Fig 1: Effects of melatonin (0, 100, 10 and 1 µM) on ALP, BMP-2, OCN, RUNX2, COX-2, NF-?B and MAPK pathway protein level expression in melatonin-untreated DPSCs and melatonin-treated DPSCs with osteogenic differentiation after 24 h incubation. a, b DPSCs with 100 µM melatonin treatment enhanced ALP, OCN and RUNX2 protein expression and downregulated COX-2 and NF-?B protein expression. c DPSCs with 100 µM melatonin treatment induced phosphorylation of p38 and ERK. The phosphorylation of JNK was not observed. d Quantitative analysis for the ratios of p-p38/p38, p-JNK/JNK and p-ERK/ERK. (GM growth medium, OM osteogenic medium, Mel melatonin) (*p < 0.05, **p < 0.01)