Researchers at the University of California, Riverside (UCR), have identified components in pomegranate juice that seem to inhibit the movement of cancer cells and weaken their attraction to a chemical signal that has been shown to promote the metastasis of prostate cancer to the bone, according to a presentation today at the American Society for Cell Biology's 50th Annual Meeting in Philadelphia.
The researchers in the UCR laboratory of Manuela Martins-Green, Ph.D., plan additional testing in an in vivo model for prostate cancer to determine dose-dependent effects and side effects of the two components.
The effect, if any, of pomegranate juice on the progression of prostate cancer is controversial.
In a 2006 study of prostate cancer patients who daily drank an eight-ounce glass of pomegranate juice, UCLA researchers detected a decline in prostate-specific antigen (PSA) levels that suggested a potential slowing of cancer progression.
The UCLA researchers did not try to define the potential biological mechanism behind pomegranate juice's effects in the study.
In Sept. 2010, the Federal Trade Commission (FTC) filed suit against Pom Wonderful, the natural foods company that provided the pomegranate juice for the UCLA research and has supported other research on pomegranate juice. The FTC charged the company with making false and misleading claims about the juice's effects on health.
In previous studies, Martins-Green and her research team used a standardized concentration of pomegranate juice on two types of laboratory-cultured prostate cancer cells that were resistant to testosterone.
Resistance to the hormone indicates a potentially strong metastatic potential. The researchers noted not only increased cell death among the pomegranate juice-treated tumor cells but also increased cell adhesion and decreased cell migration in those cancer cells that had not died.
The Martins-Green lab next analyzed the fruit juice to identify the active ingredients that had a molecular impact on cell adhesion and migration in metastatic prostate cancer cells. Martins-Green, graduate student Lei Wang and undergraduate student Jeffrey Ho identified phenylpropanoids, hydrobenzoic acids, flavones and conjugated fatty acids.
"This is particularly exciting because we can now modify these naturally occurring components of the juice to improve their functions and make them more effective in preventing prostate cancer metastasis," said Martins-Green.
"Because the genes and proteins involved in movement of prostate cancer cells are essentially the same as those involved in movement of other types of cancer cells, the same modified components of the juice could have a much broader impact in cancer treatment," she said.