The winners of the Nobel Prize for Physiology or Medicine have been announced, and among the joint winners is Tu Youyou, an 84-year-old Chinese pharmacologist who discovered artemisinin (the others are William C Campbell and Satoshi Ōmura, who discovered a new treatment for roundworm parasites). Tu, who is chief professor at the China Academy of Traditional Chinese Medicine, is the first ever Chinese medicine laureate.
She was part of a secret military project in Communist China set up by Mao Zedong in 1967, which yielded what New Scientist calls “one of the greatest drug discoveries in modern medicine” – artemisinin. Although her discovery came earlier, it was published anonymously only in 1977, after the Cultural Revolution, and it was only around the mid-2000s that her role in the discovery became known.
Here’s a juicy peek (from a New Scientist profile) into how Tu discovered it artemisinin:
She and three assistants reviewed more than 2000 recipes for traditional Chinese remedies in the academy’s library. They made 380 herbal extracts and tested them on mice. One of the compounds did indeed reduce the number of malaria parasites in the blood. It was derived from sweet wormwood (Artemisia annua), a plant common throughout China, which was in a treatment for ‘intermittent fevers’ – a hallmark of malaria.
The team carried out further tests, only to be baffled when the compound’s powers seemed to melt away. Tu reread the recipe, written more than 1600 years ago in a text appositely titled ‘Emergency Prescriptions Kept Up One’s Sleeve’. The directions were to soak one bunch of wormwood in water and then drink the juice.
Tu realised that their method of preparation, boiling up the wormwood, might have damaged the active ingredient. So she made another preparation using an ether solvent, which boils at 35°C. When tested on mice and monkeys, it proved 100 per cent effective. ‘We had just cured drug-resistant malaria,’ Tu says. ‘We were very excited.’
A Plasmodium (malaria parasite) from the saliva of a female mosquito moving across a mosquito cell. Image licensed under CC BY 2.5 via Wikipedia Commons
Malaria is one of the world’s deadliest diseases: according to the WHO’s 2014 World Malaria Report, an estimated 3.3 billion people are at risk of being infected with malaria and developing disease, and 1.2 billion are at high risk. Luckily for the world, Tu Youyou had its back: the impact of her work is enormous. Artemisinin, which WHO describes along with its derivatives as being powerful medicines “known for their ability to swiftly reduce the number of Plasmodium parasites in the blood of patients with malaria”, is now used as part of standard treatment across the globe. As there have been signs in recent years that malarial parasites are developing resistance to the drug, recommended treatment now uses an artemisinin derivative in combination with other drugs (artemisinin-combination therapies or ACTs) to fight malaria.
This week, the recipients of the Nobel Prize for Physics and Chemistry will be announced as well. Here’s looking forward to seeing more women on the list!