Neuroprotective effects of INM-176 against lipopolysaccharide-induced neuronal injury

Neuroinflammation plays a critical role in the etiology of chronic neurodegenerative diseases such as Alzheimer's disease. INM-176 is a standardized ethanolic extract of Angelica gigas, which has been traditionally used as a tonic to treat anemia. In the present study, we investigated whether INM-176 exhibits neuroprotective activities against lipopolysaccharide (LPS)-induced neuronal damage in vitro and in vivo. In primary microglial cells, INM-176 significantly inhibited LPS-induced nitric oxide release and expression of tumor necrosis factor-α and interleukin-1β. The expression levels of inducible nitric oxide synthase and cylcooxygenase-2 in BV2 microglial cells were markedly upregulated by LPS, but this increased expression was counteracted by INM-176. LPS-mediated neuronal damage in an organotypic hippocampal slice culture was also attenuated by the administration of INM-176. In addition, LPS (1 μg/2 μl, i.c.v.)-induced cognitive dysfunction in mice, as determined by passive avoidance and Y-maze tasks, was significantly attenuated by the administration of INM-176. Furthermore, the activation of microglia or astrocytes by LPS in the hippocampal regions of mice was suppressed by INM-176. These results suggest that the neuroprotective and cognition ameliorating effects of INM-176 against LPS-induced damage are mediated, in part, by its anti-inflammatory activities.     

Neuroprotective effects of the beta-carboline abecarnil studied in cultured cortical neurons and organotypic retinal cultures

Presently there is no neuroprotective pharmacological treatment of proven clinical safety and efficacy available. The purpose of this study was to investigate whether the beta-carboline, abecarnil (Abe), which has already passed clinical phase III trials in patients with anxiety disorders, is neuroprotective in in vitro models of cerebral ischemia or excitotoxicity. Abe (100 nM) protected cultured cortical neurons when applied 20 min before or 20 min after combined oxygen glucose deprivation (OGD). Furthermore, cultured cortical neurons were protected from NMDA excitotoxicity when Abe (100 nM) was administered 20 min before or concurrent with 100 microM NMDA. In contrast, in adult rat organotypic retinal cultures, Abe failed to protect retinal ganglion cells (RGCs) against glutamate (Glu) excitotoxicity. Thus, although our data demonstrate that Abe is a potential neuroprotectant in cultured neurons, the lack of effect in an organotypical model of Glu toxicity indicates that further study is required before Abe might be considered for human neuroprotection trials.     

Neuroprotective effects of ginsenoside-Rg1 in primary nigral neurons against rotenone toxicity

Ginsenoside-Rg1, the pharmacologically active component isolated from ginseng, demonstrated neuroprotective effects on primary cultured rat nigral neurons against rotenone toxicity. Rotenone, a common household pesticide known for its specific and irreversible mitochondria complex I inhibition, has been suggested to be the causal agent of Parkinson's disease (PD) by inducing degeneration of cells in the substantial nigra. The present study demonstrated that co-treatment of rotenone and Rg1 could reduce rotenone-induced cell death by 58% (SEM=+/-5.60; N=3). Rotenone-induced mitochondria membrane potential (MMP, DeltaPsim) depletion was restored and elevated by at least 38% (SEM=+/-2.15; N=3) by Rg1. In addition, Rg1 prevented cytochrome c release from the mitochrondrial membrane and increased the phosphorylation inhibition of the pro-apoptotic protein Bad through activation of the PI3K/Akt pathway. The protective effects of Rg1 was blocked by glucocorticoid receptor antagonist RU486, indicating that the action of Rg1 is mediated through glucocorticoid receptor (GR). In conclusion, Rg1 inhibits the mitochondrial apoptotic pathway and increases the survival chance of the primary cultured nigral neurons against rotenone toxicity. Thus, Rg1 and its related compounds may be developed as protective agents against neurodegenerative diseases induced by mitochondrial toxins.     

Inhibitory effects of curculigoside on human liver cytochrome P450 enzymes

1.?Curculigoside possesses numerous pharmacological activities, and however, little data available for the effects of curculigoside on the activity of human liver cytochrome P450 (CYP) enzymes.

2.?This study investigates the inhibitory effects of curculigoside on the main human liver CYP isoforms. In this study, the inhibitory effects of curculigoside on the eight human liver CYP isoforms 1A2, 2A6, 2E1, 2D6, 2C9, 2C19, 2C8, and 3A4 were investigated in human liver microsomes.

3.?The results indicated that curculigoside could inhibit the activity of CYP1A2, CYP2C8, and CYP3A4, with IC₅₀ values of 15.26, 11.93, and 9.47?μM, respectively, but that other CYP isoforms were not affected. Enzyme kinetic studies showed that curculigoside was not only a noncompetitive inhibitor of CYP1A2, but also a competitive inhibitor of CYP2C8 and CYP3A4, with Ki values of 5.43, 3.54, and 3.35?μM, respectively. In addition, curculigoside is a time-dependent inhibitor for CYP1A2, with kinact/K_I values of 0.056/6.15?μM^?1?min^?1.

4.?The in vitro studies of curculigoside with CYP isoforms suggest that curculigoside has the potential to cause pharmacokinetic drug interactions with other coadministered drugs metabolized by CYP1A2, CYP2C8, and CYP3A4. Further in vivo studies are needed in order to evaluate the significance of this interaction.     

盐酸苯环壬酯及其异构体抗NMDA神经毒性保护作用的比较

目的观察并比较盐酸苯环壬酯消旋体(phencynonate hydrochloride,PCH)及其不同旋光异构体——R(-)-PCH和S( )-PCH对NMDA(N-甲基-D-天冬氨酸)神经毒性的保护作用。方法通过建立NMDA小鼠致死模型及PC12细胞损伤模型,测定PCH不同旋光异构体对小鼠存活率、细胞存活率及乳酸脱氢酶(lactate dehydrogenase,LDH)漏出的影响。结果PCH不同旋光异构体在体内体外均能对抗NMDA的神经毒性作用。R(-)-PCH在6mg/kg时发挥最大保护效应,使小鼠存活率提高到55.6%,保护效应优于S( )-PCH;PCH消旋体的最佳保护效应与R(-)-PCH相当,但所需剂量高于R(-)-PCH。3mmol/L NMDA作用24h使细胞存活率降至对照组的63.5%,LDH漏出增加到对照组的2倍,5μmol/L R(-)-PCH作用使细胞存活率提高到对照组的80.5%(P<0.05,与对照组相比)并有效抑制NMDA所致的细胞LDH漏出;S( )-PCH对细胞存活率无明显影响,但可以有效抑制LDH的漏出;PCH消旋体的作用介于二者之间,也发挥出显著性保护作用。结论PCH不同旋光异构体均可对抗NMDA神经毒性,R(-)-PCH的保护效应优于S(-)-PCH,是优性异构体,PCH消旋体的作用介于2个异构体之间。     

Neuroprotective and Antioxidant Effects of Novel Benzofuran-2-Carboxamide Derivatives

In the present study, we synthesized a series of novel 7-methoxy-N-(substituted phenyl)benzofuran-2-carboxamide derivatives in moderate to good yields and evaluated their neuroprotective and antioxidant activities using primary cultured rat cortical neuronal cells and in vitro cell-free bioassays. Based on our primary screening data with eighteen synthesized derivatives, nine compounds (1a, 1c, 1f, 1i, 1j, 1l, 1p, 1q and 1r) exhibiting considerable protection against the NMDA-induced excitotoxic neuronal cell damage at the concentration of 100 μM were selected for further evaluation. Among the selected derivatives, compound 1f (with -CH₃ substitution at R2 position) exhibited the most potent and efficacious neuroprotective action against the NMDA-induced excitotoxicity. Its neuroprotective effect was almost comparable to that of memantine, a well-known NMDA antagonist, at 30 μM concentration. In addition to 1f, compound 1j (with -OH substitution at R3 position) also showed marked anti-excitotoxic effects at both 100 and 300 μM concentrations. These findings suggest that -CH₃ substitution at R2 position and, to a lesser degree, -OH substitution at R3 position may be important for exhibiting neuroprotective action against excitotoxic damage. Compound 1j was also found to scavenge 1,1-diphenyl-2-picrylhydrazyl radicals and inhibit in vitro lipid peroxidation in rat brain homogenate in moderate and appreciable degrees. Taken together, our structure-activity relationship studies suggest that the compound with -CH₃ substitution at R2 and -OH substitution at R3 positions of the benzofuran moiety might serve as the lead exhibiting potent anti-excitotoxic, ROS scavenging, and antioxidant activities. Further synthesis and evaluation will be necessary to confirm this possibility.     

Neuroprotective effects of novel small peptides in vitro and after brain injury

Thyrotropin-releasing hormone (TRH) and TRH analogues have been reported to be neuroprotective in experimental models of spinal cord injury and head injury. We have previously shown that a diketopiperazine structurally related to the TRH metabolite cyclo-his-pro reduces neuronal cell death in vitro and in vivo. Here we report the neuroprotective activity of other cyclic dipeptides in multiple in vitro models of neuronal injury and after controlled cortical impact (CCI) in mice. Using primary neuronal cultures, three novel dipeptides were compared to the previously reported diketopiperazine as well as to vehicle controls; each of the compounds reduced cell death after direct physical trauma or trophic withdrawal. Two of these peptides also protected against glutamate toxicity and beta-amyloid-induced injury; the latter also strongly inhibited glutamate-induced increases in intracellular calcium. Treatment with each of the test compounds resulted in highly significant improvement of motor and cognitive recovery after CCI, as well as markedly reducing lesion volumes as shown by high field magnetic resonance imaging. DNA microarray studies following fluid percussion induced traumatic brain injury (TBI) in rats showed that treatment with one of these dipeptides after injury significantly down-regulated expression of mRNAs for cell cycle proteins, aquaporins, cathepsins and calpain in ipsilateral cortex and/or hippocampus, while up-regulating expression of brain-derived neurotrophic factor, hypoxia-inducible factor and several heat-shock proteins. Many of these mRNA expression changes were paralleled at the protein level. The fact that these small peptides modulate multiple mechanisms favoring neuronal cell survival, as well as their ability to improve functional outcome and reduce posttraumatic lesion size, suggests that they may have potential utility in clinical head injury.     

Neuroprotective properties of tianeptine: interactions with cytokines

Tianeptine is an antidepressant with proven clinical efficacy and effects on hippocampal plasticity. Hypoxia increased lactate dehydrogenase (LDH) release from cortical neuronal cultures, and tianeptine (1, 10 and 100 microM) inhibited LDH release as efficiently as the N-methyl-D-aspartate (NMDA) antagonist, MK-801. However, tianeptine did not block apoptosis in cultured cortical neurones caused by NMDA, but reduced apoptosis when interleukin-1beta (IL-1beta) was included with NMDA. In 5-day old mice, intracerebral injection of ibotenate induced reproducible lesions in cortex and white matter. Lesion size was markedly reduced by co-administration of MK-801 (1 mg/kg i.p.) but neither by tianeptine or its enantiomers administered acutely (1, 3 or 10 mg/kg i.p.) nor by tianeptine administered chronically (10 mg/kg i.p. for 5 days). Chronic administration of IL-1beta (10 ng/kg i.p. for 5 days) prior to ibotenate injection exacerbated lesion size in cortex and white matter, and this exacerbation was prevented by chronic pre-treatment with tianeptine (10 mg/kg i.p.) or by acute administration of tianeptine (10 mg/kg i.p.) concomitantly with ibotenate. Thus tianeptine has neuroprotective effects against hypoxia in tissue culture and against the deleterious effects of cytokines in cortex and white matter, but not against NMDA receptor-mediated excitotoxicity.     

In vivo treatment with the K+ channel blocker 4-aminopyridine protects against kainate-induced neuronal cell death through activation of NMDA receptors in murine hippocampus

Activation of NMDA receptors has been shown to induce either neuronal cell death or neuroprotection against excitotoxicity in cultured neurons in vitro. To elucidate in vivo neuroprotective role of NMDA receptors, we investigated the effects of activation of NMDA receptors by endogenous glutamate on kainate-induced neuronal damage to the mouse hippocampus in vivo. The systemic administration of the K+ channel blocker 4-aminopyridine (4-AP, 5 mg/kg, i.p.) induced expression of c-Fos in the hippocampal neuronal cell layer, which expression was completely abolished by the noncompetitive NMDA receptor antagonist MK-801, thus indicating that the administration of 4-AP would activate NMDA receptors in the hippocampal neurons. The prior administration of 4-AP at 1 h to 1 day before significantly prevented kainate-induced pyramidal cell death in the hippocampus and expression of pyramidal cells immunoreactive with an antibody against single-stranded DNA. Further immunohistochemical study on deoxyribonuclease II revealed that the pretreatment with 4-AP led to complete abolition of deoxyribonuclease II expression induced by kainate in the CA1 and CA3 pyramidal cells. The neuroprotection mediated by 4-AP was blocked by MK-801 and by the adenosine A1 antagonist 8-cyclopenthyltheophylline. Taken together, in vivo activation of NMDA receptors is capable of protecting against kainate-induced neuronal damage through blockade of DNA fragmentation induced by deoxyribonuclease II in the murine hippocampus.     

枸杞多糖对NMDA致大鼠视网膜损伤保护作用的研究

目的探讨枸杞多糖对N-甲基-D天门冬氨酸(NM-DA)诱导大鼠视网膜损伤的保护作用及其机制。方法采用玻璃体内注射NMDA建立大鼠视网膜损伤模型。枸杞多糖(100、200和400 mg.kg-1)于NMDA注射前7天灌胃给药,共14 d。取大鼠眼组织进行病理学观察,同时采用West-ern blot法测定相关蛋白的表达。结果枸杞多糖(100、200和400 mg.kg-1)明显抑制NMDA所致视网膜神经节细胞的减少和内丛状层的变薄。枸杞多糖(100、200和400 mg.kg-1)抑制NMDA诱导视网膜NMDAR2A蛋白表达的升高;提高eNOS蛋白表达降低的同时,抑制iNOS蛋白表达的升高。结论枸杞多糖对NMDA诱导损伤的大鼠视网膜具有保护作用,其机制与调控视网膜中NMDAR2A表达,以及平衡eNOS/iNOS水平有关。     

The α7 nicotinic acetylcholine receptor subtype mediates nicotine protection against NMDA excitotoxicity in primary hippocampal cultures through a Ca dependent mechanism

Neuronal nicotinic acetylcholine receptors (nAChR) have been suggested to play a role in a variety of modulatory and regulatory processes, including neuroprotection. Here we have characterized the neuroprotective effects of nicotine against an excitotoxic insult in primary hippocampal cultures. Exposure of hippocampal neurons to 200 μM NMDA for 1 h decreased cell viability by 25±5%, an effect blocked by NMDA receptor antagonists. Nicotine (10 μM) counteracted the NMDA-induced cell death when co-incubated with NMDA or when present subsequent to the NMDA treatment. Nicotine protection was prevented by 1μM MLA, confirming that it was mediated by nAChR, and by 1 μM α-bungarotoxin, demonstrating that the α7 nAChR subtype was responsible. Both the NMDA evoked neurotoxicity and nicotine neuroprotection were Ca²⁺-dependent. In Fura-2-loaded hippocampal neurons, nicotine (10 μM) and NMDA (200 μM) acutely increased intracellular resting Ca²⁺ from 70 nM to 200 and 500 nM, respectively. Responses to NMDA were unaffected by the presence of nicotine. ⁴⁵Ca²⁺ uptake after a 1 h exposure to nicotine or NMDA also demonstrated quantitative differences between the two drugs. This study demonstrates that the α7 subtype of nAChR can support neuronal survival after an excitotoxic stimulus, through a Ca²⁺ dependent mechanism that operates downstream of NMDA receptor activation.     

Neuroprotective effects of adenosine isolated from Cordyceps cicadae against oxidative and ER stress damages induced by glutamate in PC12 cells

Glutamate has been proven to induce oxidative stress through the formation of reactive oxygen species (ROS) and increased calcium overload which results in neuronal injury, development of neurodegenerative diseases and death. Adenosine is one of the bioactive nucleosides found in Cordyceps cicadae and it has displayed several pharmacological activities including neuroprotection. In this study, the protective effects of adenosine from C. cicadae against glutamate-induce oxidative stress in PC12 cells were evaluated. The exposure of PC12 cells to glutamate (5 mM) induced the formation of ROS, increased Ca²⁺ influx, endoplasmic reticulum (ER) stress and up regulated the expression of pro-apoptotic factor Bax. However, pretreatment with adenosine markedly increased cell viability, decreased the elevated levels of ROS and Ca²⁺ induced by glutamate. Furthermore adenosine increased the activities of GSH-Px and SOD, as well as retained mitochondria membrane potential (MMP), increased Bcl-2/Bax ratio, and reduced the expression of ERK, p38, and JNK. Overall, our results suggest that adenosine may be a promising potential therapeutic agent for the prevention and treatment of neurodegenerative disorders.     

Neuroprotective biflavonoids of Chamaecyparis obtusa leaves against glutamate-induced oxidative stress in HT22 hippocampal cells

Four biflavonoids (1–4), five flavonoids glycosides (5–9), two catechins (10, 11), two lignans (12–13), neolignan glycoside (14) and phenylpropanoid glycoside (15) were isolated from the leaves of Chamaecyparis obtusa (Cupressaceae). Neuroprotective effects of the isolated compounds were evaluated employing HT22 mouse hippocampal cells, a model system to study glutamate-induced oxidative stress. The glutamate injured HT22 cells were protected significantly by amentoflavone (3), ginkgetin (4) and (−)-epitaxifolin 3-O-β-D-xylopyranoside (9). The reduced activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione reductase (GR) in response to high concentration of glutamate were preserved by pre-treatment of 3, 4 or 9, while the activities of glutathione peroxidase (Gpx) and catalase (CAT) were little affected. The reduced content of GSH induced by glutamate was also recovered by 3, 4 or 9 in accommodation with the decrease in ROS production. In addition, the phosphorylation of ERK1/2 induced by glutamate insult was clearly prevented by 3, while little changed by 4. Taken together, amentoflavone (3), ginkgetin (4) and (−)-epitaxifolin 3-O-β-D-xylopyranoside (9) derived from C. obtusa could protect HT22 neuronal cells against glutamate-induced oxidative damage through preserving antioxidant enzymes activities and/or inhibiting ERK1/2 activation.     

Lithium induces brain-derived neurotrophic factor and activates TrkB in rodent cortical neurons: an essential step for neuroprotection against glutamate excitotoxicity

Mechanisms underlying the therapeutic effects of lithium for bipolar mood disorder remain poorly understood. Recent studies demonstrate that lithium has neuroprotective actions against a variety of insults in vitro and in vivo. This study was undertaken to investigate the role of the brain-derived neurotrophic factor (BDNF)/TrkB signaling pathway in mediating neuroprotection of lithium against glutamate excitotoxicity in cortical neurons. Pretreatment with either lithium or BDNF protected rat cerebral cortical neurons from glutamate excitotoxicity. The duration of treatment required to elicit maximal neuroprotection by BDNF (1 day) was much shorter than that by lithium (6 days). K252a, an inhibitor of Trk tyrosine kinases, and a BDNF neutralizing antibody suppressed the neuroprotective effect of lithium. Treatment of cortical neurons with lithium increased the cellular BDNF content in 3 days and the phosphorylation of TrkB at Tyr490 in 5 days, suggesting that long-term lithium administration enhances BDNF expression/secretion, leading to the activation of TrkB receptor. Lithium failed to protect against glutamate excitotoxicity in cortical neurons derived from homozygous and heterozygous BDNF knockout mice, although lithium fully protected cortical neurons prepared from wild type mice littermates. Taken together, these data suggest that the BDNF/TrkB pathway plays an essential role in mediating the neuroprotective effect of lithium.     

Neuroprotective effects of RPR 104632, a novel antagonist at the glycine site of the NMDA receptor, in vitro

The NMDA antagonist and neuroprotective effects of RPR 104632 (2H-1,2,4-benzothiadiazine-1-dioxide-3-carboxylic acid), a new benzothiadiazine derivative, with affinity for the glycine site of the NMDA receptor-channel complex are described. RPR 104632 antagonized the binding of [³H]5,7-dichlorokynurenic acid to the rat cerebral cortex, with a K_i of 4.9 nM. This effect was stereospecific, since the (-)-isomer was 500-fold more potent than the (+)-isomer. The potent affinity of RPR 104632 for the glycine site was confirmed by the observation that RPR 104632 inhibited [³H]N-(1-(2-thienyl)cyclohexyl]-3,4-piperidine ([³H]TCP) binding in the presence of N-methyl- -aspartate (NMDA) (IC₅₀ = 55 nM), whereas it had no effect on the competitive NMDA site or on the dissociative anaesthetic site. RPR 104632 inhibited the NMDA-evoked increase in guanosine 3′,5′-cyclic monophosphate (cGMP) levels of neonatal rat cerebellar slices (IC₅₀ = 890 nM) in a non-competitive manner and markedly reduced NMDA-induced neurotoxicity in rat hippocampal slices and in cortical primary cell cultures. These results suggest that RPR 104632 is a high-affinity specific antagonist of the glycine site coupled to the NMDA receptor channel with potent neuroprotective properties in vitro.     

Neuroprotective effect of Smilacis chinae rhizome on NMDA-induced neurotoxicity in vitro and focal cerebral ischemia in vivo

Previous work has shown that the Smilacis chinae rhizome (SCR) markedly inhibits amyloid beta protein (25-35)-induced neuronal cell damage in cultured rat cortical neurons. The present study was conducted to further verify the neuroprotective effect of SCR on excitotoxic and cerebral ischemic injury using both in vitro and in vivo studies. Exposure of cultured cortical neurons to 1 mM N-methyl-D-aspartate (NMDA) for 12 h induced neuronal cell death. SCR (10 and 50 microg/ml) inhibited NMDA-induced neuronal death, elevation of intracellular calcium ([Ca(2+)](i)), and generation of reactive oxygen species (ROS) in primary cultures of rat cortical neurons. In vivo, SCR prevented cerebral ischemic injury induced by 3-h middle cerebral artery occlusion (MCAO) and 24-h reperfusion. The ischemic infarct was significantly reduced in rats that received SCR (30 and 50 mg/kg, orally), with a corresponding improvement in neurological function. Moreover, SCR treatment significantly decreased the histological changes observed following ischemia. Oxyresveratrol and resveratrol isolated from SCR also inhibited NMDA-induced neuronal death, increase in [Ca(2+)](i), and ROS generation in cultured cortical neurons, suggesting that the neuroprotective effect of SCR may be attributable to these compounds. Taken together, these results suggest that the neuroprotective effect of SCR against focal cerebral ischemic injury is due to its anti-excitotoxic effects and that SCR may have a therapeutic role in neurodegenerative diseases such as stroke.     

Neuroprotective role of naringenin against methylmercury induced cognitive impairment and mitochondrial damage in a mouse model

Human exposure to organomercurials like methylmercury (MeHg) may occur by consumption of contaminated seafood, affecting various vital organs especially, brain contributing to neuro disorders. The citrus flavanone, naringenin (NAR) has shown strong antioxidant and anti-inflammatory effects and therefore may exert cytoprotective effect against xenobiotic agents. Herein, we investigated the neuroprotective role of NAR against MeHg induced functional changes in mitochondria, neuronal cell death and cognitive impairment in a mouse model.A neurotoxic dose of MeHg (4 mg/kg.b.wt.) was administered orally to mice for 15 days. This resulted in the reduction of GSH and GST, an increase in mitochondrial DNA damage and memory impairment. On the contrary, NAR pre-treatment (100 mg/kg.b.wt.), helped in lowering the oxidative burden which in turn maintained mitochondrial function and prevented induced neuronal cell death, ultimately improving the cognitive impairment. As MeHg intoxication occurs chronically, consumption of the dietary components rich in NAR may have its positive human health impact, ultimately improving the quality of life.     

仙茅苷对脂多糖诱导血管平滑肌细胞增殖、迁移及表型转化的影响

目的 观察仙茅苷（curculigoside,Cur）对脂多糖（LPS）诱导血管平滑肌细胞（vascular smooth muscle cells,VSMCs）发生细胞增殖、迁移以及促进其表型转化的影响,并对其机制进行初步探讨。方法 体外分离培养大鼠血管平滑肌细胞,将血管平滑肌细胞 随机分为对照组、脂多糖组、脂多糖+不同浓度仙茅苷组及仙茅苷组。采用噻唑蓝(MTT)比色法观察并计算各组细胞增殖率;采用细胞划痕实验观察并计算细胞迁移率。应用 Western blot法检测各组细胞内α-平滑肌肌动蛋白（α-SMA）、基质金属蛋白酶9（MMP-9）及核转录因子κB（NF-κB）信号通路相关蛋白表达情况。结果 与对照组相比,脂多糖组细胞增殖率、迁移率及细胞内核转录因子κB及基质金属蛋白酶9蛋白表达水平明显提高（P<0.001）,而α-平滑肌肌动蛋白表达明显降低（P<0.001）;与脂多糖组相比,脂多糖+仙茅苷组细胞增殖率、迁移率以及细胞内基质金属蛋白酶9、核转录因子κB蛋白表达水平明显下降（P<0.001）,α-平滑肌肌动蛋白表达水平明显上升（P<0.001）。结论 仙茅苷可明显抑制由脂多糖诱导的血管平滑肌细胞表型自收缩表型向合成表型转化,进而抑制血管平滑肌细胞的增殖与迁移能力。其作用机制可能与核转录因子κB信号通路相关。     

新银杏叶提取物抗兴奋毒性神经损害研究

目的：观察新银杏叶提取物（nGBE）在不同给药模式下对谷氨酸所致海马神经元毒性作用的影响。方法：采用CO2超临界萃取的方法制备nGBE，建立新生Wistar大鼠原代培养的海马神经元谷氨酸毒性模型，采用台盼蓝染色、程序性细胞死亡检测技术及乳酸脱氢酶测定的方法，观察预处理与急救两种给药模型下nGBE的神经保护作用，并与MK-801急性给药相比较。结果：nGBE在两种给药模式下均能不同程度地提高细胞存活率，降低凋亡率，减少LDH漏出量。其中预处理的效果明显优于急救给药处理，但均弱于MK-801组。结论：银杏叶制剂按其现有的临床给药途径即用于脑血管病的急救治疗，就其抗兴奋毒性机制而言，作用较弱，但如果我们将其用于高危人群的预防干预可能有更大价值。     

New targets for pharmacological intervention in the glutamatergic synapse

Excitotoxicity is thought to be a major mechanism in many human disease states such as ischemia, trauma, epilepsy and chronic neurodegenerative disorders. Briefly, synaptic overactivity leads to the excessive release of glutamate that activates postsynaptic cell membrane receptors, which upon activation open their associated ion channel pore to produce ion influx. To date, although molecular basis of glutamate toxicity remain uncertain, there is general agreement that N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors plays a key role in mediating at least some aspects of glutamate neurotoxicity. On this view, research has focused in the discovery of new compounds able to either reduce glutamate release or activation of postsynaptic NMDA receptors. Although NMDA receptor antagonists prevent excitotoxicity in cellular and animal models, these drugs have limited usefulness clinically. Side effects such as psychosis, nausea, vomiting, memory impairment, and neuronal cell death accompany complete NMDA receptor blockade, dramatizing the crucial role of the NMDA receptor in normal neuronal processes. Recently, however, well-tolerated compounds such as memantine has been shown to be able to block excitotoxic cell death in a clinically tolerated manner. Understanding the biochemical properties of the multitude of NMDA receptor subtypes offers the possibility of developing more effective and clinically useful drugs. The increasing knowledge of the structure and function of this postsynaptic NMDA complex may improve the identification of specific molecular targets whose pharmacological or genetic manipulation might lead to innovative therapies for brain disorders.