尼莫地平对脑缺血早期神经元型一氧化氮合酶的影响

目的观察局灶性脑缺血大鼠早期缺血部位神经元型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)的变化,以及钙拮抗剂尼莫地平对其的影响。方法以线栓法制作大鼠大脑中动脉闭塞模型为基础,选取雄性SD大鼠共75只,随机分成假手术组(n=25)、模型对照组(n=25)和尼莫地平处理组(n=25)。以NDAPH-d组织化学方法观测各组大鼠脑缺血后30min、2h和6h纹状体中nNOS阳性细胞的变化;利用生物化学法和Hoechst凋亡染色分别检测各组大鼠脑缺血30min纹状体nNOS活性和6h半暗区细胞凋亡。结果脑缺血30min,与假手术组相比,模型对照组大鼠缺血侧纹状体中nNOS活性和nNOS阳性细胞数均升高(P<0.01),而尼莫地平组无明显变化(P>0.05);随脑缺血时间延长,模型对照组和尼莫地平组nNOS阳性细胞数都下降(P<0.05);脑缺血6h,尼莫地平组半暗区的凋亡细胞少于模型对照组(P<0.01)。结论钙拮抗剂尼莫地平可抑制脑缺血早期的nNOS上升,并减轻随后的脑组织损伤。

黄芪注射液联合红花注射液对脑缺血再灌注大鼠NT-3的影响

目的探讨黄芪注射液联合红花注射液治疗脑缺血性中风的作用机理。方法将SD雄性大鼠随机分为假手术组、模型组、黄芪组、红花组、黄芪加红花组,各给药组术前12h与30min分别腹腔注射相应药物,术后每隔12h注射等量药物直到最后一批大鼠被处死为止,假手术组与模型组腹腔注射等量生理盐水;采用线栓法阻断SD大鼠大脑中动脉复制局灶性脑缺血再灌注模型。分别在缺血再灌注6、12、24、48h对其神经系统体征进行客观评分后断头处死。行HE染色观察各时间点脑组织病理学形态的改变;并运用免疫组化的方法检测缺血再灌注6、12、24、48hNT-3蛋白的表达,在光镜下分别计数其阳性细胞数。结果与模型组比较,各给药组均有显著改善脑缺血再灌注模型鼠神经损伤症状的作用;能够减轻脑缺血再灌注时的病理损伤;能够促进NT-3阳性细胞在各时间点的表达;各给药组间比较,以黄芪注射液加红花注射液剂量组的治疗效果更显著。结论黄芪注射液加红花注射液促进脑缺血再灌注模型鼠NT-3的上调可能是其抗脑缺血再灌注损伤的作用机制之一;黄芪注射液加红花注射液组对脑缺血再灌注损伤的治疗作用优于红花治疗组与黄芪治疗组。

Effects of Oestrogen on Ischemia-induced Neurogenesis in the Dentate Gyrus of Rats

To study the effects of oestrogcn on ischemia-induced neurogenesis in the hippocampal dentate gyms, thirty-two adult male rats were randomly divided into four groups： the control surgery group with eestrogen administration （SE）, the control surgery group with normal saline administration （SN）, the middle cerebral artery occlusion （MCAO） group with oestrogen administration （ME） and the MCAO group with normal saline administration （MN）. The MCAO rats were occluded for 90 rain by an intraluminal filament and then recirculated. After 1, 3, 12, 24 and 28 h of MCAO, the rats of the four groups were killed to investigate the infarct volume, apoptosis and neurogenesis. The cerebral infarct volume in the ME group was significantly smaller than that of the MN group （P 〈 0.05）. No significant cell loss was seen in the dentate gyms. Cerebral ischemia led to increased neurogenosis, which is independent of cell death in the ipsilateral dentate gyrus（P 〈 0.05）. BrdU-pesitive cells in the ipsilateral dentate gyms of the ME group were significantly increased when compared with those of the MN group（P 〈 0.05）. In the SE group, BrdU-positive cells in both the ipsilateral and contralateral dentate gyms, were increased when compared with those of the SN group （ P 〈 0.05 ）. We concluded that ocstregen plays an important role in neurogenesis, which is independent of ischemia-induced by MCAO in the hippocampal dentate gyms of rats.

Effects of Pravastatin on neuroprotection and neurogenesis after cerebral ischemia in rats

Objective Statins inhibit hydroxymethylglutaryl coenzyme A （HMG-CoA） reductase activity and lower total serum cholesterol levels. We investigated the effects of Pravastatin on neuroprotection and neurogenesis in the dentate gyrus （DG）, subventricular zone （SVZ） and striatum after cerebral ischemia in rats. Methods The filament method was used for temporary middle cerebral artery occlusion （tMCAO）. Pravastatin or saline post-ischemically were administered at subsequent time points： 6 h after tMCAO, and then on every subsequent day up to day 14 after tMCAO. Neurological outcome was investigated by using a neuroscore, the beam balance test and the rotarod test. Cholesterol and triglycerides levels were determined by blood sample analysis prior to sacrifice. Infarct area was calculated by microtubule-associated protein 2 （MAP2） staining. Neurogenesis was evaluated by triple staining with bromodeoxyuridine （BrdU）, doublecortin （DCX）, and neuronal nuclei （NeuN）. Results Compared with the control groups, Pravastatin treated animals were significantly improved in neurological outcome in rotarod test, with smaller infarct size. Pravastatin increased BrdU- positive cells number in the DG （P = 0.0029） and the SVZ （P = 0.0280） but not in the striatum （P = 0.3929）. Furthermore, Pravastatin increased BrdU-labeled DCX positive cells number in the DG （P = 0.0031）, SVZ （P = 0.0316） and striatum （P = 0.0073）. We also observed a DCX-positive cells stream from the SVZ to the striatum, suggesting a migration route of those immature neurons. No significant differences of total serum cholesterol and triglycerides were observed between groups. Conclusion The Pravastatin administration strategy is safe and could promote neurological recovery in ischemic stroke. Pravastatin induces neurogenesis in the DG and SVZ, and increases the number of migration cells in the striatum. These effects are independent of the cholesterol-lowering property of Pravastatin.

Effects of Electroacupuncture at the Conception Vessel on Proliferation and Differentiation of Nerve Stem Cells in the Inferior Zone of the Lateral Ventricle in Cerebral Ischemia Rats

Objective： To observe the effects of electroacupuncture （EA） at the Conception Vessel on proliferation and differentiation of the nerve stem cells in the inferior zone of the lateral ventricle in cerebral ischemia rats. Methods： The model rats were prepared by occlusion of the middle cerebral artery for 2 hours and then by reperfusion. They were randomly divided into two groups： a control group and an EA group. Changes in differentiation and proliferation of the nerve stem cells were observed 7, 14 and 28 days after successful modeling. Results： As compared with the 7-day control group （C-7d group）, there was no significant difference （P〉0.05） in the numbers of 5-bromodeoxyuridine （Brdu） positive cells, Brdu/GFAP, Brdu/Nestin and Brdu/Nse double-labeled cells in the inferior zone of the lateral ventricle in the EA group 7 days after modeling. However, in the 14-day EA group （R-14d group） and the 28-day EA group （R-28d group）, the numbers of Brdu positive cells and Brdu/GFAE Brdu/Nestin, Brdu/Nse double-labeled cells significantly increased as compared respectively with the 14-day control （C-14d group） and the 28-day control （C-28d） group （P〈0.05 or P〈0.01）. Conclusions： EA at the Conception Vessel promotes differentiation and proliferation of the nerve stem cells in the inferior zone of the lateral ventricle in the cerebral ischemia rats, and may stimulate differentiation of the proliferous nerve stem cells towards the astrocvtes.

Basic fibroblast growth factor alleviates brain injury following global ischemia reperfusion in rabbits

The study was to explore the protective effect of basic fibroblast growth factor (bFGF) on brain injury following global ischemia reperfusion and its mechanisms. Brain injury following global ischemia was induced by four vessels occlusion and systemic hypotension. Twenty-four rabbits were randomized into three groups: group A, only dissection of vessels; group B, intravenous infusion of normal saline after reperfusion for 6 h; group C, 30 μg/kg bFGF injected intravenously at the onset of reperfusion, then infused with 10 μg/(kg&middoth) for 6 h. Serum neuron specific enolase (NSE), S-100B, tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), interleukin-8 (IL-8) were measured before ischemia, 30 min after ischemia, 0.5, 1, 3, 6 h after reperfusion. Brain water content was determined and cerebral histopathological damages were compared. NSE and S-100B were increased 1 h after reperfusion and reached their peaks 6 h after reperfusion, but were much higher in group B than those in group C 3, 6 h after reperfusion. In groups B and C, TNF-a was increased after ischemia and IL-1 and IL-8 were increased significantly 0.5 h after reperfusion, then reached their peaks 6 h, 3 h, 6 h after reperfusion respectively. TNF-a and IL-8 at the time points of 1 h and 3 h and IL-1 at 3 h and 6 h in group C were correspondingly lower than those in group B. These indices in group A were nearly unchanged. There were less severe cerebral histopathological damages in group C compared with group B, but no difference in brain water content. It could be concluded that bFGF alleviates brain injury following global ischemia and reperfusion by down-regulating expression of inflammatory factors and inhibiting their activities.

A simple and sensitive method to assess ischemia occurrence in the setting of focal cerebral ischemia in rat: A comparative study

Objective: Neurological evaluation is commonly applied to identify ischemia in focal cerebral ischemia model though it might not be sensitive. In present study, we hired sleeping time to assess ischemia occurrence. Methods: Permanent middle cerebral artery occlusion was induced in Sprague-Dawley rats under pentobarbital and ketamine anesthesia respectively. Sleeping time was recorded. Neurological evaluation was conducted by modified Bederson’s scoring system at 4 h and histopathological evaluation was performed at 3 d after middle cerebral artery occlusion. Results: Slices of brain stained by TTC, H&E and hoechst 33258 revealed extensive lesion in the two ischemic groups. The sensitivity to identify ischemia by neurological evaluation was 62.5%, but it was 81.3% and 80% respectively when evaluating by sleeping time (pentobarbital: ≥90.7 min, ketamine: ≥36.1 min). The sensitivity to identify ischemia by sleeping time was significantly higher than that by neurological evaluation (P<0.05). Conclusion: Our results suggested that to identify ischemia by sleeping time is a simple and sensitive method in the setting of focal cerebral ischemia in rat.

Effect of Batroxobin on Neuronal Apoptosis During Focal Cerebral Ischemia and Reperfusion in Rats

We have found that Batroxobin plays a protective role in ischemic brain injury, which attracted us to investigate the effect of Batroxobin on apoptosis of neurons during cerebral ischemia and reperfusion. The apoptotic cells in ischemic rat brains at different reperfusion intervals were tested with method of TdT-mediated dUTP-DIG nick end labeling (TUNEL) and the effect of Batroxobin on the apoptosis of neurons was studied in left middle cerebral artery (LMCA) occlusion and reperfusion in rat models (n = 18). The results showed that few scattered apoptosis cells were observed in right cerebral hemispheres after LMCA occlusion and reperfusion, and that a lot of apoptosis cells were found in left ischemic cortex and caudoputamen at 12 h reperfusion, and they reached peak at 24 h-48 h reperfusion. However, in the rats pretreated with Batroxobin, the number of apoptosis cells in left cerebral cortex and caudoputamen reduced significantly and the neuronal damage was much milder at 24 h reperfusion than that of saline-treated rats. The results indicate that administration of Batroxobin may reduce the apoptosis of neurons induced by cerebral ischemia and reperfusion and afford significant cerebroprotection in the model of focal cerebral ischemia and reperfusion.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxicischemic event.This devastating condition can lead to long-term neurological deficits or even death.After hypoxic-ischemic brain injury,a variety of specific cellular mechanisms are set in motion,triggering cell damage and finally producing cell death.Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury.After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury,various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes.Among them,the endocannabinoid system emerges as a natural system of neuroprotection.The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury,acting as a natural neuroprotectant.The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury,and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

EFFECT OF VASOPRESSIN ON DELAYED NEURONALDAMAGE IN HIPPOCAMPUS FOLLOWING CEREBRALISCHEMIA AND REPERFUSION IN GERBILS

Mongolian gerbils were used as delayed neuronal damage (DNDi animal models. At the end of 15Abstract:Mongolian gerbils were used as delayed neuronal damage (DND)animal models. At the end of 15 minute cerebral ischemia and at various reperfusion time ranging from 1 to 96 hours, the content of water and arginine vasopressin (AVP) in the CA1 sector of hippocampus were measured by the specific gravity method and radioimmunoassay. Furthermore, we also examined the effect of intracerebroventricular (ICV) injection of AVP, AVP antiserum on calcium, Na+, K+-ATPase activrty in the CA1 sector after ischemia and 96 hour reperfusion. The results showed that AVP contents of CA1 sector of hippocampus during 6 to 96 hour recirculation, and the water content of CA1 sector during 24 to 96 hour were significantly and continuously increased. After ICV inJection of AVP, the water content and calcium in CA1 sector of hippocampus at cerebral ischemia and 96 hour recirculation further increased, and the Na+, K+- ATPase activity in CA1 sector was remarkably decreased as compared with that of control. While ICV injection of AVP antiserum, the water content and calcium in CA1 sector were significantly decreased as com pared with that of control. These suggested that AVP was involved in the pathophysiologic process of DND in hippocampus following cerebral ischemia and reperfusion. Its mechanism might be through the change of intracellular action mediated by specific AVP receptor to lead to Ca ions over-load of neuron and inhibit the Na+, K+- ATPase activity , thereby to exacerbate the DND in hippocampus.

EFFECT OF ELECTROACUPUNCTURE ON SYNAPTIC PLASTICITY OF HIPPOCAMPAL NEURONS IN CEREBRAL ISCHEMIA RATS

Objective: To observe the effect of electroacupuncture (EA) on synaptic structure of hippocampal nerve felts and synaptophysin(SYN)expression in rats with cerebral ischemic injury. Methods: Sixty Wistar rats were randomized into sham-operation group, cerebral ischemia (CI) group and EA group, each of which was further divided into 1week (W) and 5W subgroups. CI injury model was established by occlusion of the bilateral common carotid arteries. 'Baihui'(百会 GV 20), 'Dazhui' (大椎 GV 14), 'Renzhong'(人中 GV 26) and 'Guangyuan'(关会 CV 4) were punctured and stimulated electrically. The brain tissue sections containing hippocampus region were stained with immu nohistochemical technique and observed under light microscope and transmission electronic microscope. Results: After CI, the ischemic injury as degeneration of the presynapse compositions, decrease of the synaptic numeral density, and low expression of SYN were observed in hippocampal CA1 area. By the 5th week after CI, the neonatal synapses of Cl and EA groups appeared, and SYN expression was upregulated. In EA group, the recovery of the numeral density of synapses was especially noticeable, being 93.8% of that of sham-operation group and significantly higher than that in Cl group (P<0.01). Compared with sham-operation group, the calibrated optical density (COD) values of SYN increased to 70% in CI group, and 93.3% in EA group, and COD value in EA group was significantly higher than that in Cl group (P<0.01). Conclusion: EA can function in promoting synaptic regeneration and enhancing and perfecting the actions of the reconstructed synapses in hippocampal CA1 area in Cl rats.

Effect of eye acupuncture on the expression of brainderived neurotrophic factor in hippocampus in rats with cerebral ischemia-reperfusion injury

Objective To observe the effects of eye acupuncture on expression of brain-derived neurotrophic factor （BDNF） in the hippocampus of rats after ischemia- reperfusion injury in order to study the mechanisms of eye acupuncture in improving ischemia-reperfusion injury. Methods SD rats were randomly divided into a normal group, a sham-operation group, a model group and an eye acupuncture group, with 8 rats in each. The cerebral ischemia-reperfusion injury model was established by thread occlusion method. Acupuncture at ＂liver＂, ＂upper-jiao＂, ＂lower-jiao＂, and ＂kidney＂ was performed for 20 min in the eye acupuncture group immediateness, 12 h and 23.5 h after the reperfusion. After 24 h of the reperfusion, the neurophysical behaviors were evaluated by Zea Longa neurophysical impairment score; the expression of ischemic hippocampus BDNF mRNA was measured by RT-PCR; the expression of ischemic hippocampus BDNF protein was detected by Western blot technique. Results After reperfusion 24 h, compared with the model group, the neurologic impairment score of the eye acupuncture group decreased significantly （P〈0.01）; the expressions of BDNF mRNA and protein in rat hippocampi after the eye acupuncture therapy were both obviously increased （P〈0.01）. Conclusion The eye acupuncture therapy is beneficial for neurofunctional rehabilitation by promoting the repair of the nerve cell which is induced by increasing hippocampus BDNF expression.

Effects of eye-acupuncture on the expression of brainderived neurotrophic factor in the brain of rats with cerebral ischemia reperfusion

Objective To observe the effects of eye-acupuncture therapy and bodyacupuncture therapy on the expression of brain-deprived neurotrophic factor （BDNF） in rats with cerebral ischemia reperfusion injury （CIRI）. Methods According to random number table, 48 SD rats were randomly divided into 6 groups, including normal control group （group A）, sham operation group （group B）, model group （group C）, eye-acupuncture group （group D）, non-acupoint of eye-acupuncture group （group E） and body-acupuncture group （group F）, eight rats in each group. Artery infarction reperfusion model were prepared by using suture-occluded method. Liver region, upper energizer area, lower energizer area and kidney region were selected in the group D. Acupuncture was carried out at the point located at 3 mm from the acupoint areas in the group E. Qūchí （曲池 LI 11）, Zúsānl （足三里 ST 36） and other acupoints were selected in the group F. Zea Longa scoring method was utilized for scoring the neural functions of rats; real-time PCR was carried out to examine the expression level of BDNF mRNA in the brain 72 h after ischemia reperfusion; western blot was carried out to examine the expression level of BDNF protein in the brain 72 h after ischemia reperfusion. Results The symptoms of neurologic impairments in the rats of the group D were alleviated in comparison to those in the group C （P0.01）, and the difference between the group D and the group F was not statistically significant （P0.05）; Compared with the group C, the mRNA and protein expression levels of BDNF in the brain of rats in the group D and the group F both increased （P0.01）, but the difference between the group D and the group F was not statistically significant （P0.05）. Conclusion The functions of eye-acupuncture and body-acupuncture in improving cerebral ischemia reperfusion injury are similar, and the functional mechanisms for the two different therapies may be related to the up-regulation of BDNF expression in brain and thus promote the repairing of brain tissues.

Long-term follow-up study of 72 patients with transient ischemic attacks

Objective To observe the long-term follow-up of 72 patients with transient ischemic attack (TIA) and evaluate the clinical significance of neurovascular surgical indication. Methods Seventy-two patients with TIA collected from years 1959 to 1977 were followed up by means of face-to-face communication with the patients themselves or their families till year 1998. According to the principle of life table, the recurrence of TIA after the first attack, occurrence of complete stroke and myocardial infarction, fatality rate, causes of death and survival rate every year, and the 95% confidence interval were calculated and analyzed.Results Till 1998, the recurrent rate of TIA in 72 patients was 27.9%, the occurrence rate of complete stroke 65.7%, and that of myocardial infarction 8.4%. The fatality rate was 72.7%. Among the deaths, 2 (3.8%) patients died of myocardial infarction. It was shown from the study that the main cause of death was complete stroke, accounting for 59.6% of all deaths, with the main cause in non-elderly patients being cerebral hemorrhage, and that in the elderly patients being cerebral infarction. The 20-year survival rate was 39.9% and its 95% confidence interval was (28.4%, 51.4%). Nineteen cases were indicated for neurovascular surgical operation, accounting for 26.6% of the 72 patients. Conclusions In the long-term follow-up study, about one third of the patients had the recurrent TIA. The occurrence rate of complete stroke was markedly higher than that of myocardial infarction. Presumably, the effect of neurovascular surgical operation on the prevention of complete stroke in patients with TIA is limited.

Simple diffusion delivery via brain interstitial route for the treatment of cerebral ischemia

Delivering pharmacologic agents directly into the brain has been proposed as a means of bypassing the blood brain barrier.However,despite 16 years of research on a number of central nervous system disorders,an effective treatment using this strategy has only been observed in the brain tumor glioblastoma multiforme.Within this study we propose a novel system for delivering drugs into the brain named the simple diffusion (SDD) system.To validate this technique,rats were subjected to a single intracranial (at the caudate nucleus),or intraperitoneal injection,of the compound citicoline,followed two hours later by a permanent middle cerebral artery occlusion (pMCAO).Results showed that 12 h after pMCAO,with 0.0025 g kg-1 citicoline,an infarct volume 1/6 the size of the intraperitoneal group was achieved with a dose 1/800 of that required for the intraperitoneal group.These results suggest that given the appropriate injection point,through SDD a pharmacologically effective concentration of citicoline can be administered.

Neuroprotective effects of Fructus Chebulae extracts on experimental models of cerebral ischemia

OBJECTIVE:To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and invitromodels of cerebral ischemia.METHODS:As an in vitro model,oxygen glucose deprivation followed by reoxygenation(OGD-R)and hydrogen peroxide(H2O2)induced cellular damage in rat pheochromocytoma(PC12)cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival.For in vivo,occlusion of left middle cerebral artery on rats was carried out as a focal cerebral ischemic model.RESULTS:Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H2O2by 68%and 91.4%respectively.Fructus Chebulae also de-creases the cerebral infarct volume by 39%and extent of hemisphere swelling from 17%in control group to 10%in FructusChebulaetreated group.CONCLUSION:Fructus Chebulae,as a traditional medicine,can rescue the neuronal cell death against ischemia related damage.The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.

Brazilein inhibits neuronal inflammation induced by cerebral ischemia and oxygen-glucose deprivation through targeting NOD2 expression

Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 （Nucleotide-binding oligomerization domain-containing protein 2） by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFa （tumor necrosis factor alpha） elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C 17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation.

Network pharmacological analysis of Xiao-Xu-Ming decoction against ischemic stroke and verification of its mechanism of anti-inflammation and neurovascular protection in vivo

Stroke is a major cause of severe disability and death.Xiao-Xu-Ming decoction(XXMD)is an effective prescription for stroke and its sequelae,while its effective ingredients and mechanism are still unclear.In the present study,we aimed to explore the effective ingredients and mechanism of XXMD in treating cerebral ischemia using network pharmacology.The main chemical components and targets of 12 herbs of XXMD were obtained by the TCMSP database and analysis platform database.The active components in XXMD were screened according to oral utilization and drug-like properties.Then,the cerebral ischemia targets were obtained through GeneCards,OMIM,TTD,Diligent and Drugbank databases.We analyzed the pathophysiological processes and pathways involved in the treatment of cerebral ischemia with XXMD by using the Metascape data analysis platform.Results showed thatβ-sitosterol,kaempferol,quercetin,stigmasterol,wogonin,and catechins might be the potential core active ingredients of XXMD in the treatment of cerebral ischemia.The therapeutic effect of XXMD on stroke was mainly exerted through regulating neuroinflammatory response and neurovascular protection.Furthermore,the anti-neuroinflammation and neurovascular protection of XXMD were further confirmed using cerebral ischemia rats.Collectively,our findings revealed that the mechanism of XXMD on the treatment of cerebral ischemia was related to anti-neuroinflammation and neurovascular protection.

Effect of berberine against cerebral ischemia and reperfusion involving in the methylation of PPARγ promoter

Cerebral ischemia has higher incidence and causes irreversible damage to people. As a traditional drug for anti-inflammation, berberine（BBR） has recently been reported to have protective effect against cerebral ischemia. However, the mechanism has not been explored thoroughly. By employing in vivo and in vitro models for cerebral ischemia and reperfusion, we studied the mechanism of BBR against the ischemia-reperfusion. We found that BBR regulated the expression of peroxisome proliferator-activated receptor（PPARγ） in a specific way upon ischemia-reperfusion injury. BBR enhanced the PPARγ expression during cerebral ischemia-reperfusion. By inhibiting PPARγ activity uisng GW9662, a PPARγ inhibitor, we confirmed that BBR protected the mouse brain against the ischemia in a PPARγ-dependent mechanism. In addition, we found that BBR reduced the overall global methylation, declined the expressions of DNMT1（DNA methyltransferases 1） and DNMT3a（DNA methyltransferases 3a） in the ischemia-reperfusion and reduced the methylation of PPARγ promoter region. Therefore, our data suggested that PPARγ was one of major targets of BBR, and such BBR-induced PPARγ expression during cerebral ischemia and reperfusion might be correlated to the reduced methylation of PPARγ promoter.

nNOS expression of hippocampal neurons in aged rats after brain ischemia/reperfusion and its role in DND development

Objective: To study the role of neuronal nitric oxide synthase (nNOS) in aged rats hippocampal delayed neuronal death (DND) following brain ischemia. Methods: Models of incomplete brain ischemia were induced by clipping common carotid artery. A total of 46 aged SD rats were divided into 8 groups: normal control group (Group A, n=5), sham operation group (Group B, n=5), reperfusion 1, 6, 12, 24, 48, and 96 hours groups after brain ischemia for 30 minutes (Group C, D, E, F, G, and H, n=6/group). The expression of nNOS was examined by immunohistochemistry and neuronal ultrastructural changes were observed by the transmission electron microscopy (TEM) at different time points after reperfusion. Results: Immunohistochemistry showed that nNOS expression in the hippocampal neurons was high in Group E, low expression in Group D, moderate expression in Group F and G. There was nearly no expression of nNOS in Group A, B, C, and H. Ultrastructure of hippocampal neurons was damaged more severely in reperfusion over 24 hours groups. Conclusions: Nitric oxide (NO) may be one of the important factors in inducing DND after ischemia/reperfusion.