The Role Of Diallyl Disulfide On Suppressing Osteoclastogenesis And Alleviating Inflammatory Osteolysis

Background and objectivesSkeletal homeostasis integrity is preserved by maintaining a delicate-balanced remodeling process,which is tightly regulated via osteoclastic bone resorption and osteoblastic bone formation.Osteoclasts are multinuclear giant cells responsible for bone resorption.With characteristics of excessive bone mass loss,inflammatory bone erosion,which is primarily caused by microbial products and inflammatory cytokines stimulating osteoclasts and enhancing the bone absorptive capacity constantly occurs after infection and chronic inflammation in the orthopedics field.Nowadays,inhibition of over-activated osteoclast and excessive bone resorption are gradually considered as a new strategy for the treatment of inflammatory bone erosion.Therefore,to explore the effect of Diallyl disulfide(DADS),a natural product derived from garlic with anti-inflammatory,antioxidant,and antitumor capacities,on osteoclasts is great significance for the clinical therapeutics of inflammatory bone erosion.Methods and ResultsAs osteoclast precursors,first of all,RAW264.7 cells and bone marrow macrophages(BMMs)were used to construct osteoclast differentiation and formation(osteoclastogenesis)model in vitro by employing the master regulators of osteoclast differentiation,RANKL and M-CSF.Then we investigated the effects of DADS on osteoclast differentiation,fusion and bone resorption.Lastly,we further determined whether the potential protective effects of DADS could be observed in a mouse model of LPS-induced calvarial osteolysis via subcutaneous injection.According to the results of the CCK8 assay,the dosages of DADS at 20 ?g/ml,40 ?g/ml,60 ?g/ml,and 80 ?g/ml were selected for further study.The results of TRAP stain,FAK stain and RT-qPCR revealed that DADS inhibited osteoclast differentiation,fusion and bone resorption in a dose-dependent manner.The results of Western blot and Co-Immunoprecipitation indicated that DADS suppressed osteoclastogenesis via down-regulating the activities of NF-?B and STAT3 signaling and inhibiting the combination of NF-?B p65 with NFATc1.Further more,the in vivo data from micro-CT and histological analysis similarly demonstrated the protective effects of DADS against LPS-induced inflammatory osteolysis.ConclusionsDADS could effectively inhibit the formation,fusion and bone resorption of osteoclasts,as well as reduce LPS-induced inflammatory bone destruction,suggesting that DADS has potential application value in preventing and impeding inflammatory osteolysis,and can be used as a new drug with clinical significance for in-depth exploration and research.