Enhanced sister-chromatid exchange rate in human lymphocytes exposed to 17beta estradiol in vitro

Epidemiologic data and animal experiments strongly implicate that steroid hormones are involved in the process of malignant transformation due to their capability to stimulate mitotic division and/or elevate the level of mutations in susceptible cells.

The objectives of this investigation were to evaluate the effects of 17beta estradiol in sister-chromatid exchange (SCE) test on cultured human peripheral blood lymphocytes. The lowest concentration of 17beta estradiol used in this experiment (10(-10) M) was calculated as comparable with the physiologic blood level of 17beta estradiol in women. Three experimental concentrations corresponded to minimal (7 x 10(-8) M), average (3.5 x 10(-6) M), and maximal (7 x 10(-6) M) therapeutic doses in human medicine. In addition, the highest concentrations exceed maximal therapeutic dose 10-fold (7 x 10(-5) M) and 30-fold (2.1 x 10(-4) M), respectively.

The obtained results indicate that estradiol significantly elevates SCE per cell frequency at all concentrations applied except at the lowest one. However, estradiol has not influenced mitotic activity of cultured human lymphocytes significantly.

It can be concluded that 17beta estradiol expressed genotoxic effects and therefore might represent a human health risk.