Effect of JSOG-6 on ALP activity in MC3T3-E1 cells. (A) Cell viability was measured by the MTT method as described in the Methods. (B) MC3T3-E1 cells (2 × 104 cells/mL) were incubated with JSOG-6 in the presence of ascorbic acid and β-glycerophosphate for 4 days. The ALP activity was corrected for the amount of protein. Data represent the mean ± S.D. (n = 3). *P < 0.05, **P < 0.01 indicates statistically significant differences from the control group. N.C., negative control; P.C., positive control (ascorbic acid + β-glycerophosphate).