Osthole enhances the bone mass of senile osteoporosis and stimulates the expression of osteoprotegerin by activating ß-catenin signaling.

INTRODUCTION: Osthole has a potential therapeutic application for anti-osteoporosis. The present study verified whether osthole downregulates osteoclastogenesis via targeting OPG. METHODS: In vivo, 12-month-old male mice were utilized to evaluate the effect of osthole on bone mass. In vitro, bone marrow stem cells (BMSCs) were isolated and extracted from 3-month-old OPG-/- mice and the littermates of OPG+/+ mice. Calvaria osteoblasts were extracted from 3-day-old C57BL/6J mice or 3-day-old OPG-/- mice and the littermates of OPG+/+ mice. RESULTS: Osthole significantly increased the gene and protein levels of OPG in primary BMSCs in a dose-dependent manner. The deletion of the OPG gene did not affect ß-catenin expression. The deletion of the ß-catenin gene inhibited OPG expression in BMSCs, indicating that osthole stimulates the expression of OPG via activation of ß-catenin signaling. CONCLUSION: Osthole attenuates osteoclast formation by stimulating the activation of ß-catenin-OPG signaling and could be a potential drug for the senile osteoporosis.

Association between serum vitamin B6 concentration and risk of osteoporosis in the middle-aged and older people in China: a cross-sectional study.

OBJECTIVE: To determine the relationship between serum vitamin B6 (Vit B6) concentration and the status of bone mineral density and identify the relationship between serum Vit B6 and bone metabolism parameters in middle-aged and older people in China. DESIGN: The present study was a cross-sectional study within the framework of an ongoing prospective population-based cohort study. SETTING AND PARTICIPANTS: A total of 1829 residents (men ≥50 years and women ≥45 years) from two subdistricts were recruited from July 2015 to February 2016 in Shanghai, China. MEASURES: Recruited residents were grouped (control, osteopenia and osteoporosis) according to their lumbar spine bone mineral density, measured through dual-energy X-ray absorptiometry. Serum Vit B6 concentrations, bone turnover marker concentrations and calcium and phosphorus metabolism parameters were assessed. RESULTS: No significant linear trend between serum Vit B6 concentrations and lumbar bone mass was observed in the men. In the women, the average osteoporosis risk was 61% higher at serum Vit B6 concentrations of <19.2 µg/L than at those of >26.9 µg/L (OR 1.61, 95% CI 1.00 to 2.58). However, there was no significance after controlling of serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration, respectively. In the osteoporotic women, the serum Vit B6 concentration was significantly negatively correlated to concentrations of bone turnover marker including N-terminal propeptide of type I collagen, ß-C-terminal telopeptide of type I collagen and osteocalcin. It was also positively related to the serum 25-hydroxy-vitamin D concentration and inversely related to the serum parathyroid hormone concentration. CONCLUSIONS: A relatively low serum Vit B6 concentration, even in the normal range, may be a risk factor for osteoporosis in postmenopausal women, which is dependent on serum 25-hydroxy-vitamin D concentration and parathyroid hormone concentration. TRIAL REGISTRATION NUMBER: NCT02958020; Post-results.