• Genistein;
  • Cytotoxicity;
  • Apoptosis;
  • Thiol groups


Genistein is one of the naturally occurring isoflavones present in plants such as soybeans and is commonly found in a variety of human foods. A number of studies indicated that this class of compounds exerts anticancerogenic and antimutagenic effects in various in vitro systems and in vivo animal models. We studied the effects of genistein on NIH 3T3 cells in in vitro models. The isoflavone genistein has been identified as having antiproliferative and apoptotic effects on various malignant cell types derived from solid tumors. Therefore, the cytotoxic and apoptotic properties of this compound were studied by MTT assay and Hoechst 33258/propidium iodide staining technique. The morphological changes of cells were examined in inverted fluorescent microscope. The oxidation of protein thiol groups and thiobarbituric-acid-reactive species (TBARS) was also determined. The cells were exposed to different concentrations of genistein (0–90 μM) after 24 h of incubation. The results revealed that genistein in concentrations higher than 20 μM significantly reduced cell viability, caused cell morphological changes and induced apoptotic and necrotic cell death. Oxidative modification of protein increased in the cells exposed to genistein in a dose- and time-dependent manner. In conclusion, our preliminary in vitro studies demonstrate the damaging effects of genistein on the mouse embryonic fibroblast cell line.