The use of single cell gel electrophoresis and flow cytometry to identify antimutagens from commercial soybean by-products

Single cell gel electrophoresis (alkaline Comet assay) and flow cytometric methods were combined into an assay that enables the analysis of direct DNA damage and longer-term whole cell clastogenicity in mammalian cells. We employed these techniques to analyze the antimutagenic activity of by-products of commercial soybean processing. At a concentration of 1 mg/ml, the soybean molasses by-product was found to repress 66% of the mutagenic capacity of the direct-acting mutagen 2-acetoxyacetylaminofluorene (2AAAF) in Chinese hamster lung (CHL) cells. At a concentration of 50 μg/ml, fraction PCC (an ethanol extract of soybean molasses) repressed 70% of the genotoxic potency of 500 nM 2AAAF as measured by the Comet assay. Fraction PCC was also effective in protecting CHL cells from 2AAAF-induced clastogenic damage. Using a forward mutation assay in Chinese hamster ovary cells (line AS52), PCC protected the cells against 2AAAF-induced cytotoxicity and point mutation at a specific gene target. These data indicate that agronomic crops such as soybean may yield a wealth of commercially available antimutagenic agents that may be suitable as chemoprotective food supplements.