July 28, 2006 -- The bark of the white birch tree contains a compound that might help fight prostate cancer.
That's the early word based on research in mice. The compound, called betulinol, hasn't been tested on people.
Preliminary tests show that betulonic acid, made from betulinol, may discourage human prostate cancer cells from dividing, and spur those cells to die.
Brij Saxena, PhD, who works in reproductive endocrinology at Cornell University's Weill Medical College, and colleagues, conducted the tests.
In a lab, the researchers exposed isolated human prostate cancer cells to betulonic acid for up to three days. For comparison, they also grew prostate cancer cells not exposed to the compound.
Three days later, all the prostate cancers had grown. But those with betulonic acid grew 88% less, the study shows.
Normal cells didn't appear to be affected by betulonic acid, the researchers note.
Tests on Mice
Saxena's team also studied betulonic acid on human prostate cancer cells in mice.
The researchers let the prostate cancer cells grow in the mice for 12 days. Then they split the mice into two groups of four mice each.
For 17 days, one group of mice got daily injections of betulonic acid. The other group got injections that didn't contain betulonic acid.
During those 17 days, the tumors grew in all of the mice. But tumor growth was 92% lower in the betulonic acid group, the study shows.
Lastly, the researchers studied samples of the mice's tumors. They found signs of greater cell death (apoptosis) in the cancer cells of the betulonic acid group.
The study was partly funded by Marc Pharmaceuticals, says a Cornell news release.
Cornell's research foundation and medical school collaborate with Marc Pharmaceuticals on research and licensing of betulinol derivatives.