A Cancer Cure From the Ancient Past

A plant compound sparks chain reaction that kills tumor cells.

Chinese folk medicine has yielded a promising new approach for treating cancer. Using a dash of logic and modern lab techniques, Seattle scientists have shown that a compound extracted from the wormwood plant seeks out and destroys breast cancer cells, while leaving healthy cells unscathed.

In laboratory experiments, the compound killed within 16 hours virtually all human breast cancer cells exposed to it in the test tube, reports Dr. Henry Lai, a bioengineering researcher at the University of Washington. Just as importantly, he says, nearly all of the normal cells exposed to it were still alive. A dog with a type of bone cancer known as osteosarcoma so severe that it couldn't walk across the room made a complete recovery within five days of receiving the treatment. X-rays showed the animal's tumor "had basically disappeared," says Lai, adding that he believes the dog is still alive two years later.

"Not only does (the drug) appear to be effective, but it's very selective," Lai says. "It's highly toxic to the cancer cells, but has a marginal impact on normal cells."

This anti-cancer compound is called artemisinin --- and actually, it isn't new at all. Chinese folk practitioners extracted it from the plant Aremesia annua L., commonly known as wormwood, thousands of years ago for use in the treatment of malaria, Lai says.

After a "secret recipe" for the treatment was discovered on a stone tablet in the tomb of Prince of the Han Dynasty during an archaeological dig in the 1970s, artemisinin re-emerged as a therapy for the mosquito-borne disease, Lai recalls. In fact, a purified form of the plant compound is now the drug of choice for treating malaria in many areas.