远志皂苷对Aβ1-40诱导痴呆大鼠海马神经细胞线粒体的保护作用  

Protective effect of Tenuigenin on structure and function of mitochondria of hippocampal neurons in dementia rats induced by amyloid beta-protein 1-40

作　　者：黄炎[1] 陈逸青[2] 陈勤[1] 胡冠宇[1] 曹炎贵[1] 徐雪婷[1] 

机构地区：[1]安徽大学生命科学学院、安徽省中药研究与开发重点实验室,合肥230601 [2]德国海德堡大学曼海姆医学院,德国曼海姆68167

出　　处：《中药药理与临床》2015年第1期93-97,共5页Pharmacology and Clinics of Chinese Materia Medica

基　　金：安徽省教育厅自然科学研究项目(KJ2009A116);安徽大学大学生科研训练计划项目(2013024);教育部大学生创新性实验项目(201310357035);《细胞生物学》省级精品课程项目(2009024)

摘　　要：目的:观察远志皂苷对AD大鼠海马神经细胞中线粒体结构与功能的变化,探讨远志皂苷的神经保护作用机制。方法:将50只SD大鼠随机分为假手术组、AD模型组、远志皂苷18.5 mg/kg组、37 mg/kg组和74 mg/kg组。向大鼠海马CA1区注射凝聚态Aβ1-40制备AD模型,造模成功后第3 d开始给药,远志皂苷三个剂量组分别按74 mg/kg、37 mg/kg及18.5 mg/kg剂量灌胃治疗,假手术与模型组在相应时间点灌胃等体积生理盐水,连续用药60 d。采用电镜观察神经细胞中线粒体的超微结构,免疫组化法观察海马组织CA1区细胞色素C的表达,用流式细胞法检测海马神经细胞线粒体膜电位和细胞凋亡率,用比色法检测线粒体的抗氧化酶活性和MDA含量,蛋白免疫印记技术检测海马神经细胞中Cyt c的表达水平。结果:与假手术组相比,AD模型组大鼠海马神经细胞中线粒体数目减少,结构肿胀呈空泡变性,线粒体嵴畸变或消失。而经用药60 d后,与模型组相比,18.5 mg/kg、37 mg/kg及74 mg/kg三个剂量组线粒体不仅数量增多,且线粒体结构大多趋于正常。与假手术组相比,AD模型组大鼠海马CA1区神经元胞质中Cyt c阳性率升高72.85%,且细胞形态不完整,神经细胞线粒体膜电位下降21.45%,细胞凋亡率增加84.52%,同时伴有线粒体内SOD和GSH-PX活性明显下降,而MDA浓度异常升高,线粒体中Cyt c的表达水平显著升高。经远志皂苷治疗60 d后,与AD模型组相比,18.5 mg/kg、37 mg/kg及74 mg/kg三个剂量组均可使上述各项指标明显得到改善。结论:远志皂苷能较好地保护线粒体的超微结构,稳定线粒体膜电位,降低细胞凋亡率和Cyt c的表达,提高海马神经细胞中线粒体SOD、GSH-PX活性和降低MDA的水平,从而达到减轻Aβ1-40神经毒性,保护神经元的治疗目的。Objective： To observe the changes of tenuigenin（ TEN） on the structure and function of mitochondria of hippocampal neurons in dementia rats induced by amyloid beta-protein 1-40（ Aβ1-40） and to investigate the neuroprotective mechanism of TEN. Methods： Fifty SD rats were randomly divided into sham operation group,AD model group,TEN 18. 5mg / kg,37. 0 mg / kg and 74. 0 mg / kg groups. The AD mouse model was established by injection of pre-aggregated Aβl-40 into the CA area of hippocampus. Three days after modeling,different doses of TEN（ 18. 5 mg、37. 0 mg and 74. 0 mg / kg） were used for different group treatment respectively through gastric perfusion for 60 days,while sham operation and Aβ model groups with same volume of normal saline. Ultrastructure of mitochondrias of hippocampal neurons were observed by electron microscope. Cytochrome C in CA1 area of hippocampus was investigated by immunohistochemistry. the membrane potential and apoptosis rate of hippocampal neurons were examined by flow cytometry. autioxidant enzyme activities and MDA concentration of mitochondria were detected by colorimetry. The expression levels of Cyt c were detected through western blot analysis. Results： Compared with sham operation group,the number of mitochondria of hippocampal neurons in AD rats decreased. The structure showed swelling and vacuolar degeneration with cristae aberration or disappearance. While after treatment of TEN for 60 days,numbers and structures of most mitochondrias in three different doses of TEN groups returned to normal. In model group,the expression of Cyt c in neuron cytoplasm of CA1 area of hippocampus elevated 72. 85%. The cellular morphology was not intact. Membrane potential of mitochondria declined 21. 45%. Apoptosis rate rose 84. 52%. The activities of SOD and GSH-PX were lower significantly（ P 〈0. 01,P 〈0. 01） than normal while concentration of MDA was unusually higher（ P 〈0. 01） and the expression of Cyt c increased obviously（ P 〈0. 01）. After treatment fo

关 键 词：远志皂苷 线粒体超微结构 细胞色素C 细胞凋亡率 膜电位 

分 类 号：R285.5[医药卫生—中药学]