促红细胞生成素对大鼠局灶性脑缺血再灌注神经元的保护作用及P53蛋白的表达

目的:探讨促红细胞生成素(Epo)对大鼠局灶性脑缺血再灌注神经细胞的保护作用.方法:60只SD大鼠随机分为缺血再灌注Epo治疗组(又分为高剂量A组、低剂量B组)、缺血再灌注组(C组)及假手术组(D组),采用大脑中动脉线栓法制备大鼠局灶性脑缺血再灌注模型.参考Longa的5分制法在大鼠麻醉清醒后进行评分,TTC染色法观察线栓侧的梗死体积,并检测脑组织含水量的变化,HE染色法观察脑缺血再灌注后脑组织的病理变化,TUNEL法观察神经细胞凋亡情况,western blot法观察p53蛋白的表达变化.结果:对照组比较,大鼠脑缺血再灌注后出现不同程度的脑梗死,24h后缺血中心区及周围区均可见到p53蛋白表达.缺血再灌注6h内给予Epo可显著改善大鼠神经功能评分,减少梗死体积及脑组织含水量,减轻病理学变化及神经细胞凋亡.结论:Epo通过调控神经细胞凋亡、改善缺血再灌注损伤而发挥脑保护作用,P53蛋白参与缺血再灌注后神经细胞凋亡机制.     

亚低温联合镁剂对脑缺血再灌注大鼠保护作用的研究

目的:rt-PA溶栓为缺血性卒中最有效的治疗方法,脑血流再通后挽救濒临死亡的神经细胞同时,也可能发生更为严重而持久的脑缺血再灌注损伤。本研究探讨联合应用局部亚低温(32-35℃)及硫酸镁对局灶性脑缺血再灌注大鼠的保护作用及其可能机制。方法:通过线栓法建立大鼠大脑中动脉阻塞(MCAO)及再通模型,将50只雄性Wistar大鼠随机分为假手术组、常温组、亚低温组、硫酸镁组、亚低温+硫酸镁组,每组10例,采用Longa神经功能评分、TTC染色、干湿重法、TUNEL技术,检测和比较各组脑缺血再灌注后大鼠的神经功能、脑梗死体积、脑组织含水量及凋亡细胞数。结果:与常温组相比,亚低温组与亚低温+硫酸镁组的梗死体积、神经功能评分、脑组织含水量、凋亡细胞数均明显降低,差异有显著意义(P0.05);而与亚低温组相比,亚低温+硫酸镁组局灶脑缺血大鼠的脑梗死体积、神经功能评分、脑组织含水量、凋亡细胞数均显著减少,差异有显著意义(P0.05)。结论:与单独应用亚低温相比,局部亚低温与硫酸镁联合应用,对局灶性脑缺血再灌注大鼠可发挥更有效的脑保护作用。其机制可能与抑制脑缺血再灌注后凋亡及减轻脑水肿有关。二者联用可能为缺血性卒中患者提供一种减轻溶栓后再灌注损伤的有效脑保护方法。     

缺血后适应对局灶性脑缺血/再灌注大鼠caspase-3表达的影响

目的：探讨缺血后适应对大鼠局灶性脑缺血/再灌注损伤后caspase-3表达的影响。方法：大脑中动脉线拴法复制大鼠局灶性脑缺血/再灌注损伤动物模型。将30只雄性SD大鼠随机分为3组（n=10）：假手术组（sham组）、缺血/再灌注（I/R）组和缺血后适应（IP）组。利用原位缺口末端标记法观察神经细胞凋亡的变化。应用Western blot检测大鼠局灶性脑缺血/再灌注损伤后caspase-3蛋白表达水平的变化。结果：大鼠脑缺血/再灌注后凋亡细胞数量和caspase-3蛋白表达水平均显著升高,而缺血后适应组凋亡细胞数量和caspase-3蛋白表达水平均显著低于缺血/再灌注组（P〈0.01）。结论：缺血后适应可抑制大鼠脑缺血/再灌注后细胞凋亡的发生,此作用可能与下调caspase-3蛋白表达有关。     

缺血后适应对局灶性脑缺血/再灌注大鼠p38表达的影响

目的：探讨缺血后适应对大鼠局灶性脑缺血/再灌注损伤后p38表达的影响。方法：将30只雄性SD大鼠随机分为3组（n=10）：假手术组（sham组）、缺血/再灌注（I/R）组和缺血后适应（IP）组。利用TUNEL法观察神经细胞凋亡的变化,应用Westernblot检测大鼠局灶性脑I/R损伤后p38蛋白表达水平的变化。结果：大鼠脑缺血/再灌注后凋亡细胞数量和p38蛋白表达水平均显著升高,而IP组凋亡细胞数量和p38蛋白表达水平均显著低于IR组（P〈0.01）。结论：缺血后适应可抑制大鼠脑缺血/再灌注后细胞凋亡的发生,此作用可能与下调p38蛋白表达有关。     

PEP-1 超氧化物歧化酶对大鼠脑缺血再灌注后Bcl-2 的影响

目的:观察细胞穿透肽-铜,锌超氧化物歧化酶(PEP-1-SOD1)预处理对大鼠局灶性脑缺血再灌注损伤的改善作用及其脑保护机制。方法:线栓法建立大鼠局灶性脑缺血6h后再灌注损伤模型,进行神经行为评分,并通过HE染色在光镜下观察神经细胞损伤变化,免疫组化法检测B细胞淋巴瘤基因-2(B-cell lymphoma-2,Bcl-2)蛋白的阳性表达。结果:盐水对照组(缺血再灌注组或模型组)神经障碍显著高于假手术组(P<0.05),与模型组相比,PEP-1-SOD1预处理组可降低神经障碍评分(P<0.05);光镜下,假手术组神经细胞结构正常,PEP-1-SOD1预处理组和缺血再灌注组均有不同程度的缺血再灌注损伤,PEP-1-SOD1预处理组较缺血再灌注组损伤轻;假手术组Bcl-2蛋白表达极弱,缺血再灌注组和PEP-1-SOD1预处理组在脑缺血再灌注后6h在缺血半暗带周围出现Bcl-2蛋白阳性表达,24h达到高峰,48h表达开始减少。与假手术组相比,PEP-1-SOD1预处理组和缺血再灌注组Bcl-2蛋白阳性细胞数显著增多(P<0.05);与缺血再灌注组相比,PEP-1-SOD1预处理组Bcl-2蛋白阳性细胞数显著增多(P<0.05)。结论:PEP-1-SOD1对大鼠局灶性脑缺血再灌注损伤有保护作用,PEP-1-SOD1可通过上调Bcl-2蛋白的表达发挥脑保护作用。     

甘草查尔酮A对局灶性脑缺血再灌注小鼠Nrf2/HO-1信号通路和神经炎症反应的影响

目的:探讨甘草查尔酮A对局灶性脑缺血再灌注小鼠Nrf2/HO-1信号通路和神经炎症反应的影响。方法:体重23~25 g的雄性C57BL/6小鼠总计96只,随机分为4组(n=24):假手术对照组(Sham组)、脑缺血再灌注组(MCAO组)、溶剂组(Vehicle组)、甘草查尔酮A组(LA组)。采用大脑中动脉栓塞(MCAO)模型致大鼠脑缺血损伤。72 h后行神经功能学评分,2,3,5-三苯基氯化铵(TTC)染色检测脑梗死体积,Western blot法检测脑Nrf2、HO-1、TNF-α、IL-6蛋白表达水平,TUNEL染色法检测凋亡细胞数。结果:与Sham组比较,MCAO组和Vehicle组小鼠神经功能评分明显降低(P0.05),脑梗死体积显著增加(P0.05),而核蛋白Nrf2和胞浆蛋白HO-1蛋白表达水平较低(P0.05),炎症因子IL-6和TNF-α表达水平明显增加(P0.05),脑实质炎性细胞浸润显著增多(P0.05);与MCAO组和Vehicle组比较,LA组小鼠神经功能评分明显增加(P0.05),脑梗死体积显著减少(P0.05),而核蛋白Nrf2和胞浆蛋白HO-1蛋白表达水平更高(P0.05),炎症因子IL-6和TNF-α表达水平明显减少(P0.05),脑实质炎性细胞浸润明显减少(P0.05)。结论:甘草查尔酮A可缓解脑缺血再灌注损伤后出现的神经炎症反应及细胞凋亡,进而减轻神经功能障碍和脑梗死体积,其机制可能与激活Nrf2/HO-1信号通路相关。     

丹参酮Ⅱ A与丹皮酚配伍对大鼠脑缺血再灌注损伤保护作用研究

研究丹参酮ⅡA与丹皮酚配伍(简称双丹配伍)对大鼠局灶性脑缺血再灌注损伤的脑梗死体积、自由基变化的影响,探讨双丹配伍对脑缺血损伤的保护作用.方法:复制大鼠中动脉缺血再灌注模型,分别给予双丹配伍干预,观察和评价受试动物行为学、脑梗死率、脑指数、脑含水量、SOD、MAD等指标的变化.结果:①双丹配伍的各试药组均具有明显改善局灶性脑缺血再灌注损伤大鼠的神经行为学评分,降低脑梗死率、脑指数、脑含水量、提高脑组织SOD活性、降低MDA含量;②双丹配伍各组中1∶3配伍组的总体药效作用优于1∶2和1∶4组,但数据未见统计学差异;③双丹配伍尾静脉注射的药效作用明显优于预先灌胃组.结论:双丹配伍脂质体给大鼠口服和注射对脑缺血再灌注损伤具有显著保护作用.     

PEP-1超氧化物歧化酶对大鼠脑缺血再灌注后Bcl-2的影响

目的：观察细胞穿透肽-铜,锌超氧化物歧化酶（PEP-1-SOD1）预处理对大鼠局灶性脑缺血再灌注损伤的改善作用及其脑保护机制。方法：线栓法建立大鼠局灶性脑缺血6h后再灌注损伤模型,进行神经行为评分,并通过HE染色在光镜下观察神经细胞损伤变化,免疫组化法检测B细胞淋巴瘤基因-2（B—celllymphoma-2,Bcl-2）蛋白的阳性表达。结果：盐水对照组（缺血再灌注组或模型组）神经障碍显著高于假手术组（P〈0．05）,与模型组相比,PEP-1-SOD1预处理组可降低神经障碍评分（P〈0．05）;光镜下,假手术组神经细胞结构正常,PEP-1-SDO1预处理组和缺血再灌注组均有不同程度的缺血再灌注损伤,PEP-1-SOD1预处理组较缺血再灌注组损伤轻;假手术组Bcl-2蛋白表达极弱,缺血再灌注组和PEP-1-SOD1预处理组在脑缺血再灌注后6h在缺血半暗带周围出现Bcl-2蛋白阳性表达,24h达到高峰,48h表达开始减少。与假手术组相比,PEP-1-SOD1预处理组和缺血再灌注组Bcl-2蛋白阳性细胞数显著增多（P〈0．05）;与缺血再灌注组相比,PEP-1-SOD1预处理组Bcl-2蛋白阳性细胞数显著增多（P〈0．05）。结论：PEP-1-SOD1对大鼠局灶性脑缺血再灌注损伤有保护作用,PEP-1-SOD1可通过上调Bcl-2蛋白的表达发挥脑保护作用。     

丹参酮ⅡA与丹皮酚配伍对大鼠脑缺血再灌注损伤保护作用研究

目的：研究丹参酮ⅡA与丹皮酚配伍（简称双丹配伍）对大鼠局灶性脑缺血再灌注损伤的脑梗死体积、自由基变化的影响,探讨双丹配伍对脑缺血损伤的保护作用。方法：复制大鼠中动脉缺血再灌注模型,分别给予双丹配伍干预,观察和评价受试动物行为学、脑梗死率、脑指数、脑含水量、SOD、MAD等指标的变化。结果：①双丹配伍的各试药组均具有明显改善局灶性脑缺血再灌注损伤大鼠的神经行为学评分,降低脑梗死率、脑指数、脑含水量、提高脑组织SOD活性、降低MDA含量;②双丹配伍各组中1：3配伍组的总体药效作用优于1：2和1：4组,但数据未见统计学差异;⑧双丹配伍尾静脉注射的药效作用明显优于预先灌胃组。结论：双丹配伍脂质体给大鼠口服和注射对脑缺血再灌注损伤具有显著保护作用。     

三七总皂苷对大鼠脑缺血再灌注后脑内NGF和bFGF表达的影响

目的:观察三七总皂苷(PNS)对局灶性脑缺血再灌注后脑组织神经生长因子(NGF)、碱性成纤维细胞生长因子(bFGF)蛋白表达的影响.方法:采用线栓法建立大鼠大脑中动脉栓塞局灶性脑缺血再灌注模型.实验动物随机分为假手术组、脑缺血再灌注模型组、模型 PNS治疗组和模型 尼莫地平治疗组.用免疫组织化学方法检测脑内皮质、海马等区域NGF和bFGF蛋白表达.结果:缺血2h再灌注46h后,脑内海马和皮质区的NGF表达降低,PNS能显著上调海马、皮质区及丘脑区域NGF的表达.缺血2h再灌注46h后,bFGF的表达各脑区无明显差异;但PNS能显著上调缺血再灌注损伤后胼胝体区域内bFGF的表达.结论:局灶性脑缺血再灌注后,PNS能上调缺血脑组织内NGF和bFGF表达,尤其是促进了NGF的表达,这可能是PNS对脑缺血后损伤神经元的保护机制之一.     

Ucf-101对大鼠局灶性脑缺血再灌注后Caspase-3蛋白表达的影响

目的观察Ucf—101对大鼠脑缺血再灌注后神经元caspase-3蛋白表达及细胞凋亡的影响,研究其对缺血性脑损伤是否具有保护作用。方法将36只雄性WiStar大鼠随机分为3组：假手术组、缺血组及Ucf—101组,采用线栓法建立大鼠右侧大脑中动脉闭塞（middle cerebral artery occlusion,MCAO）2h再灌注模型,于再灌注后6h和24h断头取脑,采用TTC法测梗死体积,TUNEL法原位标记DNA片段,检测TUNEL阳性细胞的变化,免疫组化法观察脑皮质神经元caspase-3的表达。结果脑缺血再灌注后不同时间点（6h、24h）,Ucf-101组与缺血组相比梗死体积明显缩小,有显著性差异（P〈0．05）;假手术组未见梗死现象。缺血组TUNEL阳性细胞数较假手术组明显增多（P〈0．05）,脑皮质caspase-3的表达较假手术组亦显著增强（P〈0．05）,给予Ucf-101处理后,TUNEL阳性细胞数较缺血组明显减少（P〈0．05）,caspase-3的表达较缺血组亦明显减弱（P〈0．05）。结论Ucf-101能有效地抑制脑缺血再灌注损伤,下调脑皮质神经元Caspase-3蛋白的表达,抑制神经元的凋亡,发挥神经保护作用。     

Neuroprotective effects of hydroxyethylpuerarin against focal cerebral ischemia-reperfusion in rats

Our present study was performed to investigate whether hydroxyethylpuerarin (HEP) has a neuroprotective effect on brain injury after focal cerebral ischemia/reperfusion by middle cerebral artery occlusion (MCAO) in adult male Wistar rats. Animals were subjected to one hour of middle cerebral artery occlusion and 48 hours of reperfusion with the pretreatment of drugs (HEP 15, 30, 60 mg/ kg or nimodipine 0.4 mg/kg i.v.) or vehicle. The behavioral tests were used to evaluate the damage to central nervous system. The percentage of brain infarct area was assessed in the brain slices stained with 2% solution of 2, 3, 5-triphenyl tetrazolium chloride (TTC). The pathologic histological changes were observed by H&E staining and the occurrence of apoptosis was determined by flow cytometry. The results showed that pretreatment with HEP at doses of 15, 30, 60 mg/kg exhibited significant neuroprotective effects on rats against focal cerebral ischemia-reperfusion injury by markedly decreasing neurological deficit scores and the percentage of infarct area, reducing necrosis and apoptosis of neurons. All these findings suggest that HEP might provide neuroprotection against focal cerebral ischemia/reperfusion injury probably through its antioxidant and anti-inflammatory property.     

Protective Effects of UCF-101 on Cerebral Ischemia–Reperfusion (CIR) is Depended on the MAPK/p38/ERK Signaling Pathway

This study was aimed to investigate the treatment mechanisms of 5-[5-(2-nitrophenyl) furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid (UCF-101) in cerebral ischemia–reperfusion (CIR) model rats. Total of 54 healthy male Wistar rats were randomly assigned into three groups, namely sham group, vehicle group, and UCF-101 group. The CIR-injured model was established by right middle cerebral artery occlusion and reperfusion. Neurological function was assessed by an investigator according to the Longa neurologic deficit scores. Meanwhile, the cerebral tissue morphology and apoptotic neurons were evaluated by H&E and TUNEL staining, respectively. Additionally, the expressions of caspase 3, p-p38, and p-ERK were detected by immunohistochemistry or/and Western blotting assays. As results, neurologic deficit and pathological damage were obviously enhanced and TUNEL positive neurons were significantly increased in CIR-injured rats, as compared with those in sham group. Furthermore, the expressions of caspase 3, p-p38, and p-ERK were also significantly increased in vehicle group than those in sham group (P < 0.05). However, UCF-101 treatment could markedly weaken the neurologic deficit with lower scores and improve pathological condition. After UCF-101 treatment, TUNEL positive neurons as well as the expression of caspase 3 were significantly decreased than those in vehicle group (P < 0.05). Besides, p-p38 was decreased while p-ERK was increased in UCF-101 group than those in vehicle group (P < 0.05). Therefore, we concluded that the protective effects of UCF-101 might be associated with apoptosis process and MAPK signaling pathway in the CIR-injured model.     

Vitexin protects brain against ischemia/reperfusion injury via modulating mitogen-activated protein kinase and apoptosis signaling in mice

Vitexin is a major bioactive flavonoid compound derived from the dried leaf of hawthorn (Crataegus pinnatifida), a widely used conventional folk medicine in China. Recent studies have shown that vitexin presents neuroprotective effects in vitro. Whether this protective effect applies to the cerebral ischemia/reperfusion (I/R) injury remains elusive. In the present study, we examined the potential neuroprotective effect of vitexin against cerebral I/R injury and underlying mechanisms. A focal cerebral I/R model in male Kunming mice was induced by middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion for 22 h. The neurological function and infarct volume were assessed by using Long's five-point scale system and triphenyl-tetrazolium chloride (TTC) staining technique, respectively. Neuronal damage was evaluated by histological staining. Extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK) and p38 phosphorylation, and apoptosis were measured via Western blot at 24 h after reperfusion. As a result, systemic vitexin treatment significantly reduced neurological deficit, cerebral infarct volume and neuronal damage when compared with the I/R group. Western blot analyses revealed that vitexin markedly upregulated p-ERK1/2 and downregulated p-JNK and p-p38. Meanwhile, vitexin increased Bcl-2 expression and suppressed the overexpression of Bax in the I/R injury mice. In conclusion, the results indicate that vitexin protects brain against cerebral I/R injury, and this effect may be regulated by mitogen-activated protein kinase (MAPK) and apoptosis signaling pathways.     

MitoK(ATP) opener,diazoxide, reduces neuronal damage after middle cerebral artery occlusion in the rat

We investigated effects of diazoxide, a selective opener of mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels, against brain damage after middle cerebral artery occlusion (MCAO) in male Wistar rats. Diazoxide (0.4 or 2 mM in 30 microl saline) or saline (sham) was infused into the right lateral ventricle 15 min before MCAO. Neurological score was improved 24 h later in the animals treated with 2 mM diazoxide (13.8 +/- 0.7, n = 13) compared with sham treatment (9.5 +/- 0.2, n = 6, P < 0.01). The total percent infarct volume (MCAO vs. contralateral side) of sham treatment animals was 43.6 +/- 3.6% (n = 12). Treatment with 2 mM diazoxide reduced the infarct volume to 20.9 +/- 4.8% (n = 13, P < 0.05). Effects of diazoxide were prominent in the cerebral cortex. The protective effect of diazoxide was completely prevented by the pretreatment with 5-hydroxydecanoate (100 mM in 10 microl saline), a selective blocker of mitoK(ATP) channels (n = 6). These results indicate that selective opening of the mitoK(ATP) channel has neuroprotective effects against ischemia-reperfusion injury in the rat brain.     

高压氧预处理对大鼠脑缺血再灌注损伤的保护作用及对其海马BDNF和GDNF基因表达的影响

目的:探讨高压氧预处理(Hyperbaric oxygen preconditioning, HBO-PC)对大鼠脑缺血再灌注损伤的保护作用及对其海马脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)、胶质细胞源性神经营养因子(glialcellline-derivedneurotrophicfactor,GDNF)基因表达的影响。方法:将32只SD雄性大鼠随机分为对照组(Sham组)、高压氧对照组(HBO组)、模型组(MCAO组)、高压氧预处理+模型组(HBO+MCAO组),对HBO组和HBO+MCAO组连续给予高压氧预处理5天,随后对MCAO组和HBO+MCAO组进行右侧颈内动脉栓线术,建立大脑中动脉闭塞(middle cerebral artery occlusion, MCAO)模型,其他两组行假手术,于术后第7天对各组大鼠进行Morris水迷宫行为学检测和神经功能评分,检测结束后处死大鼠,进行神经功能缺损评分及氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride, TTC)染色;通过蛋白免疫印迹法(Western Blot)检测大鼠海马组织BDNF和GDNF的基因表达情况。结果:(1)神经功能评分提示:Sham组和HBO组均未出现神经功能障碍,MCAO组大鼠出现明显的神经功能障碍,MCAO+HBO组神经功能评分明显高于MCAO组(P0.05)。(2)TTC检测提示:Sham组和HBO组脑组织损伤一侧均未出现梗死灶,MCAO组出现较大的梗死面积比(25.45±8.75)%,MCAO+HBO组的梗死面积比(18.84±10.55)显著小于MCAO组,差异具有统计学意义(P 0.05)。(3)Western Blot检测显示:MCAO组BDNF与GDNF基因表达水平显著低于Sham组和HBO组,差异具有统计学意义(P 0.05),而MCAO+HBO组可以逆转这一效应,差异具有统计学意义(P 0.05)。结论:高压氧预处理可以通过调节BDNF、GDNF基因表达,改善MCAO模型大鼠神经功能和认知水平,发挥神经保护作用。     

梓醇对大鼠脑缺血再灌注损伤的保护作用研究

目的:探讨梓醇对缺血再灌注大鼠脑损伤后的保护作用.方法:采用传统大脑中动脉阻塞(MCAO)方法制备大鼠局灶性缺血模型,根据随机数字表法将SD大鼠分为MCAO组、对照组(vehicle组)及梓醇处理组(catalpol组),缺血再灌注48 h后观察各组大鼠神经功能学评分和脑梗死容积.分别于术前、术后6h、24 h、48 h取大鼠脑组织样本,检测匀浆中谷胱甘肽过氧化物酶(GSH-PX)和丙二醛(MDA)的变化情况.结果:与vehicle组和MCAO组相比,catalpol处理组神经功能学评分降低(P＜0.05);其梗死容积较小(P＜0.05).组织匀浆结果显示catalpol处理组脑匀浆中GSH-PX活力升高,MDA含量下降(P＜0.05).结论:梓醇可能通过降低脑内自由基水平、控制脂质过氧化程度,对缺血再灌注引起的大鼠脑损伤产生神经保护作用.     

Caffeic acid phenethyl ester ameliorates cerebral infarction in rats subjected to focal cerebral ischemia

The effects of caffeic acid phenethyl ester (CAPE), an antioxidant derived from propolis, on the infarct volume elicited by focal cerebral ischemia were studied on Long-Evans rats. Cerebral infarction was induced by microsurgical procedures with ligation of the right middle cerebral artery (MCA) and clipping of bilateral common carotid arteries (CCA) for 60 min. The rats were sacrificed 24 h later and serial brain slices of 2 mm thickness were taken and stained for the measurement of infarct area. CAPE was administered intravenously 15 min before MCA occlusion. Pretreatment of CAPE (0.1, 1 and 10 microg/kg) significantly reduced the total infarct volume from 169.6 +/- 14.5 mm3 (control) to 61.0 +/- 24.1 mm3 (0.1 microg/kg CAPE), 47.4 +/- 9.1 mm3 (1 microg/kg CAPE), and 42.4 +/- 8.7 mm3 (10 microg/kg CAPE), respectively. Plasma nitric oxide (NO) content was significantly increased in rats subjected to focal cerebral ischemia. It is concluded that CAPE possesses neuroprotective properties in focal cerebral ischemia injury in rats possibly through its antioxidant effect and/or via the upregulation of NO production.     

Apocynum venetum Leaf Extract Attenuates Disruption of the Blood–Brain Barrier and Upregulation of Matrix Metalloproteinase-9/-2 in a Rat Model of Cerebral Ischemia–Reperfusion Injury

We investigated the neuroprotective effects of Apocynum venetum leaf extract (AVLE) on a rat model of cerebral ischemia-reperfusion injury and explored the underlying mechanisms. Rats were randomly divided into five groups: sham, ischemia-reperfusion, AVLE125, AVLE250, and AVLE500. Cerebral ischemia was induced by 1.5 h of occlusion of the middle cerebral artery. Cerebral infarct area was measured by tetrazolium staining at 24 and 72 h after reperfusion, and neurological function was evaluated at 24, 48 and 72 h after reperfusion. Pathological changes on the ultrastructure of the blood-brain barrier (BBB) were observed by transmission electron microscopy. BBB permeability was assessed by detecting leakage of Evan's blue (EB) dye in brain tissue. The expression and activities of matrix metalloproteinase (MMP)-9/-2 were measured by western blot analyses and gelatin zymography at 24 h after reperfusion. AVLE (500 mg/kg/day) significantly reduced cerebral infarct area, improved recovery of neurological function, relieved morphological damage to the BBB, reduced water content and EB leakage in the brain, and downregulated the expression and activities of MMP-9/-2. These findings suggest that AVLE protects against cerebral ischemia-reperfusion-induced injury by alleviating BBB disruption. This action may be due to its inhibitory effects on the expression and activities of MMP-9/-2.     

Ischemic brain injury caused by interrupted versus uninterrupted occlusion in hypotensive rats with subarachnoid hemorrhage: neuroprotective effects of citicoline.

This study investigated the neuroprotection provided by cytidine 5'-diphosphocholine (citicoline) during interrupted and uninterrupted occlusion of the basilar artery after subarachnoid hemorrhage (SAH) in 121 hypotensive rats. Animals were anesthetized and the basilar artery was exposed through a transclival approach. Baseline local cerebral blood flow (LCBF) values were recorded, and then the basilar artery was punctured, causing SAH. Blood was drawn to induce hypotension [60-70 mmHg mean arterial blood pressure (MABP)]. Control rats received intraperitoneal (i.p.) injections of 0.5 ml saline immediately after SAH before hypotension induction and after 60 min of occlusion. Experimental rats received 400-mg/kg citicoline i.p. at the same time points. Control group I and treatment group III were subjected to 60 min of interrupted occlusion (5 min of reperfusion after each 10 min of occlusion). Control group II and treatment group IV were subjected to 60 min of uninterrupted occlusion. MABP and LCBF were recorded every 5 minutes. Brain edema was evaluated in seven rats from each group at 24 hours after ischemic injury. At 3 days after occlusion, another set of 28 rats was killed and coronal brain slices were stained to assess infarct volume. The groups' physiological and edema findings were similar. In all groups, LCBF fell immediately after SAH and remained below baseline throughout the experiment. In the citicoline-treated rats, arterial pressure increased significantly after 30-40 min of occlusion, and brain slices showed significantly smaller infarct volumes compared to control slices (p < 0.05). Mortality was significantly lower in the citicoline-treated animals (p < 0.001). The results suggest that citicoline provides significant neuroprotection during cerebral ischemia, and that it significantly reduces mortality. Part of the neuroprotective effect may be mediated by recovery of arterial pressure.