菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症的改善作用及其机制

Effects of ethanol extract from semen cuscutae on postmenopausal osteoporosis in rats and its mechanism

目的观察菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症的改善作用并探讨其机制。方法雌性SD大鼠随机分为正常组、假手术组、模型组、雌激素对照组、菟丝子低剂量组、菟丝子高剂量组,每组10只。除正常组、假手术组外,各组均采用双侧去卵巢手术建立大鼠绝经后骨质疏松症模型;假手术组在暴露卵巢后切除卵巢周围脂肪组织,不切除卵巢;正常组正常喂养不做任何处理。于建模后两周起开始给药,菟丝子低剂量组、菟丝子高剂量组分别按0.7 g/kg、1.4 g/kg给予菟丝子乙醇提取物灌胃,雌激素对照组给予非甾体雌激素己烯雌酚灌胃,正常组、假手术组及模型组给予等容积生理盐水灌胃,连续给药12周。采用双能X线检测大鼠股骨骨密度,HE染色观察股骨组织病理形态,RT-PCR法检测股骨组织miR-21-5p,Western blotting法检测股骨组织Fas配体(FasL)蛋白。结果模型组股骨骨密度小于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组股骨骨密度大于模型组(P均<0.05)。正常组及假手术组骨皮质骨膜及骨内膜光滑,骨小梁形态粗细基本一致,皮质区仅出现轻微的松质骨改变;模型组骨小梁明显变薄,间隔增宽,互不相连,排列不齐,皮质区出现严重的松质骨改变;雌激素对照组、菟丝子低剂量组、菟丝子高剂量组骨小梁间距较模型组均有不同程度的减小,且皮质区松质骨改变变轻。模型组股骨组织miR-21-5p表达高于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组miR-21-5p表达低于模型组(P均<0.05)。模型组股骨组织FasL蛋白表达低于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组FasL蛋白表达高于模型组(P均<0.05)。结论菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症具有改善作用,其机制可能与调控miR-21-5p及其下游蛋白FasL有关。

Objective To observe the ameliorative effect of ethanol extract of semen cuscutae on postmenopausal osteoporosis in rats and to explore its mechanism.Methods Female SD rats were randomly divided into the normal group,sham operation group,model group,estrogen control group,low-dose semen cuscutae group,and high-dose semen cuscutae group,with 10 rats in each group.In addition to normal group and sham operation group,bilateral ovariectomy was performed in all groups to establish postmenopausal osteoporosis models.In the sham operation group,the adipose tissues around the ovary were removed after the ovary was exposed,but the ovary was not removed.Rats in the normal group were fed without any treatment.Starting from two weeks after modeling,rats in the low-dose semen cuscutae group and highdose semen cuscutae group were given ethanol extract of semen cuscutae by gavage at 0.7 and 1.4 g/kg,respectively;rats in the estrogen control group were given non-steroidal estrostilbestrol by gavage;rats in the normal group,sham operation group and model group were given equal volume of normal saline by gavage for 12 weeks.The bone mineral density(BMD)of rat femur was detected by dual-energy X-ray,and the pathological morphology of femur was observed by HE staining.The miR-21-5p of femur was detected by RT-PCR,and Fas ligand(FasL)protein of femur was detected by West ern blotting.Results The bone mineral density of femur in the model group was lower than that in the normal group and sham operation group,and the bone mineral density of femur was higher in the estrogen control group,low-dose semen cuscutae group and high-dose semen cuscutae group than in the model group(all P<0.05).Cortical periosteum and endosteum were smooth,trabecular shape was basically the same,and only slight cancellous bone changes appeared in the cortical area.In the model group,bone trabeculae became thinner,interval became wider,disconnected and was disordered,and there were serious cancellous bone changes in the cortical region.Compared with the model group,the bone trabecular distance decreased to different degrees,and the cortical cancellous bone changes became lighter in the estrogen control group,low-dose semen cuscutae group and high-dose semen cuscutae group.The expression of miR-21-5p in femur tissues of the model group was higher than that of the normal group and sham operation group,and the expression of miR-21-5p in the estrogen control group,low-dose semen cuscutae group and high-dose semen cuscutae group was lower than that of model group(all P<0.05).The expression of FasL protein in femur tissues of the model group was lower than that of the normal group and sham operation group,and that of estrogen control group,low-dose semen cuscutae group and high-dose semen cuscutae group was higher than that of the model group(all P<0.05).Conclusion Ethanol extract of semen cuscutae can improve postmenopausal osteoporosis in rats,and the mechanism may be related to the regulation of miR-21-5p and its downstream protein FasL.