Some Phytochemicals and Related Compounds in Vegetables as Potent Inhibitors of Human DNA Topoisomerase II

An established human DNA topoisomerase II inhibitory assay is described, and the screening results for some phytochemicals in vegetables and related compounds that may useful for chemoprevention through food are reported. The assay requires a small amount of sample and is rapid compared to bioassays using cell lines or animals. The topoisomerase II inhibitory assay is useful for screening compounds in vegetables. More than 80 compounds were screened, and 28 compounds were found to be potent inhibitors at the 10 μg/ml level. Many of the phytochemicals commonly found in vegetables are thus useful for chemoprevention.