Effect of flavonoids on androgen and glucocorticoid receptors based on in vitro reporter gene assay

The effect of 32 flavonoids on androgen (AR) and glucocorticoid receptors (GR) was investigated using an MDA-kb2 human breast cancer cell line to predict potential AR and GR activities. Among them, 5-hydroxyflavone ( 7) had the highest AR antagonistic activity with an IC 50 value of 0.3 μM, whereas 6-methoxyflavone ( 11) had the highest induced luciferase activity with an EC 150 value of 0.7 μM. Genistein ( 2) and daizein ( 1) showed a sufficient increase of luciferase activities as their concentrations increased with EC 150 values of 4.4 and 10.1 μM, respectively. These findings provide evidence of a fundamental property of their structure–activity relationship with AR and/or GR.