The latest issue of the journal Cancer Letters carries news about a derivative of the sweet wormwood plant that researchers believe could aid in stopping breast cancer before it gets started. The extract has been used since ancient times to fight malaria and has previously been shown to precisely target and kill cancer cells. The two University of Washington (UW) bioengineers who conducted the research said that the active substance, artemisinin, appeared to prevent the onset of breast cancer in rats that had been given a cancer-causing agent. UW researcher Henry Lai said that artemisinin was selectively toxic to cancer cells and was effective orally. "With the results of this study, it's an attractive candidate for cancer prevention," he added.
It seems that what makes artemisinin an effective antimalarial agent, also gives it its anti-cancer properties. The researchers explained that artemisinin reacts with iron in cells and spawns free radicals that attack the cell membrane, killing the cell. Because malaria can't eliminate iron in the blood cells it eats, artemisinin makes the stored iron toxic to the parasite. This mechanism also appears to be true for cancer as most cancer cells have a high rate of iron uptake.
The researchers carried out experiments on rats, feeding half regular food, while the other half were fed food with 0.02 percent artemisinin added. The researchers then monitored each group for the formation of breast tumors. Among the rats that didn't get artemisinin, 96 percent developed tumors, while in comparison, 57 percent of the artemisinin-fed rats developed tumors. The tumors that did develop in the artemisinin-fed rats were both "significantly fewer and smaller in size when compared with controls," said the researchers.
According to the study, artemisinin's apparent preventative effect may be due to two factors. The substance may kill precancerous cells, which tend to use more iron than ordinary cells and it may also impede angiogenesis, a tumor's ability to grow networks of blood vessels that allow it to enlarge.
Widely used in Asia and Africa as an anti-malarial, artemisinin has a track record of being relatively safe and causing no known side effects, said Lai, who believes that "the present data indicate that it may be a potent cancer-chemoprevention agent." But the researchers added that additional research needs to be undertaken before the breast cancer prevention properties of artemisinin can be validated. It should also be noted that the study was supported by Chinese pharmaceutical company Chongqing Holley Holdings, a major manufacturer of artemisinin.
Source: University of Washington
