How broccoli protects against breast cancer

An  article published in the December, 2008 issue of the journal Carcinogenesis <>  explains how broccoli and  other cruciferous vegetables protect against cancer of the breast.  Increased intake of cruciferous vegetables, which also include  cauliflower, Brussels sprouts and cabbage, has been associated with a  lower risk of breast and other cancers, yet their mechanism of action  against the disease has not been thoroughly explored.

Researchers  at the University of California Santa Barbara laboratories of Professors  Leslie Wilson and Mary Ann Jordan studied the effects of sulforaphane, one  of a group of cruciferous vegetable compounds known as isothiocyanates, on  cultured human breast cancer cells. They found that sulforaphane inhibits  tumor cell proliferation in a manner similar to that of taxol and  vincristine, which are powerful anticancer drugs. The drugs help prevent  cell division during a process known as mitosis, in which duplicated DNA  in the cells’ chromosomes is distributed to two daughter cells. The  chromosomes are separated with the assistance of tube-like structures  known as microtubules, whose function is interfered with by taxane and  vinca alkaloid drugs. Sulforaphane similarly interferes with microtubule  function during mitosis, but its action is weaker than the pharmaceutical  agents, lessening the potential for toxicity.

"Breast  cancer, the second leading cause of cancer deaths in women, can be  protected against by eating cruciferous vegetables such as cabbage and  near relatives of cabbage such as broccoli and cauliflower," first author  and UC Santa Barbara graduate student Olga Azarenko commented. "These  vegetables contain compounds called isothiocyanates which we believe to be  responsible for the cancer-preventive and anticarcinogenic activities in  these vegetables. Broccoli and broccoli sprouts have the highest amount of  the isothiocyanates.”

"Our  paper focuses on the anticancer activity of one of these compounds, called  sulforaphane, or SFN," Dr Azarenko stated. "It has already been shown to  reduce the incidence and rate of chemically induced mammary tumors in  animals. It inhibits the growth of cultured human breast cancer cells,  leading to cell death."

"Sulforaphane  may be an effective cancer preventive agent because it inhibits the  proliferation and kills precancerous cells," concurred Dr Wilson, who is a  professor of biochemistry and pharmacology at UC Santa Barbara. The  compound also has potential as an additive therapy to antimitotic drugs to  enhance their effects without increasing toxicity.