Effect of propolis on osteogenic induction of PDL cells invitro

Propolis or bee glue has long been claimed to exhibit anti-inflammation, antibacterial antifungal and antivirus as well as being an immune moderator. Periodontal ligament (PDL) cell differentiation into osteoblast is important in bone formation.

Objective

The aim of this study is to investigate the effect of propolis on osteogenic induction of PDL cells using in vitromodel 

Methods

Periodontal ligament fibroblasts (PDL) obtained from ScienCell^TM were culture in Dulbecco’s Modified Eagles Medium (DMEM) containing 10% fetal bovine serum at 37°C under 5% CO₂ and 100% humidified atmosphere. Cytotoxicity and cell proliferation assay was performed in the presence and absence of propolis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.  Effect of propolis on osteogenic induction of PDL cells was performed by growing PDL cells until confluence, which were then designated as day 0, and nodule formation was induced by propolis or 50 μg/mL ascorbic acid, 10 mM β-glycerophosphate(β-GP), and 100 nM dexamethasone.  The alkaline phosphatase activity and mineralized nodule formation assay were performed on day 7, 14, 21 and 28.

Results

The results showed that propolis up to 200 mg/ml showed no toxicity to PDL cells.  Moreover, at the concentration of 0.1 mg/ml propolis could promote PDL cell proliferation.  When induce with 0.1 mg/ml propolis, it was found that the alkaline phosphatase activity was increase markedly at day 14 then decrease. Mineralized nodule was started to form on day 21 and could be detected with Alizarin Red S on day 28.  The number of mineralized nodules induced by propolis was found to be significantly higher than those induced by dexamethasone, ascorbic acid, and β-GP.

Conclusion

The results suggested that propolis may be a good candidate for further development of drug for usage in treatment of periodontal diseases.