Oleifolioside A, a New Active Compound, Attenuates LPS-Stimulated iNOS and COX-2 Expression through the Downregulation of NF-κB and MAPK Activities in RAW 264.7 Macrophages

Figure 4

Effects of oleifoliosides A on LPS-stimulated NF-𝜅B activation and phosphorylation of MAPK signaling pathway. (a) Cells were pretreated with the indicated the concentrations of oleifoliosides A for 1 h and then stimulated with LPS (500 ng/mL) for 1 h. Nuclear extracts were prepared and analyzed for NF-𝜅B DNA-binding activity by EMSA. The C.P. represents 100-fold cold probe only. (b) Cells were transiently cotransfected with pNF-𝜅B-Luc reporter plasmid and then were pretreated with the indicated the concentrations of oleifoliosides A for 1 h. LPS (500 ng/mL) was then added and cells were further incubated 24 h. The cells were harvested and then the luciferase activities were determined by using the dual luciferase report assay system. (c) Cells were pretreated with the indicated concentrations of oleifoliosides A for 1 h before LPS (500 ng/mL) treatment for 15 min. and the levels of total/phospho-ERK1/2, JNK, and p38 MAPK were determined by Western blotting. The values are presented as mean±S.E. of three independent experiments. 𝑛=6 per experiment, ^∗𝑃<0.05 versus LPS and ^∗∗𝑃<0.01 versus LPS.