Abstract: Objective:To study the effects of ursolic acid on the differentiation of cementoblast cell line OCCM-30 cells, and to provide the theoretical basis for the repair of root restoration. Methods:The OCCM-30 cells in logarithmic growth phase were divided into control group and different concentrations of ursolic acid groups. The OCCM-30 cells in ursolic acid groups were treated with different concentrations(0.625, 1.250 and 2.500 μmol·L^-1) of ursolic acid and the cells in control group did not receive any treatment. MTT method was performed to detect the inhibitory rates of proliferation of the OCCM-30 cells in various groups at different time points (24, 48, and 72 h); ALP (alkaline phosphatase) assay was performed to detect the cell differentiation and mineralization; real-time quantitative PCR was used to determine the expression levels of osteopontin(OPN) mRNA during 24 h; the expression levels of OPN protein at 3 and 5 d after administration were detected by Western blotting method. Results:There were no significant differences in the inhibitory rates of proliferation of OCCM-30 cells between control group and different concentrations of ursolic acid groups(P>0.05).Compared with control group, the ALP activities in the OCCM-30 cells in 2.500 μmol·L^-1 ursolic acid group at 3, 5, and 7 d after administration were significantly increased(P<0.05).Compared with control group,the expression levels of OPN mRNA and protein in the OCCM -30 cells in different concentrations of ursolic acid groups were significantly increased (P<0.01). Conclusion:Appropriate concentration of ursolic acid has no effect on the inhibitory rate of proliferation of OCCM-30 cells, but it can promote the differentiation of OCCM-30 cells and up-regulate the expression levels of OPN mRNA and protein.

Key words: ursolic acid, cementoblast, cell proliferation, cell differentiation