To kill a parasite

摘要

The Chinese herb qinghao (Artemisia annua) has long been used to treat malaria―Taoist manuscripts dating back to the third century describe the use of qinghao extracts to treat malaria-related fevers. Over the past two decades, derivatives of the herb's active ingredient, artemisinin, have made an increasing contribution to malaria treatment. But the precise mechanism by which artemisinin derivatives kill the parasite has remained obscure. Writing on page 957 of this issue, Krishna and colleagues propose a radical new theory to explain the molecular basis of the antimalarial activity of artemisinin. Malaria remains a scourge of the developing world, killing over a million people each year and infecting around 500 million. Most of the victims are children under the age of five living in sub-Saharan Africa, but the disease also afflicts Southeast Asia, South America and the Indian subcontinent. The situation has worsened over recent years as resistance has developed against chloro-quine and sulphadoxine-pyrimethamine, the two drugs most commonly used to treat malaria. Hope for the containment of the disease now rests largely on a remarkable set of artemisinin drugs developed by Chinese scientists in the 1970s and early 1980s, which rapidly kill the malaria parasites.