Figure 2.

Hypothesis of AhR-mediated regulation of intracellular ROS. Different pathways of the AhR are activated at the same time, one leading to an increase in cellular ROS and the other(s) resulting in an antioxidant response. Possible antioxidant mechanisms are AhR-triggered activation of Nrf2, SOD, PONs, Srxn, CYP1A1/2, or, very likely, other enzymes which remain to be identified. Depending on the cell type, organ, ligand, or additional factors, either the prooxidant or the antioxidant AhR pathway predominates.