Harmine promotes periodontal ligament cell-induced tissue regeneration.

OBJECTIVE: to investigate whether harmine has a promotive effect on human periodontal ligament cells (hPDLCs)-induced tissue regeneration.

MATERIALS AND METHODS: Various concentrations of harmine on hPDLCs proliferation were tested. Osteogenic and cementogenic characteristics were examined in hPDLC/rhBMP-2 and hPDLC/harmine by alizarin red S staining, real-time PCR, and Western blotting assay. The activity of harmine was investigated in an ectopic transplantation nude mouse model.

RESULTS: We determined that 10 μM of harmine was the threshold concentration. hPDLC/harmine showed similar mineralized nodule formation in alizarin S staining compared to hPDLC/rhBMP-2. In real-time PCR, the highest gene expression level was observed for Runx2 in hPDLC/harmine at all time points. The level of CEMP-1 in hPDLC/harmine was higher at 7 days than hPDLCs alone. Thicker band of Runx2 in hPDLC/harmine was observed than in hPDLC/rhBMP-2 at 7 days by Western blotting. The band for CEMP-1 in hPDLC/harmine was thicker than hPDLCs alone at both 7 and 14 days. In ectopic transplantation, hPDLCs with harmine showed a comparable amount of mineralized tissue formation compared to rhBMP-2. hPDLCs with harmine or rhBMP-2 formed both bone and cementum-like tissue with Sharpey's fiber-like collagen insertion.

CONCLUSION: Harmine can be a potential candidate for promoting hPDLCs-induced tissue regeneration.