Croton Oil Fights Prostate Cancer

PISCATAWAY, N.J.--An active ingredient found in the oil of the Southeast Asian croton plant--12-O-tetradecanoylphorbol-13-acetate, commonly known as TPA--may inhibit the growth of new prostate cancer cells, according to researchers at Rutgers University (www.rutgers.edu).

We demonstrated TPA could simultaneously stop the growth of new prostate cancer cells, kill existing cancer cells and ultimately shrink prostate tumors, said Allan Conney, Ph.D., one of the studys authors.The researchers also tested the effect of TPA in combination with all-trans retinoic acid (ATRA), a vitamin A derivative that has been shown to effectively treat leukemia.

Mice with induced prostate tumors received a daily dose of TPA, ATRA or a combination of the two for 46 days. After 21 days of treatment, tumor regression became apparent in 62 percent of mice treated with TPA, compared to 31 percent of mice treated with ATRA. All mice receiving the combination treatment showed signs of tumor regression. Researchers also found TPA and the combination treatment continued to inhibit tumor growth for the duration of the study, compared to ATRA inhibiting tumor growth only for the first 28 days of treatment.

Our studies are an important early step in a long process, and we are planning additional testing in humans, Conney said. Further research with these compounds and others could provide hope for the half million new cases of prostate cancer each year.

The study is published in the March issue of Cancer Research (64, 5:1811-20, 2004) ( cancerres.aacrjournals.org).