Posted by: Hourglass PJ8 DEC 2011
An oral artemisinin-combination therapy is now one of the standard licensed treatments for uncomplicated malaria in the UK. Until recently, however, the origins of this drug were a mystery. But a recent article in New Scientist explains that it was a Chinese pharmacologist, Tu Youyou, who discovered artemisinin and its value in malaria.
Professor Tu’s part in this story begins in the 1960s, at the height of China’s Cultural Revolution, when drug resistance was developing to chloroquine, which was then the main treatment for malaria.
Of significance to China was the increase in malaria in North Vietnam, one of its few allies at the time, which was at war with South Vietnam. North Vietnam was losing more soldiers to malaria than to bullets.
China’s leader, Mao Zedong responded by establishing a covert plan, named Project 523 for the day it was announced — 23 May 1967 — to research a treatment for chloroquine-resistant malaria. The clandestine nature of the project and the political climate of the time meant that few scientific papers from the project were published for years, but it was apparently common knowledge that the research involving synthetic compounds drew a blank until, in 1969, Tu Youyou from the Academy of Traditional Chinese Medicine in Beijing was appointed head of the project group. She and her team began to work on traditional Chinese recipes and by 1971 they had reviewed 2,000 of these, made 380 herbal extracts and tested them on mice. One of the extracts was successful. This was sweet wormwood, Artemisia annua, a plant common throughout China, and used in a traditional combination treatment for intermittent fevers, a symptom of malaria.
After subjecting the extract to further tests, the Beijing team found that the activity of the drug disappeared when the extract was boiled in water. However, success in mice studies was obtained when the extract was prepared in ether, which has a boiling point of 35C. As project leader, Tu tested the drug on herself and, finding no adverse effects, began clinical trials among labourers who had contracted malaria in the forest. The trials were successful. Within 30 hours the fever had subsided and the parasite had disappeared from the blood.
Earlier this year, Professor Tu, now aged 80, was awarded the US Lasker-DeBakey clinical medical research award for this discovery.