ABSTRACT
Objective: To investigate the relationship between the anti-osteoporotic effect of Ligustrum lucidum and the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) signaling pathways. Methods: L. lucidum aqueous extract was orally administrated to ovariectomized (OVX) rats for 14 weeks. Then the femurs were removed and stained with hematoxylin & eosin (HE) and Safranin O/Fast Green staining, respectively, to evaluate the change of bone microstructure. The histomorphological parameters and bone mineral density (BMD) of the femurs were measured by micro-CT. Furthermore, rat serum GH level was determined by ELISA assay, and IGF-1 protein expression in liver and bone was determined by Western blotting and immunohistochemical staining. Results: L. lucidum prevented the disorganized femoral trabeculae and inhibited the decrease in BMD and glycosaminoglycan content in OVX rats. In addition, L. lucidum significantly inhibited the decrease of serum GH levels and improved IGF-1 protein expression of liver and bone in OVX rats. Conclusion: L. lucidum may prevent against osteoporosis through inhibition of bone loss and improvement of bone microstructure via regulating GH/IGF-1 signaling pathway.
ABSTRACT
Aim To evaluate the effects of salvianolic acid B ( Sal B ) on bone metabolism and its potential mechanism in high fat diet ( HFD) mice.Methods Thirty C57BL/6J male mice were divided into three groups with 10 mice each, namely normal , HFD and HFD+Sal B.HFD and HFD+Sal B mice were treated with HFD, and HFD+Sal B group mice were also with Sal B (125 mg· kg -1· d-1).After 12 weeks' treat-ment, femurs were harvested .The effects of Sal B on biomechanical strength were evaluated by biomechani-cal tests, and the effects of Sal B on bone microstruc-ture were evaluated by Safranin O/fast green staining and hematoxylin and eosin staining .The expression of nuclear factor-kappa B ( NF-κB)-p65 and NADPH ox-idase 4 ( Nox4 ) and cathepsin K in femurs was deter-mined by immunohistochemical staining . Results Maximum load and elastic load significantly decreased ,and the trabeculae became thinner and irregular in the femurs of HFD mice , while Sal B treatment could re-verse the descending biomechanical strength and the disorganized femurs bone micro-structures in HFD mice.In addition, the expressions of Nox4, NF-κB-p65 and cathepsin Kmarkedly increased in HFD mice , and Sal B possessed the ability to down-regulate the ex-pression of Nox4, NF-κB-p65, and cathepsin K in the femurs triggered by HFD .Conclusions Sal B treat-ment improves bone metabolism via regulating Nox 4/NF-κB/cathepsin K signaling pathway in HFD mice . The findings contribute to the understanding and exten-sion of the applications of Salvia miltiorrhiza and its constituents on osteoporosis .