Effects of quercetin on mRNA expression of steroidogenesis genes in primary cultures of Leydig cells treated with atrazine.

The effect of the phytoestrogen, quercetin (QT) on the reproductive toxicity of atrazine (ATZ) was explored in interstitial Leydig cells (ILCs). We measured the mRNA expressions of steroidogenesis genes: steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD), cytochrome-P450 (CYP) 11A1, insulin-like factor 3 (INSL-3), CYP17A1, inhibin-α (INH-α), androgen receptor (AR), estrogen receptor-α (ER-α), and luteinising hormone receptor (LHR) in isolated ILCs by real-time-PCR after cultured cells were treated in vitro with ATZ (232 μM) and QT (50 μM). The mRNA expression of tested genes increased with ATZ treatment and was normalized by quercetin except AR and ER-α expression. Treatment of cells with QT alone (15-50 μM) caused a dose-dependent increase in AR and ER-α mRNA expression. We also found that QT (50 μM) increased the expressions of AR and ER-α in the presence of a sub-threshold level of cyclic-AMP at 1h culture period to the levels seen with maximal stimulation of cyclic-AMP. Furthermore, the expressions of tested genes were unaffected by cyclic-AMP at 6h when the stimulatory effects of ATZ on tested genes were sustained. These findings suggest that ATZ may stimulate the expression of tested steroidogenesis genes in ILCs via a mechanism independent of cyclic-AMP which was partially antagonize by QT.