New evidence suggests preventive effect of herbal supplement in prostate cancer
Researchers at Northwestern University have discovered a critical new way a man can transmit the HIV virus to a woman. Scientists had long believed that the normal lining of the female vaginal tract was an effective barrier to invasion of the HIV virus during sexual intercourse. They thought the large HIV virus couldn’t penetrate the
Full Post: Discovery of new way a man can transmit the HIV virus to a woman
DHEA is a natural circulating hormone and the body’s production of it decreases with age.
Men take DHEA as an over-the-counter supplement because it has been suggested that DHEA can reverse aging or have anabolic effects since it can be metabolized in the body to androgens. Increased consumption of dietary isoflavones is associated with a decreased risk of prostate cancer. Red clover (Trifolium pretense) is one source of isoflavones. Both supplements may have hormonal effects in the prostate and little is known about the safety of these supplements.
In a recent report in Cancer Prevention Research, a journal of the American Association for Cancer Research, researchers report that DHEA levels can be manipulated in cells in the laboratory to understand its effects.
Julia Arnold, Ph.D., a staff scientist at the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health, said more research is necessary in an environment where men and women concerned about health problems tend to self-prescribe based on information they find on the Internet.
Towards this end, the NCCAM laboratory is studying signaling between human prostate cancer cells and their supporting stromal cells as they grow together in laboratory culture. “DHEA effects in the prostate tissues may depend on how these two cells types ‘talk to each other’ and further, it may be potentially harmful in tissues containing inflammation or with early cancer lesions because the cells can induce DHEA to become more androgenic,” said Arnold.
Combining DHEA with transforming growth factor beta-1 increased testosterone production in the stromal cells and prostate specific antigen protein secretion two to four-fold and gene expression up to 50-fold in the cancer cells. When these cell cultures were treated with red clover isoflavones, the androgenic effects of DHEA were reversed.
“Something is happening in the prostate tissue microenvironment that is illustrating a potential cancer prevention effect from this supplement,” said Arnold.
Red clover isoflavones may modify androgenic effects in the prostate but much more work in the laboratory and clinic is needed to validate these effects.
This sort of laboratory manipulation will allow scientists to understand the basic prostate biology as well as learn cellular and molecular mechanisms of over-the-counter supplements and other botanical or herbal agents. Arnold said NCCAM will continue to study DHEA with other supplements to determine any cancer preventive effects.
The ability of the Food and Drug Administration (FDA) to regulate the safety of dietary supplements using nanomaterials is severely limited by lack of information, lack of resources and the agency’s lack of statutory authority in certain critical areas, according to a new expert report released by the Project on Emerging Nanotechnologies (PEN). The report,
Full Post: Barriers to effective FDA regulation of nanotechnology-based dietary supplements
The Physicians’ Health Study II is a large-scale, long-term, randomized clinical trial that included 14,641 physicians who were at least 50 years old at enrollment. These physicians were given 400 IU of vitamin E every other day or its placebo, or 500 mg of vitamin C daily or its placebo. Researchers followed these patients for
Full Post: No evidence supporting the use of vitamin E and C in the prevention of cancer
Women who took beta carotene or vitamin C or E or a combination of the supplements had a similar risk of cancer as women who did not take the supplements, according to data from a randomized controlled trial in the December 30 online issue of the Journal of the National Cancer Institute. Epidemiological studies
Full Post: Vitamins C and E and beta carotene again fail to reduce cancer risk in randomized controlled trial
In perhaps the largest cancer chemoprevention trial ever conducted, researchers have found that supplementation with vitamin E or selenium, alone or in combination, was not associated with a lower risk of prostate cancer or other cancers. This study, along with another cancer prevention study, will be published in the January 7 issue of JAMA, the
Full Post: Neither vitamin E nor selenium reduce risk of prostate cancer
The report, entitled Cytosolic Phospholipase A2-: A Potential Therapeutic Target for Prostate Cancer, describes the possible role of an enzyme called cPLA2- in prostate cancer and its potential to be a treatment target for prostate cancers that no longer respond to hormone-related therapy. Hormone-related therapy is the first line of treatment for more advanced prostate
Full Post: Theraputic target for prostate cancer