穿山龙总皂苷对去卵巢模型大鼠骨质疏松的改善作用

Improvement Effect of Total Saponins of Dioscoreae Nipponicae Rhizoma on Osteoporosis in Ovariectomized Model Rats

目的探讨穿山龙总皂苷对去卵巢模型大鼠骨质疏松的改善作用。方法将80只SD大鼠分为模型组(等体积0.9%氯化钠溶液)、17β-雌二醇组(1.6 g/kg)和穿山龙总皂苷低、高剂量组(2 g/kg和4 g/kg),各20只。麻醉大鼠,结扎输卵管,切除双侧卵巢,以复制去卵巢大鼠模型。建模成功后,各组大鼠灌胃给予相应药物(10 mL/kg)或等体积0.9%氯化钠溶液,每天1次,持续8周。另取20只大鼠作为正常对照组(等体积0.9%氯化钠溶液)。检测大鼠股骨骨密度(BMD)及股骨弹性模量、刚度、最大应力、最大承载力;苏木素-伊红(HE)染色观察大鼠股骨病理形态学;采用逆转录聚合酶链式反应(RT-PCR)法和Western blot法检测大鼠股骨组织Wnt、细胞外调节蛋白激酶(ERK)mRNA和蛋白表达水平。结果与模型组比较,17β-雌二醇组和穿山龙总皂苷低、高剂量组大鼠股骨BMD、弹性模量、刚度、最大应力、最大承载力,以及股骨组织Wnt、ERK mRNA和蛋白表达水平均显著升高(P <0.05);股骨远端小梁的形态结构改善,股骨小梁密度增加,空骨腔减少,小梁排列有序。结论穿山龙总皂苷能增加去卵巢骨质疏松模型大鼠的骨密度,逆转股骨的微观结构,并增强生物力学性能。其机制可能与促进Wnt、ERK mRNA和蛋白的表达,进而激活Wnt/ERK信号通路有关。

Objective To investigate the improvement effect of total saponins of Dioscoreae Nipponicae Rhizoma on osteoporosis in ovariectomized model rats.Methods A total of 80 SD rats were divided into the model group(equal volume of 0.9% Sodium Chloride Solution) and 17β-estradiol group(1.6 g/kg) and total saponins of Dioscoreae Nipponicae Rhizoma low-and highdose groups(2 g/kg,4 g/kg),with 20 rats in each group.The ovariectomized rat model was established by ligating fallopian tubes and removing bilateral ovaries after anesthesia.After successful modeling,rats in each group were gavaged with corresponding drugs(10 mL/kg) or equal volume of 0.9% Sodium Chloride Solution once a day for eight weeks.Another 20 rats were taken as the normal control group(equal volume of 0.9% Sodium Chloride Solution).The bone mineral density(BMD),elastic modulus,stiffness,maximum stress and maximum bearing capacity of rat femur were measured.The pathomorphology of rat femur was observed by the hematoxylin-eosin(HE) staining.The expression levels of Wnt mRNA and protein and extracellular regulated protein kinase(ERK) mRNA and protein in the tissue of rat femur were detected by the reverse transcription-polymerase chain reaction(RT-PCR) and Western blot.Results Compared with those in the model group,the BMD,elastic modulus,stiffness,maximum stress,maximum bearing capacity,the expression levels of ERK mRNA and protein and Wnt mRNA and protein in the 17β-estradiol group and total saponins of Dioscoreae Nipponicae Rhizoma low-and high-dose groups were significantly increased(P <0.05),and the morphological structure of distal femoral trabecular was improved,the density of femoral trabecular was increased,the empty bone cavity was reduced,and the trabecular arrangement was orderly in the 17β-estradiol group and total saponins of Dioscoreae Nipponicae Rhizoma low-and high-dose groups.Conclusion Total saponins of Dioscoreae Nipponicae Rhizoma can increase BMD,reverse the microstructure of femur and enhance its biomechanical properties in ovariectomized rats with osteoporosis.The mechanism may be related to promoting the expression of Wnt mRNA and protein and ERK mRNA and protein,and activating Wnt/ERK signaling pathway.