by indigenous peoples as a medicine against aches and fevers.
“This shows that Western medicine does not dominate the market for new treatments, and there are many more traditional medicines that still need to be investigated,” Ryan Shenfy, professor of chemistry and director of the study, explains in an interview with DW.
What are the active substances in plants?
The best known example of botanical medicine is opium which is obtained from poppies. Its active parts are mainly alkaloids, codeine and morphine. They belong to opiates and have a strong effect on the central nervous system. There are opiates of natural origin, such as endorphins and pure opiates, synthetic or semi-synthetic production.
Afghan farmers harvest opium in a poppy field.
Likewise, there are other phytotherapeutic drugs that have scientifically proven medicinal effect.
Treating Parkinson’s disease with velvet pills
The so-called velvet bean (Mucuna purines) has been a part of Chinese and Ayurvedic medicine for more than 3,000 years. Ancient texts describe how healers used extracts of the pill to reduce tremors in patients and treat the disease now known as Parkinson’s.
Current studies show that velvet pills contain a compound called levodopa, which is a precursor to dopamine. As a drug, levodopa is used to treat Parkinson’s disease, and helps stop tremors by boosting dopamine signals in areas of the brain that control movement.
The modern history of levodopa began in the early 20th century, when Polish biochemist Casimir Funk synthesized this substance. Decades later, in the 1960s, scientists discovered that levodopa was an effective treatment for stopping tremors in Parkinson’s patients. The drug revolutionized the treatment of disease and is still used today.
The healing power of plants
According to current clinical studies, hawthorn (Crataegus monogyna) lowers blood pressure and may be useful in treating cardiovascular disease. Hawthorn fruit contains compounds such as bioflavonoids and proanthocyanidins, which have an antioxidant effect.
Hawthorn fruit has an antioxidant effect.
The Greek physician Dioscorides was the first to discover the medicinal effects of hawthorn in the first century BC. Extracts of this plant are not yet suitable for medicinal use in the general public. The studies concerned have not yet been completed.
Fight cancer with Pacific yew
In European mythology, the yew occupies a special place in medicine. Since most of the tree is poisonous, it is often associated with death but also immortality.
The Pacific yew (Taxus brevifolia), a conifer plant native to North America, has the most positive medicinal qualities.
In the 1960s, scientists discovered that the bark of the tree contains the compound paclitaxel, on the basis of which an effective cancer drug was developed. It can prevent cancer cells from dividing and thus prevent the spread of disease.
Willow bark is another traditional medicine with a long history. 4,000 years ago, the Sumerians and ancient Egyptians used the bark to cope with pain.
Willow bark contains a compound called salicin, from which aspirin was developed. It is used to reduce pain, lower fever, and prevent strokes. It was first used during the influenza pandemic in 1918 to treat high fever. Today it is the most widely used drug in the world.