Harmine Stimulates Differentiation of Cementoblasts

Objectives: To test the effect of Harmine, a carboline alkaloid, in stimulation of cementoblast differentiation.
Methods: 1. Cell line OCCM-30 (cementoblast) is used in vitro. Differential medium is used to stimulate cell differentiation. 2. Cell growth assay was performed to test the effect of harmine on cell growth speed. 3. PCR, ALP activity assay and mineralization assay are used to exam the effect of Harmine in cell differentiation. 4. Potential signal pathways during cell differentiation are studied by western blot.
Results: 1. Harmine inhibits growth of OCCM-30. The inhibition showed a dose-dependent manner. At the same time, the scratch assay experiment indicates harmine decreased OCCM-30 migration speed. 2. PCR results show that the peak expression of BSP and Col1a1 in control group occurs 10 days after differentiation medium added. On the other hand, the Harmine group showed the highest expression level at 4 days. OPN was induced by Harmine at 4, 10 and 14 days. The highest expression level of OPN showed in 4 days in the Harmine group compares to 10 days in the control group. 3. The stimulation effect was proved in protein level by western blots.
Conclusions: In summary, we have found novel cementogenic effects of harmine. Harmine promotes cementoblast differentiation and mineralization accompanied by increases in Col1a, OPN and BSP expression. The cementoblast differentiation stimulation effect indicates that harmine is a candidate which could be used to prevent root resorption during tooth movement. Further animal experiments may need to test the clinic application of harmine during orthodontic treatment.