URBANA The University of Illinois scientists who linked eating tomatoes with a reduced risk of prostate cancer have developed a tool that will help them trace the metabolism of tomato carotenoids in the human body. And they've secured funding from the National Institutes of Health to do it.
"Scientists believe that carotenoidsthe pigments that give the red, yellow, and orange colors to some fruits and vegetablesprovide the cancer-preventive benefits in tomatoes, but we don't know exactly how it happens," said John W. Erdman, a U of I professor of human nutrition.
The researchers will use isotopic labeling of three tomato carotenoids with heavier carbon atoms than are commonly seen in nature, which will allow tracking of the tomato components' absorption and metabolism in the body, he said.
"We have two questions we'd like to answer. First, are the carotenoids themselves bioactive, or are their metabolic or oxidative products responsible for their benefits? Second, is lycopene alone responsible for the tomato's benefits, or are other carotenoids also important?" he said.
Previous Erdman animal studies have shown that whole tomato powder, which contains all of the fruit's nutritional components, is more effective against prostate cancer than lycopene alone.
"Lycopene, which gives the fruit its red color, has received a lot of attentionit's even advertised as an ingredient in multivitamin supplements, but two little-known colorless carotenoids, phytoene and phytofluene, probably also have benefits," said Nancy Engelmann, a doctoral student in Erdman's laboratory who helped to develop the new method.
Engelmann learned to optimize the amount of carotenoids in tomato cell cultures by treating already high-achieving tomato varieties with two plant enzyme blockers. The best performers were then chosen for culturing and carbon-13 labeling, she said.
The scientists grew tomato cells with non-radioactive car
|Contact: Phyllis Picklesimer|
University of Illinois College of Agricultural, Consumer and Environmental Sciences