Chinese pharmacologist Youyou Tu developed key antimalarial drug artemisinin.
Three scientists who developed therapies against parasitic infections have won this year’s Nobel Prize in Physiology or Medicine.The winners are: William C. Campbell, a microbiologist at Drew University in Madison, New Jersey; Satoshi Ōmura, at Kitasato University in Japan; and Youyou Tu, a pharmacologist at the China Academy of Traditional Chinese Medicine (now known as the China Academy of Chinese Medical Sciences) in Beijing.
In the 1970s, Campbell and Ōmura discovered a class of compounds, called avermectins, that kill parasitic roundworms that cause infections such as river blindness and lymphatic filariasis. The most potent of these was released onto the market in 1981 as the drug ivermectin. Tu, who won a Lasker prize in 2011, developed the antimalarial drug artemisinin in the late 1960s and 1970s. She is the first China-based scientist to win a science Nobel.
In the 1960s, the main treatments for malaria were chloroquine and quinine, but they were proving increasingly ineffective. So in 1967, China established a national project against malaria to discover new therapies.
Working at the China Academy of Chinese Medical Sciences, Tu and her team screened more than 2,000 Chinese herbal remedies that showed potential antimalarial activity. An extract from the wormwood plant Artemisia annua proved especially effective and by 1972, the researchers had isolated chemically pure artemisinin.
“It’s great news, I’m very happy about this. She totally deserves it,” says Yi Rao, a neuroscientist at Peking University who has researched the discovery of artemisinin. But Rao points out that because of controversy over credit for the discovery, Tu has never won any major award in China. She has not been elected to either of China’s major academies — neither the Chinese Academy of Sciences nor the Chinese Academy of Engineering.
“Though other people were involved, Tu was clearly the undisputed leader,” says Rao. “But she’s never been given fair recognition within China.”
Working in Japan, Ōmura isolated strains of a group of soil bacteria called Streptomyces that were known to have antimicrobial properties. In 1974, he pulled out a promising strain from soil near a golf course, and sent it along, with others, to a team led by Campbell at the Merck Institute for Therapeutic Research in Rahway, New Jersey. (Ōmura’s institute had signed a research partnership with Merck in 1973).
Campbell’s team isolated the avermectins from the bacterial cultures, and tweaked the structure of one of the most promising compounds to develop it into a drug — ivermectin. In 1987, Merck announced that it would donate the drug to anyone who needed it for treatment of onchocerciasis (also known as river blindness). A decade later, the firm began giving away the drug to treat lymphatic filariasis. Each year, Merck gives away some 270 million treatments of the drug, according to the Mectizan Donation Program, in Decatur, Georgia.
The award highlights the global acceptance of the importance of parasitic infections, and neglected tropical diseases in general, says Stephen Ward, who researches drugs for neglected tropical diseases at the Liverpool School of Tropical Hygiene and Medicine. “It may refocus us on the idea that the immense diversity of products out there in the natural world is a great starting point for drug discovery,” he adds. Updates to follow.
http://www.nature.com/news/anti-parasite-drugs-sweep-nobel-prize-in-medicine-2015-1.18507 Original web page at Nature