Artemisinin has already been proven to be about 10 times as effective against cancer as standard chemotherapy, which kills one normal cell for every five to 10 cancer cells, making it very toxic indeed to the body. The wormwood derivative, by contrast, kills 100 cancer cells for every normal cell.
In a new research effort, however, scientists at the University of Washington recently added a little chemical twist to artemisinin in the form of a tag that's irresistibly attracted to iron-starved proteins in cancer cells. (All cancer cells - whether of the breast, blood, bone or brain - multiply so quickly they need large amounts of iron, and they're unique among cells in their internal concentration of this element.)
The tag slips in, dragging the deadly artemisinin with it. The wormwood product then interacts explosively with iron atoms, producing a blast of poisonous free radicals, which kill the cancer cell. "The compound is like a special agent planting a bomb inside the cell," said Tomikazu Sasaki, chemistry professor at the University of Washington and senior author of the study.
Henry Lai, a University of Washington bioengineering professor and co-author of the study, was similarly colorful in his description of artemisinin's activity. "The compound," he said, "is like a little bomb-carrying monkey riding on the back of a Trojan horse." The modified artemisinin is absorbed only by the iron-rich cancer cells. It works so well, in fact, that it destroys fully 12,000 cancer cells for every normal cell it kills, making it essentially side-effect-free.
"Most currently available drugs are targeted to specific cancers," said Lai. "This compound works on a general property of cancer cells: their high iron content." The study found the new compound to be highly selective and effective in destroying human leukemia cells. Preliminary results show that the chemical is just as powerful against human breast and prostate cancer cells, and that it annihilates breast cancer in rats.