Combining a compound found in broccoli with an antimalarial drug lowers rates of prostate cancer in mice, a new study shows.
“Men with prostate cancer suffer significant impairments in quality of life, not only from the disease itself, but also from the treatments,” says senior author Shivendra Singh, professor in the University of Pittsburgh’s Department of Pharmacology and Chemical Biology. “Because the predominant risk factors for prostate cancer, such as age, race, and genetics, cannot be avoided, there is a great need for preventative treatments for those most at risk.”
Cruciferous vegetables—such as broccoli, watercress, and cabbage—are associated with a lower risk of prostate cancer. The phytochemical sulforaphane in cruciferous vegetables is believed to be responsible.
When scientists tested sulforaphane in the lab, they found it works to prevent early-stage prostate cancer, but not late-stage. Singh and his colleagues hypothesized that this was due to a cellular mechanism called autophagy, which limits the ability of drugs to destroy cancer.
The antimalarial drug chloroquine inhibits autophagy. When chloroquine and sulforaphane were given to mice predisposed to prostate cancer, only 12 percent of the mice developed late-stage prostate cancer, compared to half in the control group. The study will be published in the Oct. 1 issue of the journal Cancer Research.
“These results are very promising, but I do not recommend that men take chloroquine while eating broccoli in an attempt to prevent prostate cancer,” says Singh. “Certainly eating broccoli and other cruciferous vegetables is good for you, but chloroquine can have side effects, and it has not been tested in humans for the purpose of preventing prostate cancer.”
Researchers from Penn State Milton S. Hershey Medical Center participated in the study.
The National Cancer Institute supported the research.