CHAMPAIGN, Ill. -- Instead of traveling to Brazil's tropical rain forest or diving into the ocean, a team of University of Illinois scientists are looking for disease-fighting compounds closer to home, harvesting potential agents from the trash piles of byproducts at crop-processing plants.
Initial laboratory tests on cultured mammalian and human cells indicate an ethanol extract of soybean molasses represses the ability of at least one dietary carcinogen to damage the DNA of normal cells, the researchers report.
A report is being published in the May issue of Agricultural Research Magazine. More details will appear later in the journal "Teratogenesis, Carcinogenesis and Mutagenesis." At the Environmental Mutagen Society Meeting, March 27 to April 1, in Washington, D.C., the team announced that the structure of the active compound -- named phytochemical complex 100 (PCC 100) -- contains a combination of chemicals known as saponins. Very little work has been done on their biological effects.
The team also reported at the meeting that PCC suppresses the growth rate of cancer cells and that an isolated soy-protein fraction drastically reduces the growth rate of human colon cancer. The work was based on a newly developed cell-growth kinetic assay.
The soy protein finding did not come as a surprise, because the apparent positive effects of soy protein and its estrogen-like isoflavones have been documented. But the still-evolving technique may allow scientists to more precisely identify the specific protein agents and the anti-cancer mechanisms that are involved, said team leader Michael J. Plewa, a geneticist in the department of crop sciences.
"It is strange to be running off to the rain forest to yank up weird plants when we may already be sitting on mountains of very useful pharmaceutical agents in our own corn and soybean fields," he said. "During crop processing, raw materials are modified by mechanical disruption, chemical extraction and changes in temperatures and pressures. Agents you take out of plants for food or processing products may not necessarily be the ones that are actually in the plants or seeds themselves. They may have been modified."
Plewa's team includes U. of I. colleagues A. Lane Rayburn, B.A. Francis and several students, and M. Berhow of the U.S. Department of Agriculture. Collaborative work is continuing with BIBRA International in the United Kingdom and Archer Daniels Midland Co. in Decatur, Ill. Funding for exploring the byproducts and developing assays to find anti-mutagens and anti-carcinogens comes from the U.S. Soybean Board and Illinois Soybean Operating Board.
"We are looking to prevent environmental carcinogens ingested in our diet from affecting normal cells in our bodies, and to isolate agents that slow down the growth rate of already existing cancer cells," Plewa said. "If we can repress their growth, we might be able to extend the use and heighten the effectiveness of therapeutic drugs, chemotherapy and radiation."