Anti-Osteoporosis Effect of Desmodium Renifolium(Linn.)Schindl Based on OPG/RANKL/RANK Pathway
Objective To investigate the effect and potential mechanism of Desmodium renifolium(Linn.)Schindl on ovariectomized osteoporosis rat model.Methods Sixty 3-month-old female SD rats were randomly divided into Sham group,model group,Xianlin Gubao group(0.24 g·kg-1),Desmodium renifolium low-dose group(1.35 g·kg-1,medium-dose group(2.7 g·kg-1)and high-dose group(5.4 g·kg-1).Osteoporosis was induced by performing double ovariectomy in rats.After 14 weeks treatment,the contents of osteocalcin(BGP),osteoprotectin(OPG)and alkaline phosphatase(ALP)in serum were determined.Hematoxylin-eosin(HE)staining was used to observe the changes of bone trabeculae.The osteoclast progenitor-cell line RAW264.7 was divided into negative control group,Receptor activator of nuclear factor-κB ligand(RANKL)group,Xianlin Gubao group,Desmodium renifolium low-dose,medium-dose and high-dose drug groups.The RANKL group and drug groups were induced with 50 ng·mL-1 RANKL.Meanwhile,Xianlin Gubao group and different concentrations of drug-containing serum of Desmodium renifolium,were added for intervention.Tartrate-resistant acid phosphatase(TRAP)staining was performed 10 days after intervention to observe the differentiation of osteoclasts,and quantitative real-time PCR(qPCR)was used to determine the mRNA expression.Results Compared with Sham group,the contents of OPG in serum of model group were significantly decreased(P<0.01),while ALP and BGP were significantly increased(P<0.01),bone trabeculae were significantly reduced,broken,sparsely arranged,and the space between bone trabeculae was large,the OPG mRNA expression in model group were significantly decreased(P<0.01),and the mRNA expression of receptor activator of nuclear factor-κB ligand(RANKL),TNF receptor associated factor 6(TRAF6),nuclear factor of activated t-cells,cytoplasmic 1(NFATC1),cathepsin K(CTK)and calcitonin receptor(CALCR)in model group were significantly increased(P<0.01),all these aspects showed remarkable improvement after Desmodium renifolium intervention.After 10 days of RAW264.7 culture,no osteoclasts were found in the Control group.Compared with the negative control group,osteoclasts in RANKL group were significantly increased,treatment with Desmodium renifolium markedly decreased osteoclast number,the result of RANKL/RANK/OPG signaling mRNA expression were consistent with the animal experiments.Conclusion Desmodium renifolium exerts effects on osteoporosis in ovariectomized rats,its mechanism might be realized by inhibiting osteoclast proliferation and differentiation,and regulating OPG/RANKL/RANK signaling pathway.