Genotoxicity of Genistein : A Molecular Analysis

Abstract

Genistein is a naturally occurring phytoestrogen found in soy products. High intakes of soy products are associated with lower incidences of cancer, especially breast cancer. Genistein may act as a chemopreventative agent by affecting estrogen receptors, inhibiting topoisomerase II causing DNA damage, disrupting proliferative pathways, or by acting as an antioxidant. Research, however, is limited on possible adverse effects of genistein consumption, including gentoxicity. Levels of poly-ADPribose polymerase (PARP) and the phosphorylated histone protein H2AX are increased in the presence of DNA damage, and both were used as markers of genotoxicity in this study. Our project looked at the genotoxic effects of genistein on Sprague-Dawley rats. The rats were treated with 50 mg, 100 mg, or 150 mg of genistein by insertion of genistein pellets into the neck. Our control group consisted of rats with placebo pellets inserted into the neck. Kidney and liver samples were taken from each group and assayed for genotoxicity by SDS-PAGE followed by western blot. Protein levels of both PARP and p-H2AX were indetectable compared to positive controls indicating that no DNA damage was present. Further study is needed to verify the safety of genistein containing products.