Figure 9.

Effect of santonin, a sesquiterpene lactone without inhibitory activity of NF-κB DNA binding, on 1,25-(OH)₂D₃-induced HL-60 cell differentiation. The cells were treated with 5 nM 1,25-(OH)₂D₃ alone or in combination with either santonin or PT for 72 h. As controls, the cells were treated with either santonin or PT alone. The percentage of differentiated cells from each treatment was determined by the NBT reduction assay (A), and the NF-κB DNA binding activity was analysed by the EMSA (B). S and NS indicate the presence of an unlabelled, identical oligonucleotide and non-specific oligonucleotide, respectively. *P<0.001, relative to any other groups. Data are representative of two independent experiments.