Some of the most successful drugs we know about have come from plants, including the cancer drug Taxol, the malarial treatment artemisinin, and even aspirin. The latter two were identified because of their use in herbal remedies that targeted known symptoms.
Many plants produce a complex mixture of chemical compounds, and the lure of finding new drugs has resulted in what has been termed “bioprospecting,” or searching plants for compounds that have activity in various drug assays. Choosing plants that are already used in traditional herbal remedies would seem to be the right place to start, but it’s not clear which (or what percentage) of these remedies are based on anything more than a placebo effect. Now, a study in PNAS suggests that a combined knowledge of evolution and local lore might hold the key to finding the plants with the best chance of producing a useful drug.
The challenge of working with plants that are used as herbal remedies is that there are so many: most indigenous cultures seem to have had them, and most involve plant species that don’t have a global range. In addition, some of the more popular ones seem to have been shared between cultures, and it’s not clear whether that is a product of their effectiveness.
How do we make sense of all this mess? The authors of the new study make two assumptions to help narrow things down. The first is that, if a remedy is successful, it will be discovered by more than one culture. The second is that a given remedy wouldn’t be limited to a single species, but is likely to be made by that species’ closest relatives.
Read more at Ars Technica