Protective effect of cinnamic aldehyde on hormone-induced osteoclasts differentiation and its molecular mechanisms / 中国药理学通报

ABSTRACT

Aim To investigate the protective effect of cinnamic aldehyde ( CA ) on hormone-induced osteo-clasts proliferation and bone resorption in vitro and its molecular mechanisms. Methods RAW264. 7 cells induced into osteoclast were treated with RANKL and M-CSF and then were divided into control group, dexa-methasone ( DEX ) group and different doses of CA (11. 6, 23. 2, 46. 4 μg·L-1 ) groups. OCs were ob-served after tartrate resistant acid phosphatase( TRAP) staining. The cell proliferation was determined by MTT assay at different time points. The expression levels of TRACP5 b in cell cultured supernatants were measured by ELISA. RT-PCR technique was applied to examine the transcriptional levels of RANK and NFATc1 . Re-sults In MTT assay, the proliferation of osteoclasts stimulated by dexamethasone was promoted seriously compared with negative control group ( P < 0. 05 ) . Meanwhile, DEX could strengthen the content of TRACP5 b and up-regulate the expressions of RANK and NFATc1 mRNA. After administration of CA, the proliferation was inhibited, while the enhanced expres-sion of TRAP5b was reversed,and the over-expressions of RANK and NFATc1 mRNA were obviously down-regulated in a time-and-dose-dependent manner ( P <0. 05 ) . Conclusion The results suggest that CA in-hibits proliferation and bone resorption of osteoclast in-duced by DEX, which may be mediated by down-regu-lation of RANK and NFATc1 mRNA.