Studies identify new chemical compounds that could lead to development of new malaria drugs

May 21 2010

Researchers have identified thousands of chemical compounds that could be used to develop new malaria drugs, two studies published in the journal Nature on Wednesday show, the Wall Street Journal reports.

"Existing drugs and other tools, such as bed nets, have helped reduce the disease's impact in some countries. But the malaria parasite has developed resistance to many available drugs, making it vital that new therapies are found," the newspaper writes (Whalen, 5/19).

For one study, researchers "combed through more than 300,000 candidate chemicals" and identified 1,100 agents that inhibited the growth of Plasmodium falciparum, Agence France-Presse reports. "An even more select subset of 172 compounds all had chemical structures unlike those in existing antimalarial drugs, according to the study," AFP reports. Their novel structure "could prove crucial in beating back the emerging threat of drug-resistant variants," the news service notes, adding that the researchers used one of the compounds to effectively treat malaria in a mouse (5/19).

The other study, "led by Francisco-Javier Gamo of GlaxoSmithKline's [GSK] Tres Cantos Medicines Development Campus in Spain, screened 1,986,056 compounds from the company's library. The team found more than 13,000 that halted growth of the parasite by 80 percent - with more than 8,000 of these working on a strain that was resistant to other drugs," Scientific American's "Observations" blog writes (Harmon, 5/19).

The researchers also found that drugs that stop kinase enzymes from functioning were able to prevent the parasite's growth, "suggesting that they were inhibiting these enzymes within the parasite. A number of kinase-inhibiting drugs are already on the market to treat diseases such as cancer; Glaxo's finding could lead to similar drugs being tested against malaria," the Wall Street Journal notes. GSK also "said it would set up a database containing the chemical structure of all the drugs that appeared effective, so that any researchers can carry out further tests on the chemical compounds."

In an accompanying editorial, David Fidock, an associate professor at Columbia University Medical Center, wrote, "Neither group claims to have discovered the next antimalarial drug. Instead, they provide a remarkable diversity of novel chemical structures on which to base new antimalarial drug-discovery and development campaigns" (5/19). According to Fidock, who wrote that the findings were just a "starting point," the studies "offer tremendous opportunities to develop the next generation of antimalarial drugs," AFP writes (5/19).

Study Finds Climate Change Not Linked To Increased Malaria Transmission

A paper also published in Nature, "adds to the growing voice of dissent from epidemiologists who challenge the prediction that global warming will fuel a worldwide increase in malaria," Nature News reports. Epidemiologists Peter Gething and Simon Hay of the Malaria Atlas Project at the University of Oxford and colleagues looked at data on the incidence of malaria between 1900 and 2007 and found although temperatures rose during the twentieth century, malaria "lost ground," Nature News writes. 

"According to the models the researchers used to tease out the factors affecting the incidence of malaria, the impact of public-health measures such as improved medications, widespread insecticide use and bed nets have overwhelmed the influence of climate change. 'Malaria is still a huge problem,' says Gething. 'But climate change per se is not something that should be central to the discussion. The risks have been overstated,'" Nature News reports (Ledford, 5/19).

"I'd say what we've shown is that if we can provide people with existing technologies such as drugs and bednets, we have the capacity as a global community to reduce the misery this disease causes," Gething added, BBC reports. "Climate change is, in our view, an unwelcome distraction from the main issues," he said (Black, 5/20).

"Gething and colleagues' study is the first of its kind to provide a detailed statistical model of global trends over the twentieth century, but it does have limitations," Nature News reports in and article that includes reaction from experts not involved in the study (5/19).

Chris Drakeley of the Malaria Centre at the London School of Hygiene and Tropical Medicine, who was not involved in the study said, "I don't doubt climate change is happening, but we have also seen an increase in the coverage of treatment, and in the last 20 years there has been a huge amount of information and education on malaria made available in Africa; and that's all changed much faster than the climate," BBC reports (5/20).