Missing Piece in Anti Malarial Drug Jigsaw Found

Artemisinins are one of the only treatments for drug resistant forms of the malaria parasite. Drug resistant parasites are found in most parts of the world, and kill millions of children every year. Even though artemisinins have been used for decades to treat patients with malaria, no one knew how they worked. Now scientists at St George’s Medical School have discovered how artemisinins attack the malaria parasite. After years of clinical and laboratory based research, Professor Sanjeev Krishna and colleagues have finally shown that artemisinins kill parasites by inhibiting one of the two calcium pumps which are key molecular motors of all complex cells. This research is published today in Nature.

Artemisinins are a potent and relatively cheap form of treatment made from natural extracts of sweet wormwood. But scientists have been trying to solve the problem of how these drugs work since they were first discovered in China in the 1970s. Solving this mystery shows us how to make best use of existing artemisinins and will also open the way to the development of new compounds. The St George’s group is world-renowned in the study of infectious diseases, and has worked in collaboration with colleagues at the University of Southampton, Osaka City University, Japan, University of Liverpool and the Liverpool School of Tropical Medicine to unravel the details of how artemisinins actually inhibit a calcium pump of parasites.

To carry out this revolutionary research, Professor Krishna’s group used frog’s eggs to study the calcium pumps of parasites in isolation. Their research has shown that artemisinins are particularly useful because they only affect one type of calcium pump, that of malaria parasites, without interfering with any other pumps. This method of study using frogs eggs was pioneered at St George’s and is now applied to study other transport proteins of the malarial parasite.

“We are particularly pleased to have found the missing piece in the antimalarial jigsaw and solved one of the longest running mysteries about how a critical antimalarial works. We cannot wait to apply this information in areas where there is a lot of drug resistance in parasites” says Sanjeev Krishna.