URBANA, Ill. After a recent University of Illinois study showed that injection of the soy peptide lunasin dramatically reduced colon cancer metastasis in mice, the researchers were eager to see how making lunasin part of the animals' daily diet would affect the spread of the disease.
"In this new study, we find that giving lunasin orally at 20 mg/kg of body weight reduced the number of metastatic tumors by 94 percentwe went from 18 tumors to only one. And that was done using lunasin alone; no other type of therapy was used," said Elvira de Mejia, a U of I professor of food chemistry and food toxicology.
In the first study, injections of lunasin were used in concert with the chemotherapy drug oxaliplatin, yielding impressive results: a sixfold reduction in metastatic tumors to the liver.
"We learned in that study that lunasin can penetrate the cancer cell, cause cell death, and interact with at least one type of receptor in a cell that is ready to metastasize," said Vermont Dia, a postdoctoral associate in the de Mejia laboratory.
That led the scientists to do this study in which they experimented with oral doses of the peptide. "After all, soy is a food, and we wanted the animals to consume it as a food. Because this lunasin would be digested, we needed to figure out how much should be fed to achieve the desired concentration in the bloodstream," de Mejia said.
Using mice that had been injected with human colon cancer cells, the scientists began by feeding the animals 8 mg/kg of lunasin daily, which reduced the number of new tumors in the liver by 55 percent. They increased the dose five times, at last achieving a 94 percent reduction in tumors at 20 mg/kg of lunasin.
"We were very impressed by the reduction, but the results were short of statistical significance from the control group. More animals are needed to strengthen the power of the analysis. It's a small study but very promising," de Mejia said. <
|Contact: Phyllis Picklesimer|
University of Illinois College of Agricultural, Consumer and Environmental Sciences