灯盏乙素和灯盏花素对急性心肌梗死的保护作用

目的研究灯盏乙素和灯盏花素对急性心肌梗死的保护作用。方法建立大鼠急性心肌梗死模型后,腹腔注射不同剂量灯盏乙素和灯盏花素,4h后取出心脏行氯化硝基四氮唑蓝（NBT）染色,测量心肌梗死面积,比较两种药物对心肌梗死面积影响的量效关系;建立犬急性心肌梗死模型,股静脉注射50mg/kg灯盏花素或灯盏乙素,记录不同时间点的心外膜电图,比较两种药物对心肌缺血程度和范围的影响。结果灯盏乙素单体能够降低心肌梗死面积,抑制梗死区心肌细胞的凋亡,50mg/kg灯盏乙素能够降低左冠状动脉前降支结扎后犬心外膜电图抬高的∑ST段。结论灯盏乙素单体是灯盏花素的主要药理活性成分,较灯盏花素具有更好的量效关系。     

Cerebroprotective effect of resveratrol through antioxidant and anti-inflammatory effects in diabetic rats

Oxidative stress and inflammation have been implicated in cerebral ischemia/reperfusion injury and complication of diabetes. The present study was designed to evaluate whether resveratrol has cerebroprotective action through antioxidant and anti-inflammatory actions in diabetic rats. Bilateral common carotid artery occlusion (30 min) and reperfusion (4 h) was employed to induce cerebral infarction in diabetic Wistar rats. Diabetes was induced by streptozocine (50 mg/kg) intraperitoneally at once. Diabetic animals were divided into groups as: normal, sham, ischemia–reperfusion, and resveratrol-treated (5, 10, 20, and 30 mg/kg). These were used for estimation of cerebral infarction. Furthermore, 20 mg/kg dose was selected for estimation of oxidative stress markers (malondialdehyde, superoxide dismutase, and catalase). Inflammatory markers like TNF-α, IL-6, IL-10, and myeloperoxidase were estimated and histological characters were studied. Resveratrol produced dose-dependent reduction in percent cerebral infarction. With resveratrol of 20 mg/kg dose, levels of oxidative stress markers and inflammatory markers like malondialdehyde, TNF-α, IL-6, and myeloperoxidase were reduced and there was a significant increase in the levels of antioxidant and anti-inflammatory markers like catalase, superoxide dismutase, and IL-10. In the present study, we found that mechanism(s) responsible for the cerebroprotective effect of resveratrol in the diabetic rat brain involves antioxidant and anti-inflammatory actions.     

Caffeic acid ameliorates early and delayed brain injuries after focal cerebral ischemia in rats

AIM:To investigate the effects of caffeic acid on early and delayed injuries after focal cerebral ischemia in rats, and the possible relation to 5-lipoxygenase inhibition. METHODS: Transient focal cerebral ischemia was induced by middle cerebral artery occlusion in Sprague-Dawley rats. Caffeic acid (10 and 50 mg/kg) was ip injected for 5 d after ischemia. The brain injuries were observed, and the levels of cysteinyl leukotrienes and leukotriene B4 in the brain tissue were measured. RESULTS: Caffeic acid (50 mg/kg) ameliorated neurological dysfunction and neuron loss, and decreased infarct volume 24 h after ischemia; it attenuated brain atrophy, infarct volume, and particularly astrocyte proliferation 14 d after ischemia. In addition, it reduced the production of leukotrienes (5-lipoxygenase metabolites) in the ischemic hemispheres 3 h and 7 d after ischemia. CONCLUSION: Caffeic acid has protective effect on both early and delayed injuries after focal cerebral ischemia in rats; and this effect may partly relate to 5-lipoxygenase inhibition.     

Nilvadipine, a new calcium channel blocker, reduces ischemic brain injury in rats.

The effects of nilvadipine, a dihydropyridine type calcium channel blocker, on cerebral infarction induced by focal brain ischemia was studied in rats. The area of infarction was measured 24 hr after occlusion of the middle cerebral artery (MCA) in spontaneously hypertensive rats using triphenyltetrazolium chloride. Nilvadipine, given immediately after MCA occlusion, reduced the area of infarction significantly at doses of 0.32 mg/kg (i.p.) and 3.2, 10 and 32 mg/kg (p.o.). Nicardipine suppressed the area of infarction at a dose of 32 mg/kg (p.o.). The results suggest that nilvadipine is effective against ischemic brain injury.     

Neuroprotective effect of guggulipid alone and in combination with aspirin on middle cerebral artery occlusion (MCAO) model of focal cerebral ischemia in rats

This study was designed to test the pre-treatment doses of guggulipid (50?mg/kg), aspirin (100?mg/kg) per orally and co-administration of both drugs for 28 days followed by middle cerebral artery occlusion – a model of focal cerebral ischemia in rats. Middle cerebral artery was occluded for two hours, followed by reperfusion for 22 hours for the induction of focal cerebral ischemia in rats. Neurobehavioral tests like locomotor activity and grip strength tests were performed before sacrificing the animal. After neurobehavioral tests, the animals were sacrificed for the measurement of infarction areas and biochemical estimations in brain. Locomotor activity and grip strength were significantly improved in guggulipid and aspirin pre-treated rats. Guggulipid and aspirin pre-treatment reduced the infarction areas as compared with middle cerebral occluded (MCAO) rats. An elevation of nitrite, thiobarbituric acid reactive substance (TBARS), acetylcholine esterase activity (AchE) and reduction in antioxidant enzymes like superoxide dismutase (SOD), glutathione (GSH) and catalase were observed following MCAO. Pre-treatment with guggulipid and aspirin caused a reduction in TBARS and nitrite levels, AchE, but elevated GSH level, SOD and catalase activities as compared with MCAO rats. The protective effects observed in this study were due to antioxidant, anti-inflammatory and anti-hyperlipidemic properties of guggulipid. The protective effect of guggulipid in cerebral ischemia, that it may have a role in reversing the symptoms and may offer significant neuroprotection in stroke.     

二维三七桂利嗪胶囊对大鼠局灶性脑缺血再灌注损伤的保护作用

目的:观察二维三七桂利嗪胶囊对大鼠局灶性脑缺血再灌注损伤的影响.方法:SD大鼠分别用292,146和73 mg·kg-1的二维三七桂利嗪胶囊灌胃10 d,线拴法制备大鼠大脑中动脉缺血模型(middle cerebral arteryocclusion,MCAO),缺血3 h后再灌注3 h,分别取脑组织测定脑梗死范围、脑指数、脑含水量并观察脑组织形态结构,取血测定血清乳酸脱氢酶(LDH)和超氧化物歧化酶(S0D)活性.结果:3个剂量的二维三七桂利嗪胶囊能够不同程度地缩小缺血再灌注损伤后脑梗死范围、降低脑指数、脑含水量和血清LDH活性,提高SOD活性并减轻光镜下脑组织缺血性损伤.结论:二维三七桂利嗪胶囊对大鼠局灶性脑缺血再灌注损伤具有保护作用.     

葡萄籽原花青素对大鼠心肌缺血再灌注损伤的保护作用

目的研究葡萄籽原花青素对大鼠心肌缺血再灌注损伤的保护作用。方法 SD大鼠50只随机等分为5组:假手术组、模型组、葡萄籽原花青素低、中、高剂量组。结扎大鼠左冠状动脉前降支,30 min后剪断结扎线形成再灌注模型。测定5组大鼠在1 h后的血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、谷草转氨酶(AST)、超氧化物歧化酶(SOD)和丙二醛(MDA)的含量,并比较心肌梗死面积。结果不同剂量的葡萄籽原花青素(50～200 mg/kg)均可降低大鼠CK、LDH、AST和MDA的水平,提高大鼠体内SOD的水平,还能有效降低大鼠心肌梗死的面积,与模型组比较,均有显著差异(P<0.05)。结论葡萄籽原花青素可以显著的改善心肌缺血再灌注大鼠体内的生化指标,减少心肌梗死的面积,对于心肌缺血再灌注具有很好的保护作用。     

银杏叶提取物对大鼠局灶性脑缺血后血管新生的影响

目的探讨银杏叶提取物是否可以促进大鼠局灶性脑缺血后梗死周围区的血管新生,寻求促使脑缺血后血管新生、开发脑储备能力的有潜力的中医药疗法。方法采用线栓法建立大鼠大脑中动脉闭塞（MCAO）模型,术后24h采用银杏叶注射液以10mg／（kg体重·d）的剂量连续腹腔注射治疗6d,于缺血后第7d、14天分别观察银杏叶组和对照组大鼠脑梗死体积、脑梗死灶周围血管密度（层粘连蛋白,Laminin的表达）和神经功能缺失评分的变化。结果与对照组比较,大鼠局灶性脑缺血后第7天和14天银杏叶组的梗死体积明显减小,梗死周围血管密度较对照组明显增加,并显示出更好的神经功能评分（P〈0．05）。结论银杏叶提取物可促进局灶性脑缺血后大鼠脑梗死周围区的血管新生,从而开发脑储备能力,这可能是银杏叶提取物改善脑缺血后神经功能恢复的机制之一。     

羟基红花黄色素A对实验性脑缺血的保护作用

红花为菊科植物红花(Carthamus tinctoriusL.)的干燥花,是传统的活血化瘀类代表药物[1]。红花的化学成分比较复杂,研究表明,红花的花中含有黄酮类、脂肪酸、色素、挥发油以及多炔等化合物[2]。目前认为,红花活血化瘀的主要成分集中在水溶性的黄色素部分;红花黄色素主要成分有羟基红花黄色素A(hydroxysafflor yellow A,HSYA)、红花明苷A、红花明苷B及其他含量较低的成分。在红花黄色素中含量最高且具有活性的成分为羟基红花黄色素A[2]。作者采用经典的大鼠大脑中动脉阻塞性脑缺血模型,观察HSYA对局灶性脑缺血大鼠的行为评分、缺血区面…     

Neuroprotective effects of scutellarin on rat neuronal damage induced by cerebral ischemia/reperfusion

AIM: To investigate the neuroprotective effect and mechanisms of scutellarin, a flavonoid extracted from Erigeron breviscapus Hand Mazz, against neuronal damage following cerebral ischemia/reperfusion. METHODS: Rats were pretreated ig with scutellarin for 7 d and then subjected to cerebral ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion (MCAO). The infarct volume and neurological deficit were determined by TTC staining and Longa's score. The permeability of the blood-brain barrier was evaluated by measurement of the Evans blue (EB) content in the brain with a spectrophotometer. The total NOx content was determined. Nitric oxide synthase (NOS) isoforms (iNOS, eNOS, nNOS) and the key angiogenic molecules, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), were detected by Western blotting. RESULTS: Scutellarin significantly reduced infarct volume (P<0.05 or P<0.01), ameliorated the neurological deficit and reduced the permeability of the blood-brain barrier (BBB) (P<0.05). When rats were pretreated with scutellarin (50 or 75 mg/kg), upregulation of eNOS expression and downregulation of VEGF, bFGF, and iNOS expression was observed, whereas scutellarin had no effect on nNOS expression. CONCLUSION: Scutellarin has protective effects for cerebral injury through regulating the expression of NOS isoforms and angiogenic molecules.     

灯盏乙素的大鼠药代动力学和血小板聚集抑制率的相关性研究

目的：探讨灯盏花素注射液中灯盏乙素血药浓度与其药效学的相关性,为临床合理用药提供科学依据。方法：Wistar大鼠随机分为3.75、7.5和15 mg/kg三个剂量组,尾静脉注射灯盏花素注射液。给药前和给药后不同时间点取血测定三组血药浓度和ADP诱导的血小板聚集率,用统计学方法计算两者的相关性。结果：瞬时血药浓度（C）与ADP诱导的血小板聚集抑制率（Y）进行线性回归,相关系数r均〉0.7。经统计学处理,各给药剂量下的瞬时血药浓度均与ADP诱导的大鼠血小板聚集抑制率呈显著正相关（P〈0.01）。结论：灯盏乙素明显抑制ADP诱导的血小板聚集,并且其血药浓度与药效呈现一定的关系。本试验为灯盏乙素用于防治血栓性疾病提供了进一步的科学依据。     

A study of the cardioprotective effect of breviscapine during hypoxia of cardiomyocytes

Breviscapine is a flavonoid extracted from Erigeron breviscapus. Hand.-Mazz, and it has been reported that breviscapine can activate K+ channels and block Ca2+ channels. In this paper, we studied the cardioprotective effects of breviscapine on electrocardiogram (ECG) changes (ST-segment elevation), infarction size in dog heart subjected to myocardial infarction caused by left coronary artery ligation and lactate dehydrogenase (LDH) leakage, changes of intracellular free Ca2+ levels, apoptosis and necrosis in cultured neonatal rat cardiomyocytes subjected to hypoxia. Additionally, the effect of breviscapine on myocardial oxygen consumption was detected in dog myocardium in vitro. The results showed that breviscapine treatment (1 mg/kg, 2 mg/kg and 4 mg/kg) significantly reduced ST-segment elevation and infarction size in hearts subjected to myocardial infarction, that breviscapine treatment (14.29 microg/mL, 28.57 microg/mL and 57.14 microg/mL) significantly decreased oxygen consumption in myocardium, and that breviscapine treatment (5 microg/mL, 10 microg/mL and 20 microg/mL) significantly reduced LDH leakage, intracellular free Ca2+ levels, apoptosis and necrosis in cardiomyocytes subjected to hypoxia. In conclusion, the present study indicates that breviscapine is in favor of myocardial protection.     

Cannabinoid agonists induce contractile responses through Gi/o-dependent activation of phospholipase C in the bovine ciliary muscle

Oxygen free radicals have been involved in the pathophysiology of cerebral ischemia, especially after spontaneous or thrombolytic reperfusion. In this study with rats, we have combined a severe focal ischemic insult (2 h) and a prolonged reperfusion time (7 days) to assess the possible sustained neuroprotective effect of ebselen (10 or 100 mg/kg), a small, lipophilic organoselenium compound which mimics glutathione peroxidase. Parietal cortical perfusion was measured by laser-Doppler flowmetry, and focal cerebral ischemia was carried out by the intraluminal thread method. We have measured plasma selenium levels, brain reduced glutathione levels, as a marker of oxidative stress, and infarct volume associated with cerebral ischemia. Focal ischemia did not alter reduced glutathione levels, while 60 min reperfusion following ischemia induced a significant (P < 0.05) decrease in reduced glutathione levels of the ipsilateral hemisphere. Pretreatment with ebselen, which induced significant (P < 0.05) increase in plasma selenium levels, did not significantly alter the decrease in reduced glutathione levels. The ischemic insult induced 30% mortality on average, with deaths always occurring within 12-48 h. Surviving rats suffered up to 25% body weight loss 1 week after the ischemic insult. Infarct volumes were 26.8 +/- 4.7% of the hemisphere in placebo-treated rats, 26.6 +/- 3.6% in 10 mg/kg ebselen-treated rats, and 25.6 +/- 6.4% in 100 mg/kg ebselen-treated rats (not significantly different). Single-dose administration of ebselen does not reduce the size of brain infarct resulting from severe focal cerebral ischemia in rats. In contrast to previous studies with relatively earlier endpoints, we have delayed the measurement of infarct volume to 1 week after the ischemic insult.     

Acute and subacute toxicological evaluation of scutellarin in rodents

Acute and subacute investigations were carried out to evaluate the safety of scutellarin, an active flavone glycoside that has been used to treating cardiocerebral vascular diseases and cerebral infarction in rodents. For the acute study, scutellarin was administered to mice by gavage at different dose levels. Scutellarin caused dose-dependent general behavior adverse effects, but the LD₅₀ values could not be detected, and the maximum tolerated dose was more than 10 g/kg. In the subacute study, scutellarin was administered orally at doses of 100 and 500 mg/kg daily for 30 days to rats. Body weight, heart rate, blood pressure, biochemical, hematological and urine parameters were determined at the end of the experimental day. Daily oral administration for up to 30 days did not result in death or significant changes in hematology, blood chemistries or urinalysis. However, a 30 day regimen of scutellarin at doses of 100 or 500 mg/kg led to non-dose related decreases in BUN and triglyceride levels. Scutellarin was found to be minimally toxic or non-toxic in rodents. In view of the doses of the components used, the results from acute and subacute toxicity studies suggest that this component has a sufficient margin of safety for therapeutic use.     

白三烯受体拮抗剂ONO-1078对内皮素-1诱导的大鼠局灶性脑缺血的保护作用

目的观察白三烯受体拮抗剂ONO-1078对内皮素-1诱导的大鼠局灶性脑缺血的保护作用。方法向大脑中动脉附近微量缓慢注射内皮素-1(120 pmol,6 μL,>6 min),诱导大鼠局灶性脑缺血模型,在注射内皮素-1前1 h ip ONO-1078(0.1 mg·kg^-1)。观察神经症状、脑水肿程度、脑梗死体积、纹状体和皮层的存活神经元数的变化。结果 脑内微量注射内皮素-1引起动物出现明显神经症状、脑梗死、脑水肿及皮层和纹状体的存活神经元减少。预先ip ONO-1078显著抑制脑水肿,减小脑梗死体积,增加纹状体和皮层的存活神经元数,可减轻神经症状,但无显著意义。结论ONO-1078对内皮素-1诱导的脑缺血损伤有保护作用,白三烯参与了脑缺血后的组织损伤过程。     

Neuroprotective effects of breviscapine against apoptosis induced by transient focal cerebral ischaemia in rats

Breviscapine, a flavonoid isolated from the traditional Chinese medicinal herb Erigerin breviscapus, has been proved to be effective in protecting the brain against ischaemic damage, but the mechanisms remain unknown. In this study, we have demonstrated the effects of breviscapine on neuronal apoptosis in a rat model of transient focal cerebral ischaemia. Rats were administered with breviscapine (50 or 100 mg kg(-1)/day) intragastrically for seven successive days, then subjected to 2-h brain ischaemia induced by middle cerebral artery occlusion, followed by 24-h reperfusion. After reperfusion, the rats were killed and the brain samples were collected. Haematoxylin-eosin staining was used to evaluate the histopathological changes. Terminal deoxynucleotidyl transferase-mediated biotiny-lated UTP nick end labeling (TUNEL) and flow cytometry (FCM) analysis were used to detect the level of apoptosis. The expressions of bcl-2 and caspase-3 in the cortex were determined by Western blot. Significant increases in the number of haematoxylin-eosin- and TUNEL-positive staining cells and DNA fragmentation were observed at 24 h after reperfusion, and the increases were inhibited by breviscapine (50 and 100 mg kg(-1)). Breviscapine at both doses markedly inhibited the expression and activation of caspase-3 and up-regulated the expression of bcl-2. These findings suggested that breviscapine attenuated neuroapoptosis and regulated the protein expression related to apoptosis after transient focal cerebral ischaemia, which may have contributed, in part, to the protective effects of breviscapine on cerebral ischaemic damage.     

灯盏乙素在兔体内药代动力学

目的建立测定灯盏乙素血浆浓度的固相萃取-高效液相色谱（SPE-HPLC）法,并研究家兔iv灯盏花素的药代动力学。方法采用甲醇-水-磷酸为流动相，Nucleosil C₁₈色谱柱为固定相,紫外检测波长335 nm,外标法定量。给家兔分别iv灯盏花素10,20和40 mg·kg^-1,SPE-HPLC法检测血浆药物浓度。结果线性范围0.02～10.0 mg·L^-1,最低检测浓度0.02 mg·L^-1,方法回收率96.15%～99.31%,日内、日间RSD值均小于10%。家兔iv灯盏花素时,灯盏乙素血浆浓度变化符合三房室模型。灯盏乙素低、中剂量组的主要药代动力学参数无显著性差异,而高剂量组与低、中剂量组比较差异显著。结论该法准确、灵敏、简便,适用于灯盏乙素血浆浓度的测定。灯盏花素经兔iv后的药代动力学符合三房室模型，剂量为10～20 mg·kg^-1时,药物的体内变化为线性动力学过程,而40 mg·kg^-1时未表现线性动力学特征。     

西洋参茎叶皂苷对局灶性脑缺血大鼠脑组织酸中毒及自由基代谢的影响

目的 探讨西洋参茎叶皂苷对大鼠局灶性脑缺血损伤的保护作用及其作用机制.方法 采用大鼠大脑中动脉内栓线阻断法制备局灶性脑缺血损伤模型,通过化学比色法、硫代巴比妥酸法检测西洋参茎叶皂苷对脑缺血损伤大鼠脑组织乳酸（LA）、乳酸脱氢酶（LDH）、丙二醛（MDA）、超氧化物歧化酶（SOD）四个生化指标的影响.结果 西洋参茎叶皂苷（100、50 mg/kg）可明显降低LA、MDA含量及提高LDH、SOD活性.结论 西洋参茎叶皂苷对大鼠局灶性脑缺血损伤具有保护作用,其作用机制可能与抑制酸中毒、对抗自由基和拮抗过氧化损伤有关.     

果糖二磷酸钠镁对大鼠脑缺血/再灌注损伤的保护作用

目的 :研究果糖二磷酸钠镁对大鼠脑缺血/再灌注引起脑损伤的保护作用。方法 :自大鼠颈总动脉插入尼龙线栓栓塞大脑中动脉 ,造成大鼠脑缺血 ,缺血1h后拔出线栓实现再灌注。脑缺血10min后给予400mg/kg 果糖二磷酸钠镁 (FDPM )或400mg/kg1 ,6—二磷酸果糖 (FDP)或30mg/kg 硫酸镁 (MgSO4) ,分别于脑缺血1h再灌注2h、5h、23h时进行神经病学评分 ,并于脑缺血1h再灌注23h时测定脑梗塞面积及脑组织丙二醛 (MDA)含量 ,观察大鼠脑组织病理学变化。结果 :与模型组相比 ,FDPM组明显减低脑缺血/再灌注大鼠神经病学评分 ,缩小脑梗塞面积 ,降低脑组织MDA含量 ,减轻脑组织的病理改变 ,其作用强于FDP组和MgSO4 组。结论 :FDPM可显著保护大鼠脑缺血/再灌注引起的脑损伤。     

Enalapril and moexipril protect from free radical-induced neuronal damage in vitro and reduce ischemic brain injury in mice and rats.

Angiotensin-converting enzyme inhibitors have been demonstrated to protect spontaneously hypertensive rats from cerebral ischemia. The present study investigated the protective effect of enalapril and moexipril in models of permanent focal cerebral ischemia in normotensive mice and rats. To elucidate the mechanism of neuroprotection the influence of these angiotensin-converting enzyme inhibitors on glutamate-, staurosporine- or Fe2+/3+-induced generation of reactive oxygen species and neuronal cell death in primary cultures from chick embryo telencephalons was studied. Treatment with moexipril or enalapril dose-dependently reduced the percentage of damaged neurons, as well as mitochondrial reactive oxygen species generation induced by glutamate, staurosporine or Fe2+/3+. Furthermore, moexipril and enalapril attenuated staurosporine-induced neuronal apoptosis as determined by nuclear staining with Hoechst 33258. In mice, 1 h pretreatment with enalapril (0.03 mg/kg) or moexipril (0.3 mg/kg) significantly reduced brain damage after focal ischemia as compared to control animals. Additionally, moexipril (0.01 mg/kg) was able to reduce the infarct volume in the rat model after focal cerebral ischemia. The results of the present study indicate that the angiotensin-converting enzyme inhibitors enalapril and moexipril promote neuronal survival due to radical scavenging properties.