依普拉芬对去卵巢大鼠骨质疏松骨保护效果及NO调控机制研究

Effects of ipriflavone on protection on bone quality in ovariectomized (OVX) rats and its possible mechanisms through NO pathway

目的研究人工合成的植物雌激素-依普拉芬对去卵巢大鼠骨密度及生物力学的影响;同时与雌激素对照,探讨其骨保护效果及NO调控作用机制。方法60只6月龄SD雌性大鼠,随机分成6组:假手术组和手术切除大鼠双侧卵巢组,后者分为阴性对照组、依普拉芬低、中、高剂量组和雌激素对照组,分别给予基础饲料和不同剂量受试物,12周后进行骨密度、血清NO及NOS浓度测定;免疫组化方法检测股骨NOS表达。结果与假手术组相比,去卵巢大鼠阴性对照组股骨密度、生物力学指标和血清NO、eNOS浓度以及股骨eNOS表达明显降低,血清iNOS浓度以及股骨iNOS表达增加,依普拉芬组骨密度、生物力学指标血清NO、eNOS浓度以及股骨eNOS表达均高于阴性对照组,与假手术组差异无显著意义。同时低于雌激素组。血清iNOS浓度以及股骨iNOS表达均低于阴性对照组,与假手术组以及雌激素组差异无显著意义。结论一定浓度的依普拉芬可以通过提高去卵巢大鼠eNOS的表达来提高NO的浓度,促进成骨,增加骨密度,达到防治骨质疏松症的作用。

Objective To evaluate the effect of Ipriflavone （7-isopropoxyisoflavone, IP）on bone mineral density （BMD） and biomechanics and synthesis of nitric oxide （NO） and nitric oxide synathase（NOS） in ovariectomized （OVX） rats. Methods 60 six-month-old Sprague-Dawley female rats were randomly assigned to six groups： sham, OVX, ovx ＋ ipriflavone （50 mg/kg/d）, ovx ＋ ipriflavone （ 100 mg/kg/d） ovx ＋ ipriflavone （200 mg/kg/d） and ovx＋ 17β-estradiol （E2） （10ug/kg/d）. Diet and different doses of the test compounds were given. After 12weeks, bone mineral density（BMD）,indexes of biomechanics and the level of serum NO and NOS were detected in grouped rats. The expression of NOS in femur was detected by immunohistochemistry and in situ hybridization. Results In comparison with sham group, BMD and the level of serum NO, eNOS, expression of eNOS in femur of ovariectomized（OVX） rats decreased significantly（ P 〈 0.01 ）. The level of serum iNOS and expression of iNOS in femur increased significantly（ P 〈 0.01 ） . Some indexes of biomeehanical decreased significantly （P 〈 0.01 ）. Ipfiflavone could significantly increase BMD,the level of serum NO, eNOS,expression of eNOS in femur and some indexes of biomechanical comparison with OVX（ P 〈 0.01 ）. There was no statistical significance of the difference between Ipriflavone and sham group. Estrogen group obtained higher level of NO and eNOS than other groups. The level of serum iNOS and expression of iNOS in femur were less than OVX group（ P 〈 0.01 ）. There was no statistical significance of the difference between Ipritlavone, 17t3-estradiol and sham group. Conclusions Ipriflavone could increase significantly the synsthesis of NO by promoting expression of eNOS in ovariectomized （OVX） rats and consequently increase BMD of OVX rats and benefit postmenopausal osteoporosis （PMOP）.