Kruiden tegen kanker*
Uit een Duitse laboratoriumstudie blijkt dat het kruid hop wellicht veelbelovend kan werken tegen het ontstaan van prostaatkanker. Hop is rijk aan de bioactieve stof xanthohumol, een bioflavonoïde die in de studie de werking van het mannelijke hormoon testosteron kan blokkeren en daardoor de kans op prostaatkanker doet verminderen. Eerdere studies hebben al laten zien dat xanthohumol het vrouwelijke hormoon oestrogeen kan blokkeren waardoor hop de kans op borstkanker kan verminderen.
Hops Compound May Prevent Prostate Cancer
The natural compound xanthohumol blocks the effects of the male hormone testosterone, therefore aiding in the prevention of prostate
cancer.
"We hope that one day we can demonstrate that xanthohumol prevents prostate cancer development, first in animal models and then in humans, but we are just at the beginning," said Clarissa Gerhauser, Ph.D., group leader of cancer chemoprevention in the Division of Epigenomics and Cancer Risk Factors at the German Cancer Research Center, in Heidelberg, Germany.
Gerhauser presented these findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference, held in Houston.
Xanthohumol is derived from hops and belongs to the group of flavonoids that are found in many plants, fruit, vegetables and spices. Studies to date have shown that xanthohumol blocks the action of estrogen by binding to its receptor, which may lead to prevention of breast cancer.
Since testosterone receptors act similarly to that of estrogen by binding, then stimulating hormone-dependent effects, such as gene expression and cell growth the researchers examined whether xanthohumol might not only block the effects of estrogen, but also of the male hormone androgen.
Gerhauser and colleagues stimulated hormone-dependent prostate cancer cells with testosterone, which led to a massive secretion of prostate specific antigen (PSA). PSA is used for screening and early detection of prostate cancer in men. Cells were then treated with testosterone and xanthohumol and the effects were examined.
"Xanthohumol prevented the receptor from translocating to the cell nucleus, thus inhibiting its potential to stimulate the secretion of PSA and other hormone-dependent effects," she said.
Molecular modeling results showed that xanthohumol directly binds to the androgen receptor
structure.
The researchers suggest that this compound may have beneficial effects in animals when they measured the anti-androgenic potential of xanthohumol in a rat model, they found that although xanthohumol was not able to prevent an increase in prostate weight after testosterone treatment, it could reduce testosterone-increased seminal vesicle weight.
"Although the prostate weights were not changed, xanthohumol still reduced the effects of hormone signaling, such as gene expression, measured in the prostate tissue," said
Gerhauser.
The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, the AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes 30,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and nearly 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowship and career development awards. The AACR Annual Meeting attracts more than 16,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes six major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists. CR provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship and advocacy.
Source: American Association for Cancer Research
(Februari 2010)
