Combined treatment with Cinnamaldehyde and ß-TCP had an additive effect on bone formation and angiogenesis in critical size calvarial defect in ovariectomized rats.

Accumulating evidence suggests that improvements in osteogenesis and angiogenesis play an important role in repairing osteoporotic bone defects. Cinnamomum cassia (C. cassia), a traditional Chinese medicinal herb, is reported to show anabolic effects on osteoblasts. However, whether C. cassia could actually repair bone defects in osteoporotic conditions remains unknown. The purpose of this study was to evaluate the effect of combined treatment with Cinnamaldehyde (main oil isolated from the C. cassia) and ß-tricalcium phosphate (ß-TCP) on bone formation and angiogenesis in critical size calvarial defects in ovariectomized (OVX) rats. Using a previously established OVX model, 5 mm critical size calvarial defect was established in OVX rats. All OVX rats were then randomly divided into OVX group (OVX rats + empty defect), TCP group (OVX rats + ß-TCP), and CTCP group (Cinnamaldehyde 75 mg/kg/day for 12 weeks + ß-TCP). Twelve weeks after treatment, according to Micro-CT and HE staining, combination of Cinnamaldehyde and ß-TCP had an additive effect on bone regeneration compared with other groups (p < 0.05). Based on dynamic fluorochrome-labelling analysis, Cinnamaldehyde+ß-TCP continuously promoted new bone mineralization compared with other groups at each time point (p < 0.05). Microfil perfusion suggested that CTCP group showed more neovascularization compared with other groups (p < 0.05). Immunohistochemical assay supported the findings that Cinnamaldehyde+ß-TCP enhanced expression of OCN, VEGF and CD31. The present study demonstrated that combined treatment with Cinnamaldehyde and ß-TCP promoted bone formation and angiogenesis in osteoporotic bone defects, which provides a promising new strategy for repairing bone defects in osteoporotic conditions.

Administration of cinnamaldehyde promotes osteogenesis in ovariectomized rats and differentiation of osteoblast in vitro.

To explore the effect of cinnamaldehyde on the distal femur in ovariectomized rats and its influence on osteoblast in vitro. Female Sprague-Dawley rats which underwent either bilateral ovariectomy or sham operation were divided into five groups randomly: group OVX (OVX, N = 10) and group sham (SHAM, N = 10) received normal saline (NS) by gavage at a dose of 50 ml/kg·d; group low dose, group middle dose and group high dose received cinnamaldehyde by gavage at a dose of 25 mg/kg·d (OLD, N = 10), 50 mg/kg·d (OMD, N = 10), and 75 mg/kg·d (OHD, N = 10) respectively. Distal femurs were harvested for hematoxylin and eosin (HE) staining, micro-ct scanning and immunohistochemical analysis. Murine mesenchymal stem cells were cultured and dealt with the presence of either cinnamaldehyde at a dose of 15ug/ml (OLD), 30ug/ml (OMD), 60ug/ml (OHD) or vehicle. ALP staining and western blot were performed to observe the influence of cinnamaldehyde on the differentiation of osteoblast. HE and micro-ct results indicated that osteogenesis were promoted with the treatment of cinnamaldehyde. Immunohistochemical results showed that cinnamaldehyde increased the number of osteoblast and decreased the number of osteoclast. In vitro studies indicated that cinnamaldehyde promoted expression of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and collagen type Iɑ1 (COL1ɑ1). The treatment effect behaved as dose-dependently. Thus, cinnamaldehyde inhibits osteoclastogenesis and promotes osteoblastogenesis, and may plays an important role in the treatment of osteoporosis clinically.