淫羊藿总黄酮对去卵巢大鼠骨组织Ⅰ型胶原代谢及组织蛋白酶K表达的影响

Effects of total flavonoids of Herba Epimedii on the metabolism of typeⅠcollagen and the expression of cathepsin K in the bone of ovariectomized rats

目的观察淫羊藿总黄酮(HEF)对去卵巢大鼠骨组织中Ⅰ型胶原蛋白代谢及组织蛋白酶K表达的影响。方法54只雌性SD大鼠随机分成6组。假手术组为阴性对照组,其余各组切除卵巢后分别不给予或给予HEF(每日40,80和160mg/kg)和尼尔雌醇(每日0.1mg/kg)治疗12周。测定大鼠全身骨密度和尿NTx/Cr比值,采用免疫组化法和Western印迹测定Ⅰ型胶原蛋白和组织蛋白酶K的含量。结果12周后,HEF可以增加去卵巢大鼠的全身骨密度(均P＜0.05)。HEF各组Ⅰ型胶原的表达升高,组织蛋白酶K的表达及尿中NTX/Cr水平明显下降,并呈剂量依赖关系,以高剂量组最为显著(P＜0.01)。结论HEF可能通过促进大鼠骨Ⅰ型胶原蛋白的合成、抑制其水解吸收从而提高大鼠骨密度,改善骨质量。

Objective To investigate the effects of total flavonoids of Herba Epimedii （HEF） on the metabolism of type Ⅰ collagen 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 type Ⅰ collagen （NTx） in the urine were determined by ELISA. The amounts of type Ⅰ collagen 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 FIEF treated groups were increased （ all P 〈 0.05 ）, and the expression levels of type Ⅰ collagen 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 type Ⅰ collagen in the bone.