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 .