Experiments conducted in laboratories have raised US scientists' hopes that herbal supplement can be helpful in fighting prostate cancer.

Dr. Julia Arnold, a staff scientist at the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health, has revealed that the current research focused on the preventative effects of dietary isoflavones present in red clover.

She highlighted the fact that DHEA is a natural circulating hormone whose production in the body decreases with age, and which is taken by men as an over-the-counter supplement because it is thought to be effective in reversing aging, or have anabolic effects since it can be metabolized in the body to androgens.

The also said that increased consumption of dietary isoflavones is associated with a decreased risk of prostate cancer, and that red clover (Trifolium pretense) is one source of isoflavones.

During the study, the research team combined DHEA with transforming growth factor beta-1, which 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.

Upon treating the cell cultures with red clover isoflavones, the researcher found that 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.

The researchers said that their study showed that red clover isoflavones might modify androgenic effects in the prostate, but insisted that much more work in the laboratory and clinic was needed to validate such effects.