Neuroprotective effect of Naomaitong extract following focal cerebral ischemia induced by middle cerebral artery occlusion in rats

OBJECTIVE: To examine the neuroprotective effect of extract from Naomaitong following focal cerebral ischemia reperfusion induced by occlusion of middle cerebral artery(MCA), and to determine the biochemical alterations in urine using proton nuclear magnetic resonance spectroscopy and principal component analysis.METHODS: Wistar rats were randomly assigned tothree groups: sham-operated group, MCA focal cerebral ischemia reperfusion model group, and active extract of Naomaitong treatment group. The model was established by an improved MCA occlusion(MCAO) method. Sham-operated rats received the same surgical procedure, but without occlusion. The Naomaitong treatment group were treated with active extract from Naomaitong at a dose of3.0 g·kg-·1d-1. Brain tissues and urine samples were collected from all groups for histopathological assessment and proton nuclear magnetic resonance spectroscopy-based metabonomics, respectively.RESULTS: Hematoxylin-eosin and triphenyl tetrazolium chloride staining of brain tissues showed a significant decrease in cerebral infarction area in the Naomaitong group. In model rats, metabonomic analyses showed increased urinary levels of glutamate, taurine, trimetlylamine oxide, betaine, and glycine, and reduced levels of creatinine and creatine.Naomaitong regulated the metabolic changes by acting on multiple metabolic pathways, including glycine metabolism, glutaminolysis, transmethylation metabolism and creatinine metabolism.CONCLUSION: These data demonstrate that extract from Naomaitong is neuroprotective against focal cerebral ischemia induced by MCAO, and can alleviate biochemical changes in urinary metabolism. Metabonomics may be a useful approach for assessing the biochemical mechanisms underlying the neuroprotective actions of extract from Naomaitong.     

灯盏乙素乙酯对大鼠大脑中动脉结扎所致局灶性脑缺血的保护作用及机制研究

观察灯盏乙素乙酯对大鼠大脑中动脉结扎所致局灶性脑缺血的保护作用,并探讨其作用机制。该实验选用SPF级雄性SD大鼠84只,随机分为7组:假手术组、模型组、阳性药组(尼莫地平组12 mg·kg~(-1))、灯盏花素片组(48 mg·kg~(-1))、灯盏乙素乙酯高、中、低剂量组(100,50,25 mg·kg~(-1))。采用线栓法制备大鼠大脑中动脉结扎(MCAO)模型,观察大鼠MCAO时神经功能状态,TTC染色法测脑梗死面积,半自动生化分析仪测定血清中MDA,SOD,NO的变化。分别采用200 mg·L~(-1)OxLDL和100μg·L~(-1)TNF-α作用人脐静脉内皮细胞(HUVECs)24 h,建立Ox-LDL和TNF-α细胞损伤模型,测定细胞上清液中MDA,SOD,NO,ET,6-keto-PGF_(1α),TXB_2,IL~(-1),IL-6,IL-8,ICAM-1和PECAM-1水平。结果显示,灯盏乙素乙酯能有效改善MCAO大鼠神经功能,明显减小脑梗死面积。与模型组比较,血清中SOD和NO活性提高,MDA含量降低;细胞上清液中SOD,6-keto-PGF_(1α)和NO活性提高,IL~(-1),IL-6,IL-8,ICAM-1,PECAM-1,TXB_2,ET和MDA含量降低。结果表明,灯盏乙素乙酯对大鼠大脑中动脉结扎所致局灶性脑缺血具有一定的保护作用,其作用机制可能与抗氧化应激,改善血管内皮细胞功能及减轻炎性反应有密切关系。     

Neuroprotective effect of Longshengzhi capsule following permanent middle cerebral artery occlusion in rats

ObjectiveLongshengzhi capsule (LSZC) is an optimized preparation based on the traditional Chinese Medicine formula Buyanghuanwu Decoction (BYHWD), and is approved by the China Food and Drug Administration for treating stroke-induced disability and vascular diseases. Herein, we examined the pharmacodynamics, anti-apoptotic and anti-oxidant actions, and potential mechanisms of action of LSZC following stroke in rats.MethodsPermanent middle cerebral artery occlusion (MCAO) was used as an ischemic stroke model. LSZC was administered intragastrically. We examined the survival rate, bodyweight, and neurological deficits in stroke rats. Brain infarct size was determined by 2,3,5-triphenyltetrazolium chloride staining. Brain pathology was examined using hematoxylin and eosin staining, Nissl staining, and TdT-mediated dUTP Nick-End Labeling staining. Malondialdehyde, catalase, superoxide dismutase, and glutathione levels were examined by commercial kits. Expression of Nrf2, heme oxygenase-1, Bax, Bcl-2, cleaved caspase-3, and caspase-3 proteins in brain tissue was measured by Western blot.ResultsLSZC markedly improved the survival rate and bodyweight, and reduced infarct volume and neurological deficit scores, in MCAO stroke rats. LSZC also significantly attenuated oxidative stress, as indicated by decreased expression of malondialdehyde, and upregulation of Nrf2, heme oxygenase-1, catalase, superoxide dismutase, and glutathione. Moreover, LSZC significantly decreased apoptosis, including a decrease in Bax and cleaved caspase-3 expression, and an increase in Bcl-2, as well as a reduction in numbers of apoptotic neurons.ConclusionLSZC treatment is neuroprotective against ischemic stroke, potentially via reducing oxidative stress and apoptosis. The Nrf2 and apoptotic signaling pathways may play important roles in the antioxidant and anti-apoptotic actions of LSZC.     

依达拉奉对大鼠局灶性脑缺血的保护作用

 目的探讨自由基清除剂依达拉奉对大鼠脑缺血及再灌注损伤的保护作用。方法大脑中动脉阻断法制备大鼠脑缺血再灌注模型,缺血60min后再灌注24h,术前30min及再灌注2h后尾静脉给药。观察不同浓度的依达拉奉对脑缺血再灌注引起的神经功能缺损症状及病理损伤的影响,检测脑组织内丙二醛(MDA)含量的变化以及脑组织超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)活性的变化。结果依达拉奉能轻度改善脑缺血再灌注24h后神经功能缺失症状;0.3～3.0mg·kg^-1依达拉奉能显著减少梗死体积和脑水肿,减少神经元损伤(P<0.05);依达拉奉剂量依赖性的降低脑组织MDA含量,增加LDH活性,0.3～3.0mg·kg^-1与对照组相比有显著性差异;但依达拉奉对脑组织SOD活性变化无明显影响。结论依达拉奉对大鼠脑缺血有保护作用,其机制可能与减轻脑水肿,清除自由基有关。     

Protective effect of hydroalcoholic extract of Mimusops elengi Linn. flowers against middle cerebral artery occlusion induced brain injury in rats

Ethnopharmacological relevance

In the traditional Indian and Thai system of medicine, Mimusops elengi Linn., flower is used as brain tonic and to calm anxiety and panic attacks.

Aim of the study

The present study was designed to investigate the neuroprotective effect of hydroalcoholic extract of Mimusops elengi (ME) against cerebral ischemic reperfusion injury in rats.

Materials and methods

Male rats were pretreated with ME (100 and 200 mg/kg) for seven days and focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) method. After 60 min of MCAO and 24 h of reperfusion, a battery of behavioral tests assessed the extent of neurological deficits. Infarct volume and brain edema were measured in TTC stained brain sections and the extent of blood brain barrier (BBB) disruption was observed by Evan's blue extravasation. Oxidative and nitrative stress parameters were estimated in the brain homogenates. Further, simultaneous quantification of five polyphenolic biomarkers were done using HPLC.

Results

Pretreatment with ME at doses of 100 and 200 mg/kg significantly improved the neurobehavioral alterations and reduced the infarct volume, edema and extent of BBB disruption induced by ischemia reperfusion injury. It also prevented the alteration in the antioxidant status and reduced the nitrite levels when compared to ischemic animals. Further, HPLC studies revealed that ME contains five bioactive polyphenolic compounds.

Conclusions

These results clearly indicate the neuroprotective effect of ME against stroke like injury. The observed protective effect might be attributed to the polyphenolic compounds and their antioxidant and anti-inflammatory property.     

Synergistic protective effect of astragaloside IV-tetramethylpyrazine against cerebral ischemic-reperfusion injury induced by transient focal ischemia

Ethnopharmacological relevance

Astragaloside IV and tetramethylpyrazine have been extensively used in the cardio-cerbrovascular diseases of medicine as a chief ingredient of glycoside or alkaloid formulations for the treatment of stroke and myocardial ischemia diseases.

Aim of the study

To investigate the effects of astragaloside IV (ASG IV) and tetramethylpyrazine (TMPZ) on cerebral ischemia-reperfusion (IR) injury model in rat model.

Materials and methods

Rats were randomly divided into the following five groups: sham group, IR group and treatment group including ASG IV, ASG IV–TMPZ and nimodipine treatment. The therapeutic effect was evaluated by micro-positron emission tomography (Micro-PET) using ¹⁸F-fluoro-2-deoxy-d-glucose. The neurological examination, infarct volume and the levels of oxidative stress- and cell apoptosis-related molecules were assessed.

Results

Micro-PET imaging showed that glucose metabolism in the right hippocampus was significantly decreased in the IR group compared to the sham group (P < 0.01). ASG IV and ASG IV–TMPZ treatments reversed the decreased glucose metabolism in the model group (P < 0.05 and P < 0.01, respectively). IR induced the increase of Caspase-3 mRNA levels, MDA content and iNOS activity, but it caused the decrease of SOD activity and Bcl-2 expression compared the sham group (P < 0.01). ASG IV–TMPZ and ASG IV reversed the IR-induced changes of these parameters, i.e. the down regulation of Caspase-3 mRNA, MDA content and iNOS activity, and the up regulation of SOD activity and Bcl-2 expression (P < 0.05).

Conclusion

This study showed that ASG IV–TMPZ played a pivotal synergistic protective role against focal cerebral ischemic reperfusion damage in a rat experimental model.     

桑椹乙酸乙酯萃取物对链脲佐菌素致高血糖大鼠的降血糖作用

目的 研究桑椹乙酸乙酯萃取物(EEM)对链脲佐菌素(STZ)诱导的糖尿病大鼠的降糖作用.方法 用STZ诱导出1型糖尿病大鼠模型分成5组,分别用水、格列苯脲和0.1、0.2、0.3g/kg EEM连续灌胃3周,每周测定血糖.结果 与模型对照组相比,0.2 g/kg EEM能显著降低糖尿病大鼠血糖、糖化血清蛋白,刺激胰岛素分泌,增加体质量,调节血脂,增强机体抗氧化能力,同时具有一定的保护肾脏的功能,但对肝脏有一定副作用.结论 EEM能有效的控制糖尿病大鼠血糖水平,一定程度改善糖脂代谢紊乱.     

Neuroprotective effect of Paeoniae Radix Rubra on hippocampal CA1 region of mice induced by transient focal cerebral ischemia via anti-gliosis and anti-oxidant activity

Objective: Stroke is the second leading cause of death worldwide. This study aimed to investigate the neuroprotective effect of Paeoniae Radix Rubra(PRR) on ischemic stroke of mice.Methods: The focal ischemic stroke model was produced via middle cerebral artery occlusion. The experimental mice were divided into four groups: vehicle-sham group, PRR-sham group, vehicle-ischemia group, and PRR-treated ischemia group. The cerebral infarction volume was detected with TTC staining.The number of neurons in the hippocampal CA1 of the ischemic side, and the activation of astrocytes and microglia were observed via immunohistochemical staining. Western blotting was used to determine the expression changes of SOD1, SOD2, and Catalase protein levels in the hippocampus.Results: PRR significantly reduced the cerebral infarct volume induced by ischemic injury and inhibited the astrocytes and microglia activation in the hippocampal CA1 region. The decreased levels of SOD1,SOD2, and Catalase that was induced by ischemic reperfusion were simultaneously improved after PRR treatment.Conclusion: PRR improved neuronal injuries that were induced by transient cerebral ischemia via inhibiting gliosis and elevating anti-oxidants.     

Neuroprotective effects of Eleutherococcus senticosus bark on transient global cerebral ischemia in rats

Ethnopharmacological relevance

Eleutherococcus senticosus Maxim., classified into the family of Araliaceae, is used in a variety of diseases in traditional Korean medicine including ischemic heart disease.

Aim of the study

To determine the neuroprotective effects of Eleutherococcus senticosus on global cerebral ischemia.

Materials and methods

A four-vessel occlusion (4-VO) rat model was used to evaluate the potential protective effects against transient global cerebral ischemia ethanol extracts of Eleutherococcus senticosus was orally administered at doses of 3, 30, and 300 mg/kg twice at times of 0 and 90 min after reperfusion. The effects on memory deficit were investigated by using a Y-maze neurobehavioral test after brain ischemia, and the effects on hippocampal neuronal damage were measured 7 days after ischemia. The expressions of glial fibrillary acid protein (GFAP), CD11b antibody (OX-42), and cyclooxygenase-2 (COX-2) were investigated by immunohistochemistry.

Results

Oral administration of Eleutherococcus seticosus at 30, 100 and 300 mg/kg significantly reduced hippocampal CA1 neuronal death by 3.5%, 25.9% and 53.1%, respectively, compared with a vehicle-treated group. Oral administration of Eleutherococcus senticosus at 300 mg/kg inhibited 81.9% of the decrease in spontaneous alternation induced by 4-VOin the Y-maze test, and also attenuated ischemia-induced activation of COX-2, GFAP and OX-42 in the hippocampal CA1 region.

Conclusion

Eleutherococcus senticosus protects delayed neuronal death in the CA1 region of the hippocampus against global cerebral ischemia in rats with the recovery of spatial memory, which can be considered as the normal functioning of the hippocampus. Regarding the immunohistochemical study, the effect of Eleutherococcus senticosus may be attributable to its anti-inflammatory properties through the inhibition of COX-2 expression, microglia and astrocyte expression.     

Electro-acupuncture attenuates nitric oxide release from rat striatum after transient middle cerebral artery occlusion

Nitric oxide (NO) is an important diffusible neurotransmitter, which also has neurotoxicity when it is overproduced. To investigate whether electro-acupuncture (EA) could inhibit the excessive NO release during cerebral ischemia, we detected NO directly by our self-made NO sensitive electrode. The electrode was placed into rat striatum after transient middle cerebral artery occlusion. NO level was significantly increased upon the onset of ischemia and reperfusion. EA apparently antagonized the ischemia-elicited rise of NO, although it could not suppress the NO level to baseline. The results indicated that EA might inhibit directly the elevation of NO following cerebral ischemia.     

Neuroprotective effect of Buyang Huanwu decoction against focal cerebral ischemia/reperfusion injury in rats--time window and mechanism

Ethnopharmacological relevance

Buyang Huanwu Decoction, a traditional Chinese medicine, consists of different herbal medicines, and has been traditionally used for centuries to treat paralysis and stroke. However, its optimal therapeutic time window and the mechanism are still unclear.

Aim of the study

This study was designed to explore the therapeutic time window and mechanism of Buyang Huanwu Decoction on transient focal cerebral ischemia/reperfusion injury.

Materials and methods

Middle cerebral artery occlusion was conducted in male Sprague-Dawley rats, and 40 g/kg of Buyang Huanwu Decoction was intragastrically infused at different time points, and the same dose was infused every 24 h for 3 days. The level of glutamate in cerebrospinal fluid and the expression of metabotropic glutamate receptor-1 RNA in striatum were detected before, during, and after ischemia/reperfusion. Neurological deficit scores and brain infarction volumes were measured at 72 h after reperfusion.

Result

Cerebral ischemia/reperfusion resulted in significant neurological deficit and extensive cerebral infarct volume, associated with a large amount of glutamate in cerebrospinal fluid and elevation of metabotropic glutamate receptor-1 RNA expression. Buyang Huanwu Decoction significantly suppressed the release of glutamate, and reduced the expression of metabotropic glutamate receptor-1 RNA. The neurological defect score and infarction volume were significantly improved by administration of Buyang Huanwu Decoction, when compared with the Ischemia group.

Conclusions

Administration of Buyang Huanwu Decoction, within 4 h of post-transient focal stroke, reduced significant cerebral ischemia/reperfusion damage. The neuroprotective mechanism of Buyang Huanwu Decoction is, in part, associated with the down-regulation of metabotropic glutamate receptor-1 RNA and inhibition of glutamate release resulting from cerebral ischemia.     

Anti-embolic effect of Taorenchengqi Tang in rats with embolic stroke induced by occluding middle cerebral artery

OBJECTIVE: To investigate the anti-embolic effect of Taorenchengqi Tang(TRCQT), a formulas from Traditional Chinese Medicine, plus aspirin in rats with embolic stroke induced by selective occlusion of the middle cerebral artery(MCA). Possible side effects of hemorrhagic incident and other bleeding events and anti-platelet effect were also explored.METHODS: Ninety rats were randomly separatedinto 9 groups(n = 10): group 1 a sham-operated group(n = 10); groups 2 and 3 orally treated with an isovolumetric solvent(distilled water) for 1 and3 months, followed by thromboembolic occlusion(n = 10); groups 4 and 5 orally treated with aspirin(5 mg/kg) alone for 1 and 3 months, followed by thromboembolic occlusion(n = 10); groups 6 and 7orally treated with TRCQT(0.5 g/kg) alone for 1 and3 months, followed by thromboembolic occlusion(n = 10); groups 8 and 9 orally treated with TRCQT plus aspirin for 1 and 3 months, respectively followed by thromboembolic occlusion(n = 10). The ischemic stroke in rats was induced by selective MCA occlusion. One was orally administered. After the treatments, rats' brains were removed, sectioned and stained with triphenyltetrazolium chloride(TTC) for infarct volume measurement. The incidence of subarachnoid hemorrhage(SAH) and intracerebral hemorrhage(ICH) were observed. A potential gastric bleeding side effect was assessed by measuring hemoglobin(Hb), and prothrombin time(PT). Collagen-induced platelet activation and tail vein bleeding time were measured.RESULTS: Treatment with TRCQT alone or in combination with aspirin reduced infarct volume for 1(P 0.05), and 3(P 0.01) months without SAH and ICH incidences, and gastric bleeding. TRCQT treatment for 1 month was also not altered PT. Moreover, a concentration dependent inhibition of collagen-induced platelet activation, followed by increasing of tail vein bleeding time was observed after TRCQT treatment.CONCLUSION: Either TRCQT alone or TRCQT plus aspirin exhibits potent neuroprotective effect by reducing infarct volume without changing the status of SAH, ICH and gastric bleeding possibly via inhib-iting the platelet activation and increasing bleeding time.     

脑髓康对短暂性大脑中动脉阻断小鼠的行为学影响与机制研究

目的:观察脑髓康对短暂性大脑中动脉阻断(tMCAo)小鼠学习记忆与运动能力的影响及机理。方法:采用tMCAo方法诱导血管性痴呆模型,并在手术后连续7天用脑髓康或对照药物进行干预。分别通过恐惧记忆的学习与精确区分、转棒实验评价小鼠学习记忆能力与活动能力;免疫荧光法染色小鼠CA1脑区小胶质细胞、肿瘤坏死因子,ELISA试剂盒检测血清中IL-6、IL-10表达水平,多通道在体电生理的方法记录小鼠大脑海马CA1脑区放电水平。结果:仅有脑髓康9g/kg组能对恐惧记忆进行精确区分;各给药组较模型组均显著提高小鼠的运动能力;脑髓康4.5、9g/kg组的海马肿瘤坏死因子、小胶质细胞水平明显低于模型对照组和尼莫地平组;9g/kg组脑髓康组IL-6含量显著低于模型组和尼莫地平组,IL-10含量显著高于模型组和尼莫地平组;海马CA1脑区神经元放电水平明显提高,与尼莫地平组水平相当。结论:脑髓康能更好地改善tMCAo小鼠对于精确信号的学习记忆能力,其神经保护机制与抑制炎症反应、调控免疫细胞表达、促进神经元放电有关。     

Neuroprotective effect of calycosin on cerebral ischemia and reperfusion injury in rats

Ethnopharmacological relevance

Radix Astragali has been commonly used as traditional herbal medicine in China for reinforcing vital energy, strengthening superficial resistance and promoting the discharge of pus and the growth of new tissue.

Aim of the study

The present study was to investigate the neuroprotective effect of calycosin isolated from the roots of Radix Astragali on cerebral ischemic/reperfusion injury.

Materials and methods

After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), Sprague-Dawley rats were intragastrically administered different doses of calycosin (7.5, 15, 30 mg/kg, respectively). Neurological deficit, infarct volume, histopathology changes and some oxidative stress markers were evaluated after 24 h of reperfusion.

Results

Treatment with calycosin significantly ameliorated neurologic deficit and infarct volume after cerebral ischemia reperfusion. Calycosin also reduced the content of malondialdehyde (MDA), protein carbonyl and reactive oxygen species (ROS), and up-regulated the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in a dose-dependent manner. Moreover, calycosin can also inhibit the expression of 4-Hydroxy-2-nonenal (4-HNE).

Conclusion

These results suggest that calycosin has a neuroprotective effect against cerebral ischemia/reperfusion injury. The mechanism might be attributed to its antioxidant effects.     

槐定碱对永久性大脑中动脉栓塞大鼠脑细胞的作用及机制研究

目的探究槐定碱对永久性大脑中动脉栓塞(permanent middle cerebral artery occlusion,p MCAO)大鼠脑细胞的作用及机制。方法 SD大鼠随机分为对照组、模型组和槐定碱低、中、高剂量(2.5、5.0、10.0mg/kg)组,给予槐定碱5d后,建立p MCAO大鼠模型。考察槐定碱对pMCAO大鼠神经功能评分的影响;考察槐定碱对pMCAO大鼠脑梗死率的影响;采用流式细胞术检测各组大鼠缺血半暗带区细胞凋亡率;采用苏木素-伊红(HE)染色法观察各组大鼠脑组织病理变化;采用Western blotting法考察各组大鼠脑组织B细胞淋巴瘤-2(B-cell lymphoma 2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated Xprotein,Bax)和半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)蛋白表达情况。结果与模型组比较,槐定碱组大鼠神经缺陷症状改善,脑梗死率显著降低(P0.05、0.01),缺血半暗带细胞凋亡率明显降低(P0.05、0.01),脑组织损伤有所改善,脑组织Caspase-3和Bax蛋白表达水平显著降低(P0.05、0.01),Bcl-2蛋白表达水平显著升高(P0.05、0.01)。结论槐定碱对pMCAO大鼠脑细胞具有保护作用,其机制可能与上调Bcl-2及下调Bax、Caspase-3蛋白表达水平,进而抑制细胞凋亡有关。     

Protective effect of Khamira Abresham Uood Mastagiwala against free radical induced damage in focal cerebral ischemia

The effect of Khamira Abresham Uood Mastagiwala (KAUM) (a preparation of Indian System of Unani Medicine) on the activity of antioxidant enzymes, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT) and the content of glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) was studied in the middle cerebral artery occluded (MCAO) rats after 15 days pretreatment (200 mg/kg body weight (b.wt.), orally) of Khamira Abresham Uood Mastagiwala. The rats were trained and assessed for neurobehavioral activity using Cook's climbing pole. The middle cerebral artery of adult male Wistar rats was occluded for 2 h and reperfused for 22 h. The activity of GPx, GST, GR, catalase and content of GSH was decreased significantly in MCAO group as compared with sham. The rats of MCAO + KAUM group have shown a significant protection in the activity of above-mentioned antioxidant enzymes and content of glutathione when compared with MCAO group. The significantly elevated level of TBARS in MCAO group was depleted significantly by the pretreatment of animals with KAUM in MCAO group. The neurobehavioral assessment has also strengthened the above biochemical data thereby indicating that the therapeutic intervention of KAUM, which is a potent cardiac and melancholic tonic, can be used to prevent or reduce the deterioration caused by free radicals thereby preventing subsequent pathological and biochemical changes which occur during cerebral ischemia.     

Neuroprotective activityof Cymbopogon martinii against cerebral ischemia/reperfusion-induced oxidative stress in rats

Ethnopharmacological relevance

Cymbopogon martinii (Roxb.) Watson (Family: Graminae), commonly known as Palmarosa, is traditionally prescribed for central nervous system (CNS) disorders such as neuralgia, epileptic fits and anorexia. Although the plant possesses diverse pharmacological actions, the neuroprotective action has got little attention.

Aim of the study

The present study evaluated neuroprotective effect of essential oil of Cymbopogon martinii (EOCM) against global cerebral ischemia/reperfusion (I/R)-induced oxidative stress in rats.

Materials and methods

Global ischemic brain damage was induced by bilateral common carotid artery (BCCA) occlusion for 30 min, followed by 60 min reperfusion on Wistar albino rats. The biochemical levels of lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), total thiols and glutathione (GSH) were estimated and brain coronal sections and histopathological studies were performed.

Results

BCCA occlusion, followed by reperfusion caused varied biochemical/enzymatic alterations viz. increase in LPO and decrease in SOD, CAT, total thiols and GSH. The prior treatment of EOCM (50 mg/kg and 100 mg/kg, p.o. for 10 days) markedly reversed these changes and restored to normal levels as compared to I/R groups. Moreover, brain coronal sections and histopathological studies revealed protection against ischemic brain damage in the EOCM-treated groups.

Conclusion

This study, for the first time, shows potent neuroprotective effect of EOCM against global cerebral I/R-induced oxidative stress in rats, suggesting its therapeutic potential in cerebrovascular diseases (CVD) including stroke.     

大鼠大脑中动脉梗死模型的评价标准探讨

[目的]选择适合的评价方法及纳入排除标准,以提高对脑缺血模型是否成功的准确判定程度。[方法]采用线栓法建立Wistar大鼠的大脑中动脉阻塞(MCAO)模型,用激光多普勒分别测量造模前、后局部脑血流量(rCBF)。分别在缺血后1、2、3、6、9、12、15、18、21、24 h进行Longa神经行为学评分,断头取脑,利用2,3,5-氯化三苯基四氮唑(TTC)染色法对脑梗死情况进行判定。[结果]经解剖和TTC染色验证,神经行为学评分法对44只MCAO大鼠模型判读准确,准确率为75.86%,结合解剖结果,准确率为86.21%。多普勒脑血流量检测法对51只模型MCAO大鼠模型判读准确,准确率为87.93%。结合解剖结果,准确率为100%。[结论]激光多普勒血流测量法对大鼠大脑中动脉梗死模型是否成功的判断具有良好的敏感性和准确性,尤其适用于超急性期大脑中动脉梗死模型的判定。     

芍药苷对中动脉阻塞模型大鼠环氧酶通路表达的影响

目的探讨芍药苷对大鼠大脑中动脉阻塞(MCAO)诱导的环氧酶代谢通路表达的影响。方法 120只雄性SD大鼠,随机分为假手术组、模型组、芍药苷低、中、高(10、20、40 mg/kg)剂量组、尼莫地平组。线栓法制作大鼠大脑中动脉缺血90 min,再灌注24 h模型。观察芍药苷对神经症状、梗死体积及脑含水量的影响,采用免疫组化SP法检测COX-2的表达情况,ELISA法测缺血侧额区皮质肿瘤坏死因子-α(TNF-α)、白介素1-β(IL-1β)、血栓素A2(TXA2)和前列腺素I2(PGI2)水平。结果芍药苷处理组较模型组能显著改善大鼠神经缺损症状,缩小梗死体积,降低缺血侧脑含水量,抑制COX-2阳性表达,减少TNF-α、IL-1β、TXA2的释放,提高PGI2水平。结论芍药苷可能通过抑制花生四烯酸的环氧酶代谢通路产生脑神经保护作用。