Evening primrose oil, often used by women to relieve period pain, has been found to suppress the breast cancer gene in cells from women with Her-2 positive cancer. The researchers, from Northwestern University, believe that gamma-linolenic acid (GLA), a substance in evening primrose oil and several other plant oils used in herbal medicine, is the active component that inhibits action of the cancer gene Her-2/neu, responsible for almost 30 percent of all breast cancers. Her-2/neu-positive tumors are very aggressive and the prognosis for patients is generally poor.
Interestingly, GLA also seemed to increase the response in cancer cells to the cancer drug Herpetin. Ruth Lupu, who led the study, explained that treating cancer cells that overexpressed Her-2/neu with GLA not only suppressed protein levels of the oncogene, but also caused a 30- to 40-fold increased response in breast cancer cells to the drug Herpetin (trastuzumab), a monoclonal antibody that is used for the treatment of many women with breast cancer.
"Treating the cancer cell lines with both GLA and Herceptin led to a synergistic increase in apoptosis [cell death] and reduced cancer growth. These findings may reveal a previously unrecognized way of influencing the poor outcome of Her-2/neu-positive cancer patients," Lupu explained.
Co-researcher Javier Menendez said that GLA appeared to work in quite a different way to Herceptin. "While Herceptin attempts to neutralize thousands of Her-2/neu molecules commonly found in the surface of overexpressing cancer cells, GLA would be more efficient to reduce Her-2/neu levels by preventing the transcription of few Her-2/neu gene copies." Lupu added that, "Results of the study reveal a valuable means by which an inexpensive herbal medicine might regulate breast cancer cell growth, metastasis formation and response to chemotherapies and endocrine therapies."
While the study, published in the Journal of the National Cancer Institute, offered promising results, Lupu emphasized that further studies were necessary before GLA could enter clinical trials. The substance GLA is one of two essential fatty acids - fats that are necessary for maintaining normal functioning and growth of cells, nerves, muscles and organs. As well as evening primrose oil, other sources of GLAs include borage oil and black current seed oil.
Source: Northwestern University
