Pomegranate extract may lower breast cancer risk

January 12, 2010

     Compounds from pomegranate may reduce the incidence of hormone-dependent breast cancer, says a new study from the City of Hope in Duarte, California and the University of California, Los Angeles.
A metabolite of the Ellagic acid found in pomegranates inhibits the enzyme called aromatase; the enzyme that converts androgen to estrogen and that also plays a key role in the development of breast cancer. The researchers said they were surprised by their findings. “We previously found other fruits, such as grapes, to be capable of the inhibition of aromatase. But, phytochemicals in pomegranates and in grapes are different,” said principal investigator Shiuan Chen, PhD. Pomegranate, a rich source of antioxidants, has been linked to improved heart health, but a growing body of science indicates the fruit protect against prostate cancer. Studies have also reported a role in joint health by slowing cartilage loss in arthritis. It is these antioxidants, and particularly Ellagitannin compounds like Punicalagins and Punicalins, which accounts for about half of the fruit's antioxidant ability, that are reportedly behind the proposed health benefits.
     Dr. Chen and his co-workers screened 10 Ellagitannin-derived compounds from pomegranates, including Ellagic acid, Gallagic acid, and Urolithins A and B against a breast cancer cell line. According to the researchers, Ellagitannin are converted to Ellagic acid in the body, and this is then converted to Urolithins by gut microflora. The results showed that urolithin B was the most potent inhibitor of breast cancer cell growth at doses of 2.35 and 4.7 micromoles per litre in the in-cell assay. “The ingestion of pomegranate juice can lead to concentrations of circulating Urolithins reaching up to 18 micromoles per litre in blood,” said the researchers. “Taken together with the results of current studies and reports of the presence of Urolithin A and Urolithin B in the blood and urine of human subjects following pomegranate ingestion, the results of these analyses suggest that pomegranate intake may be a viable strategy for the chemoprevention of breast cancer. The research is published online ahead of print in the journal Cancer Prevention Research.