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A NEW drug could help turn the tide in the battle against malaria. It has yet
to be tested in people but animal studies look very promising.

Every year, about half a billion people suffer from malaria. Most of the
cases are in Africa, and around 1.8 million African children die of the disease
each year. New drugs are desperately needed, as drug-resistant strains of
malaria spread. In Thailand, Cambodia and Myanmar some strains don鈥檛 respond to
any drugs. Now Henri Vial at the Montpellier University II in France and his
colleagues have developed a drug that prevents the malaria parasite reproducing
in red blood cells. Code-named G25, the drug kills the parasite by preventing it
taking up a substance called choline, which it needs to build cell
membranes.

鈥淭his is a new approach. No one in the world has tried it before,鈥� says Vial.
His team tested the G25 in owl monkeys (Aotus lemurinus) infected with malaria.
Just 0.03 milligrams of the drug per kilogram of body weight was enough to kill
the parasite. With quinine, a dose 30 times as great is needed. One reason why
G25 works at such low doses is that infected red blood cells seem to take it up
more readily than uninfected red cells, though it鈥檚 still unclear why. The
infected cells had 300 times the concentration of G25 compared with surrounding
fluid.

This selectivity suggests that the drug might have few side effects. The
researchers were able to give monkeys 30 times the parasite-curbing dose before
they saw any adverse effects. With quinine, ill effects start at just 50 per
cent over the therapeutic dose.

鈥淭here is an absolute dearth of new anti-malarial drugs,鈥� says Geoffrey
Pasvol, an expert in tropical medicine at Imperial College, London. 鈥淭his looks
like a wonder drug.鈥� But Vial cautions that even if G25 lives up to its
potential, it will be seven or eight years before a version is ready for the
market.