Tu Youyou

Tu Youyou the Chinese pharmaceutical chemist and malariologist (born 1930) whose discovery of the antimalarial drug artemisinin has saved millions of lives, and who in 2015 became the first Chinese citizen to receive a Nobel Prize in Physiology or Medicine for work carried out in her own country.

Life and Education

Tu Youyou was born on 30 December 1930 in Ningbo, in the coastal province of Zhejiang, China, the only daughter among several children of a family of modest means. Her father is said to have chosen her given name from a classical phrase drawing on the Book of Songs, and the name carries connotations of a quiet and persistent pursuit of learning. As a child she attended local schools in Ningbo, where she showed an aptitude for science and a patient, methodical temperament.

In 1951 she entered the School of Pharmacy at Peking University, then one of the leading scientific institutions in the new People's Republic of China, and she graduated in 1955 with a degree in pharmaceutical science. After graduating she was assigned to the Academy of Traditional Chinese Medicine in Beijing, where she began a career of research into the chemistry of medicinal plants used in traditional remedies.

She married Li Tingzhao, a fellow scientist, and the couple had a family. Her working life unfolded amid the political upheavals of the mid twentieth century, but she remained attached to the laboratory and to her research programme. Her early work concerned the isolation of active substances from plants, and it was this patient skill in natural-product chemistry that would later make her valuable to a secret national project.

The Search for an Antimalarial Drug

In 1967, during the Vietnam War, the government of North Vietnam appealed to China for help in combating malaria, which was causing heavy losses among soldiers and civilians. In response, the Chinese authorities launched a secret military research programme known as Project 523, named for its launch date of 23 May 1967, aimed at finding new treatments. Tu Youyou was placed in charge of a research group within the programme.

Her team studied both traditional medical texts and the malaria parasite itself. In reviewing ancient sources she found a recipe, recorded in a fourth-century manual of emergency remedies, for a preparation of the plant sweet wormwood, known in Chinese as qinghao, and attributed to the physician Ge Hong. The text warned that the plant should be steeped in cold water rather than boiled, and this detail proved decisive, because heat was destroying the active compound.

Working with low-technology methods in difficult conditions, her group extracted the active ingredient using a low-temperature ether process, tested it in animal models, and in 1971 obtained a substance that was highly effective against the malaria parasite while leaving the infected animals unharmed. That compound, later named artemisinin, became the basis of a new class of antimalarial medicines that came into wide use around the world.

The Clinical Trials and the Drug's Development

Because the compound had to be tested in human beings before it could be used, and because the political situation discouraged formal clinical trials, Tu consulted classical texts on the safety of the plant and then volunteered to take the first dose herself, followed by members of her team, in an act of self-experimentation that has become one of the best-known episodes in modern biomedical research. The results showed the drug to be well tolerated at effective doses.

Trials then proceeded among patients in Hainan province and later in other malarial regions of southern China, where the compound acted quickly to clear the parasite from the blood. The team, working with collaborators, went on to develop a series of artemisinin derivatives, including dihydroartemisinin, artesunate and artemether, which could be given by mouth or by injection and which proved especially valuable against severe and drug-resistant forms of the disease.

For many years the discovery was little known outside China, published in Chinese journals and credited to a collective rather than to individuals, in keeping with the conventions of the time. It was only gradually that the wider scientific world came to appreciate the importance of the compound, and that Tu Youyou came to be recognised as the leader of the group that had identified it.

Artemisinin and Global Health

Malaria remains one of the most serious infectious diseases of the tropical world, and the older drugs, including chloroquine, had lost much of their effectiveness as the parasite developed resistance. Artemisinin changed the picture. Used in combination therapies, in which the compound is paired with a second drug to slow the emergence of resistance, it became the standard treatment recommended by international health authorities for uncomplicated falciparum malaria.

The scale of the benefit is difficult to overstate. Artemisinin combination therapies have been credited with a large share of the fall in malaria deaths since the early 2000s, and the compound is now included in the list of essential medicines maintained by the World Health Organization. It has been given to hundreds of millions of patients, particularly in sub-Saharan Africa and in Southeast Asia, where the burden of the disease is heaviest.

The World Health Organization has warned that partial resistance to artemisinin has appeared in some regions of Southeast Asia, and this has prompted research into new combinations and new compounds. The drug nonetheless remains the backbone of antimalarial treatment, and its continuing use rests on the discovery made by Tu Youyou and her colleagues.

Awards, Recognition and Legacy

In 2011 Tu Youyou received the Lasker-DeBakey Clinical Medical Research Award, an American honour often regarded as a precursor to the Nobel Prize, for the discovery of artemisinin and its use in treating malaria. The award brought her work to the attention of the international scientific community and confirmed the standing of the Chinese contribution to the field.

In 2015 the Nobel Assembly awarded her the Nobel Prize in Physiology or Medicine, jointly with the Irish-born American scientist William C. Campbell and the Japanese microbiologist Satoshi Omura, for discoveries concerning therapies against parasitic diseases. She was the first scientist working at a Chinese institution and the first Chinese citizen to win the prize in medicine, and her award was widely celebrated in China as a vindication of traditional medicine and of patient laboratory work.

Tu Youyou continued to serve as chief researcher at the China Academy of Traditional Chinese Medicine and to guide younger scientists. She has spoken modestly of her achievement, attributing it to the team effort of a difficult period, and she has urged the careful scientific study of traditional remedies. Her life is remembered as an example of quiet persistence rewarded by a discovery of global importance.

See also

• Artemisinin
• Malaria
• Traditional Chinese medicine
• Project 523