Sesamin Promotes Osteoblastic Differentiation and Protects Rats from Osteoporosis

BACKGROUND Osteoporosis is a common osteopathy, resulting in fractures, especially in elder people. Sesamin has many pharmacological effects, including supplying calcium. However, how sesamin might prevent osteoporosis is still under study. MATERIAL AND METHODS Bone marrow stromal cells (BMSCs) extracted from rat femur were induced for osteoblastic differentiation. Cell proliferation, alkaline phosphatase (ALP), osterix (OSX), SRY-box 9 (SOX9), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), ß-catenin, low density lipoprotein receptor-related protein 5 (LRP5), and glycogen synthase kinase-3ß (GSK-3ß) levels in BMSCs were detected in the presence or absence of sesamin (1 μM or 10 µM). In addition, FH535 (1 μM) was used to silence Wnt/ß-catenin in vitro. Ovariectomized (OVX) rats were established and intragastrically administrated sesamin (80 mg/kg), and then the rat bones were analyzed by micro-computed tomography. Osteocalcin and collagen type I were measured in the rat femurs. RESULTS Sesamin had no influence on BMSC proliferation. Higher sesamin concentration promoted Wnt/ß-catenin activity and enhanced more expressions of ALP, OSX, SOX9, RUNX2, and OCN, gradually and significantly (P<0.05). Silencing Wnt/ß-catenin weakened the enhancement on RUNX2 and OCN expression. Sesamin (80 mg/kg) promoted bone structure in ovariectomized rats, and significantly enhanced osteocalcin and collage type I expression (P<0.05). CONCLUSIONS Sesamin promoted osteoblastic differentiation of rat BMSCs by regulating the Wnt/ß-catenin pathway, and improved rat bone structure. Sesamin could have therapeutic and preventive effects on osteoporosis.