Figure 2.

Melatonin stimulates osteoblast differentiation in human MSCs. (A) Human MSCs were seeded in 96-well plates at a density of 8 × 10³ cells/well and then treated with or without ODM containing indicated concentrations of melatonin for first 4 days. (B) The cells were treated with or without ODM containing indicated concentrations of melatonin for 14 days, followed by Alizarin Red S staining and visualized by phase-contrast microscopy at a final magnification of 200X. (C) The mineralized layers were dissolved and quantified using a microplate reader at 570 nm. Data are represented as mean ± SEM of three individual experiments (n = 3). Statistical significance was determined using Student's t-test (^*p < 0.05; ^**p < 0.01; compared with untreated control).