Figure 2: Effects of quercetin on ALP activity (a) and matrix mineralization (b)–(e). (a) For the ALP activity assay, cells were incubated in CM or OIM with or without quercetin or E2 for 7 days. Each value represents the mean ± SD from triplicate experiments. indicates a significant difference between the two groups at . (b)–(e) For the calcium nodule assay, the cells were incubated in CM (b), OIM with DMSO (c), OIM with quercetin (d), or OIM with E2 (e) for 21 days.