Potent doses of broccoli sprout extract activate a “detoxification” gene and may help prevent cancer recurrence in survivors of head and neck cancer, according to new research that confirms preliminary results released last year.
“With head and neck cancer, we often clear patients of cancer only to see it come back with deadly consequences a few years later,” says lead author Julie Bauman, associate professor of medicine at the University of Pittsburgh.
“Unfortunately, previous efforts to develop a preventative drug to reduce this risk have been inefficient, intolerable in patients, and expensive. That led us to ‘green chemoprevention’—the cost-effective development of treatments based upon whole plants or their extracts.”
Cruciferous vegetables, such as broccoli, cabbage, and garden cress, have a high concentration of the naturally occurring molecular compound sulforaphane, which previously has been shown to protect people against environmental carcinogens.
For the study, published in the journal Cancer Prevention Research, Bauman and colleagues treated human head and neck cancer cells in the laboratory with varying doses of sulforaphane and a control, and compared them to normal, healthy cells that line the throat and mouth. The sulforaphane induced both types of cells to increase their levels of a protein that turns on genes that promote detoxification of carcinogens, like those found in cigarettes, and protect cells from cancer.
In a small preclinical trial, 10 healthy volunteers drank or swished fruit juice mixed with broccoli sprout extract for several days. The volunteers had no significant problems tolerating the extract and the lining of their mouths showed that the same protective genetic pathway activated in the laboratory cell tests was activated in their mouths, meaning that the sulforaphane was absorbed and directed to at-risk tissue.
Researchers also studied how the extract performed in mice predisposed to head and neck cancer. The mice who received the sulforaphane developed far fewer tumors than their counterparts who did not receive the extract.
The results of the mouse, human, and lab studies have been so successful that Bauman has started a larger clinical trial in volunteers previously cured of head and neck cancer. These participants are taking capsules containing broccoli seed powder, which is more convenient to take regularly than the extract mixed with juice.
“Head and neck cancers account for approximately 3 percent of all cancers in the US, but that burden is far greater in many developing countries,” she says. “A preventative drug created from whole plants or their extracts may ease the costs of production and distribution, and ultimately have a huge positive impact on mortality and quality of life in people around the world.”
Other researchers from the University of Pittsburgh and from Johns Hopkins University and the University of California at San Francisco are coauthors of the study, which was supported by National Institutes of Health and the Lewis B. and Dorothy Cullman Foundation.
Source: University of Pittsburgh