Effect of daphnetin on DR3, PDCD5, FasL and p53 protein expression in CIA rats synovial cells. Cells were cultured, treated and harvested as described Materials and Methods. Four experimental groups consisting of untreated cell control, 5-aza-dc at 20 μM, daphnetin at 40 μg/mL, or combination of 5-aza-dc (20 μM) and daphnetin (40 μg/mL). The results show the mean ± S.D. of six independent experiments. ▲P < 0.05 compared with control, ●P < 0.05 compared with 5-aza-dc, ★P > 0.05 compared with 5-aza-dc, *P < 0.05 compared with daphnetin.