摘要
目的:研究菟丝子总黄酮对内分泌衰退痴呆模型小鼠学习记忆功能的影响,并探讨其可能的作用机制。方法:将50只昆明种雌性小鼠随机分为模型组,雌激素对照组(0.3 mg·kg-1),菟丝子总黄酮低剂量组(35mg·kg-1),菟丝子总黄酮中剂量组(70 mg·kg-1)和菟丝子总黄酮高剂量组(140 mg·kg-1),采用背部去卵巢法切除双侧卵巢,另取10只小鼠作为假手术对照组,建立内分泌衰退小鼠模型,术后各治疗组进行灌胃给药治疗三个月,假手术组和模型组均给予0.9%生理盐水。给药结束后采用Morris水迷宫观察小鼠行为学变化;放射免疫法检测小鼠血液中雌激素的水平;HE染色光镜观察海马神经元病理形态;流式细胞仪检测小鼠海马神经细胞凋亡率和免疫印迹法检测海马区神经细胞凋亡相关蛋白(Bcl-2、Bax、Csapase-3)及Cyt-c蛋白的表达水平。结果:与假手术组相比,模型组小鼠学习记忆能力明显下降(P<0.01);血液中雌激素水平显著降低(P<0.01);海马神经细胞凋亡率显著增加(P<0.01);Cyt-c、Caspase-3、Bax蛋白表达水平大大增加(P<0.01),Bcl-2蛋白表达降低明显(P<0.01)。与模型组相比,TFSC各治疗组小鼠学习记忆能力显著增强(P<0.05,P<0.01,P<0.01);血液中雌激素水平上升显著(P<0.05,P<0.01,P<0.01);小鼠海马区神经细胞凋亡率明显下降(P<0.05,P<0.01,P<0.01);同时Cyt-c、Caspase-3、Bax蛋白表达水平均大大降低,Bcl-2蛋白表达均明显增加(P<0.05,P<0.05,P<0.01)。结论:TFSC可上调脑细胞中Bcl-2蛋白的表达水平,抑制Bax、Caspase-3和Cyt-c蛋白的表达量,进而增强神经元的可塑性和营养性,以防止神经细胞从内源性线粒体途径丢失或凋亡,进一步改善内分泌衰退型痴呆小鼠的学习记忆能力。TFSC可能是通过促进或增强下丘脑-脑垂体-性腺轴功能,从而达到增加雌激素水平和改善内分泌系统功能的目的。
Objective：To discover and research the influence and mechanism of total flavonoids from semen cuscutae （TFSC）on learning-memory function of Alzheimer’s disease mice with hypoendocrinism.Methods：50 female Kunming mice were randomly divided into five groups：model group,control group with estrogen （0.3 mg·kg-1 ）,experimental groups with low-dose（35 mg·kg-1 ）,middle-dose（70 mg·kg-1 ）,high-dose（140 mg·kg-1 ）of TFSC treatment.The mod-el of Alzheimer disease with hypoendocrinism were built by removing bilateral ovaries from backside .Another 10 female Kunming mice were treated with sham operation as the control group.After ovariectomization,four groups of mice were intragastric administrated with estrogen or TFSC for three months,sham operation group and model group mice were in-tragastric administrated with NS.The learning-memory ability of the mice were assessed by Morris water maze behavioral test;The levels of estrogen in serum were tested by radioimmunoassay;Neuronal pathological morphology in hippocam-pus were observed through hematoxylin-eosin staining（HE）.The apoptotic rate of hippocampal neurons were tested by flow cytometry;The expression of apoptosis-related proteins （Bcl-2,Bax,Caspase-3）and Cyt-c in hippocampal neu-rons were measured by Western blotting.Results：Compared with sham operation group,the abilities of learning-memory of the mice in model group were apparently declined（P＆lt;0.01）;The estrogen level of serum in model mice significantly reduced（P＆lt;0.01）;The apoptosis rate of hippocampal neurons in model mice significantly increased（P＆lt;0.01）;the expression of Bax,Caspase-3 and Cyt-c of hippocampal neuron of model mice significantly reduced（P＆lt;0.01）,the ex-pression of Bcl-2 increased significantly（P＆lt;0.01）.Compared with the model group,the abilities of learning-memory of the mice of TFSC treatment significantly increased（P＆lt;0.05,P＆lt;0.01,P＆lt;0.01）,the estrogen level of serum rised（P＆lt;0.05,P＆lt;0.01,P＆lt;0.01）;Apoptotic rate and expression of Caspase-3,Bax,Cyt-c detected from hippocampal neu-rons remarkably decreased.In contrast,the level of Bcl-2 increased（P ＆lt;0.05,P＆lt;0.05,P＆lt;0.01）.Conclusions：TF-SC can improve the expression of Bcl-2 and inhibit the proteins of Bax,Caspase-3 and Cyt-c in hippocampal neurons to block the apoptosis from endogenously mitochondria apoptosis pathway.TFSC can also enhance the plasticity and nutri-tion of neurons in order to improve the learning-memory ability of Alzheimer’s disease mice with hypoendocrinism.TFSC may improve the function of hypothalamus-pituitary-gonad axis to regulate estrogen levels and improve endocrine system.
出处
《激光生物学报》
CAS
CSCD
2014年第3期218-226,共9页
Acta Laser Biology Sinica
基金
安徽省教育厅自然科学研究项目(KJ2012A031)
<细胞生物学>省级精品课程项目(2009024)
安徽省教育厅教学研究项目(2012jyxm080)
教育部大学生创新性实验项目(201210357043)
作者简介
通讯作者：陈勤（1958-），男，安徽当涂人，教授，博士，研究方向：细胞信号转导与药物基础研究。（电子邮箱）chenqin169@163．com
