The present study investigated the protective effects of scutellarin on cobalt chloride (CoCl2)- induced apoptosis in PC12 cells. Incubation of PC12 cells with 500 μM CoCl2 for 24 h resulted in significant apoptosis as evaluated by the crystal violet, electron microscopy and flow cytometry assays. The increase of caspase-3 activity, decrease of Bcl-XL expression, phosphorylation of p38 mitogenactivated protein kinase (MAPK) and accumulation of intracellular reactive oxygen species (ROS) were also seen in CoCl2-treated PC12 cells. Scutellarin at 0.1, 1 and 10 μM significantly protected against the apoptotic cell death induced by CoCl2. Scutellarin decreased caspase-3 activity, increased Bcl-XL expression, inhibited p38 phosphorylation and attenuated ROS production. These results demonstrate that scutellarin can protect PC12 cells from cobalt chloride induced apoptosis by scavenging ROS, inhibiting p38 phosphorylation, up-regulating Bcl-XL expression and decreasing caspase-3 activity, and may reduce the cellular damage in pathological conditions associated with hypoxia-mediated neuronal injury.

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.

Microvascular changes in the brain are significant causes of cerebral edema and ischemia injury. A number of studies suggest that angiotensin (Ang) Ⅱ may be involved in the initiation and regulation of processes occurring in brain ischemia. We recently reported that Ang Ⅱ injures brain microvascular endothelial cells (BMEC) partially via stimulating intercellular adhesion molecule-1 (ICAM-1) expression. However, the signaling cascade leading to Ang Ⅱ-induced ICAM-1 expression in BMEC was unclear. The present study tested the hypothesis that Ang Ⅱ induces ICAM-1 expression via an AT1 receptor/nuclear factor-кB (NF-кB) pathway in BMEC. Ang Ⅱ directly stimulated the expression of ICAM-1 mRNA and protein in primary cultured BMEC. Ang Ⅱ treatment also resulted in the degradation of InBa and increase of NF-кB p65 subunit in the nucleus as well as the DNA binding activity of nuclear NF-кB. These effects were abolished by pretreatment with the selective AT1 receptor antagonists, losartan and compound EXP-2528, or losartan plus the AT2 receptor antagonist PD123319, but not by PD123319 alone. Moreover, there were no significant differences between the losartan and losartan plus PD123319 groups. These findings indicate that Ang ⅡⅡ-induced ICAM-1 upregulation in brain microvascular endothelial cells may be mediated via an AT1 receptor/NF-nB pathway.

This study was undertaken to find out the effects of acetylpuerarin on hippocampal neurons and intracellular free calcium in primary culture subjected to oxygen-glucose deprivation/reperfusion. Methods: According to different reperfusion time (1h, 6h, 12h, 24h), three concentrations (1.6 μmol l−1, 0.4 μmol l−1, 0.1 μmol l−1) of acetylpuerarin, and MK-801 (10 μmol l−1), a positive control drug, neurons were randomly divided into 21 groups. Each group was observed by inverted phase contrast microscope; neuron viability was measured by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT); intracellular Ca2+ was observed by Fura-2/AM ester through fluorospectrophotometer. Results: The injured neurons were protected and degeneration and necrosis were alleviated in treatment groups of acetylpuerarin and MK-801. Acetylpuerarin increased the neuron viability at high, middle and low concentrations. Fluorescence detection results showed that the calcium concentration in the group treated with acetylpuerarin and MK-801 was lowered in each reperfusion time. Conclusion: Our results demonstrated that acetylpuerarin could protect the hippocampal neurons from ischemia-reperfusion injury in rats by alleviating the morphological damage, increasing neuron viability and decreasing calcium concentration in neuron.

Mounting evidence has suggested that paeonol possesses plenty of pharmacologic actions. Our research is to determine if paeonol can protect cultured rat hippocampal neurons from oxygen-glucose deprivation(OGD)-induced injury and elucidate the underlying mechanism. We cultivated the rat hippocampal neurons as the object of study and then established the model of oxygen-glucose deprivation. Neuronal viability was measured by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), while intracellular Ca2+ concentration was observed by fluorospectrophotometer. The binding force of N-methyl-D-aspartate (NMDA) receptor was evaluated by liquid scintillation counting. Compared with oxygen-glucose deprivation group, paeonol treatment obviously increased cell survival rate and reduced the activity of the binding force of NMDA receptors, reversing the overload of intracellular Ca2+. These results demonstrate that paeonol protected rat neurons from oxygen-glucose deprivation-induced injury, resulting in alleviating the morphological damage and increasing neuron viability and suggest that paeonol may exhibit its protective effect against oxygen-glucose deprivation-induced injury by targeting on NMDA receptors.

The objective of this study is to investigate the anti-inflammatory effect of hydroxyethylpuerarin on focal brain ischemia injury in rats and to explore its mechanisms of action. After 24 h of reperfusion following 2 h of cerebral ischemia, the infiltration of neutrophils was observed by myeloperoxidase (MPO) activity determination, the expression of intercellular adhesion molecule-1(ICAM-1) was observed by western blot and reverse transcriptase-polymerase chain reaction(RT-PCR) analysis, and the nuclear translocation and DNA binding activity of nuclear factor-κB (NF-κB)were observed by western blot and electrophoretic mobility shift assay (EMSA). The results showed that hydroxyethylpuerarin could obviously inhibit the MPO activity and ICAM-1 expression following 2 hours of ischemia with 24 hours of reperfusion. The nuclear translocation and DNA binding activity were also decreased by hydroxyethylpuerarin treatment. These results suggested that hydroxyethylpuerarin could inhibit neutrophil-mediated inflammatory response after brain ischemia reperfusion in rats. This effect may be mediated by down-regulation of ICAM-1 and NF-κB activity.

脑血管内皮细胞受损是脑血管疾病特别是脑缺血发病的早期病变和基本动因。血管紧张素Ⅱ（an.giotensinⅡ,AngⅡ）是肾素一血管紧张素系统（renin-angioteminsystem，RAS）重要的生物活性肽，与高血压、动脉粥样硬化、心肌肥厚等许多心血管疾病密切相关，但在脑血管疾病发生发展中的作用及机制尚不明确。本文研究了血管紧张素Ⅱ（AngⅡ）对牛脑微血管内皮细胞（BCMECs）凋亡的诱导作用及其机制。方法：利用培养的牛脑微血管内皮细胞（BCMEC），以透射电子显微镜和流式细胞仪技术，检测体外培养的BCMECs凋亡。结果：BCMECs经10-5mol•L-1AngⅡ刺激18h后，呈现胞浆浓缩、染色质凝集、核碎裂和凋亡小体形成等凋亡的超微结构变化。流式细胞术显示AngⅡ（10-5mol•L-1-10-5mol•L-1）呈浓度依赖性诱导BCMECs凋亡。10-5mol•L-1AngⅡ诱导的BCMECS凋亡不能被10-4mol•L-1ATl受体拮抗剂氯沙坦所抑制，而能被150U•ml-1超氧化物歧化酶所抑制。结论：AngⅡ能诱导BCMECS凋亡，其机制可能与激活ATl受体刺激BCMEC产生的氧自由基有关。AngⅡ诱导脑血管内皮细胞凋亡可能是其参与脑血管疾病的机制之一。AngⅡ诱导的BCMECS凋亡不被ATl受体拮抗剂氯沙坦抑制，而超氧化物歧化酶抑制AngⅡ诱导的脑血管内皮细胞凋亡，其机制需进一步研究。

目的观察血管紧张素转化酶抑制药卡托普利对大鼠局灶性脑缺血再灌注损伤后炎症反应的影响。方法采用血管内栓线阻断法制备大鼠局灶性脑缺血再灌注损伤模型，于脑缺血1h、再灌注24h后测定脑组织中髓过氧化物酶（MP0）活性，免疫组织化学方法测定细胞间黏附分子（ICAM-1）表达。结果卡托普利可明显抑制MPO活性及ICAM-1的表达。结论卡托普利可抑制脑缺血再灌注损伤后炎症反应。

目的观察绞股蓝总皂苷对大鼠急性局灶性脑缺血再灌损伤NO的保护作用。方法采用大脑中动脉内栓线阻断法（MCAO）造成大鼠局灶性脑缺血再灌注模型，测定脑亚细胞器内NO含量的变化并观察病理组织学变化。结果脑缺血再灌注后脑亚细胞器内NO含量显著升高，海马CA1区存活的锥体细胞数显著降低。绞股蓝总皂苷能显著降低脑亚细胞器内NO含量，升高海马CA1区存活的锥体细胞数。结论绞股蓝总皂苷通过降低NO的毒性，发挥保护脑组织，减轻缺血再灌注损伤。

目的观察拟人参皂苷元对大鼠局灶性脑缺血损伤的保护作用，并探讨其作用机制。方法缺血前给予拟人参皂苷元1.25、2.5、5、10、20mg•kg-1，灌胃7d，末次给药1h后制备大鼠大脑中动脉栓塞局灶性缺血模型（McAO），12h后测定大鼠脑梗死面积并进行脑组织病理观察，制备脑组织匀浆测定超氧化物歧化酶（s0D）活性和丙二醛（MDA）含量。结果大鼠脑缺血12h后，脑组织出现大面积梗死灶，且MDA含量增加，SOD活力降低。拟人参皂苷元（5mg•kg-1）能减小脑梗死面积，改善缺血损伤所致的脑组织病理形态学改变，并且降低缺血脑组织中MDA含量，升高s0D的活性。结论拟人参皂苷元对大鼠局灶性脑缺血损伤具有明显保护作用，该作用可能与抑制脂质过氧化、提高抗氧化酶活性有关。