Morphogenesis and remodeling of bone involve the synthesis of bone matrix by osteoblasts and the coordinate resorption of bone by osteoclasts. Osteoclasts are multinucleated giant cells differentiated from the precursors of monocyte/macrophage cell lineage. When osteoclasts more activated than osteoblasts cells can cause osteoporosis in human body. RANK signaling pathways is mediated by cytoplasm factor several different protein kinases signaling; these proteins are NF-κB kinase, JNK, p38, ERK, influence osteoclast formation and activation.
Stevioside is a natural sweetener that exists in leaves of Stevia rebaudiana Bertoni. Stevioside synthesis of new compounds derived from acid hydrolysis modified. Isosteviol derived compounds in the previous paper, having good biological activity, including anti-inflammation, antibacterial activity. In this study, the NC-8 (ent-16-oxobeyeran-19-N-methylureido) that is modification by biocatalytic or chemical of isosteviol .
Recently paper show, NC-8 inhibited HBV viral secretion of surface antigen and gene expression by interfere NF-κB signaling pathway. Both osteoblasts formation activation and NC-8 inhibits HBV by NF-κB signaling pathway. Thus, in this study we explore whether NC-8 will influence the formation of osteoclasts cells from RANKL induced RAW 264.7 cells by NF-κB signaling pathway.
We use MTT Assay observed NC-8 will result in RAW 264.7 cell toxicity and use tartrate- resistant acid phosphatase(TRAP) staining as the identification of osteoclast- specific staining. The experimental, we found that cytotoxic of NC-8 for RAW 264.7, the IC50 value is 40 μg/ml. In TRAP staining that NC- 8 is a novel effect which inhibits osteoclasts-like cell formation. Our experiments found that, RANKL induced ERK, p38 and JNK phosphorylation was inhibited by NC-8.
The novel function of NC- 8 demonstrated in this study indicates a new role for NC- 8 in negative regulation osteoclastogenesis and will be valuable in developing better strategies for treating osteopenic disorders in the future.
