Fig. 3.

The effects of R1 on NF-κB target gene expression in vitro and on PXR activation. (A) The levels of the mRNA expression of NF-κB target genes in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages following R1 treatment (0 and 25 μM, for 48 hours) were detected by semiquantitative reverse-transcription PCR. The results are representative of three independent experiments. (B) Wild-type human/mouse PXR transactivation reporter assay. Transient transactivation assays were performed in HT-29 cells cotransfected with CYP3A4-reporter, pRL-TK, and pSG5-hPXR or pSG5-mouse PXR (mPXR). The cells were incubated with R1 (0, 1, 10, or 25 μM), rifampicin (Rif; 10 μM, for hPXR), or PCN (10 μM, for mPXR) for 24 hours. A standard dual-luciferase assay of the cell lysates was performed, and the results are expressed as the fold induction compared with that of the control cells. *P < 0.05; **P < 0.01; ***P < 0.001 versus vehicle-treated cells. COX2, cyclooxygenase 2; iCAM-1, intercellular adhesion molecule-1; IFNr, interferon-r.