Figure 4.

The induction of CYP1A1 by selected MICTs and their binary combinations. (A) Type I synergism, where the efficacy of the binary mixture is higher than the effect of each compound alone; (B) Type II synergism, where the efficacy of the binary mixture is higher than the sum of the efficacies of two single compounds. AZ-AHR cells were incubated with vehicle (DMSO; 0.2% v/v), TCDD (20 nM), or MICTs alone or in binary combinations for 4 h. The levels of CYP1A1 mRNA were determined by qRT-PCR and are expressed as a percent of induction by TCDD. Each dot represents one independent experiment. The experiments were performed in technical triplicates and three biological replicates at least.