Antiosteoporotic activity of nodakenetin, a coumarin compound from Angelica decursiva, by activation of the Wnt/β-catenin signaling pathway

<i>Angelica decursiva</i> (Umbelliferae) is a medicinal plant widely used to treat colds, coughs and fevers in Korea, Japan, and mainland China. The anti-inflammatory activity of nodakenetin, a furano-coumarin compound from <i>A. decursiva</i>, has been reported, although, the antiosteoporotic activity remains unknown. This study sought to investigate the antiosteoporotic activity and precise mechanism of action of nodakenetin in <i>vitro</i> cell culture and <i>in vivo</i> bone remodeling models. The transcriptional activity of nodakenetin on the Wnt signaling pathway was assessed using the TOPflash/FOPflash assay. The effect of nodakenetin on the osteoblast differentiation was measured using Alizarin red staining and alkaline phosphatase (ALP) activity. Western blotting and real-time RT-PCR were used to assess the effect of nodakenetin on the expression of markers related to Wnt/β-catenin pathway and osteoblast differentiation. The <i>in vivo</i> antiosteoporotic activity of nodakenetin was assessed using an ovariectomized (OVX)-induced bone loss mouse model. Nodakenetin activated the Wnt/β-catenin pathway through regulation of DKK1, β-catenin and other target proteins of the Wnt/β-catenin pathway in HEK293 and MC3T3-E1 cells. Nodakenetin induced the differentiation of MC3T3-E1 cells as shown by enhanced Alizarin red staining and ALP activity. Induction of osteoblast differentiation was related to upregulated expression of bone formation biomarkers such as bone morphogenic proteins and Runx2. Oral administration of nodakenetin in the OVX mouse model effectively protected the deterioration of bone microstructure in OVX mice. Nodakenetin exhibits antiosteoporotic activity in <i>vitro</i> and <i>in vivo</i> through the activation of the Wnt/β-catenin pathway and subsequent induction of osteoblast differentiation.