依达拉奉对大鼠急性脊髓损伤后bcl-2/bax表达及细胞凋亡的实验研究

目的观察依达拉奉对大鼠急性脊髓损伤后bcl-2/bax表达及细胞凋亡率的影响,探讨其对急性脊髓损伤后脊髓组织的保护作用。方法成年SD雄性大鼠60只,随机分成对照组和依达拉奉组,均采用改良Allen’s撞击法,致伤力为50gcf(10g×5cm)损伤T9～10制作动物模型,术后实验组给予依达拉奉3mg/kg,对照组给予等量生理盐水。每组分别于6h、12h、24h、72h、7d5个时间点处死动物取材,每个时间点6只大鼠,对受损脊髓部位进行免疫组织化学检测神经细胞凋亡因子bcl-2和bax基因的表达及用原位末端标记法(TUNEL法)标记神经元凋亡细胞。结果与对照组相比,依达拉奉组bcl-2蛋白表达水平显著提高,bax蛋白表达水平明显下降。对照组检测到较高的细胞凋亡率。依达拉奉组细胞凋亡率较对照组明显下降。结论依达拉奉可能通过清除氧自由基、上调bcl-2和下调bax蛋白表达来抑制大鼠脊髓损伤后神经细胞凋亡,从而保护大鼠神经组织。     

实验性大鼠颅眶联合伤后依达拉奉对视神经的保护作用

目的：探讨实验性大鼠颅眶联合损伤（cranio-orbital injury,COI）后视神经损伤机制及依达拉奉的保护作用。方法：144只清洁级SD大鼠,雌雄各半,随机分为对照组、损伤组和治疗组,每组48只。损伤组和治疗组大鼠利用液压冲击颅脑损伤仪建立颅眶联合伤模型,治疗组造模以后腹腔注射依达拉奉30 mg·kg-1,每日2次,共14日。3组分别在造模后3、6、10、14 d取视网膜组织,检测视网膜神经节细胞（retinal ganglion cells,RGCs）活性氧（reactive oxygen species, ROS）含量及不同时间点RGCs凋亡率,光镜下观察视网膜HE染色微观结构,共聚焦显微镜下观察RGCs的TUNEL荧光标记凋亡情况。结果：造模后损伤组RGCs的ROS含量逐渐升高,第10天达到高峰,RGCs凋亡率变化趋势与此相一致,与对照组及治疗组差异有统计学意义（P＜0.05）,治疗组与对照组相比较无明显差异。光镜下损伤组视网膜结构紊乱,损伤组RGCs的TUNEL荧光标记阳性率明显高于其余两组。结论：COI后RGCs的ROS含量明显升高,导致细胞出现凋亡失调。依达拉奉通过清除ROS逆转这一病理过程,具有明确的视神经保护作用,值得临床推广。     

依达拉奉对急性脊髓损伤后的大鼠神经组织氧化损害保护作

目的 探讨依达拉奉对急性脊髓损伤后的大鼠神经组织保护机制.方法 90只SD大鼠随机分为假手术组(n=30),ASCI对照组(n=30)和依达拉奉干预组(n=30),采用改良的Allen法,制成中度脊髓损伤大鼠模型;每组分别于6h、12h、24h、48h、72h5个时点,每个时点6只大鼠,检测各组各时点血清及脊髓中的NO、SOD、MDA的含量及脊髓组织含水量变化;TUNEL法检测72h后各组脊髓中的神经细胞凋亡及Caspase-3mRNA阳性细胞.结果 对照组各时点SOD活性明显低于假手术组,而NO、MDA含量明显高于假手术组,对照组各时点含水量与SOD活性呈明显负相关,与MDA含量呈明显正相关,依达拉奉干预组各时点SOD活性明显高于对照组,而NO、MDA含量明显低于对照组,依达拉奉干预组各时点含水量与SOD活性呈明显负相关,与MDA含量呈明显正相关,假手术组脊髓中无或偶见凋亡细胞及阳性染色细胞,对照组可见大量凋亡细胞及阳性染色细胞,依达拉奉干预组凋亡细胞及阳性染色细胞数量较对照组明显减少.结论 依达拉奉通过有效地清除氧自由基,可明显抑制急性脊髓损伤后的脂质过氧化反应及降低神经细胞的凋亡,从而达到保护其神经组织的作用.     

依达拉奉对培养乳鼠海马神经元缺血再灌注损伤的保护作用

目的:探讨依达拉奉对海马神经元缺血再灌注损伤的保护作用及其机制.方法:原代培养海马神经元细胞,制成缺血再灌注损伤模型,分别用 1 μmol·L-1、10 μmol·L-1、100 μmol·L-1、300 μmol·L-1 依达拉奉干预后,在细胞水平上研究依达拉奉对脂质过氧化、线粒体膜电位以及细胞内钙离子浓度的作用.结果:海马神经元在缺血再灌注损伤后,依达拉奉干预均能有效地降低脂质过氧化产物丙二醛含量,增加细胞内超氧化物歧化酶活性.与正常细胞相比,缺血再灌注损伤后,海马神经元的线粒体膜电位降低了60%,加入 100 μmol·L-1和 300 μmol·L-1依达拉奉可以显著提高损伤海马神经元的线粒体膜电位,达到正常神经元线粒体膜电位的82% 和87%.与正常对照组比较, 缺血再灌注损伤组细胞内钙离子浓度增加了81%.依达拉奉 100 μmol·L-1、300 μmol·L-1组的胞内钙离子浓度分别降低了35%和36%.结论:海马神经元缺血再灌注损伤后,依达拉奉具有清除氧自由基、抑制脂质过氧化、稳定线粒体膜电位及降低细胞内钙离子浓度的作用.     

依达拉奉对大鼠星形胶质细胞水通透性的影响

目的 探讨依达拉奉对缺氧复氧大鼠星形胶质细胞模型水通透性和水通道蛋白4（AQP4）的影响.方法 原代培养大鼠星形胶质细胞,通过95％（体积分数）N2培养8h和95％（体积分数）的空气复氧培养6h,构建缺氧复氧水肿模型.设置空白组（正常细胞）、对照组（水肿细胞未经受药物刺激）和刺激组（接受0.1、1、10或100μg/mL的依达拉奉溶液刺激）.采用细胞水通透性系数（Pd）检测、荧光定量PCR和Western Blot定量空白组、对照组和刺激组细胞水肿、AQP4 mRNA AQP4蛋白表达.结果 缺氧8h和复氧6h后细胞水肿,且AQP4表达量上升.0.1μg/mL依达拉奉刺激后,模型细胞水通量、AQP4 mRNA水平和蛋白表达量与未刺激过的水肿星形胶质细胞比较,差异无统计学意义（P均＞0.05）,1、10或100μg/mL依达拉奉刺激后,水肿星形胶质细胞水通量、AQP4 mRNA水平和蛋白表达量显著低于未刺激过的水肿星形胶质细胞（P均＜0.05）,与正常的星形胶质细胞比较,差异无统计学意义（P均＞0.05）.结论 1、10或100 μg/mL依达拉奉可通过抑制AQP4 mRNA水平和蛋白表达,从而抑制细胞水肿.     

依达拉奉通过抑制内质网应激途径对谷氨酸刺激神经元损伤的保护作用

目的 研究依达拉奉通过抑制内质网应激(ERS)途径对氧化应激损伤神经元的保护作用.方法 神经元原代培养鉴定后分为谷氨酸刺激组(A组)、依达拉奉预处理组(B组)和空白对照组(C组).流式细胞术检测细胞凋亡率,免疫荧光观察半胱天冬氨酸蛋白酶12 (Caspase-12)表达的变化,Western blot检测蛋白激酶R样内质网激酶(PERK)和Caspase-12的蛋白表达.结果 与C组相比,A组细胞凋亡率、PERK及Caspase-12的表达均明显增加(P＜0.05);而B组能显著抑制A组各观察指标的增加过程(P＜0.05).结论 依达拉奉可能通过抑制ERS途径降低神经元的凋亡,从而对神经元起保护作用.     

钩藤碱对缺血再灌注诱导大鼠星形胶质细胞损伤的作用

目的:以原代培养的大鼠大脑星形胶质细胞进行缺血再灌注损伤处理,观察钩藤碱(Rsy)对星形胶质细胞损伤的保护作用.方法:1～3 d龄SD大鼠乳鼠大脑星形胶质细胞原代培养,含连二亚硫酸钠的无糖Earle's液进行缺血缺氧处理造模,MTT法测定细胞存活率,Hoechst 33258荧光显微镜观察细胞形态学变化,流式细胞仪检测细胞坏死、凋亡率,用LDH试剂盒测定LDH漏出率.结果:与模型组比较,钩藤碱0.02、0.2 mg·mL-1均能显著提高细胞存活率,显著降低细胞坏死率和细胞凋亡率,也能显著降低细胞LDH漏出率.结论:钩藤碱对缺血再灌注损伤后星形胶质细胞的坏死凋亡具有显著抑制作用,提示钩藤碱可能通过抑制星形胶质细胞凋亡和坏死而对脑缺血损伤产生保护作用.     

依达拉奉对硝普钠诱导PC12细胞氧化应激的保护作用

目的研究依达拉奉对硝普钠诱导PC12细胞损伤的保护作用,并探讨其作用机制。方法以500μmol.L-1硝普钠诱导PC12细胞氧化应激损伤,MTT法测定细胞存活率,倒置显微镜观察细胞形态,流式细胞仪检测细胞凋亡,蛋白免疫印迹检测Bax和Bcl-2表达变化。结果依达拉奉在25μmol.L-1能增加氧化应激损伤细胞活力,在75μmol.L-1其保护作用达到峰值,能明显改善细胞形态结构,减少早期凋亡细胞数目,升高细胞Bcl-2/Bax比值。结论依达拉奉对硝普钠诱导的PC12细胞损伤具有保护作用,其机制可能与依达拉奉清除NO,抑制线粒体凋亡通路有关。     

金钗石斛多糖对脂多糖作用大鼠皮层胶质细胞-神经元体系的保护作用

目的观察金钗石斛多糖(NDP)对脂多糖(LPS)作用的新生大鼠大脑皮层胶质细胞-神经元混合培养体系的保护作用。方法原代制备新生大鼠大脑皮层胶质细胞-神经元混合培养体系,NDP作用于LPS刺激的胶质细胞-神经元混合培养体系,观察细胞生长情况,并采用Real time PCR法检测体系中炎症相关因子IL-1β、TNF-α、COX-2的基因表达。结果 NDP作用于LPS刺激的大鼠皮层胶质细胞-神经元混合培养体系后,胶质细胞激活减少、神经元损伤减轻,较单用LPS作用的模型组相比,炎症相关因子IL-1β、TNF-α、COX-2的基因表达明显降低。结论 NDP能抑制LPS对小胶质细胞和星形胶质细胞的激活,减少炎性因子的生成。     

依达拉奉对糖尿病大鼠局灶性脑缺血的神经保护作用

目的糖尿病是一种代谢性疾病,各种器官的结构和功能都发生了一定改变,包括中枢神经系统。本实验的研究目标探讨依达拉奉的对糖尿病大鼠脑缺血损伤保护作用。方法①应用高剂量腹腔注射链脲佐菌素(STZ)制作实验型2型糖尿病大鼠模型。②非糖尿病大鼠(n=20)和糖尿病大鼠(n=60)均制作大脑中动脉脑缺血模型。制模后局部大脑中动脉缺血30min再给给予依达拉奉及24h再灌注。三十只糖尿病大鼠MCAO 30min后,立即依达拉奉(100mg/kg,腹腔)。PCR检测凋亡诱导因子(AIF)被用来评估细胞凋亡。免疫组化检测细胞色素C。结果依达拉奉治疗后糖尿病大鼠的凋亡相关蛋白和细胞色素C较无药物治疗的明显减低(P<0.05)。免疫组化检测细胞色素C。结论依达拉奉治疗后糖尿病大鼠上减少改善糖尿病大鼠脑缺血再灌注损伤可能通过减低凋亡诱导因子,细胞色素C。     

The radical scavenger edaravone prevents oxidative neurotoxicity induced by peroxynitrite and activated microglia

The free radical scavenger edaravone has been used as an anti-oxidative agent in acute ischemic brain disorders. We examined the effect of edaravone on the production of nitric oxide (NO), reactive oxygen species (ROS) and proinflammatory cytokines by activated microglia, and we also examined its neuroprotective role in cortical neuronal cultures oxidatively stressed by the peroxynitrite donor N-morpholinosydnonimine (SIN-1) or activated microglia. Edaravone significantly suppressed the production of NO and ROS by activated microglia, though it did not suppress production of inflammatory cytokines. In addition, edaravone significantly suppressed neuronal cell death and dendrotoxicity induced by either SIN-1 or activated microglia in a dose-dependent manner. These results suggest that edaravone may function as a neuroprotective agent counteracting oxidative neurotoxicity arising from activated microglia, as occurs in either inflammatory or neurodegenerative disorders of the central nervous system.     

Pharmacological and clinical profile of the free radical scavenger edaravone as a neuroprotective agent

The involvement of oxygen radical species has been implicated in ischemic and post-ischemic brain cell damage. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; M.W. 174.20, MCI-186, Radicut Injection) has an inhibitory effect on lipid peroxidation by scavenging free radicals and prevents vascular endothelial cell injury. In rat brain ischemic models, post-ischemic treatment with edaravone reduces .OH production and infarction of the ischemic penumbral area and suppresses delayed neuronal death. It also improves neurological deficits and diminishes deterioration of brain edema observed after ischemia. We investigated the efficacy and safety of edaravone in acute ischemic stroke patients. Edaravone improved the core neurological deficits, impaired activities of daily living, and disability, without serious safety problems. Edaravone was approved in Japan for the treatment of acute brain infarction within 24 h after onset in April, 2001. We hope that edaravone represents a promising neuroprotective agent that can contribute to the treatment of acute ischemic stroke.     

Neuroprotective effect of Smilacis chinae rhizome on NMDA-induced neurotoxicity in vitro and focal cerebral ischemia in vivo

Previous work has shown that the Smilacis chinae rhizome (SCR) markedly inhibits amyloid beta protein (25-35)-induced neuronal cell damage in cultured rat cortical neurons. The present study was conducted to further verify the neuroprotective effect of SCR on excitotoxic and cerebral ischemic injury using both in vitro and in vivo studies. Exposure of cultured cortical neurons to 1 mM N-methyl-D-aspartate (NMDA) for 12 h induced neuronal cell death. SCR (10 and 50 microg/ml) inhibited NMDA-induced neuronal death, elevation of intracellular calcium ([Ca(2+)](i)), and generation of reactive oxygen species (ROS) in primary cultures of rat cortical neurons. In vivo, SCR prevented cerebral ischemic injury induced by 3-h middle cerebral artery occlusion (MCAO) and 24-h reperfusion. The ischemic infarct was significantly reduced in rats that received SCR (30 and 50 mg/kg, orally), with a corresponding improvement in neurological function. Moreover, SCR treatment significantly decreased the histological changes observed following ischemia. Oxyresveratrol and resveratrol isolated from SCR also inhibited NMDA-induced neuronal death, increase in [Ca(2+)](i), and ROS generation in cultured cortical neurons, suggesting that the neuroprotective effect of SCR may be attributable to these compounds. Taken together, these results suggest that the neuroprotective effect of SCR against focal cerebral ischemic injury is due to its anti-excitotoxic effects and that SCR may have a therapeutic role in neurodegenerative diseases such as stroke.     

Edaravone inhibits JNK-c-Jun pathway and restores anti-oxidative defense after ischemia-reperfusion injury in aged rats

Edaravone, a potent antioxidant, is currently being used in the management of acute ischemic stroke in relatively high-aged populations. Mitogen activated protein kinase (MAPK) pathways have been shown to play important roles in neuronal cell death. We examined the role of MAPK pathways and the effect of treatment with edaravone in the brain after cerebral ischemia-reperfusion (I/R) injury in a bilateral carotid artery occlusion (BCAO) model with ischemia for 85 min followed by reperfusion for 45 min in aged rats. Western immunoblotting, immunostaining, enzyme-linked immunosorbent assay (ELISA), spectrophotometry, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) and triphenyl tetrazolium chloride (TTC) staining were performed to evaluate various proteins in the homogenate, c-Jun NH2-terminal kinase (JNK) in the tissue sections, protein carbonyl, glutathione peroxidase (GSHPx), apoptosis and infarct size, respectively. Our results showed that I/R injury resulted in a reduction of GSHPx, but protein carbonyl content and inducible nitric oxide synthase were increased. The activation of JNK and its downstream molecule c-Jun was significantly increased after injury, whereas the activities of p38 MAPK and extracellular-regulated kinase 1/2 were slightly but not significantly increased. Edaravone (3 mg/kg, i.v.) treatment significantly reduced all of these changes. Our findings suggest that the JNK pathway differentially mediates neuronal injury in aged rats after BCAO, and edaravone treatment significantly reduces the neuronal damage after I/R injury by inhibiting oxidative stress and the JNK-c-Jun pathway with concomitant inhibition of overall MAPK activity in the brains of aged rats.     

Neuroprotective effects of edaravone: a novel free radical scavenger in cerebrovascular injury

Recanalization and neuroprotection have been mainly targeted for the specific treatment of acute ischemic stroke. Free radicals play a crucial role in brain ischemic injury by exacerbating membrane damage through peroxidation of unsaturated fatty acids of cell membrane, leading to neuronal death and brain edema. Free radicals have been implicated in stroke pathophysiology as pivotal contributors to cell injury. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) is a novel potent free radical scavenger that has been clinically used to reduce the neuronal damage following ischemic stroke. Edaravone exerts neuroprotective effects by inhibiting endothelial injury and by ameliorating neuronal damage in brain ischemia. Edaravone provides the desirable features of NOS: it increases eNOS (beneficial NOS for rescuing ischemic stroke) and decreases nNOS and iNOS (detrimental NOS). Post- reperfusion brain edema and hemorrhagic events induced by thrombolytic therapy may be reduced by edaravone pretreatment. Increased productions of superoxide and NO in the brain after reperfusion and a concomitant surge in oxygen free radicals with increased NO during recirculation lead to formation of peroxynitrite, a superpotent radical. Edaravone, which inhibits oxidation and enhances NO production derived from increased eNOS expression, may improve and conserve cerebral blood flow without peroxynitrite generation during reperfusion. Clinical experience with edaravone suggests that this drug has a wide therapeutic time window. The combination therapy (a thrombolytic plus edaravone) is likely to target brain edema, reduce stroke death and improve the recovery from neurological deficits in stoke patients.     

Edaravone, a radical scavenger, inhibits mitochondrial permeability transition pore in rat brain

Edaravone, a radical scavenger, prevents ischemia/reperfusion injury in the brain, but the detailed mechanism is not known. This study examines the effect of edaravone on mitochondrial permeability transition pore (PTP) in rat brain. Edaravone at 10 - 100 microM inhibited Ca(2+)- and H(2)O(2)-induced swelling of mitochondria isolated from rat brain. Addition of Ca(2+) generated reactive oxygen species (ROS) in isolated mitochondria. Edaravone (10 - 100 microM) inhibited Ca(2+)-induced generation of ROS. These results suggest that edaravone inhibits opening of mitochondrial PTP in the brain, and they imply that inhibition of mitochondrial PTP may account for the neuroprotective effect of edaravone.     

黄芪提取物对缺氧/复氧诱导神经元损伤的保护作用

目的探讨黄芪提取物在缺氧/复氧所致神经元损伤中的保护作用。方法原代培养大鼠海马神经元细胞,建立缺氧/复氧损伤的海马神经元凋亡模型。采用四唑盐(MTT)法和LDH释放法检测细胞活力;Hoechst染色、Annexin V/PI双染流式细胞术检测细胞凋亡;Western blot法检测AKT和磷酸化AKT蛋白的表达。结果经缺氧/复氧后细胞活力明显下降,出现凋亡典型的形态学特征,磷酸化AKT蛋白表达下降;黄芪提取物能明显提高损伤海马神经元细胞活力,降低细胞凋亡率,促进磷酸化AKT蛋白的表达。结论黄芪提取物对缺氧/复氧神经元具有保护作用,其机制可能与激活PI3K/AKT细胞信号通路有关。     

Schizandrin protects primary cultures of rat cortical cells from glutamate-induced excitotoxicity

The neuroprotective effect of schizandrin on the glutamate (Glu)-induced neuronal excitotoxicity and its potential mechanisms were investigated using primary cultures of rat cortical cells. After exposure of primary cultures of rat cortical cells to 10 microM Glu for 24 h, cortical cell cultures exhibited remarkable apoptotic death. Pretreatment of the cortical cell cultures with schizandrin (10, 100 microM) for 2 h significantly protected cortical neurons against Glu-induced excitotoxicity. The neuroprotective activity of schizandrin was the most potent at the concentration of 100 microM. Schizandrin reduced apoptotic characteristics by DAPI staining in Glu-injured cortical cell cultures. In addition, schizandrin diminished the intracellular Ca2+ influx, inhibited the subsequent overproduction of nitric oxide (NO), reactive oxygen species (ROS), and cytochrome c, and preserved the mitochondrial membrane potential. Furthermore, schizandrin also increased the cellular level of glutathione (GSH) and inhibited the membrane lipid peroxidation malondialdehyde (MDA). As indicated by Western blotting, schizandrin attenuated the protein level changes of procaspase-9, caspase-9, and caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Taken together, these results suggest that schizandrin protected primary cultures of rat cortical cells against Glu-induced apoptosis through a mitochondria-mediated pathway and oxidative stress.     

依达拉奉对谷氨酸所致神经干细胞损害的保护作用

目的探讨依达拉奉对谷氨酸所致神经干细胞损害的保护作用及机制。方法取大鼠13.5 d胚胎皮质,提取神经干细胞,分为谷氨酸处理组(500μmol/L)、依达拉奉干预组(500μmol/L谷氨酸+500 ng/mL依达拉奉)和正常对照组。谷氨酸及依达拉奉处理24 h后,应用光学显微镜高倍下观察各组细胞的形态和数量;并对各组细胞作DAPI及TUNEL染色,计数阳性细胞。结果与正常对照组比较,谷氨酸处理组细胞的数量减少(P<0.05);依达拉奉组细胞的数量较谷氨酸组明显增多(P<0.05)。谷氨酸处理组的TUNEL阳性细胞明显多于正常对照组(P<0.05),依达拉奉组的TUNEL阳性细胞明显少于谷氨酸组(P<0.05)。结论依达拉奉通过拮抗谷氨酸诱导的细胞凋亡对谷氨酸所致的神经干细胞损害起到保护作用。     

Protective effect of edaravone against hypoxia-reoxygenation injury in rabbit cardiomyocytes

1 We examined whether edaravone (Eda), a clinically available radical scavenger, directly protects cardiomyocytes from ischemia/reperfusion (I/R) injury, and whether the timing of its application is critical for protection. 2 Cardioprotective effects of edaravone were tested in the modified cell-pelleting model of ischemia and under exogenous oxidative stress (hydrogen peroxide: H2O2) in isolated adult rabbit ventricular cells. Cell death and reactive oxygen species (ROS) generation were detected using propidium iodide (PI) and DCFH-DA, respectively. These parameters were evaluated objectively using flow cytometory. 3 Hypoxia and reoxygenation aggravated the proportion of dead cells from 32.2+/-1.8% (Baseline) to 51.3+/-2.7% (Control). When 15 microm edaravone was applied either throughout the entire experiment (Through) or only at reoxygenation (Reox), cell death was significantly reduced to 39.9+/-1.8% (P<0.01 vs Control) and 43.3+/-2.5% (P<0.05 vs Control), respectively. In contrast, when edaravone was applied 10 min after reoxygenation, its protective effect disappeared. Cardioprotection by edaravone was more remarkable than that afforded by other free radical scavengers, such as ascorbate and superoxide dismutase (SOD). There is a positive correlation between the cardioprotective effect of edaravone and the extent of ROS reduction. 4 Edaravone blunted the H2O2-induced changes in electrical properties, and significantly prolonged the time to contracture induced by H2O2 in single ventricular myocytes. 5 Taken together, edaravone directly protects cardiomyocytes from I/R injury by attenuating ROS production, even when applied at the time of reoxygenation, suggesting that edaravone could be a potent cardioprotective therapeutic agent against hypoxia-reoxygenation injury.