Fraxinellone alleviates inflammation and promotes osteogenic differentiation in lipopolysaccharide-stimulated periodontal ligament stem cells by regulating the bone morphogenetic protein 2/Smad pathway.

The aim of the present study was to investigate the role of fraxinellone in periodontitis and identify its potential mechanisms. Lipopolysaccharide-induced periodontal ligament stem cells (PDLSCs) was employed to simulate the periodontitis in vitro. The levels of inflammatory factors were evaluated. After treatment with fraxinellone, alkaline phosphatase activity was determined. Additionally, calcium nodules staining was evaluated by alizarin red staining and the expression of osteogenesis differentiation-associated proteins was detected using western blot analysis. Moreover, the levels of proteins in bone morphogenetic protein 2 (BMP2)/Smad pathway were measured. Subsequently, BMP2 was silenced by transfection with small hairpin RNA to explore the underlying mechanisms of fraxinellone in lipopolysaccharide-induced PDLSCs. Lipopolysaccharide stimulation significantly upregulated the levels of inflammatory factors, which were inhibited by fraxinellone intervention. Moreover, fraxinellone notably promoted osteogenic differentiation and calcification shown by increasing levels of alkaline phosphatase, calcification and osteogenic marker proteins. Furthermore, the expression of BMP2, phosphorylated Smad1 and phosphorylated Smad5 was remarkably upregulated when fraxinellone exposure in lipopolysaccharide-induced PDLSCs. What's more, BMP2 silencing dramatically restored the effects of fraxinellone on inflammation and osteogenic differentiation of PDLSCs stimulated by lipopolysaccharide. These data demonstrated that fraxinellone alleviates inflammation and promotes osteogenic differentiation in lipopolysaccharide-stimulated PDLSCs by regulating the BMP2/Smad pathway, providing experimental supports for the clinical application of fraxinellone in the treatment of periodontitis.