Figure 6.

Pretreatment effect of PT and curcumin on 1,25-(OH)₂D₃-induced HL-60 cell differentiation. HL-60 cells were pretreated with 10 μM PT for various periods (24, 12, 2, 0.5, 0.2 h, respectively) or not pretreated (A), or with PT at various doses (10, 5, 0.5 μM, respectively) for 24 h (B), or with curcumin at various doses (20, 5, 0.5 μM, respectively) for 24 h (C). After washing with DMEM, the cells were treated with 5 nM 1,25-(OH)₂D₃ for 48 h, and analysed by the NBT reduction assay for cellular differentiation and by the EMSA for NF-κB DNA binding activity. S and NS indicate the presence of an unlabelled, identical oligonucleotide and non-specific oligonucleotide, respectively. Data are representative of two independent experiments. *P<0.001, relative to an untreated group with PT. **P<0.005, relative to an untreated group with PT. ***P<0.005, relative to an untreated group with curcumin.