Figure 4.

Costunolide inhibits TNFα-induced NF-κB activity and MMP-9 expression. (a) MDA-MB-231 cells were transfected with the NF-κB-dependent luciferase reporter, pretreated with costunolide for 1 hour, and then exposed to TNFα for 6 hours. In addition, after cotransfected with TNFRI and NF-κB-dependent luciferase reporter, treated with costunolide for 6 hours. Luciferase assay were done by using dual-luciferase reporter assays. All transfections included the RLTK-Luc for transfection efficiency. **P < 0.001. (b) MDA-MB-231 cells were pretreated with costunolide for 1 hour and then exposed to TNFα for 6 hours. MMP-9 expression was analyzed by RT-PCR, western blotting, and zymography.