Biblioteca Virtual en Salud

Objective:

To investigate the effects of ursolic acid (UA) on the proliferation and differentiation of osteoclasts (OC), and to explore its role in orthodontic force-induced root resorption and its relationship with OC.

Methods:

The mononuclear / macrophage cells RAW264.7 were induced to the OC.Tacrolimus acid phosphatase (TRAP) staining and bone resorption lacunae observation were used to identify the induction.CCK-8 method was used to select the appropriate concentration of UA for RAW264.7 cell-free biotoxicity and to observe its effect on the proliferation and differentiation of RAW264.7.In experimental groups, UA with gradient concentrations (1.0,2.5,5.0,10.0,20.0and 40.0 μmol·L-1)were added.UA was not added in control group.

Results:

The TRAP staining and bone resorption lacunae observation showed that after the RAW264.7 cells were induced for 5 d, the TRAP staining positive cells were found;the resorption lacunae were rounded,and oval, etc,the bottom wall was coarser,and the boundary was clear,which indicated that the RAW264.7 cells were successfully differentiated into the osteoclasts.The CCK-8 detection results showed that high concentration of UA (> 10.0 μmol·L-1) significantly inhibited the proliferation of OC;the appropriate concentration of UA (5.0 μmol·L-1) was in the biological safety concentration range and could inhibit the OC proliferation;low concentration of UA (<2.5 μmol·L-1) had no effect.

Conclusion:

RANKL can induce the differentiation and maturation of RAW264.7 cells.UA is correlated with the proliferation and differentiation of OC;UA has inhibitory effect on OC at the appropriate concentration (5.0 μmol·L-1) in a time-dependent manner.