Fig. 3.

Assessment of inhibitory action of zerumbone on the function of mouse COX-2 gene activation, as measured in the mouse MMDD1 model cells. a Cells were transiently transfected with the pCOX-2-Luc reporter plasmid using the luciferase assay. The longer plasmid contains the near full length mouse COX-2 promoter, and the shorter plasmid contains only the C/EBP response element that is adjacent to the start codon. MMDD1 cells were pre-treated with 2 μM zerumbone for 1 h, followed by 10 nM TCDD treatment for 20 h. *Significantly different from control P ≤ 0.01. a Significant lower than control P ≤ 0.01. b Significantly lower than TCDD treatment alone P ≤ 0.01. b DNA binding activity of nuclear proteins from U937 macrophages to the C/EBP element of the COX-2 promoter. Cells were treated with 10 nM TCDD or 0.1% DMSO (Vehicle control) for 3 h. Antibodies for C/EBPα, β, and δ isoforms were used in supershift analysis. A 100-fold excess of unlabeled oligonucleotide was added (Lane 6). C) DNA binding activity of nuclear proteins from U937 macrophages to the C/EBP element of the COX-2 promoter. Cells were treated with 10 nM TCDD in absence (lane 2) or presence (lane 4) of 10 μM zerumbone for 3 h