Youyou Tu received the 2015 Nobel Award in Medicine “for her discoveries concerning a novel therapy against Malaria” – and, while the drug she developed may be novel, she drew inspiration from centuries-old traditional Chinese medicine.
Tu was born in Ningbo, Zhejiang, China in 1930. A serious battle with tuberculosis as a teenager inspired her to go into medical research to help cure patients. She studied pharmacognosy (medicines derived from plants and other natural sources) at Beijing’s Peking University, then was assigned to work in what is now the China Academy of Chinese Medical Sciences. In the 1950s, she partook in a government-sponsored training program designed to integrate Western and traditional Chinese medicine.
In the 1960s, drug-resistant malaria parasites were quickly becoming a global public health emergency, especially in Southeast Asia, where it was taking a large toll on soldiers in the Vietnam War. In 1964, Chinese military institutes began confidential antimalarial research and established a malaria research office (codenamed National 523) to coordinate these efforts. After two years of unsuccessfully screening thousands of compounds, the group recruited Tu to build and lead a Project 523 research group focused on looking for potential antimalarial drugs among traditional Chinese medicines.
Tu began by poring through traditional Chinese medical literature, including texts that were thousands of years old, and speaking to Chinese medical practitioners, eyes and ears alert for traditional remedies (herbal, animal, and mineral) that had been used to treat malaria’s symptoms. She narrowed down over 2,000 “hits” to 640 that seemed the most promising and published them in a brochure entitled “Antimalarial Collections of Recipes and Prescriptions” in 1969.
Tu and her 523 group then began preparing and screening these compounds, but with minimal success. One herb, qinghao (sweet wormwood), showed some promise, but it only worked some of the time, so Tu set to find out why. Upon returning to the literature, she was struck by instructions in Ge Hong’s A Handbook of Prescriptions for Emergencies to prepare the herb by soaking it in water, then wringing it out and drinking the juice. This recipe was surprising because medicinal herbs were typically boiled to extract those chemical compounds that cause biological effects, called “active ingredients.”
From her scientific training, Tu knew that heat could destroy chemical compounds and began to suspect that the method she was using to extract the active ingredients of qinghao was inactivating them in the process, so she redesigned her preparation to extract chemicals from the stems and leaves without boiling them. She found that an extract of the plant prepared using a chemical called ethyl ether could treat malaria in rodents and she was later able to purify the extract to remove toxic portions. She announced the discovery in 1972 and began preparing for clinical trials – this was no easy feat as China’s cultural revolution had shut down most pharmaceutical workshops, forcing Tu and her team to extract large quantities of extract by themselves.
This was not the only selfless move Tu made to expedite the project – to settle debates about toxicity, she volunteered to be the first person to take the compound. She showed the drug to be safe and clinical trials were allowed to proceed, with the first in Fall of 1972. As trials with the extract showed success, Tu set out to isolate the active compound(s) that were doing the “curing” – to do this she started isolating & purifying the different chemicals present in the extract separately, then testing whether they could treat malaria on their own. This allowed her to identify the active compound artemisinin (Qinghaosu). While studying the compound further, Tu modified part of the chemical, producing a new compound, dihydroartemisinin, which was even more effective. After Tu’s team and collaborators carried out further safety and efficacy studies, both compounds were approved by China’s Ministry of Health (in 1986 and 1992).
Tu received the Lasker Prize in 2011 and the Nobel Prize in Physiology or Medicine in 2015 (in both cases, the first Chinese scientist to do so), but she maintains that the biggest reward is knowing that she’s saving lives – and she definitely is – artemisinin-based combination therapies (ACTs) are now standard first-line malaria treatment credited with saving millions of lives. Tu is currently Chief Scientist at the China Academy of Traditional Chinese Medicine, where she has worked since 1965.