Isolating antigenotoxic components and cancer cell growth suppressors fromagricultural by-products

Commercial processing wastes or by-products of crops were found to be sourc es of antimutagens and human tumor cell growth suppressors. We developed a microplate method to measure genomic DNA damage in Chinese hamster ovary ce lls with a modified single cell gel electrophoresis (SCGE) assay. This allo wed us to measure the repression of 2-acetoxyacetylamino-fluorene (2AAAF)-i nduced DNA damage by very small amounts of complex mixtures, fractions or i ndividual chemicals isolated from agricultural by-products. We previously d emonstrated that PCC, an ethanol extract of a commercial soybean processing by-product, repressed induced genomic DNA damage in mammalian cells. PCC w as separated into a series of chemically defined fractions and two fraction s (PCC70 and PCC100) repressed mutagen-induced damage. Of the isoflavones i solated from soybean fraction PCC70, daidzein expressed antigenotoxic activ ity, however, genistin and genistein enhanced DNA damage. An antigenotoxic response also was observed with a fraction isolated from com distillate sol ids (CDS40). We developed a microplate assay to measure the suppression of the growth rate of human cancer cells in which the cytostatic/cytotoxic sta tus at each concentration of the test sample was quantitatively determined. Genistein, genistin, daidzein and daidzin isolated from soybean fraction P CC70 expressed a wide range of growth suppression of HT-29 human colon canc er cells. The biological assays were integrated with, and directed, the sep aration and analytical chemistry component of this project. Compounds were purified from biologically active fractions and the structure of individual chemicals was determined with analytical HPLC and LC-mass spectroscopy (LC -MS). This research may lead to the isolation of novel chemoprotectants fro m agronomic commercial processing products and by-products. (C) 2001 Elsevi er Science B.V. All rights reserved.