Comparison of estrogen and genistein in their antigenotoxic effects, apoptosis and signal transduction protein expression patterns

Issue title: The Proceedings of the 3rd International Conference on Food Factors (ICoFF 03)

Article type: Research Article

Authors: Park, Ock Jin

Affiliations: Department of Food and Nutrition, Hannam University, 133 Ojeong-dong Daedeok-gu, Daejeon 306-791, Korea. Tel.: +82 42 629 7493; Fax: +82 42 629 7490; E-mail: ojpark@hannam.ac.kr

Abstract: The antigenotoxic effects of estrogen and genistein (isoflavones) were compared by measuring the degree of protection against plasmid DNA strand breakage induced by peroxyl free radicals using the DNA strand scission assay with pBR322 DNA. Isoflavones decreased DNA strand breakage by AAPH radical treatment at the all of three concentrations tested (0.5, 1.0, 1.5 μg/ml) with the range of 89.5% to 99.6%. Compared to genistein, estrogen was not as effective as genistein showing 46.9% to 29.6% protection, and this protective effect was decreased as estrogen concentrations increased from 0.1 to 0.3 μg/ml. DNA ladder experiments showed that genistein induced apoptosis in cultured cell lines, whereas estrogen did not induce any apoptosis. The effects of cell signal trandsduction protein expression patterns were compared between estrogen and genistein. The increased expression of cyclin B_{1} by estrogen was tampered by genistein at the highest concentration. Antigenotoxic and antiproliferative effects of genistein shown in this study support the hypothesis that it has a chemopreventive effect against particular types of cancers.

Keywords: isoflavones (genistein), genotoxicity, apoptosis, antiproliferative effects

Journal: BioFactors, vol. 21, no. 1-4, pp. 379-382, 2004