Baicalin Promotes Osteogenic Differentiation of Human Cementoblast Lineage Cells Via the Wnt/β Catenin Signaling Pathway

Background: Baicalin constitutes a natural bioactive flavonoid extracted from Scutellaria baicalensis Georgi that mediates bone formation. However, the biological functions of baicalin in cementoblasts remain unclear. The purpose of this study was to examine the effects of baicalin on osteogenic differentiation of human cementoblast (HCEM) cells. Methods: HCEM cells were cultured and treated with 0, 0.01, 0.1 or 1 µM baicalin. Alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2) mRNA and protein levels were examined by real-time polymerase chain reaction and western blot analysis, respectively. Cell mineralization was assessed using Alizarin red staining. Glycogen synthase kinase-3 beta (GSK3β) phosphorylation was measured in 1 µM baicalin-treated HCEM cells with or without the Wnt signaling pathway inhibitor, DKK-1 using ELISA and western blotting. Results: The protein levels of ALP and Runx2 and the intensity of Alizarin red staining were enhanced by baicalin in a dose-dependent manner compared to that of the non-treated control. The ratio of phosphorylated to total GSK3β increased in the presence of baicalin but was reduced by the addition of DKK-1. Treatment of HCEMs with baicalin up-regulated mRNA levels of ALP and Runx2, which were reduced by DKK-1. In addition, the protein levels of ALP and Runx2, ALP activity, and calcium deposition were also enhanced by baicalin, and these parameters were inhibited by DKK-1. Conclusion: Baicalin enhanced osteogenic differentiation of HCEM cells through the Wnt/beta catenin signaling pathway which may be useful for periodontal tissue regeneration. Keywords: Dental cementum, Wnt, beta catenin, alkaline phosphatase, human cementoblast lineage cells, baicalin.