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 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.

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.

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.

Neuroprotective effect of dioscin on cerebral ischemia/reperfusion mice by reducing glial cell activation and maintaining the levels of SODs

In the present study, we aimed to explore the neuroprotective effect of dioscin, a natural steroid saponin, on transient focal cerebral ischemia induced by middle cerebral artery occlusion （MCAO） in mice and its related mechanism, We observed that dioscin （1,5 mg/kg, intracerebroventricular injection 30 min before MCAO） dramatically reduced the cerebral infarct volume, leading to improved neurological symptoms and reduced death of neuron, astrocytes and microglia in the infarct region. The gliosis and the reduced expressions of SOD1 and SOD2 by MCAO in the hippocampal CA1 region were significantly elevated by 1.5 mg/kg dioscin administration. These findings suggested that pretreatment of dioscin had a neuroprotective effect on mice transient focal cerebral ischemia via inhibiting the gliosis and elevating the SOD levels.

Engineering the protein targeting two pathways of cerebral ischemia reperfusion injury provides better neuroprotective effect than targeting one pathway

We hypothesized that neuroprotective agents targeting various pathways involved in cerebral ischemia/reperfusion(I/R)injury might be superior to that targeting single pathway.Here,we prepared a fusion protein(B-I)by combining anti-apoptotic Bcl-x L(B)and anti-inflammatory IL-10(I).B-I could cross blood brain barrier by its N-terminal TAT domain,and be cleaved into separate B and I by Caspase-1.B-I treatment significantly reduced the cerebral infarct volume,better than B or I treatment alone,and equivalent to B and I treatment(B+I).Treatment with B or B-I significantly attenuated I/R-induced neuronal apoptosis as shown by the decrease in apoptotic rate and the inhibition of caspase-3 activity.Moreover,all recombinant proteins,especially B-I,remarkably attenuated I/R-induced up-regulation of TNF-α.These results suggested that fusion protein B-I inhibiting both inflammation and apoptosis provided better neuroprotective effects than inhibiting either one alone.Our study suggested that multiple pathways targeting brain I-R injury could enhance the neuroprotective effect,and it provided a new idea for the study of neuroprotective drugs for ischemic stroke.

The protective effect of W026B on global cerebral ischemia/reperfusion injury model in rats

Cerebral ischemia seriously affects the quality of life and health of human worldwide.W026B is a newly synthesized lignan derivative that has a protective effect on the focal cerebral ischemia/reperfusion model,while it is unclear whether W026B has a cerebral protective effect on the model of global cerebral ischemia/reperfusion(GCI/R).In this study,we investigated the protective effect of W026B on the four-vessel occlusion GCI/R model.The results showed that W026B obviously increased the survival rate of rats during 7 d after GCI/R and significantly improved neurological deficits within 7 d after GCI/R.It evidently enhanced the number of survival neurons in the hippocampus of GCI/R rats.Furthermore,W026B notably lowered the level of ROS,and increased the activity of SOD in the hippocampus of GCI/R rats.Moreover,it also decreased the expression of NF-κB p65 and the level of IL-6 apparently.In addition,W026B evidently lowered the activity of caspase-3.In conclusion,this study firstly proves that W026B has the protective effect on GCI/R rats.Its cerebral protective effect maybe related to the inhibition of oxidative stress,inflammatory response,and cell apoptosis during GCI/R.These results provide new evidence with the protective effect of W026B on cerebral ischemia/reperfusion injury.