Researchers at University of Washington have updated a traditional Chinese medicine to create a compound that is more than 1,200 times more specific in killing certain kinds of cancer cells than currently available drugs, heralding the possibility of a more effective chemotherapy drug with minimal side effects.

The new compound puts a novel twist on the common anti-malarial drug artemisinin, which is derived from the sweet wormwood plant. Sweet wormwood has been used in herbal Chinese medicine for at least 2,000 years, and is eaten in salads in some Asian countries.

The scientists attached a chemical homing device to artemisinin that targets the drug selectively to cancer cells, sparing healthy cells. The compound kills 12,000 cancer cells for every healthy cell, meaning it could be turned into a drug with minimal side effects. The results were published in the latest issue of journal Cancer Letters.

"The compound is like a special agent planting a bomb inside the cell," said Tomikazu Sasaki, chemistry professor at UW and senior author of the study.

A cancer drug with low side effects would be more effective than currently available drugs, since it could be safely taken in higher amounts, he said.

In the study, the UW researchers tested their artemisinin-based compound on human leukemia cells. It was highly selective at killing the cancer cells.

The researchers also have preliminary results showing that the compound is similarly selective and effective for human breast and prostate cancer cells, and that it effectively and safely kills breast cancer in rats, Sasaki said.

(Xinhua News Agency October 15, 2008)