Effects Of Ursolic Acid On Proliferation And Mineralization Of Cementoblasts.

Objective:Orthodontic inflammatory root absorption is caused by mechanical force or biological factors during the process of orthodontic treatment,leads to different degrees of root tissue absorption,such as shorter root, root surface depression, and even teeth losing and falling out, is one of the common complications of orthodontic[1].Root absorption and repairing mainly rely on cementoblasts, activated cementoblast contributes to predentin, then turns into a mature cementum by mineralization.Currently there is no standard method of clinical treatment of root absorption, thus how to promote cementoblast’s function is the method to repair orthodontic inflammatory root absorption.Ursolic acid is a pentacyclic triterpene compound, is widely distributed in plants,such as Greece sage, oleander [2].It has less adverse reactions,low toxicity and processes anti-hepatitis, anti-tumor, anti-biosis, anti-viral, anti-diabetic, immunity improvement[3-8];Other studies have shown that ursolic acid, in ossification and bone resorption, inhibits bone mineral density loss[9], promote bone formation[10].The impact of ursolic acid on cementoblast is not yet clear, so this study will investigate if ursolic acid can promote cell proliferation and mineralization ? Explore the possibility of the ursolic acid in repairing root absorption.Metheds:1.Cultivate cell line OCCM- 30, and confirm the appropriate concentrational range.2.To detect ursolic acid on cementoblast cell proliferation, proliferation was detected by using cck-8, cell cycle and apoptosis were checked by flow cytometry analysis.3. To detect ursolic acid on cementoblast mineralization,the activity of alkaline phosphatase was tested by enzyme-linked method on microplate,the mineralization was tested by alizarin red S staining.Results:1.The appropriate concentration of ursolic acid promoting cementoblast is 2.5uM.2. Ursolic acid group(2.5 uM) compared with the control group, cell proliferation and cell proliferation index increased and early apoptosis rate reduced.3. Ursolic acid group(2.5 uM) compared with the control group, the activity of alkaline phosphatase and the quantity of the mineralized nodules were up-regulated.Conclusion:Ursolic acid promotes functions of cementoblast.Concentration of 2.5 uM ursolic acid can promote of cell proliferation, the cell percentage in G1 phase of cell cycle decreased, inhibit cell early apoptosis, enhance the activity of alkaline phosphatase, promote the formation of mineralized nodules.With the deepening of the study of ursolic acid, it is expected to be clinical drug for the treatment of root absorption.