The croton plant, long known to oriental herbalists and homeopaths as a purgative, has an oil in its seeds that shows promise for the treatment of prostate cancer the second leading cause of cancer death in men in the United States. The active ingredient in the oil is 12-O-tetradecanoylphorbol-13-acetate, a compound generally known as TPA.
The finding was reported in the March 1, 2004, issue of Cancer Research by Xi Zheng, Allan Conney and other scientists at the Susan Lehman Cullman Laboratory for Cancer Research at Rutgers, The State University of New Jersey, and the Cancer Institute of New Jersey (CINJ).
"We demonstrated that TPA could simultaneously stop the growth of new prostate cancer cells, kill existing cancer cells and ultimately shrink prostate tumors," said Conney, the William M. and Myrle W. Garbe Professor of Cancer and Leukemia Research at Rutgers' Ernest Mario School of Pharmacy, and a member of CINJ.
In addition to studies on the effect of TPA alone, the researchers also tested TPA in combination with all-trans retinoic acid (ATRA), a vitamin A derivative previously shown to be effective in treating leukemia.
"We knew that ATRA is an effective synergist with TPA in treating leukemia cells in the laboratory, but prostate cancer is a different situation, probably involving different molecular mechanisms," Conney said.
The studies by Zheng and Conney are the first to show an impressive synergy between TPA and ATRA in inhibiting the growth of cultured prostate cancer cells and the first to assess their combined effects, and the effects of TPA alone, on human tumors grown in mice.
Scientists, intrigued by the skin-irritating property of croton see
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Contact: Joseph Blumberg
blumberg@ur.rutgers.edu
732-932-7084 x652
Rutgers, the State University of New Jersey
17-Mar-2004