Curried Cauliflower Effective Against Prostate Cancer

RUTGERS, New Jersey, January 16, 2006 (ENS) - Turmeric, the mild spice that gives curry its deep yellow color, appears to have good potential for the treatment and prevention of prostate cancer, particularly when combined with certain vegetables, Rutgers University scientists have discovered.

The scientists tested turmeric, also known as curcumin, along with phenethyl isothiocyanate (PEITC), a naturally occurring substance particularly abundant in a group of vegetables including broccoli, Brussels sprouts, cabbage, cauliflower, kale, kohlrabi turnips, and watercress.

"The bottom line is that PEITC and curcumin, alone or in combination, demonstrate significant cancer-preventive qualities in laboratory mice, and the combination of PEITC and curcumin could be effective in treating established prostate cancers," said Ah-Ng Tony Kong, a professor of pharmaceutics at Rutgers.

Professor Ah-Ng Tony Kong studies cancer prevention and treatment at Rutgers University's Ernest Mario School of Pharmacy. (Photo courtesy Rutgers)

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 have not decreased in past decades despite tremendous efforts and resources devoted to treatment. This is because advanced prostate cancer cells are barely responsive even to high concentrations of chemotherapeutic agents or radiotherapy.

The authors observed that by comparison to the high incidence of prostate cancer in the United States, the incidence of this disease is low in India where people eat large amounts of plant foods rich in phytochemicals – nonnutritive plant chemicals that have protective or disease-preventive properties.

As a result, the scientists have been investigating intervention options based on compounds found in edible and medicinal plants. They have had some success, and a majority of patients with prostate cancer are now combining the conventional therapies with these compounds as alternative, supplementary or complementary medications.

For Kong's study, researchers used mice bred so that their immune systems would not reject foreign biological material. They injected the mice with cells from human prostate cancer cell lines to grow tumors against which the compounds could be tested.

Curried cauliflower is a deep golden color due to the turmeric in the curry. (Photo courtesy State of Victoria)

The researchers injected the mice 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.

They found the injections "significantly retarded" the growth of cancerous tumors. Using PEITC and curcumin in tandem produced even stronger effects.

The group 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. But when curcumin and PEITC were given in tandem, tumor growth was "significantly reduced."

The paper, "Combined Inhibitory Effects of Curcumin and Phenethyl Isothiocyanate on the Growth of Human PC-3 Prostate Xenografts in Immunodeficient Mice," is available at cancerres.aacrjournals.org.

The authors are Tin Oo Khor, Young-Sam Keum, Wen Lin, Jung-Hwan Kim, Rong Hu, Guoxiang Shen, Changjiang Xu, Avanthika Gopalakrishnan, Bandaru Reddy, Xi Zheng, AllanConney and Ah-Ng Tony Kong, all from Rutgers.