Focal Cerebral Ischemia-reperfusion Model Research Articles

Study on the anti-mitochondrial apoptosis mechanism of Erigeron breviscapus injection based on UPLC-Q-TOF-MS metabolomics and molecular docking in rats with cerebral ischemia-reperfusion injury

Ethnopharmacological relevanceErigeron breviscapus is a common medicine of eight ethnic minorities, including Miao, Naxi, and Yi. As early as the Ming Dynasty (AD 1368–1644), Lanmao's Materia Medica of Southern Yunnan (AD 1436) recorded that the medicine is used for the treatment of “Zuo tan you huan.” In modern pharmacological research, Erigeron breviscapus injection is the most commonly used preparation in the treatment of ischemic stroke caused by acute cerebral infarction, but its mechanism of action in the treatment of ischemic stroke is not well understood. Aim of the studyIn this study, a metabonomics study based on ultraperformance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) was used in investigating the effect of a traditional Chinese medicine preparation Erigeron breviscapus injection on the rat model of focal cerebral ischemia-reperfusion and the affinity of its main components with the targets of mitochondrial apoptotic pathways. Materials and methodsThis study used molecular docking technology to verify the effective binding ability of main effective components of Erigeron breviscapus injection to target proteins related to mitochondrial apoptosis pathway. This study developed a metabonomics method based on the ultra-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC Q-TOF MS) to evaluate the efficacy and study the mechanism of traditional Chinese medicine preparation. With pattern recognition analysis (principal component analysis and partial least squares-discriminate analysis) of urinary metabolites, a clear separation of focal cerebral ischemia-reperfusion model group and healthy control group was achieved. ResultsErigeron breviscapus injection can significantly reduce the area of cerebral infarction, improve tissue morphological lesion in rats, and can increase the number of Nissl bodies. It may be a promoting factor by inhibiting hippocampal nerve cell apoptosis and Bax protein expression and by exerting effects against ischemia reperfusion after the induction of apoptosis. Thus, it plays a role in brain protection. Moreover, it can considerably promote the recovery of neurological deficiency signs in advance. Meanwhile, Erigeron breviscapus decreased malondialdehyde content and T-NOS activity. Its curative effect from strong to weak order: low dose > high dose > medium dose. The representative components of Erigeron breviscapus have good affinity with the active sites of mitochondrial apoptosis-related proteins. Metabolomics found that the potential biomarkers regulated by breviscapine are kynurequinolinic acid, succinylornithine, and leucine proline. It is speculated that it may participate in TRP–kynurequinolinic acid and succinylornithine–urea cycle–NO metabolic pathways. ConclusionsThis paper revealed the potential biomarkers and metabolic pathways regulated by Erigeron breviscapus. It was speculated that the mechanism is related to its inhibition of mitochondrion-mediated apoptosis. Erigeron breviscapus could restore the metabolic profiles of the model animals to normal animal levels. The mechanism may be related to the potential biomarkers of quinolinic acid, succinylornithine, and leucine proline and the metabolic pathways involved. However, the exact mechanism by which Erigeron breviscapus inhibits mitochondrion-mediated apoptosis remains to be further explored.

Acupuncture combined with exercise training at different time points on nerve repair of cerebral ischemia-reperfusion injury in rats and its effects on the expressions of Nestin, bFGF and EGF.

The aim of the study was to observe the neuroreparative effect of electroacupuncture in rats with cerebral ischemia-reperfusion injury, and to explore the difference in the therapeutic effect of acupuncture on different acupoint groups after cerebral ischemia-reperfusion. Experimental rats were randomly divided into: sham operation group, model group, electroacupuncture group, rehabilitation group, and Diankang group (electroacupuncture + rehabilitation training). There were 24 rats in each group, and the focal cerebral ischemia-reperfusion model was established by Zea-Longa suture method. After modeling, it took 4 hours to electroacupuncture at Baihui and Dazhui points, which was used to observe the changes of nerve function in rats with signs of keel nerve function defect. Protein expression was detected by immunohistochemistry. Compared with the model group, the EA 3d, 7d, 10d groups and the rehabilitation group had no significant difference in promoting the expression of Nestin (p>0.05). There was a significant difference (p<0.01). After cerebral ischemia-reperfusion injury, the expression of bFGF and EGF on the ischemic side was stronger. The peak of bFGF expression appeared earlier, and the peak of EGF expression appeared later. The expression of bFGF and EGF in cerebral ischemic cortex at different time points of ischemia in electroacupuncture group, rehabilitation group and Diankang group was increased, and the response was enhanced. The effect of Diankang group on the upregulation of bFGF and EGF was more significant (p<0.01, p<0.05). Under the influence of different effects, Diankang is superior to simple treatment in improving ischemic neurological dysfunction. This may be related to the fact that Diankang can promote the proliferation of neural stem cells and the expression of neurotrophic factors on the ischemic side of the rat brain.

Transcutaneous Electrical Acupoint Stimulation Pretreatment Alleviates Cerebral Ischemia-Reperfusion Injury in Rats by Modulating Microglia Polarization and Neuroinflammation Through Nrf2/HO-1 Signaling Pathway.

Cerebral ischemia-reperfusion injury (CIRI) may lead to severe disability even death, but the strategies for prevention and treatment are still limited. Transcutaneous electrical acupoint stimulation (TEAS) has been reported to have a significant neuroprotection against CIRI, but the underlying mechanisms remain obscure. In this study, we established a focal cerebral ischemia-reperfusion model in male Sprague-Dawley rats. TEAS pretreatment was applied to Baihui (GV20), Sanyinjiao (SP6) and Zusanli (ST36) acupoints for 5 consecutive days before CIRI. After 24h reperfusion, the brain damage was assessed using Zea-Longa score, brain water content (BWC) and infarct volume. Meanwhile, the number of activated microglia and the TNF-α were detected by immunofluorescence and ELISA respectively. Moreover, Western Blot and RT-qPCR were conducted to detect the proteins and mRNA expressions of Nrf2, HO-1, iNOS and Arg-1. We found that TEAS pretreatment significantly reduced Longa score, BWC, infarct volume and the number of activated microglia. Besides, TEAS pretreatment increased Nrf2 and HO-1 levels, while lowered the expression of TNF-α. Subsequently, we also discovered that the microglia M1 phenotype maker iNOS decreased and the M2 maker Arg-1 increased after TEAS pretreatment. However, these effects of TEAS pretreatment were markedly eliminated by brusatol. These findings clearly suggested that TEAS pretreatment exerted neuroprotection against CIRI, which might be related to modulating microglia polarization and neuroinflammation via Nrf2/HO-1 pathway.

Effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion in mice

Objective: To explore the effect of metformin combined with intermittent fasting on endoplasmic reticulum stress after cerebral ischemia-reperfusion injury in mice. Methods: One hundred 10-Week-old healthy KM mice of SPF grade, weighing 25-28 g, were divided into 5 groups by the random number table method: sham group, focal cerebral ischemia group (I/R group), intermittent fasting group (IF group), metformin group (Met group), metformin+intermittent fasting group (Met+IF group). In IF group, food was provided ad libitum from 8∶00 to 16∶00 daily, but the mice were fasted for the rest of the time. In Met group, the mice underwent intraperitoneal injection of metformin (10 mg/kg). In Met+IF group, the mice received the same eating method as the IF group and the same method of metformin injection as Met Group. In Sham group, I/R group and IF group, the mice were intraperitoneally injected with equal volume of normal saline. Mice in all groups were not restricted to drinking water. Random plasma glucose and body weight changes in mice during preconditioning were monitored, and a focal cerebral ischemia-reperfusion model was established 14 days later. The cerebral infarction volume was measured after 1 hour of ischemia and 24 hours of reperfusion. The brain tissues of mice were subjected to Western blot to detect the contents of endoplasmic reticulum stress-related proteins, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), and apoptosis proteins (Caspase-3 and Cleaved-caspase 3). Results: After different interventions, there was no significant difference in random plasma glucose changes among the four groups (all P<0.05). The blood glucose level of the mice in the Met+IF group was lower than the sham group, I/R group, IF group and Met group (all P<0.05). GRP78/β-actin in sham group, I/R group, IF group, Met group, IF+Met group were 0.48±0.05, 1.35±0.10, 0.94±0.05, 0.70±0.14, 0.41±0.37, respectively; CHOP/β-actin were 0.27±0.04, 1.03±0.03, 0.72±0.04, 0.63±0.04, 0.44±0.01, respectively; Caspase-3/β-actin were 0.51±0.04, 1.04±0.04, 0.83±0.03, 0.76±0.03, 0.63±0.05, respectively; Cleaved-Caspase-3/β-actin were 0.17±0.06, 1.01±0.20, 0.75±0.06, 0.51±0.12, 0.29±0.08, respectively, with statistically significant differences (all P<0.001). The counts of GRP78-positive cells in the hippocampus immunohistochemistry in the sham group, I/R group, IF group, Met group, and IF+Met group were 53±5, 192±11, 162±12, 140±10, 114±13, respectively, while the counts of CHOP-positive cells were 35±4, 177±12, 120±12, 100±7, 69±10, respectively, with statistically significant differences (all P<0.001). The relative volume of cerebral infarction in I/R group, IF group, Met group and IF+Met group were 0, 0.333±0.046, 0.258±0.023, 0.116±0.039, 0.111±0.039, respectively, and there were statistically significant differences (all P<0.001). Conclusion: Both Metformin and intermittent fasting can alleviate endoplasmic reticulum stress after cerebral ischemia and reperfusion in mice, and the combination of the two has a better effect.

Mechanism of Electroacupuncture at Baihui and Shenting Alleviating Cerebral Ischemia-reperfusion Injury via Regulating BNIP3L-Mediated Mitophagy

<sec><title>Objective</title> The purpose of this study is to explore the mechanism of electroacupuncture at Baihui and Shenting acupoints to alleviate cerebral ischemia-reperfusion injury by regulating BNIP3L-mediated mitophagy. </sec><sec><title>Methods</title> A total of 60 SD rats were randomly divided into sham operation group (<italic>n</italic>=15) and operation group (<italic>n</italic>=45) by using the random number table method. Only the blood vessels were separated and exposed in the sham operation group, without ligation and no nylon thread inserted. The rats in the operation group were treated with the middle cerebral artery occlusion (MCAO) method to prepare the focal cerebral ischemia-reperfusion (I/R) model, and the Zea Longa method was used to score the neurological function 2h after the operation. Finally, 30 rats were included in the operation group. The included operation group rats were further randomly divided into the model group, electroacupuncture group, and electroacupuncture+3-MA group, with 10 rats in each group. After grouping, each group was treated with different methods such as electroacupuncture for 7 days, and the Zea Longa method was used to evaluate the neurological function again on the 1, 3, 5, and 7 days. After 7 days of intervention, the left cerebral cortex tissue of each group was obtained, hematoxylin-eosin (HE) staining was used to observe the pathological changes of the brain tissue, the expression level of LC3-Ⅱ/LC3-Ⅰ protein was detected by Western blot, and the tissue immunofluorescence technology was applied to detect the expression and colocalization of mitophagy-related protein BNIP3L and SQSTM1 labeled. The TUNEL method detected the apoptosis rate of rat nerve cells in each group. </sec><sec><title>Results</title> 1) The neurological scores of the rats in the operation group were significantly increased 2 hours after the MCAO, and the rats in the sham-operation group did not show symptoms of neurological deficit. On the 7th day after the intervention, the neurological scores of the rats in the model group and the electroacupuncture+3-MA group still increased significantly, which were significantly different from those in the sham operation group (<italic>P</italic><0.05). However, the neurological scores of rats in the electroacupuncture group reduced after electroacupuncture intervention, which was significantly different from the model group and electroacupuncture+3-MA group (<italic>P</italic><0.05). 2) The results of HE staining showed that the cell body of neurons in the sham operation group was large, polygonal (multiple protrusions), the nucleus was lightly colored, and the characteristic structure of Nissl body could be seen in the cytoplasm. In the model group, neurons shrank, the cytoplasmic structure was unclear, cytoplasmic eosinophilic staining was enhanced, Nissl bodies gathered or disappeared, nuclear pyknosis, and some cell bodies deformed and shrunk to triangles and the spaces around the cells widened. The electroacupuncture group could reduce the pathological damage caused by ischemia-reperfusion to a certain extent. 3) Western blot results showed that the autophagy level (LC3-Ⅱ/LC3-Ⅰ) of the model group decreased on the 7th day after MCAO, there wass a significant difference compared with the sham operation group (<italic>P</italic><0.05), while the electroacupuncture group could activate the level of autophagy, which was significantly different from the model group (<italic>P</italic><0.05). 4) In the model group, the level of mitophagy in the cortical infarction area was absent, as evidenced by the weakened red fluorescence and the intensity of green fluorescence. However, the intervention of electroacupuncture could activate the mitophagy of nerve cells in the infarct area, which was manifested by increased expression of red fluorescence and green fluorescence and enhanced colocalization (orange). 5) TUNEL test results indicated the apoptotic rate of rats in the model group rising, and there was a significant difference compared with the sham operation group (<italic>P</italic><0.05). However, the apoptotic rate of the electroacupuncture group decreased, which was significantly different from that of the model group (<italic>P</italic><0.05). The results of the electroacupuncture+3-MA group showed that the autophagy inhibitor 3-MA could reverse the neuroprotective effect of electroacupuncture in MCAO model rats. </sec><sec><title>Conclusion</title> Electroacupuncture at Baihui and Shenting acupoints can alleviate neurological damage in rats with cerebral ischemia-reperfusion. The specific mechanism is related to regulating BNIP3L-mediated mitophagy to reduce cerebral ischemia-reperfusion injury and cell apoptosis. </sec>

The Mechanism of Gastrodin Participating in Improving the Cerebral Ischemia-Reperfusion Injury Through Notch 1 and NF-κB Signaling Pathways

Background: The purpose of this study was to investigate whether Gastrodin can activate the Notch 1 signaling pathway in the ischemic brain area to produce neuroprotective effects against cerebral ischemia-reperfusion injury, and to elucidate the role of Notch 1 and NF-κB signaling pathways in the Gastrodin-induced cerebral ischemic tolerance. Material and methods: The focal cerebral ischemia reperfusion model of middle cerebral artery embolism was established. TTC staining was applied to detect cerebral infarction. Tunel/NeuN immunofluorescence double labeling was employed to detect apoptosis. WB was used to detect the expressions of proteins related to the Notch 1 and NF-κB pathways. Results: Gastrodin can reduce neuron apoptosis in hippocampus after MCAO/R injury. After DAPT blocked Notch 1 signaling, the neuroprotective effects of Gastrodin improving neural function score, reducing cerebral infarction volume, and inhibiting neuronal apoptosis, were all reversed. Compared with the MCAO/R group, DAPT blocking Notch 1 signaling can also improve the neurological score of rats after MCAO/R injury, reduce cerebral infarct volume, and reduce neuronal apoptosis. Gastrodin can activate Notch 1 and NF-κB signaling pathways in cerebral ischemic areas and increase the expression of related proteins. After DAPT inhibited the Notch 1 signaling in the ipsilateral brain region, the phosphorylation level was significantly decreased, indicating that the activity of the NF-κB pathway was regulated by the Notch 1 signaling. Conclusion: Gastrodin-mediated protection against cerebral ischemia-reperfusion injury is related to the activation of Notch 1 signaling and the up-regulation of NF-κB signaling pathway activity in neurons of ischemic brain area.

Crocin regulates the proliferation and migration of neural stem cells after cerebral ischemia by activating the Notch1 pathway.

To investigate the effects of crocin on proliferation and migration of endogenous neural stem cells and the Notch1 signalling pathway in rats after cerebral ischemia reperfusion. SD rats were randomly divided into the sham operation group, model group and administration group (crocin). Middle cerebral artery occlusion (MCAO/R) was used to establish the focal cerebral ischemia reperfusion model in rat. After surgical treatment, the treatment group was treated with crocin. Quantitative polymerase chain reaction (qPCR) was used to detect the changes in the expression of Notch1, Bax and bcl-2 proteins in rat endogenous neural stem cells after cerebral ischemia reperfusion. ELISA was used to detect changes in inflammatory factors. Neural stem cells were cultured in vitro, which were divided into: the normal control group, the hypoglycaemic deprivation/reoxygenation group, hypoglycaemic deprivation/reoxygenation group with alow concentration of crocin, and hypoglycaemic deprivation/reoxygenation group with ahigh concentration of crocin. The cell proliferation assay detects cell activity. The cell migration assay tests the cell migration ability. And flow cytometry was used to determine cell apoptosis. Compared with the sham group, the Notch1 signalling pathway was activated in the model group. The expression of Notch1 in the crocin group was increased compared to the model group. Crocin can inhibit the release of inflammatory factors. The results of our experiments showed that crocin could induce the proliferation and migration of neural stem cells and inhibit the apoptosis of neural stem cells in the hypoglycaemic/reoxygenation model group. Crocin sufficiently promotes the proliferation and migration of neural stem cells and inhibits the apoptosis of these cells in rats after ischemia-reperfusion by manipulating the Notch signalling pathway.

Salvianolic acid A attenuates ischemia reperfusion induced rat brain damage by protecting the blood brain barrier through MMP-9 inhibition and anti-inflammation

Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia Miltiorrhiza Bge, a traditional Chinese medicine, which has been used for the treatment of cerebrovascular diseases for centuries. The present study aimed to determine the brain protective effects of SAA against cerebral ischemia reperfusion injury in rats, and to figure out whether SAA could protect the blood brain barrier (BBB) through matrix metallopeptidase 9 (MMP-9) inhibition. A focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion (MCAO) for 1.5-h followed by 24-h reperfusion. SAA was administered intravenously at doses of 5, 10, and 20 mg·kg−1. SAA significantly reduced the infarct volumes and neurological deficit scores. Immunohistochemical analyses showed that SAA treatments could also improve the morphology of neurons in hippocampus CA1 and CA3 regions and increase the number of neurons. Western blotting analyses showed that SAA downregulated the levels of MMP-9 and upregulated the levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) to attenuate BBB injury. SAA treatment significantly prevented MMP-9-induced degradation of ZO-1, claudin-5 and occludin proteins. SAA also prevented cerebral NF-κB p65 activation and reduced inflammation response. Our results suggested that SAA could be a promising agent to attenuate cerebral ischemia reperfusion injury through MMP-9 inhibition and anti-inflammation activities.

Effects of ginkgolide K on platelet aggregation activity and neuroprotection

To investigate the antagonism effects of different concentrations of ginkgolide K(GK) on platelet activating factor (PAF)-induced platelet aggregation and neuroprotective effect on cells and animal models of ischemia-reperfusion injury. GK-containing serum in rabbit was prepared, and the effects of GK-containing serum on PAF-induced platelet aggregation was observed by platelet aggregation assay. The effect of different concentrations of GK on apoptosis of SH-SY5Y cells injured by oxygen-glucose deprivation/reoxygenation (OGD/R) was investigated by Hoechst 33342/PI double staining in OGD/R cell model. The focal cerebral ischemia-reperfusion model (I/R)was established in rats to detect the effects of GK on neurobehavioral scores and cerebral infarction volume. GK could inhibit PAF-induced platelet aggregation, reverse the apoptosis induced by OGD/R injury and improve the neurobehavioral score and cerebral infarction volume after cerebral ischemia-reperfusion injury in rats in a dose-dependent manner. GK can inhibit PAF-induced platelet aggregation and improve nerve injury after cerebral ischemia-reperfusion.

Effects of laser acupoint irradiation on energy metabolism of brain tissue of rats with cerebral ischemia-reperfusion

The protective effect and mechanism of low-intensity laser acupoint irradiation on focal cerebral ischemia-reperfusion (CIR) injury in rats were investigated. Male Sprague-Dawley rats were randomly divided into a sham group, a CIR model (model) group, and a model plus laser irradiation (laser) group. The focal CIR model was induced by middle cerebral artery occlusion in all except the rats in the sham group. After modeling, the Baihui, Mingmen, and left Zusanli points of the rats in the laser group were irradiated with 15 mW using a semiconductor laser, and each point was irradiated for 15 min once a day for 7 d. The treatments used in the sham and model groups were the same as in the laser group except that the laser output power was zero. After treatment, the expressions of serum superoxide dismutase (SOD) activity and serum malonaldehyde (MDA) content, the expression of growth-associated protein (GAP-43), the activities of succinic dehydrogenase and lactic dehydrogenase in brain tissue, were measured. The results showed that acupoint irradiation with a semiconductor laser can improve energy metabolism, enhance the expression of GAP-43, increase the levels of expression of serum SOD, and decrease the serum MDA content in a rat model of focal CIR, suggesting the mechanism for reduction of CIR injury.

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

ObjectiveTo 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. MethodsWistar rats were randomly assigned to three 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 of 3.0 g·kg−1·d−1. Brain tissues and urine samples were collected from all groups for histopathological assessment and proton nuclear magnetic resonance spectroscopy-based metabonomics, respectively. ResultsHematoxylin-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. ConclusionThese 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.

Effects of the Rabdosia rubescens total flavonoids on focal cerebral ischemia reperfusion model in rats

The effect of the Rabdosia rubescens total flavonoids on focal cerebral ischemia reperfusion model in rats was observed. The model group, nimodipine group, cerebral collateral group, and large, medium and small dose group of the Rabdosia rubescens total flavonoids were administered with corresponding drugs but sham operation group and model group were administered the same volume of 0.5%CMC, 1 times a day, continuous administration of 7 d. After 1h at 7 d to medicine, left incision in the middle of the neck of rats after anesthesia, we can firstly expose and isolate the left common carotid artery (CCA), and then expose external carotid artery (ECA) and internal carotid artery (ICA). The common carotid artery and the external carotid artery are ligated. Then internal carotid artery with arterial clamp is temporarily clipped. Besides, cut the incision of 0.2mm from 5cm of the bifurcation of the common carotid artery. A thread Line bolt is inserted with more than 18–20mm from bifurcation of CCA into the internal carotid artery until there is resistance. Then the entrance of the middle cerebral artery is blocked and internal carotid artery is ligated (the blank group only exposed the left blood vessel without Plugging wire). Finally it is gently pulled out the plug line after 2h. Results: Compared with the model mice, Rabdosia rubescens total flavonoids can significantly relieve the injury of brain in hippocampus and cortex nerve cells; experimental rat focal cerebral ischemia was to improve again perfusion model of nerve function defect score mortality; significantly reduce brain homogenate NOS activity and no content, MDA, IL-1, TNF-a, ICAM-1 content; increase in brain homogenate SOD and ATPase activity (P<0.05, P<0.01); and reduce the serum S-100β protein content. Each dose group of the Rabdosia rubescens total flavonoids has a better Improvement effect on focal cerebral ischemia reperfusion model in rats.

Assessment of the MRI and Behavioral Test Results in a Focal Cerebral Ischemia-Reperfusion Model in the Rat after Separate and Combined Use of Mouse-Derived Neural Progenitor Cells, Human-Derived Neural Progenitor Cells and Atorvastatin.

To assess the efficacy of Neural progenitor cell (NPC) transplantation in ischemic stroke, and to investigate whether atorvastatin enhances therapeutic potency of NPC after stroke. The focal cerebral ischemia-reperfusion model was performed by transient occlusion of middle cerebral artery. Rats were assigned randomly to receive intracerebral transplantation of mouse NPC alone (mNPC), human NPC alone (hNPC), mouse NPC plus oral atorvastatin (mNPC+A), human NPC plus oral atorvastatin (hNPC+A), oral atorvastatin alone, or intracerebral Dulbecco"s Modified Eagle"s medium injection (control group). Adhesive removal, rotarod, cylinder tests, and magnetic resonance imaging (MRI) were used for assessment of rats during 4 weeks. After sacrification on 28th day, rats were investigated by immunofluorescent staining. The hNPC and mNPC groups showed significantly improved functional outcome and reduced infarct area ratio compared with the control group. The hNPC group had significantly better performance and lower infarct area ratio than the mNPC group. Addition of atorvastatin to stem cell therapy significantly improved functional outcome, although it did not affect the infarct area ratio on MRI. Anti-inflammatory response in the infarct area was higher in the mNPC group. NPC transplantation significantly reduced the amount of microglia and a significant increase in the amount of astrocytes. CD8a+ T lymphocyte and granzyme B activities were not detected in any of the subjects. Both hNPC and mNPC treatments significantly improved functional outcome, and reduced infarct area ratio after stroke. Atorvastatin enhanced the therapeutic potency of NPCs, including neurological improvement.

A neuroprotective action of carnosine in conditions of experimental focal cerebral ischemia-reperfusion

To assess neuroprotective properties of preventive injections of carnosine in experimental focal cerebral ischemia in rats. A focal ischemia in Wistar rats induced by the 60 min-occlusion of the middle cerebral artery with the following 24h-reperfusion was used. Animals received carnosine mixed with ration in daily dose of 150 mg/kg of body mass during 7 days before surgery. Carnosine decreased the size of the lesion by 20%, neurological deficit by 43% with a simultaneous increase in the antioxidant status of blood plasma and brain tissue compared to the animals of the control group. The authors showed for the first time the neuroprotective effect of low dose of carnosine (150 mg/kg of body mass) mixed with ration used in preventive treatment courses in the experimental focal cerebral ischemia-reperfusion model.

Effect of exercise preconditioning on nerve growth factor and learning-and-memory abilities in rats suffered from focal cerebral ischemia

Objective To investigate the effect of exercise preconditioning on the expression of nerve growth factor(NGF) and its receptor TrkA as well as learning-and-memory abilities in rats suffered from focal cerebral ischemia. Methods Thirty-six male SD rats were randomly divided into sham operation group (Sham-MCAO, n=12), focal cerebral ischemia-reperfusion group (MCAO, n=12) and exercise preconditioning + cerebral ischemia-reperfusion group (EX+ MCAO, n=12). Rats in EX+ MCAO group were placed in the treadmill device and accepted 4 weeks exercise training. Then method of middle cerebral artery occlusion was applied to prepare transient focal cerebral ischemia reperfusion model. Garcia’s method was used to assess the neural function in rats. Western blotting was applied to test the expression of NGF and TrkA protein in the successfully established experimental MCAO rats. Morris water maze experiment was utilized to test the learning-and-memory abilities of the rats. Results (1)Compared with Sham-MCAO group, the expression of NGF in rats’ brain tissue was lower in MCAO group (cerebral ischemia 1h reperfusion 24h) (P 0.05). Conclusion Exercise preconditioning can up-regulate the expressions of NGF and TrkA protein, which can also improve the learning-and-memory abilities in rats suffered from focal cerebral ischemia reperfusion injury. Key words: Exercise preconditioning; NFG; TrkA; Focal cerebral ischemia reperfusion; Learning and memory

Protective effect of novel edaravone and danshensu conjugate on focal cerebral ischemia-reperfusion injury in rats and its underlying mechanism

To investigate the protective effect of edaravone and danshensu conjugate (IM-009) on focal cerebral ischemia-reperfusion injury in rats and its underlying mechanisms. Rats were randomly assigned into 6 groups, including a sham group, a model group, an edaravone-treated group, a danshensu-treated group, a low dose of IM-009-treated group and a high dose of IM-009-treated group. The focal cerebral ischemia-reperfusion model was established by intraluminal filament. After the drug treatment, the infarct volume and extent of brain edema were measured. The levels of MDA and SOD were determined by the corresponding assay kit. The scavenging effect of IM-009 on hydroxyl radical and superoxide anion was also measured in a cell free system. 1) In comparison with the model group, the infarct volume and water content in rat brain after IM-009 treatment were significantly reduced. The protective effect of IM-009 at higher dose was much stronger than that of edaravone or danshensu (all P<0.05). 2) IM-009 significantly reduced the levels of MDA and increased the activity of SOD (all P<0.05). 3) IM-009 demonstrated strong activities in scavenging .OH and .O(2)(-) (all P<0.05). IM-009 is able to protect rats from ischemia-reperfusion injury. The protective effect of IM-009 could be due to its radical-scavenging action.

Effects of Shouwu-Yizhi capsule on learning and memory and the expressions of presenilin 1,β-amyloid precursor protein mRNAs in the hippocampus following cerebral ischemia reperfusion in rats

Objective To investigate the effects of Shouwu-Yizhi capsule on learning and memory, and the expressions of presenilin 1（PS1）,β-amyloid precursor protein （APP） mRNAs in the hippocampus following cerebral ischemia reperfusion in rats. Methods Sprague–Dawley rats were randomly divided into a Shouwu-Yizhi group, a piracetam group, a model group, and a sham operation group with 20 rats in each group. Focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion for 2 hours. Seven days after ischemia reperfusion, the rats in the Shouwu-Yizhi and piracetam groups were administered intragastrically Shouwu-Yizhi solution （52 mg/ml） and piracetam solution （28 mg/ml） for 28 days, both in dose of 1 ml/（100 g·d） for 28 days;and the rats in the model and sham operation groups were given intragastrically equivalent volumes of normal saline. Learning and memory were tested using the Morris water maze, and the expressions of PS1 and APP mRNAs were measured using real-time quantitative fluorescent PCR. Results Water maze test showed that the escape latency （12.98±0.70s vs. 9.43±0.78s） was significantly shorter, and the frequency of crossing platform （5.08±0.39 vs. 7.62±0.43） significantly lower in the model groupthan those in the sham operation group; the escape latency （9.77±0.58s vs. 12.98±0.70s） was significantly shorter and the frequency of crossing platform （7.40±0.44 vs. 5.08±0.39） significantly lower in the Shouwu-Yizhi group than those in the model group（all P〈0.01）. The expressions of PS1 （0.99±0.01 vs. 1.08± 0.03）and APP （1.06±0.03 vs. 1.12±0.04） mRNAs in the hippocampus in the Shouwu-Yizhi group were significantly decreased than those in the model group （P<0.05 or 0.01）. Conclusion Shouwu-Yizhi capsule may inhibit the expressions of PS1 and APP mRNAs in the hippocampus, and improve the learning and memory following cerebral ischemia reperfusion in rats. Key words: Brain ischemia; Presenilin-1; Amyloid beta-protein precursor; Gene expression; Learning; Memory; Shouwu-Yizhi eapsule

Total Bakkenolides Protects Neurons Against Cerebral Ischemic Injury Through Inhibition of Nuclear Factor-&amp;#954;B Activation

Total bakkenolides is the major component of the rhizome of Petasites trichinous Franch.. In this study, we investigated its neuroprotective effects in a rat transient focal cerebral ischemia-reperfusion model, and in an in vitro cerebral ischemia model, oxygen-glucose deprivation of cultured nerve cells. Oral administration of total bakkenolides immediately after reperfusion at doses of 5, 10 and 20 mg/kg markedly reduced brain infarct volume and neurological deficits. Total bakkenolides significantly attenuated cell death and apoptosis in primarily cultured neurons subject to 1-h hypoxia followed by 24-h reoxygenation. Morphologic observations directly confirmed its protective effect on neurons. We also demonstrated that total bakkenolides could inhibit nuclear factor-κB (NF-κB) activation by blocking the classic activation pathway through suppression of phosphorylation of IκB-kinase complex, NF-κB/p65 and inhibitor protein IκB, inducing nuclear translocation of NF-κB/p65 and degradation of IκB. Further, total bakkenolides inhibited the activation of Akt and the extracellular signal-regulated kinase 1/2, two important upstream activators of NF-κB. In conclusion, our results provide a strong pharmacological basis for further understanding the potential therapeutic role of total bakkenolides in cerebral ischemic disease and shed new light on its neuroprotective mechanism.

Azadirachta indica mitigates behavioral impairments, oxidative damage, histological alterations and apoptosis in focal cerebral ischemia–reperfusion model of rats

Azadirachta indica Linn. (Meliaceae) has been used from ancient times as a remedy for various ailments. The present study was designed to investigate the antioxidant and anti-apoptotic properties of A. indica seed extract (ASE) in transient middle cerebral artery occlusion (MCAO) rat model. Antioxidant potential of ASE was determined in vitro. Further, ASE was evaluated against neurological deficits, histological alterations (TTC, CV and H&E) and oxidative damage (TBARS, GSH and nitrite) in MCAO rats. Moreover, caspase-3 and -9 were analyzed to evaluate the anti-apoptotic activity of ASE. ASE has shown potent in vitro reducing power (126.2 mg AsAE/g extract) and free radical scavenging activities (DPPH 171.0 and NO 176.0 μg/ml). Furthermore, ASE inhibited oxidative stress and decreased the activities of caspase-3 (26.7 %, p < 0.05) and caspase-9 (31.2 %, p < 0.01) thus, reduced neuronal loss in MCAO rats. Our data revealed that ASE has potent antioxidant and anti-apoptotic properties, and may be explored for its active constituents against neurodegenerative diseases.

Roles of inflammation response in microglia cell through Toll-like receptors 2/interleukin-23/interleukin-17 pathway in cerebral ischemia/reperfusion injury

Microglial activation is one of the causative factors of neuroinflammation in cerebral ischemia. Activation via Toll-like receptors (TLRs) causes increased proinflammatory cytokine expression, such as interleukin-23 (IL-23) and interleukin-17 (IL-17), leading to inflammatory immune responses and neuronal damage. In this study, using a rat focal cerebral ischemia reperfusion (IR) model and an in vitro oxygen-glucose deprivation reperfusion (OGDR) system, we found that TLR2, IL-23 and IL-17 form an axis that leads to increased neuronal apoptosis. TLR2 activation results in IL-23 production which stimulates IL-17 production by microglia. This microglial axis may be a potential therapeutic target to control neuroinflammation in brain IR.