According to researchers at Rutgers University, New Jersey, the curry spice turmeric has the potential for the treatment and prevention of prostate cancer.
It seems this is particularly the case when it is combined with certain vegetables.
The scientists tested turmeric, also known as curcumin, along with phenethyl isothiocyanate (PEITC), a naturally occurring substance in certain vegetables such as watercress, cabbage, winter cress, broccoli, brussels sprouts, kale, cauliflower, kohlrabi and turnips.
They say that in experiments in laboratory mice, PEITC and curcumin, alone or in combination, showed significant cancer-preventive qualities.
Ah-Ng Tony Kong, a professor of pharmaceutics at Rutgers, says they believe the combination of the two could be effective in treating established prostate cancers.
It is estimated that Prostate cancer is the second leading cause of cancer death in men in the United States, with a half-million new cases appearing each year.
The incidence and mortality of prostate cancer has not decreased in the last decade despite tremendous efforts and resources devoted to treatment because advanced prostate cancer cells are unresponsive to even high concentrations of chemotherapy or radiotherapy.
Kong and his colleagues at Rutgers' Ernest Mario School of Pharmacy noticed that in contrast to the high incidence of prostate cancer in the United States, the incidence of the disease is very low in India.
This has been attributed to the high consumption of plant-based foods rich in phytochemicals which have protective or disease-preventive properties.
This led scientists to investigate intervention options based on compounds found in edible and medicinal plants.
The researchers used mice bred so that their immune systems would not reject foreign biological material and then injected the mice with cells from human prostate cancer cell lines to grow tumors against which the compounds could be tested.
Kong says they undertook the study to evaluate how effective PEITC and curcumin might be in preventing and treating prostate cancer as even though laboratory data had been convincing they needed to test the treatment on live animals.
The mice were injected with curcumin or PEITC, alone or in combination, three times a week for four weeks, beginning a day before the introduction of the prostate cancer cells.
The researchers found the injections significantly retarded the growth of cancerous tumors, and the use of PEITC and curcumin together produced even stronger effects.
The team then evaluated the therapeutic potential of curcumin and PEITC in mice with well-established tumors, and the results showed that PEITC or curcumin alone had little effect, whereas the combination of curcumin and PEITC significantly reduced tumor growth.
As a result of their success, many patients with prostate cancer are now combining the conventional therapies with these compounds as alternative, supplementary or complementary medications.
The research is published in the current issue of the journal Cancer Research.