, PARIS, May 20 – A massive screening of chemicals has turned up thousands of compounds that could lead to new drugs in the fight against malaria, a pair of studies published in Nature reported Thursday.
Malaria affects a quarter of a billion people worldwide, and claims upward of 850,000 lives every year, overwhelming children in the poorer nations of Africa and Asia.
Preventative measures such as the use of insecticide-treated bednets has helped cut infection rates dramatically in some of the worst-hit countries, and treatments based on a class of drugs called artemisinin have sharply reduced mortality.
But the rise of new, drug-resistant strains of the disease could wipe out that progress unless alternative compounds are found, the World Health Organisation (WHO) has warned.
An international team of researchers led by R. Kiplin Guy of St. Jude Children\’s Research Hospital in Memphis, Tennessee combed through more than 300,000 candidate chemicals.
They identified 1,100 agents out of more than 300,000 candidates that inhibited growth of the deadly P. falciparum parasite that causes the disease by at least 80 percent.
An even more select subset of 172 compounds all had chemical structures unlike those in existing antimalarial drugs, according to the study.
The fact that these novel agents acted on different targets in the mosquito-borne parasite could prove crucial in beating back the emerging threat of drug-resistant variants.
As a proof of principle, the researchers showed that one of the compounds was effective in treating malaria in a mouse model, albeit at a very high concentration.
In a second study, Jose Garcia-Bustos of GlaxoSmithKline and colleagues screened around two million agents in the pharmaceutical giant\’s in-house chemical library.
Setting a similar threshold for blocking the parasite\’s growth, the researchers uncovered 13,500 promising active compounds.
Significantly, 8,000 of them were equally effective against multi-drug resistant P. falciparum parasites.
More than 11,000 of the "hits" were proprietary compounds owned by the drug company, which has taken the unusual step of transferring them to the public domain, where they are available researchers anywhere in the world.
"These reports offer tremendous opportunities to develop the next generation of antimalarial drugs," commented David Fidock, a researcher at the Columbia University Medical Center in New York.
Also writing in Nature, Fidock cautioned that it is only a "starting point," and that time was running short.