A Trojan Horse To Fight Malaria

THE NUMBERS DEFY THE imagination: 1 million children killed every year, 200 million people afflicted. Malaria is steadily gaining resistance to medicine's scant arsenal of drugs. Although Americans think of malaria as a Third World disease, the mosquitoes that carry it are found in North America and could easily become infected with drug-resistant strains.

The good news is, the plasmodium parasite that causes malaria has chinks in its armor, and Stanford University biochemist Kasturi Haldar and her colleagues think they have discovered one. At a late stage in the parasite's life cycle, the plasmodium hides in a small sack inside a host's red blood cells and extends a tangle of membranes to the surrounding plasma. The membranes import nutrients from the bloodstream, writes Haldar in a recent issue of the journal Science.

The plasmodium's membranes could provide an important target for antimalaria drugs. The researchers demonstrated that this lifeline will import toxins that closely resemble nutrients. The toxins' chemical structure is very different from that of today's quinoline-based drugs. So if drugs are designed around these nutrient look-alikes, "there's no reason there should be any resistance," Haldar says.