Scott Bauer, USDA Agricultural Research
Annual wormwood, Artemisia annua L., yields
the important antimalarial drug artemisinin.
Researchers at UW and WSU are exploring its
ability to treat cancer
In the decades since, scientists have discovered artemisinin reacts with iron within a cell to form a free radical, a highly reactive charged particle that destroys the cell. Because the malaria parasite is high in iron, artemisinin targets malaria-infected cells.
Since rapidly dividing cancer cells also need iron to form new DNA, Lai theorized they would also make targets for artemisinin. Subsequent research showed this to be the case.
Lai and colleagues at the UW developed a variant several thousand times more potent than natural artemisinin, which was licensed in 2004 to a Chinese company.
“Artemisinin is a promising low-cost cancer treatment because it’s specific, it’s cheap and you don’t have to inject it,” Lai said. “It’s 100 times more specific than traditional chemotherapy,” he added. “In breast cancer, it’s even better.”
Lai says he’s long hypothesized that high oxygen levels would enhance artemisinin’s effects, because oxygen promotes the formation of free radicals. In 2010, he put the theory to the test in a hyperbaric chamber that co-author Raymond Quock, WSU professor and chair of pharmaceutical sciences, has been using to study highly pressurized oxygen’s ability to relieve pain.
Hyperbaric chambers, filled with oxygen at high pressure, help scuba divers who surface too quickly gradually readjust to normal oxygen levels. A photo of pop singer Jackson in the mid-80s sleeping in a portable hyperbaric chamber sparked rumors that he was trying to heal scars from plastic surgery, retain his youthful appearance or extend his lifespan. The photo turned out to be a publicity stunt, but the U.S. Food and Drug Administration has approved hyperbaric oxygen therapy for several ailments, including decompression sickness, carbon-monoxide poisoning, severe burns and slow-to-heal wounds.
In clinical practice, the artemisinin-hyperbaric study could lead to people or animals spending time in a hyperbaric chamber to enhance the artemisinin’s effectiveness.
Other co-authors are Yusuke Ohgami, Catherine Elstad and Eunhee Chung of WSU and Donald Shirachi of the Chico Hyperbaric Center. The research was funded by the Washington State University College of Pharmacy and the Chico Hyperbaric Center.
In related artemisinin work, funded through a $1.5 million grant from the state’s Life Sciences Discovery Fund to a team led by UW chemistry professor Tomikazu Sasaki:
• UW researchers are developing synthetic artemisinin compounds with enhanced potency and anti-cancer selectivity, and WSU researchers are conducting a clinical trial evaluating these compounds’ ability to treat cancer in dogs. The molecular-engineered artemisinin compounds, which are stronger and more targeted than natural artemisinin but can still be taken by mouth, are licensed to Artemisia Biomedical of Newcastle, Wash.
• WSU crop scientists are planting Artemisia annua in eastern Washington to test whether the region could plant artemisinin as a commercial crop.
• Researchers are working with Northwest Organic Foods, a Washington chicken-feed company, to try adding artemisinin, instead of small amounts of arsenic, to chicken feed. Artemisinin acts as a natural preventative for avian coccidia infection, one of the poultry industry’s most costly parasitic diseases.
Ray Quock, Professor and Chair, Pharmaceutical Sciences, 509-335-5956, [email protected]
Eric Sorensen, WSU Science Writer, 509-335-4846, [email protected]