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.
ABSTRACT
Obejective To study the effect of daidzein(Daid) on the enzymes of bone metabolism and bone rebuilding in ovariectomized rats.Method Sixty 3-mon female SD rats were divided into 6 groups:Sham,OVX,OVX-D1～D4 groups.Every day the rats in Sham and OVX groups were given distilled water,and the rats in OVX-D1,OVX-D2,OVX-D3,OVX-D4 groups were given 25,50,75,100 mg/kg bw Daid respectively.After 6 mon,all of rats were killed,and the blood,liver and femur were collected.The content of calcium and phosphorus in serum and the enzymes of bone metabolism were measured.Results The content of calcium,phosphorus and ATPase in serum was increased,but the activity of serum alkaline phosphatase(ALP) and tartrate-resistant acid phosphatase(TRAP-5b) was decreased dose-dependently in OVX-D groups compared with OVX group.Conclusion The expression of bone metabolism-associated enzymes could be inhibited,which resulted in inhibition of bone formation and absorbsion in ovariectomized rats.The new balance between bone formation and absorption could be rebuilt by Daid,through the mechanism of decreasing rate of bone conversion.