Revealed: How drugs 'beat malaria'

A team at La Trobe University says its research also helps in understanding how these drugs are developing worrying resistance to a pathogen that kills more than 800,000 children worldwide each year.

Team leader Prof Leann Tilley says that the research, published in 'Proceedings of the National Academy of Science' journal, points to new ways of boosting the action of anti- malarial drugs to overcome this drug resistance problem.

Plasmodium falciparum is the most pathogenic human malaria parasite. It afflicts more than 200 million people worldwide. Treatment relies heavily on combination therapies, including artemisinin drug, extracted from the wormwood herb.

"Recent reports of decreased clinical effectiveness of artemisinin-based drugs are extremely concerning. It is therefore critical to understand the way artemisinin works so we can overcome the pathogen's resistance to drug," she said.

The latest research shows that artemisinin targets a point of critical vulnerability in the malaria parasite.

"The parasite invades and grows within the red blood cells of its human victims. As it grows it consumes the haemoglobin of the red blood cell and releases an iron- containing pigment, called 'haem'," Prof Tilley said.

The research also found that supplies of this haemoglobin-derived iron are essential if artemisinin is to destroy the parasite.

"Decreasing the production of this iron renders the parasites resistant to artemisinin. We have also shown that the parasite can slow its growth and reduce its haemoglobin uptake rate in response to artemisinin treatment. This helps it avoid the toxic effects of artemisinin," she said.