Fig. 4

PAP enhanced PKA/CREB signaling, and H89 reversed the anti-inflammatory effects of PAP in LPS-stimulated BV2 cells. a Intracellular cAMP level was measured in BV2 cells treated with PAP in the presence or absence of LPS for 30 min. b Western blot analysis to assess the phosphorylated and total forms of CREB using the same cell lysates as a. c EMSA to assess CREB DNA binding activity. d Transient transfection analysis of CRE-luc reporter gene activity. e Western blot to detect the nuclear translocation of CREB. f Cells were pretreated with H89 for 30 min, then treated with PAP for 1 h followed by LPS for 16 h. The production of NO, TNF-α, IL-1β, IL-10, and ROS was measured. Data are shown as the mean ± SEM of three independent experiments. *p < 0.05, control vs. LPS-treated group; ^#p < 0.05, LPS vs. LPS+PAP-treated group; ^##p < 0.05, LPS+PAP vs. LPS+PAP+H89 group