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.

Inhibition of osteoclastogenesis for periprosthetic osteolysis therapy through the suppression of p38 signaling by fraxetin.

Periprosthetic osteolysis belongs to osteolytic diseases, which often occur due to an imbalance between osteoclast and osteoblast number or activity. Fraxetin, a natural plant extract, inhibits osteoblast apoptosis and has therapeutic potential for treating osteolytic diseases. However, data pertaining to the effects of fraxetin on osteoclasts are limited. In the present study, it was demonstrated that the inhibition of osteoclastogenesis by fraxetin had an important role on the therapy of titanium particle­induced osteolysis in vivo. In addition, fraxetin was demonstrated to suppress receptor activator of nuclear factor­κB ligand (RANKL)­mediated osteoclast differentiation and bone resorption in vitro in a dose­dependent manner. Fraxetin inhibited osteoclast differentiation and function through the suppression of p38 signaling and subsequently, the suppression of osteoclast­specific gene expression, including tartrate­resistant acid phosphatase, nuclear factor of activated T­cells, cytoplasmic 1, and cathepsin K. In conclusion, fraxetin administration may have potential as a treatment method for periprosthetic osteolysis and other osteolytic diseases.

Effects of the 1, 4-dihydropyridine L-type calcium channel blocker benidipine on bone marrow stromal cells.

Osteoporosis (OP) often increases the risk of bone fracture and other complications and is a major clinical problem. Previous studies have found that high blood pressure is associated with bone formation abnormalities, resulting in increased calcium loss. We have investigated the effect of the antihypertensive drug benidipine on bone marrow stromal cell (BMSC) differentiation into osteoblasts and bone formation under osteoporotic conditions. We used a combination of in vitro and in vivo approaches to test the hypothesis that benidipine promotes murine BMSC differentiation into osteoblasts. Alkaline phosphatase (ALP), osteocalcin (OCN), runt-related transcription factor 2 (RUNX2), ß-catenin, and low-density lipoprotein receptor-related protein 5 (LRP5) protein expression was evaluated in primary femoral BMSCs from C57/BL6 mice cultured under osteogenic conditions for 2 weeks to examine the effects of benidipine. An ovariectomized (OVX) mouse model was used to investigate the effect of benidipine treatment for 3 months in vivo. We found that ALP, OCN, and RUNX2 expression was up-regulated and WNT/ß-catenin signaling was enhanced in vitro and in vivo. In OVX mice that were intragastrically administered benidipine, bone parameters (trabecular thickness, bone mineral density, and trabecular number) in the distal femoral metaphysis were significantly increased compared with control OVX mice. Consistently, benidipine promoted BMSC differentiation into osteoblasts and protected against bone loss in OVX mice. Therefore, benidipine might be a suitable candidate for the treatment of patients with postmenopausal osteoporosis and hypertension.