Fig. 1.

All-trans-retinoic acid suppresses the induction of ARE-driven luciferase activity. AREc32 cells were incubated for 24 h with DMEM supplemented with antibiotics containing either tBHQ (10 μM), Sul (10 μM), or β-NF (10 μM). ATRA (1 μM) was added to the medium concomitantly. Luciferase activity was assayed and the activity of cells treated with DMSO (0.1% vol/vol) was set at 1. Data show mean ± SD from triplicate samples and represent the results of three separate experiments. **, P < 0.005