PTGS2 and Erythema: Herein, the levels of Nrf2 and HO-1 were significantly diminished by UVB stimulation accompanied by ROS production whereas RBE remarkably inhibited the Nrf2/HO-1 signaling and inflammatory responses indicated by the suppression of c-Jun as well as NF-κB. UVB-mediated COX-2 expression is associated with erythema, and therefore, COX-2 could be a feasible target for preventing photo-inflammation [18, 49, 50].