Researchers who tested more than 2,000 drugs for activity against the malaria parasite say a commonly-used allergy drug holds promise for treating the disease.
The findings were published yesterday (2 July) in Nature Chemical Biology.
Research into drugs for diseases that mostly affect developing countries is time-consuming and hampered by a lack of funding.
One solution is to test collections of existing drugs for possible new applications, but such drug libraries are generally small.
David Sullivan of the Johns Hopkins Bloomberg School of Public Health in the United States and his colleagues are creating a new, comprehensive collection.
So far they have included 2,687 drugs that have been approved for medical use or are being tested for approval.
The researchers screened these for compounds that harm the malaria parasite Plasmodium falciparum.
One of the most promising candidates was astemizole, a drug used to treat allergic reactions. It is sold in generic form in more than 30 countries including Cambodia, Thailand and Vietnam.
The researchers tested astemizole in mice infected with one of two strains of malaria: one that is sensitive to the existing malaria drug chloroquine and one that is not.
At low doses, astemizole reduced the number of chloroquine-susceptible parasites by 81 per cent but was less effective against chloroquine-resistant malaria.
Jean-René Kiechel, project manager for the Drugs for Neglected Diseases initiative, says the research shows that an "opportunistic approach… has potential for breakthrough".
Nick White, professor of tropical medicine at the University of Oxford in the United Kingdom and Mahidol University in Thailand, says astemizole's potential as an anti-malarial drug needs to be further investigated, but that the research is "a good start".
Sullivan and colleagues are now expanding the Johns Hopkins Clinical Compound Library to include every available drug ever used in phase II clinical trials or approved by the US Food and Drug Administration and its foreign counterparts.
They will then make the collection available to any researcher interested in screening it for potential drugs against diseases in developing countries.
Reference: Nature Chemical Biology doi:10.1038/nchembio806 (2006)