共查询到20条相似文献,搜索用时 15 毫秒
1.
In transverse hippcampus slices a short period of hypoxia/hypoglycemia induced by perfusion with O2/glucose-free medium caused early loss and incomplete restoration of evoked field potentials to only 50% in the CA1 region. We report about a study investigating the effect of an ethanolic Gynostemma pentaphyllum extract in this system. When given with reperfusion the extract completely protected the cells of the slices from functional injury. The extract also protected at the subcellular level isolated mitochondria which had been subjected to hypoxia/reoxygenation in combination with elevated extramitochondrial Ca2+ concentration from functional injury. In isolated mitochondria the extract protected from Ca2+-induced opening of the mitochondrial permeability transition pore and reduced lipid peroxidation. Our data demonstrate that the ethanolic extract of Gynostemma pentaphyllum has a high potential to protect from ischemia/reperfusion injury. It should be beneficial as prophylactic nutrition supplement and during revascularization of arterial blood vessels from stroke and other ischemic events such as coronary occlusion. 相似文献
2.
Huang X Li Q Zhang Y Lü Q Guo L Huang L He Z 《Cellular and molecular neurobiology》2008,28(4):559-568
1. The neuroprotective effect of cactus polysaccharide (CP) on oxygen and glucose deprivation (OGD) and reoxygenation (REO)-induced
damage in the cortical and hippocampal slices of rat brain was investigated. 2. Cell viability was evaluated by using the
2, 3, 5-triphenyl tetrazolium chloride (TTC) method. The fluorescence of propidium iodide (PI) staining was used for quantification
of cellular survival, and lactate dehydrogenase (LDH) activity in incubation medium was assessed by LDH assay to evaluate
the degree of injury. 3. The OGD ischemic condition significantly decreased cellular viability and increased LDH release in
the incubation medium. CP (0.2 mg/l∼2 mg/l) protected brain slices from OGD injury in a dosage dependent manner as demonstrated
by increased A 490 value of TTC, decreased PI intensity and LDH release. At the above concentration, CP also prevented the increase of nitric
oxide (NO) content and inducible nitric oxide synthase (iNOS) activity induced by OGD. 4. CP can protect the brain slices
(cortical and hippocampus) against injury induced by OGD. Its neuroprotective effect may be partly mediated by the NO/iNOS
system induced by OGD insult.
Xianju Huang and Qin Li have contributed equally to this article. 相似文献
3.
Hepatocytes of a primary cell culture that are exposed to high glucose, insulin, and linoleic (LA) acid concentration respond with lipid accumulation, oxidative stress up to cell death. Such alterations are typically found in patients with non-alcoholic fatty liver disease (NAFLD). We used this cellular model to study the effect of an ethanolic Gynostemma pentaphyllum (GP) extract in NAFLD. When hepatocytes were cultured in the presence of high insulin, glucose, and LA concentration the extract completely protected the cells from cell death. In parallel, the extract prevented accumulation of triglycerides (TGs) and cholesterol as well as oxidative stress. Our data further demonstrate that GP stimulates the production of nitric oxide (NO) in hepatocytes and affects the molecular composition of the mitochondrial phospholipid cardiolipin (CL). We conclude that GP is able to protect hepatocytes from cell death, lipid accumulation, and oxidative stress caused by diabetic-like metabolism and lipotoxicity. Therefore, GP could be beneficial for patients with diabetes mellitus and NAFLD. 相似文献
4.
利用离体海马脑片缺氧无糖(oxygen-glucose deprivation,OGD)损伤模型,探讨七氟醚预处理对神经细胞的保护作用及该作用与线粒体内膜ATP敏感钾通道(mitochondrial ATP-sensitive potassium channels,mitoKATPchannels)的关系,随机将脑片用2%、4%、6%七氟醚,以及6%七氟醚复合mitoKATP通道阻滞剂5-羟基奎酸盐(5-hydroxydecanoic acid,5-HD)预处理30 min,观察OGD损伤14 min复氧1 h期间顺向群峰电位(orthodromic population spike,OPS)的变化,并应用透射电镜观察细胞超微结构的改变.结果表明,与单纯OGD组相比,七氟醚预处理可使海马脑片OPS消失时间明显延长(P<0.01),使OPS明显恢复,其中4%、6%七氟醚组的恢复率均为71.4%(P<0.05 vs OGD),相应恢复程度为(61.0±42.3)%和(78.7±21.1)%(P<0.01),而且6%七氟醚的保护作用可被5-HD取消.OGD组的海马CA1区锥体细胞明显水肿,核膜皱缩、破裂,染色质聚集,线粒体肿胀畸形,嵴断裂或消失,而4%和6%七氟醚组仅见海马CA1区锥体细胞轻度水肿,核膜皱缩不明显,染色质均匀,线粒体轻度肿胀.结果提示,七氟醚预处理对大鼠海马脑片OGD损伤有一定的保护作用,且七氟醚对神经细胞的保护作用与激活mitoKATP通道有关. 相似文献
5.
Oxygen-glucose deprivation (OGD) leads to depression of evoked synaptic transmission, for which the mechanisms remain unclear. We hypothesized that increased presynaptic [Ca2+]i during transient OGD contributes to the depression of evoked field excitatory postsynaptic potentials (fEPSPs). Additionally, we hypothesized that increased buffering of intracellular calcium would shorten electrophysiological recovery after transient ischemia. Mouse hippocampal slices were exposed to 2 to 8 min of OGD. fEPSPs evoked by Schaffer collateral stimulation were recorded in the stratum radiatum, and whole cell current or voltage clamp recordings were performed in CA1 neurons. Transient ischemia led to increased presynaptic [Ca2+]i, (shown by calcium imaging), increased spontaneous miniature EPSP/Cs, and depressed evoked fEPSPs, partially mediated by adenosine. Buffering of intracellular Ca2+ during OGD by membrane-permeant chelators (BAPTA-AM or EGTA-AM) partially prevented fEPSP depression and promoted faster electrophysiological recovery when the OGD challenge was stopped. The blocker of BK channels, charybdotoxin (ChTX), also prevented fEPSP depression, but did not accelerate post-ischemic recovery. These results suggest that OGD leads to elevated presynaptic [Ca2+]i, which reduces evoked transmitter release; this effect can be reversed by increased intracellular Ca2+ buffering which also speeds recovery. 相似文献
6.
7.
Pinto MC Mourão FA Binda NS Leite HR Gomez MV Massensini AR Gomez RS 《Neurochemistry international》2012,61(5):713-720
Brain ischemic tolerance is a protective mechanism induced by a preconditioning stimulus, which prepare the tissue against harmful insults. Preconditioning with N-methyl-d-aspartate (NMDA) agonists induces brain tolerance and protects it against glutamate excitotoxicity. Recently, the glycine transporters type 1 (GlyT-1) have been shown to potentiate glutamate neurotransmission through NMDA receptors suggesting an alternative strategy to protect against glutamate excitotoxicity. Here, we evaluated the preconditioning effect of sarcosine pre-treatment, a GlyT-1 inhibitor, in rat hippocampal slices exposed to ischemic insult. Sarcosine (300mg/kg per day, i.p.) was administered during seven consecutive days before induction of ischemia in hippocampus by oxygen/glucose deprivation (OGD). To access the damage caused by an ischemic insult, we evaluated cells viability, glutamate release, nitric oxide (NO) production, lactate dehydrogenase (LDH) levels, production of reactive oxygen species (ROS), and antioxidant enzymes as well as the impact of oxidative stress in the tissue. We observed that sarcosine reduced cell death in hippocampus submitted to OGD, which was confirmed by reduction on LDH levels in the supernatant. Cell death, glutamate release, LDH levels and NO production were reduced in sarcosine hippocampal slices submitted to OGD when compared to OGD controls (without sarcosine). ROS production was reduced in sarcosine hippocampal slices exposed to OGD, although no changes were found in antioxidant enzymes activities. This study demonstrates that preconditioning with sarcosine induces ischemic tolerance in rat hippocampal slices submitted to OGD. 相似文献
8.
9.
Heat-processed Gynostemma pentaphyllum extract improves obesity in ob/ob mice by activating AMP-activated protein kinase 总被引:1,自引:0,他引:1
Gauhar R Hwang SL Jeong SS Kim JE Song H Park DC Song KS Kim TY Oh WK Huh TL 《Biotechnology letters》2012,34(9):1607-1616
Gynostemma pentaphyllum is widely used in Asian countries as a herbal medicine to treat dyslipidemia, type 2 diabetes and inflammation. An ethanol extract of G. pentaphyllum lessened obesity by activating AMP-activated protein kinase (AMPK). The levels of damulins A and B, components responsible for AMPK activation in the extract, were increased by autoclaving in a time-dependent manner. Heat-processed G. pentaphyllum extract, actiponin containing damulins A (0.93?%, w/w) and B (0.68?%, w/w), significantly stimulated fat oxidation and glucose uptake via AMPK activation in L6 myotube cells. Oral administration of actiponin to ob/ob mice for 8?weeks decreased body weight gain, liver weight, and blood cholesterol levels with AMPK activation in the soleus muscle. Our results demonstrate the beneficial effect of G. pentaphyllum on improving obesity and have elucidated the underlying molecular mechanisms. 相似文献
10.
According to Wang and Xie, their recently published genus Trirostellum is
distinguished from its allied genera by a number of characteristics: (1) the stamens
with their filaments coherent into a central column; (2) the female flowers possessing
rudimentary stamens; (3) the ovary 3-celled, with one ovule in each cell; (4) the fruits
dehiscent, 3-rostrated at the apex; (5) the fruits possessing persistent perianth; (6)
the seeds tuberculate and winged. However, upon a careful comparison of Trirostellum yixingensis Z.P. Wang et Q. Z. Xie, the type species of Trirostellum with Gynostemma pentaphyllum (Thunb.) Mak., the type species of Gynostemma Bl. and some
other species of Gynostemma as well,we have found that the representatives of the
above two genera are identical in most of the important diagnostic characteristics except that the fruits of the former genus are dehiscent with three long beaks at the
apex, while the fruits of the latter genus are indehiscent with very short beaks.
Besides, results obtained from chromosome counting haove shown that the somatic
chromosome number of Trirostellum yixingensis is 2n=22, while that of Gynostemma
pentaphyllum is 2n=28.Yet these morphological and chromosomal differences seem
not sufficient for generic demarcation. We, therefore, suggest that Trirostellum bereduced to a sectional or subgeneric rank of Gynostemma Bl. 相似文献
11.
In the present study, the cardiovascular activity of the aqueous extract of Gynostemma pentaphyllum Makino leaves was investigated in the anaestetized guinea-pigs and has been compared with two of its isolated gypenosides (III, VIII) and with verapamil, a well-known Ca-antagonistic drug. The results obtained showed that the intravenous administration of the decoction of G. pentaphyllum (2.5, 5 and 10mg/kg) produced a protective effect against pitressin-induced coronaryspasm, arrhythmias and pressor response. Extract also increased the dose of ouabain required to cause ventricular tachyarrhythmias and lethality. Further extract reversed ouabain-induced persistent ventricular tachycardia and restored sinus rhythm in a dose-dependent manner. The results obtained have also shown that gypenosides III and VIII caused similar protective effects in both experimental models used; however, the duration of the action is lower than that of the extract containing corresponding quantities of gypenosides III and VIII. 相似文献
12.
Siqueira IR Cimarosti H Fochesatto C Nunes DS Salbego C Elisabetsky E Netto CA 《Life sciences》2004,75(15):1897-1906
Alcoholic infusions of Ptychopetalum olacoides Bentham (PO, Olacaceae) are used in traditional medicine by patients presenting age associated symptoms and those recovering from stroke. The aim of this study is to evaluate the neuroprotective properties of PO ethanol extract (POEE) using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation). Mitochondrial activity, an index of cell viability, was assessed by the MTT assay; in addition, the free radicals content was estimated by the use of dichlorofluorescein diacetate as probe. The OGD ischemic condition significantly impaired cellular viability, and increased free radicals generation. In non-OGD slices, incubation with POEE (0.6 microg/ml) increased (approximately 40%) mitochondrial activity, without affecting free radicals levels. In comparison to OGD controls, slices incubated with POEE (0.6 microg/ml) during and after OGD exposure had significantly increased cellular viability. In addition, at this same concentration, POEE prevented the increase of free radicals content induced by OGD. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this study suggests that Ptychopetalum olacoides contains useful neuroprotective compounds and, therefore, deserves further scrutiny. 相似文献
13.
目的:探讨绞股蓝多糖对糖尿病大鼠肾功能的影响及其保护的可能机制。方法:采用大鼠高脂高糖饲料结合腹腔注射链脲佐菌素建立2型糖尿病模型。灌胃给予绞股蓝多糖8周后,测定大鼠空腹血糖(FBG),血清肌酐、血清尿素氮、24 h尿量及尿蛋白等指标;组织病理切片观察肾形态,肾小球体积;Western blot法检测肾皮质NF-κB的表达。结果:绞股蓝多糖(GPS)可剂量依赖性的降低DN组的FBG、血肌酐、24 h尿量和尿蛋白;但血尿素氮模型组与GPS组无统计学差异;中、高剂量GPS治疗后,肾脏指数较模型组明显降低(P0.05);与模型组(149.8±12.2%)比较,高剂量GPS可抑制肾小球体积肥大至108.9±9.6%。进一步研究发现,GPS可剂量依赖性的降低DN组肾脏NF-κB蛋白的表达,高、中剂量组水平与模型组相比有统计学差异(P0.05)。结论:绞股蓝多糖对实验性糖尿病肾病具有保护作用,其机制可能与抑制肾炎症相关通路NF-κB的表达有关。 相似文献
14.
Alexander S. Finch Maria Moldovan Jonathan Frank Robert Bagnell Laurence M Katz Robert D. Pearlstein 《Journal of thermal biology》2010
The purpose of this study was to determine if mild hypothermia alters mitotic activity in normal and post-ischemic hippocampal slices. (1) Normothermic oxygen–glucose deprivation (OGD 60 min) increased mitotic activity in the hippocampus up to 4d post-OGD. (2) Mild hypothermia (33 °C for 24 h) initiated after OGD stress reduced mitotic activity compared to normothermic controls up to 8 d post-OGD. (3) Mild hypothermia stimulated mitotic activity in normal (no OGD stress) hippocampus up to 24 h post-hypothermia. In conclusion, mild transient hypothermia can increase or decrease mitotic activity depending upon the experimental condition of the hippocampal slices when hypothermia is induced. 相似文献
15.
为研究运动控制关键核团黑质在代谢负荷下发生的即时性损伤,研制了多通道组织灌流槽,改进了以MTT、甲酚紫染色考察脑组织损伤的方法,获得了20 min的短时程糖氧剥夺所引起的小鼠黑质区即时性功能和形态损伤的组织化学依据。1)MTT检测显示,糖氧剥夺使黑质区域MTT与线粒体琥珀酸脱氢酶的反应产物甲臜晶体密度减少,并且这种减少在黑质的中部到吻侧的背部区域最为明显(约42.5%);2)甲酚紫染色结果表明,糖氧剥夺不影响脑片黑质区面积和着色斑块的数密度,而使斑块的平均面积减低(6.9%)。上述研究结果提示短时程糖氧剥夺可导致黑质区空间依存性的线粒体功能损伤,并且具有与凋亡相似的形态学特征。 相似文献
16.
Li Q Huang XJ He W Ding J Jia JT Fu G Wang HX Guo LJ 《Cellular and molecular neurobiology》2009,29(2):169-180
We previously reported that inhibition of Rho-kinase (ROCK) by hydroxyl fasudil improves cognitive deficit and neuronal damage
in rats with chronic cerebral ischemia (Huang et al., Cell Mol Neurobiol 28:757–768, 2008). In this study, fasudil mesylate
(FM) was investigated for its neuroprotective potential in rats with ischemia following middle cerebral artery occlusion (MCAO)
and reperfusion. The effect of fasudil mesylate was also studied in rat brain cortical and hippocampal slices treated with
oxygen-glucose deprivation (OGD) injury. Gross anatomy showed that cerebral infarct size, measured with 2,3,5-triphenyltetrazolium
chloride (TTC) staining, was significantly smaller in the FM-treated than in the non-FM-treated ischemic rats. In the brain
regions vulnerable to ischemia of ischemic rats, fasudil mesylate was also found to significantly restore the enzyme protein
expression level of endothelial nitric oxide synthase (eNOS), which was decreased in ischemia. However, it remarkably reduced
the protein synthesis of inducible nitric oxide synthase (iNOS) that was induced by ischemia and reperfusion. In rat brain
slices treated with OGD injury, fasudil mesylate increased the neuronal cell viability by 40% for cortex and by 61% for hippocampus,
respectively. Finally, in the presence of OGD and fasudil mesylate, superoxide dismutase (SOD) activity was increased by 50%
for cortex and by 58% for hippocampus, compared to OGD only group. In conclusion, our in vivo study showed that fasudil mesylate
not only decreased neurological deficit but also reduced cerebral infarct size, possibly and at least partially by augmenting
eNOS protein expression and inhibiting iNOS protein expression after ischemia-reperfusion.
Xian-Ju Huang contributed equally to this article. 相似文献
17.
为克隆绞股蓝的β-香树脂醇合酶基因(β-amyrin synthase,bAS),探讨绞股蓝bAS的性质特征及其与绞股蓝三萜生物合成及调控的可能关系。本研究根据绞股蓝转录组测序的结果设计合成bAS全长扩增引物,采用RT-PCR技术扩增绞股蓝bAS的开放阅读框架(open reading frame,ORF)全长序列并连接克隆载体进行测序,利用ExPASy等在线工具及MEGA-X软件对测序结果做相应的生物信息分析。测序结果显示绞股蓝bAS的cDNA的ORF全长共2 283 bp,编码760个氨基酸。该序列信息已提交GenBank,登录号为GM251742。对绞股蓝bAS的氨基酸序列进行了性质与结构预测和系统发育分析。bAS的全长cDNA序列的成功克隆,为绞股蓝bAS基因结构与功能研究提供了基础,并可为研究绞股蓝三萜合成通路的调节方式提供新的认识。 相似文献
18.
Lok J Leung W Zhao S Pallast S van Leyen K Guo S Wang X Yalcin A Lo EH 《Journal of neurochemistry》2011,118(2):248-255
Oxidative stress is a pathway of injury that is common to almost all neurological conditions. Hence, methods to scavenge radicals have been extensively tested for neuroprotection. However, saving neurons alone may not be sufficient in treating CNS disease. In this study, we tested the cytoprotective actions of the glutathione precursor gamma-glutamylcysteine ethyl ester (GCEE) in brain endothelium. First, oxidative stress was induced in a human brain microvascular endothelial cell line by exposure to H(2)O(2). Addition of GCEE significantly reduced formation of reactive oxygen species, restored glutathione levels which were reduced in the presence of H(2)O(2), and decreased cell death during H(2)O(2)-mediated injury. Next, we asked whether GCEE can also protect brain endothelial cells against oxygen-glucose deprivation (OGD). As expected, OGD disrupted mitochondrial membrane potentials. GCEE was able to ameliorate these mitochondrial effects. Concomitantly, GCEE significantly decreased endothelial cell death after OGD. Lastly, our in vivo experiments using a mouse model of brain trauma show that post-trauma (10 min after controlled cortical impact) administration of GCEE by intraperitoneal injection results in a decrease in acute blood-brain barrier permeability. These data suggest that the beneficial effects of GCEE on brain endothelial cells and microvessels may contribute to its potential efficacy as a neuroprotective agent in traumatic brain injury. 相似文献
19.
Seven dammarane glycosides, gypenosides GC1 to GC7, together with ten known compounds, gypenosides V, XIV, XLII-XLVI, gynosaponins TN-1, -2, and gymnemaside VI, were isolated from the methanol extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated by both analysis of 1D and 2D NMR spectra and chemical degradation. 相似文献
20.
Paloma González-Rodríguez Irene F. Ugidos Diego Pérez-Rodríguez Berta Anuncibay-Soto María Santos-Galdiano Enrique Font-Belmonte José Manuel Gonzalo-Orden Arsenio Fernández-López 《Journal of cellular physiology》2019,234(6):9592-9604
Brain-derived neurotrophic factor (BDNF) is considered as a putative therapeutic agent against stroke. Since BDNF role on oxidative stress is uncertain, we have studied this role in a rat brain slice ischemia model, which allows BDNF reaching the neural parenchyma. Hippocampal and cerebral cortex slices were subjected to oxygen and glucose deprivation (OGD) and then returned to normoxic conditions (reperfusion-like, RL). OGD/RL increased a number of parameters mirroring oxidative stress in the hippocampus that were reduced by the BDNF presence. BDNF also reduced the OGD/RL-increased activity in a number of antioxidant enzymes in the hippocampus but no effects were observed in the cerebral cortex. In general, we conclude that alleviation of oxidative stress by BDNF in OGD/RL-exposed slices relies on decreasing cPLA2 activity, rather than modifying antioxidant enzyme activities. Moreover, a role for the oxidative stress in the differential ischemic vulnerability of cerebral cortex and hippocampus is also supported. 相似文献