Effects of total flavonoids of Herba Epimedii on the metabolism of typeⅠcollagen and the expression of cathepsin K in the bone of ovariectomized rats / 中华内分泌代谢杂志

ABSTRACT

Objective To investigate the effects of total flavonoids of Herba Epimedii(HEF)on the metabolism of typeⅠcollagen and the expression of cathepsin K in the bone of ovariectomized(OVX)rats. Methods Fifty-four female SD rats were allocated into 6 groups;OVX group,sham operation group,OVX rats followed by three doses of HEF(40,80 and 160 mg?kg~(-1)?d~(-1))and nilestriol(0.1 mg?kg~(-1)?d~(-1))for 12 weeks respectively.Bone mineral density(BMD)of whole body was determined by dual-energy X-ray absoptiometry.The level of cross-linked N-telopeptide of typeⅠcollagen(NTx)in the urine were determined by ELISA.The amounts of typeⅠcollagen protein and cathepsin K protein in bone tissue were detected by immunohistochemical method and Western blotting.Results Compared with OVX group,the total BMD values in the HEF treated groups were increased(all P＜0.05),and the expression levels of typeⅠcollagen in three HEF treated groups rose significantly in a dose-dependent manner after 12 week,and simultaneously,both the expression of cathepsin K in bone and the level of NTx/Cr were reduced markedly(P＜0.05),being most significant(P＜0.01)in the group treated with the highest dose of HEF(160 mg?kg~(-1)?d~(-1)).Conclusion HEF seems to be able to elevate BMD and improve bone quality of rats via promoting synthesis and inhibiting proteolysis and absorption of typeⅠcollagen in the bone.