Figure 1.

Effect of CGA on BMP-4-stimulated OPG release in MC3T3-E1 cells. The cultured cells were pretreated with the indicated doses of CGA for 60 min, then stimulated with 30 ng/ml BMP-4 or vehicle (●) or vehicle (○) for 48 h. Levels of OPG in the culture medium were determined by ELISA. Data are presented as the mean ± standard error of the mean of three replicate experiments from three independent cell preparations. CGA, chlorogenic acid, BMP-4, bone morphogenic protein-4; OPG, osteoprotegrin; N.S., no significant difference.