FIGURE 2.

In the co‐culture system, melatonin upregulates the expression of OPG and decreases the expression and secretion of RANKL. The expression (A) and secretion (B) of RANKL and OPG in MC3T3‐E1 cells cultured for 7 days with RANKL (30 ng/mL) and M‐CSF (10 ng/mL) with high glucose in the presence of varying concentrations (0.1 or 1 μmol/L) of melatonin. Data are represented as the mean ± SD (n = 3). **p < 0.01. OPG, Osteoprotegerin; RANKL, receptor activator of nuclear factor κ B ligand; M‐CSF, macrophage colony‐stimulating factor