News and Events

2005 Media Releases

Malaria research discovers new hope for old drug

Many people in third world countries are dying for want of new medicines against tropical killer diseases such as malaria.

Now, La Trobe University malaria researchers believe there may be a way to bring back one of the oldest anti-malarial drugs to combat the most dangerous of the malaria parasites – at a cost much less than for new drugs.

Head of a La Trobe University malaria research group, Professor of Biochemistry, Leann Tilley, says her group, in association with the Liverpool School of Tropical Medicine in the UK, is investigating an antimalarial drug combination that might make this possible.

‘We are studying the mechanism of action of the antimalarial drug, chloroquine, which was for many decades an indispensable part of our armoury against the most deadly of the malaria parasites, Plasmodium falciparum.

‘Unfortunately chloroquine has now been rendered useless by parasite resistance. Another anti-malarial drug, primaquine, is already licensed for treating a less virulent form of malaria caused by Plasmodium vivax.

‘We have found that when used in combination, chloroquine and primaquine are effective against chloroquine-resistant P. falciparum.’

Professor Tilley says chloroquine-resistant parasites have evolved a mutant transport protein that expels chloroquine via a pore in the membrane of the parasite's food vacuole.

‘We believe that primaquine, which has a similar structure to chloroquine, binds to the same transport protein, but can't be extruded via the pore. As primaquine competitively displaces chloroquine the parasite is no longer able to expel chloroquine, and thus is killed.’

She says the main advantage of chloroquine-primaquine combinations compared with other possible combinations is the low cost.

‘Treatment with chloroquine costs about ten cents (US) and primaquine about 15 cents. By comparison newer drugs, such as the artemisinin derivatives, cost about US$3 and need to be used in combination with other expensive drugs.’

Professor Tilley will present a paper on this research on Wednesday 28 September at the Australian Society for Microbiology conference being held in Canberra next week, from 25 to 29 September.

Wednesday, 21 September 2005Malaria research discovers new hope for old drug

For further information:

Contact: Professor Tilley, Tel:+61 3 9479 1375, or Email: l.tilley@latrobe.edu.au

More information about malaria research at La Trobe University