Sweet wormwood and artemisinin
The plant origins – and future – of malaria treatment
In 2015, 438,000 people died from malaria. The greatest toll was on sub-Saharan Africa, where over 90 per cent of malaria deaths occur. Malaria-ravaged countries face an ever-evolving threat as malaria parasites adapt to resist our best drugs.
The primary antimalarial drug of choice – artemisinin – is produced from the sweet wormwood plant, Artemisia annua, and its synthetic forms. This plant has long been used in Chinese medicine. It now is used in combination with other drugs to try to stop the parasites from developing resistance to it, but even these combinations are becoming less effective.
Recent research suggests that we might be able to use the dried leaves of the whole plant to overcome the parasites’ resistance: feeding mice with sweet wormwood leaves proved more effective than giving them comparable doses of standard artemisinin treatments. The researchers think the whole plant may act as a form of combination therapy, because it naturally makes a range of artemisinin-related compounds, which may have slightly different actions. However, the World Health Organization advises against using the plant this way because of the risk of taking too low a dose, which would allow the malaria parasite to survive and evolve to become even harder to stop.Lead image:
Science Museum, London/Wellcome Images
- Whole plant therapy shows promise to beat malaria parasites’ drug resistance (2015)
- University of York: artemisia project
- Scitable: Genetic modification
- Transgenic plants as green factories for vaccine production (2013)
- Dried whole-plant Artemisia annua slows evolution of malaria drug resistance and overcomes resistance to artemisinin (2014)
- WHO: Artemisinin resistance fact sheet
- WHO: Malaria fact sheet