Induction of AHR activity by IMA-derivatives. (A) HepG2 40/6 cell cultures stimulated for 4 h with a concentration series of LAQ and IMA-compounds. TCDD (10 nM) was used as a full AHR agonist and set at 100% luminescent activity (n = 2). (B) CYP1A1 mRNA expression levels, (C) CYP1A1 enzyme activity (luminescent assay), and (D) percentage cell death (24 h measurement, lactate dehydrogenase (LDH) assay) of primary human keratinocytes (n = 3) stimulated for 48 h (re-stimulated after 24 h) with a concentration series of the IMA-compounds, LAQ, and TCDD. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. Mean +/− SEM.