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), β-catenin, low density lipoprotein receptor-related protein 5 (LRP5), and glycogen synthase kinase-3β (GSK-3β) 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/β-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/β-catenin activity and enhanced more expressions of ALP, OSX, SOX9, RUNX2, and OCN, gradually and significantly (P<0.05). Silencing Wnt/β-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/β-catenin pathway, and improved rat bone structure. Sesamin could have therapeutic and preventive effects on osteoporosis.

Keywords: Bone Marrow Cells, Cell Dedifferentiation, Osteoblasts, Osteoporosis, Sesame Oil, Alkaline Phosphatase, Collagen Type I, Dioxoles, Lignans, Mesenchymal Stem Cells, osteocalcin, Osteogenesis, Ovariectomy, beta Catenin