BackgroundA decrease of bone mass is a major risk factor for fracture. Several natural products have traditionally been used as herbal medicines to prevent and/or treat bone disorders including osteoporosis. Praeruptorin A is isolated from the dry root extract of Peucedanum praeruptorum Dunn and has several biological activities, but its anti-osteoporotic activity has not been studied yet.Materials and MethodsThe effect of praeruptorin A on the differentiation of bone marrow–derived macrophages into osteoclasts was examined by phenotype assay and confirmed by real-time PCR and immunoblotting. The involvement of NFATc1 in the anti-osteoclastogenic action of praeruptorin A was evaluated by its lentiviral ectopic expression. Intracellular Ca2+ levels were also measured.ResultsPraeruptorin A inhibited the RANKL-stimulated osteoclast differentiation accompanied by inhibition of p38 and Akt signaling, which could be the reason for praeruptorin A-downregulated expression levels of c-Fos and NFATc1, transcription factors that regulate osteoclast-specific genes, as well as osteoclast fusion-related molecules. The anti-osteoclastogenic effect of praeruptorin A was rescued by overexpression of NFATc1. Praeruptorin A strongly prevented the RANKL-induced Ca2+ oscillation without any changes in the phosphorylation of PLCγ.ConclusionPraeruptorin A could exhibit its anti-osteoclastogenic activity by inhibiting p38/Akt-c-Fos-NFATc1 signaling and PLCγ-independent Ca2+ oscillation.

The fruits of Prunus mume, maesil (Rosaceae), have been widely used as a valuable source of foods and herbal medicines from ancient times in Northeast Asia. Specially, phenolic compounds of main compounds in maesil were reported to have various activities. This study aims to develop the simultaneous analytical method of nine phenolic compounds in maesil and to evaluate these compound contents in samples during the ripeness. Twenty-one species of samples and nine phenolic compounds were used for this study. In results, compounds 1–9 contents in unripe fruits were 0.16∼1.81 mg/g. However, these compounds in ripe samples were 0.09∼1.66 mg/g. Compounds 1–9 contents in ripe fruits were generally reduced rather than those in unripe fruits. Otherwise, the contents of compounds 2, 5, 8, and 9 in seed part were relatively higher than those in flesh part. In contrast, contents of compounds 1, 3, and 7 in flesh part were relatively higher than those in seed part. Generally, the contents of compounds 1–9 in unripe fruits were higher than those in ripe fruits. However, the contents of compounds 1–9 in each part (seed and fresh) of fruits were different according to species of compounds. It indicates that the selection of harvesting time and process part of fruits as the source of foods and medicines is important.