Arbutin promotes MC3T3-E1 mouse osteoblast precursor cell proliferation and differentiation via the Wnt/β-catenin signaling pathway

Arbutin is a natural compound extracted from various plants, including bearberry leaves, that exerts multiple effects including skin whitening, anti-inflammatory and oxidative stress-protective properties. However, the effects of arbutin on osteoblasts remain unknown. The aim of the present study was to investigate the function and the mechanisms of arbutin on the proliferation and differentiation of MC3T3-E1 mouse osteoblast precursor cells in vitro. The proliferation of MC3T3-E1 cells treated with arbutin was assessed using a Cell Counting Kit-8 assay and a 5-ethynyl-2′-deoxyuridine labeling assay. Additionally, cell cycle and apoptosis were examined using flow cytometry analysis. The effects of arbutin on osteoblast differentiation were investigated using alkaline phosphatase (ALP) staining and by examining the mRNA expression levels of collagen type I α1 chain (COL1A1), bone γ-carboxyglutamate protein (BGLAP) and Sp7 transcription factor (SP7). To further investigate the molecular mechanism underlying arbutin function in promoting osteogenesis, the mRNA and protein expression levels of runt-related transcription factor 2 (RUNX2) and β-catenin were analyzed by reverse transcription-quantitative polymerase chain reaction and western blotting. Arbutin significantly promoted MC3T3-E1 cell proliferation and increased the ratio of cells in S-phase. Treatment with arbutin increased ALP activity and the mRNA expression levels of COL1A1, BGLAP and SP7 in MC3T3-E1 cells. Furthermore, the protein and the mRNA expression levels of RUNX2 and β-catenin increased significantly following treatment with arbutin. Collectively, the present findings suggested that arbutin was able to promote proliferation and differentiation of MC3T3-E1 cells via the Wnt/β-catenin signaling pathway.