Wednesday Dec 3, 2008 (foodconsumer.org) -- An anti-cancer compound found in cruciferous vegetables such as broccoli and cabbage inhibits cancer cell growth by lowering the activity of an enzyme involved in progression of breast cancer, according to a study published this week in the journal Proceedings of the National Academy of Sciences.

Indole-3-carbinol or i3c has been known since 1970s for its anticancer properties and it has been undergoing clinical trials in humans after it was found that the compound stops the growth of breast and prostate cancer cells in mice.

The current study was believed to be the first of its kind to demonstrate that i3c lowers the activity of an enzyme called elastase, which would otherwise shorten a cellular chemical, cyclin E that is involved in controlling the cell cycle. The shortened version of cyclin E promotes proliferation of cancer cells.

The study led by Gary Firestone, UC Berkeley professor of molecular and cell biology and colleagues could lead to discovery of much more potent anticancer drugs. In fact, according to a press release by UC Berkeley, Firestone's group has already modified i3c and boosted its anticancer activity in cell culture by at least a factor of 100.

Further research is underway to understand exactly how i3c affects elastase so that the researchers may modify i3c to create even more potent anti-cancer drugs.

Cruciferous vegetables are one of the important vegetables people can eat to help prevent a variety of cancers.   The most effective vegetables are probably the allium vegetables such as garlic, onion and leeks, according to some sources.