Figure 7. Effects of Nrf2-siRNA transfection and tin protoporphyrin IX (SnPP) on compound 33-induced suppression of proinflammatory cytokine and ROS synthesis. (A) Nrf2 protein levels were assayed using Western blotting after transfection with Nrf2-siRNA or Nrf2-negative control siRNA. Effects of Nrf2 silencing on compound 33-induced suppression of (B) TNF-α, (C) IL-6, and (D) IL-1β. To explore the function of the Nrf2/HO-1 signaling pathway in inflammatory responses and oxidative stress, SnPP, an inhibitor of HO-1, was administered to RAW264.7 cells; compound 33 was administered 1 h later. (E) TNF-α, (F) IL-6, and (G) IL-1β mRNA and (H) ROS levels were analyzed. * P <0.05, ** P <0.01, compared to the 33+ LPS group.