Neuroprotective potential ofIndigofera oblongifolia leaf methanolic extract against lead acetate-induced neurotoxicity

Lead (Pb) is one of the most common environmental toxicants, exposure to which can cause signiifcant neurotoxicity and an associated decline in brain function. hTis study investigated the possible neuroprotec-tive role ofIndigofera oblongifolia leaf methanolic extract (IOLME) against lead-induced neurotoxicity. Rats were intraperitoneally injected with lead acetate, with or without IOLME (intragastric administration for 5 days), and the neuroprotective effect of IOLME was assessed by measuring the lead concentration, redox status (lipid peroxidation, nitric oxide and glutathione), enzymatic antioxidant activities (superoxide dis-mutase, catalase, glutathione peroxidase and reductase), PCR assays of apoptosis markers (Bax and Bcl-2) and histopathology of the brain. The increases in the lipid peroxidation, nitric oxide, and apoptosis, the decreases in the glutathione level and the activity of antioxidant enzymes, and the altered histology of the brain induced by lead acetate were mitigated in the brain of rats pre-treated with IOLME. These ifndings indicate that IOLME has beneifcial effects and it mitigates lead acetate-induced neurotoxicityviaits antiox-idant and anti-apoptotic activities.     

铅对鼠龄30 d小鼠小脑组织结构及抗氧化能力的影响

为观察铅对小鼠小脑皮质结构及抗氧化能力的影响，应用分光光度法检测了脂质过氧化相关指标超氧化物歧化酶、过氧化氢酶、碱性磷酸酶、酸性磷酸酶活力和丙二醛的含量。结果显示，鼠龄30 d的小鼠染铅后，可见小脑皮质浦肯野细胞固缩、萎缩且数量减少，颗粒细胞排列紊乱、数量也减少。小鼠小脑皮质组织中超氧化物歧化酶、过氧化氢酶、碱性磷酸酶、酸性磷酸酶活力显著降低，丙二醛的含量显著升高。双因素方差分析结果显示，铅对染铅小鼠以上因子的影响剂量效应大于时间效应，证实铅可使鼠龄30 d小鼠小脑组织结构发生改变，并抑制其抗氧化能力。     

Protective effect of oxysophoridine on cerebral ischemia/reperfusion injury in mice

Oxysophoridine, a new alkaloid extracted from Sophora alopecuroides L., has been shown to have a protective effect against ischemic brain damage. In this study, a focal cerebral ischemia/reperfusion injury model was established using middle cerebral artery occlusion in mice. Both 62.5, 125, and 250 mg/kg oxysophoridine, via intraperitoneal injection, and 6 mg/kg nimodipine, via intragastric administration, were administered daily for 7 days before modeling. After 24 hours of reperfusion, mice were tested for neurological deficit, cerebral infarct size was assessed and brain tissue was collected. Results showed that oxysophoridine at 125, 250 mg/kg and 6 mg/kg nimodipine could reduce neurological deficit scores, cerebral infarct size and brain water content in mice. These results provided evidence that oxysophoridine plays a protective role in cerebral ischemia/reperfusion injury. In addition, oxysophoridine at 62.5, 125, and 250 mg/kg and 6 mg/kg nimodipine increased adenosine-triphosphate content, and decreased malondialdehyde and nitric oxide content. These compounds enhanced the activities of glutathione-peroxidase, superoxide dismutase, catalase, and lactate dehydrogenase, and decreased the activity of nitric oxide synthase. Protein and mRNA expression levels of N-methyl-D-aspartate receptor subunit NR1 were markedly inhibited in the presence of 250 mg/kg oxysophoridine and 6 mg/kg nimodipine. Our experimental findings indicated that oxysophoridine has a neuroprotective effect against cerebral ischemia/reperfusion injury in mice, and that the effect may be due to its ability to inhibit oxidative stress and expression of the N-methyl-D-aspartate receptor subunit NR1.     

Dose-dependent neuroprotective effect of enoxaparin on cold-induced traumatic brain injury

Recent evidence exists that enoxaparin can reduce brain injury because of its anticoagulant activity. To investigate the potential therapeutic effect of enoxaparin on cold-induced traumatic brain injury, at 20 minutes after modeling, male BALB/c mouse models of cold-induced traumatic brain injury were intra-peritoneally administered 3 and 10 mg/kg enoxaparin or isotonic saline solution. Twenty-four hours later, enoxaparin at 10 mg/kg greatly reduced infarct volume, decreased cell apoptosis in the cortex and obviously increased serum level of total antioxidant status. By contrast, administration of enoxaparin at 3 mg/kg did not lead to these changes.These findings suggest that enoxaparin exhibits neuroprotective effect on cold-in-duced traumatic brain injury in a dose-dependent manner.     

Persimmon leaf flavonoid induces brain ischemic tolerance in mice

The persimmon leaf has been shown to improve cerebral ischemic outcomes; however, its mechanism of action remains unclear. In this study, mice were subjected to 10 minutes of ischemic preconditioning, and persimmon leaf flavonoid was orally administered for 5 days. Results showed that the persimmon leaf flavonoid significantly improved the content of tissue type plasminogen activator and 6-keto prostaglandin-F1 α in the cerebral cortex, decreased the content of thromboxane B2, and reduced the content of plasminogen activator inhibitor-1 in mice. Following optical microscopy, persimmon leaf flavonoid was also shown to reduce cell swelling and nuclear hyperchromatism in the cerebral cortex and hippocampus of mice. These results suggested that persimmon leaf flavonoid can effectively inhibit brain thrombosis, improve blood supply to the brain, and relieve ischemia-induced pathological damage, resulting in brain ischemic tolerance.     

Persimmon leaf flavonoid promotes brain ischemic tolerance

Persimmon leaf flavonoid has been shown to enhance brain ischemic tolerance in mice, but its mechanism of action remains unclear. The bilateral common carotid arteries were occluded using a micro clip ...     

Chrysophanol attenuates lead exposure-induced injury to hippocampal neurons in neonatal mice

Previous studies have shown that chrysophanol protects against learning and memory impairments in lead-exposed adult mice. In the present study, we investigated whether chrysophanol can alleviate learning and memory dysfunction and hippocampal neuronal injury in lead-exposed neonatal mice. At the end of lactation, chrysophanol（0.1, 1.0, 10.0 mg/kg） was administered to the neonatal mice by intraperitoneal injection for 15 days. Chrysophanol significantly alleviated injury to hippocampal neurons and improved learning and memory abilities in the lead-poisoned neonatal mice. Chrysophanol also significantly decreased lead content in blood, brain, heart, spleen, liver and kidney in the lead-exposed neonatal mice. The levels of malondialdehyde in the brain, liver and kidney were significantly reduced, and superoxide dismutase and glutathione peroxidase activities were significantly increased after chrysophanol treatment. Collectively, these findings indicate that chrysophanol can significantly reduce damage to hippocampal neurons in lead-exposed neonatal mice.     

Melatonin reduces traumatic brain injur y-induced oxidative stress in the cerebral cortex and blood of rats

Free radicals induced by traumatic brain injury have deleterious effects on the function and antioxidant vitamin levels of several organ systems including the brain. Melatonin possesses antioxidant effect on the brain by maintaining antioxidant enzyme and vitamin levels. We investigated the effects of melatonin on antioxidant ability in the cerebral cortex and blood of traumatic brain injury rats. Results showed that the cerebral cortex β-carotene, vitamin C, vitamin E, reduced glutathione, and erythrocyte reduced glutathione levels, and plasma vitamin C level were decreased by traumatic brain injury whereas they were increased following melatonin treatment. In conclusion, melatonin seems to have protective effects on traumatic brain injury-induced cerebral cortex and blood toxicity by inhibiting free radical formation and supporting antioxidant vitamin redox system.     

脑神经肽对人胚神经细胞生长发育及对小鼠急性缺血脑组织的影响

目的和方法应用体外培养的人胚背根神经节和大脑皮层神经元，研究了神经肽对神经组织和神经细胞生长发育的影响，还通过小鼠的急性脑缺血模型研究神经肽对急性脑缺血的作用。结果发现神经肽可使背根神经节突起的长度和密度增加，皮层神经元存活数增加，神经元分化率增高，胞体增大，突起延长，细胞生长加快。超微结构观察显示神经肽可增强细胞内的合成代谢和细胞间连接。脑神经肽可使小鼠脑组织水肿较轻神经元无明显空泡，细胞超微结构改变较轻微，脑组织LDH活性高于对照组。结论神经肽对神经组织具有营养作用，并对急性脑缺血也具有保护作用。     

Antioxidant effects of the orientin and vitexin in Trollius chinensis Bunge in D-galactose-aged mice

Total flavonoids are the main pharmaceutical components of Trollius chinensis Bunge, and orientin and vitexin are the monomer components of total flavonoids in Trollius chinensis Bunge. In this study, an aged mouse model was established through intraperitoneal injection of D-galactose for 8 weeks, followed by treatment with 40, 20, or 10 mg/kg orientin, vitexin, or a positive control (vitamin E) via intragastric administration for an additional 8 weeks. Orientin, vitexin, and vitamin E improved the general medical status of the aging mice and significantly increased their brain weights. They also produced an obvious rise in total antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase levels in the serum, and the levels of superoxide dismutase, catalase and glutathione peroxidase, Na+-K+-ATP enzyme, and Ca2+-Mg2+-ATP enzyme in the liver, brain and kidneys. In addition, they significantly reduced malondialdehyde levels in the liver, brain and kidney and lipofuscin levels in the brain. They also significantly improved the neuronal ultrastructure. The 40 mg/kg dose of orientin and vitexin had the same antioxidant capacity as vitamin E. These experimental findings indicate that orientin and vitexin engender anti-aging effects through their antioxidant capacities.     

Neuroprotective effect of an antioxidant in ischemic brain injury

The production of reactive oxygen species (ROS) has been implicated in reperfusion injury after cerebral ischemia, and antioxidant enzymes are believed to be among the major mechanisms by which the cells counteract the deleterious effect of ROS after cerebral ischemia. ROS also mediate the mitochondrial signaling pathway that may lead to apoptosis following cerebral ischemia. The recent development and availability of transgenic and knockout mutant rodents that either overexpress or are deficient in antioxidant genes have provided powerful tools for dissecting the molecular and cellular mechanisms of signaling pathways, direct oxidative damage, or both that are involved in ischemic brain injury. This article focuses on the contribution of ROS or an antioxidant system to the molecular pathway of postischemic apoptosis following transient focal cerebral ischemia by using transgenic mice that overexpress the cytosolic antioxidant copper/zinc superoxide dismutase.     

Effects of maternal lead administration on monoaminergic,GABAergic and glutamatergic systems

The effects of perinatal exposure to lead (300 mg/l) on the development of monoaminergic and aminoacidergic systems were evaluated in the striatum, cerebral cortex (Cx), dorsal hippocampus (d-Hipp) and basal-medial hypothalamus. Maternal exposure to lead produced regional alterations in monoamine content, with increases in dopamine and serotonin or their metabolites. Further, decreased glutamate levels were seen in all brain regions studied, while GABA content decreased only in the Cx. Together, these results show that lead causes alterations to neurotransmitter systems during development. These may be related to lead-induced neurobehavioral impairment.     

Cyclosporin A protects against ischemia-reperfusion injury in the brain

We investigated the protective effect of Cyclosporin A (CsA) against ischemia-reperfusion injury in the brain using a transient focal ischemia model in rats. In CsA-treated rats, ischemic brain edema formation 1 day after reperfusion in the cerebral cortex perfused by the middle cerebral artery (MCA) and infarct size were decreased compared with those in olive oil treated control rats. These results suggest that CsA is beneficial in reducing ischemia-reperfusion injury, possibly by the suppression of immunological reactions.     

Intravenous transplantation of bone marrow mesenchymal stem cells promotes neural regeneration after traumatic brain injury

To investigate the supplement of lost nerve cells in rats with traumatic brain injury by intravenous administration of allogenic bone marrow mesenchymal stem cells, this study established a Wistar rat model of traumatic brain injury by weight drop impact acceleration method and administered 3 × 106 rat bone marrow mesenchymal stem cells via the lateral tail vein. At 14 days after cell transplantation, bone marrow mesenchymal stem cells differentiated into neurons and astrocytes in injured rat cerebral cortex and rat neurological function was improved significantly. These findings suggest that intravenously administered bone marrow mesenchymal stem cells can promote nerve cell regeneration in injured cerebral cortex, which supplement the lost nerve cells.     

Astrocyte-Dependent Vulnerability to Excitotoxicity in Spermine Oxidase-Overexpressing Mouse

Transgenic mice overexpressing spermine oxidase (SMO) in the cerebral cortex (Dach-SMO mice) showed increased vulnerability to excitotoxic brain injury and kainate-induced epileptic seizures. To investigate the mechanisms by which SMO overexpression leads to increased susceptibility to kainate excitotoxicity and seizure, in the cerebral cortex of Dach-SMO and control mice we assessed markers for astrocyte proliferation and neuron loss, and the ability of kainate to evoke glutamate release from nerve terminals and astrocyte processes. Moreover, we assessed a possible role of astrocytes in an in vitro model of epileptic-like activity in combined cortico-hippocampal slices recorded with a multi-electrode array device. In parallel, as the brain is a major metabolizer of oxygen and yet has relatively feeble protective antioxidant mechanisms, we analyzed the oxidative status of the cerebral cortex of both SMO-overexpressing and control mice by evaluating enzymatic and non-enzymatic scavengers such as metallothioneins. The main findings in the cerebral cortex of Dach-SMO mice as compared to controls are the following: astrocyte activation and neuron loss; increased oxidative stress and activation of defense mechanisms involving both neurons and astrocytes; increased susceptibility to kainate-evoked cortical epileptogenic activity, dependent on astrocyte function; appearance of a glutamate-releasing response to kainate from astrocyte processes due to activation of Ca²⁺-permeable AMPA receptors in Dach-SMO mice. We conclude that reactive astrocytosis and activation of glutamate release from astrocyte processes might contribute, together with increased reactive oxygen species production, to the vulnerability to kainate excitotoxicity in Dach-SMO mice. This mouse model with a deregulated polyamine metabolism would shed light on roles for astrocytes in increasing vulnerability to excitotoxic neuron injury.     

积雪草苷对脑缺血再灌注大鼠Nrf-2/TXNIP/NLRP-3通路及小胶质细胞活化的影响

目的 观察积雪草苷(Asiaticoside,ASI)对脑缺血再灌注(Cerebral ischemia reperfusion,CIR)大鼠皮层中核因子相关因子-2(Nuclear factor-erythroid 2-related factor-2,Nrf-2)、氧还蛋白相互作用蛋白(Thiredoxin-interactive protein,TXNIP)、NOD样受体蛋白-3(Nod-like receptor protein-3,NLRP-3)通路蛋白表达水平的影响。方法 改良Longa法阻塞大脑中动脉制备CIR大鼠模型,分为CIR组、低、中、高剂量ASI组,15只/组,另取15只不插入线栓为Sham组,低、中、高剂量ASI组分别给予10、20、40 mg/mL ASI溶液灌胃,Sham组、CIR组生理盐水灌胃,容积2 mL·kg^-1·d^-1,连续3 d,末次给药6 h后麻醉处死大鼠,取脑组织,红四氮唑(triphenyltetrazolium chloride,TTC)法检测脑梗死体积,苏木素伊红(Haematoxylin-eosin,HE)法观察脑皮层病变,免疫荧光法检测脑皮层小胶质细胞活化,试剂盒检测活性氧(Reactive oxygen species,ROS)、总抗氧化能力及白细胞介素-1β(Interleukin-1β,IL-1β)水平,Western blot法检测脑皮层组织Nrf-2/TXNIP/NLRP-3通路蛋白表达水平。结果 Sham组大鼠脑皮层组织无损伤; CIR组大鼠脑皮层可见神经元变性、细胞萎缩及炎性细胞浸润等; 低、中、高剂量ASI组大鼠脑皮层组织损伤依次减轻,高剂量ASI组仅可见个别神经细胞萎缩。与Sham组比较,CIR组大鼠脑梗死体积、脑皮层钙离子结合蛋白1(Ionized calcium binding adapter molecule 1,Iba1⁺)活化小胶质细胞、ROS及IL-1β水平、TXNIP、斑点样蛋白(Apotosis-associated speck-like protein,ASC),NLRP-3及天冬氨酸蛋白水解酶(Cysteinyl aspartate specific proteinase 1,Caspase-1)蛋白表达水平升高(P均<0.05),总抗氧化能力、Nrf-2核移位及血红素氧合酶-1(Heme oxygenase-1,HO-1)蛋白表达水平降低(P均<0.05); 与CIR组比较,低、中、高剂量ASI组大鼠脑梗死体积、脑皮层Iba1⁺活化小胶质细胞、ROS及IL-1β水平、TXNIP,ASC,NLRP-3及Caspase-1蛋白表达水平剂量依赖性降低(P均<0.05),总抗氧化能力、Nrf-2核移位及HO-1蛋白表达水平剂量依赖性增高(P均<0.05)。结论 ASI可促进脑皮层中Nrf-2通路蛋白表达,降低氧化应激,抑制TXNIP/NLRP-3通路蛋白表达,抑制IL-1β等释放,减轻小胶质细胞活化,改善CIR所致大鼠脑损伤。     

Pretreatment with scutellaria baicalensis stem-leaf total flavonoid protects against cerebral ischemia/ reperfusion injury in hippocampal neurons

Previous experimental studies have shown that cerebral infarction can be effectively reduced following treatment with scutellaria baicalensis stem-leaf total flavonoid （SSTF）. However, the mechanism of action of SSTF as a preventive drug to treat cerebral infarction remains unclear. In this study, Sprague-Dawley rats were pretreated with 50, 100, 200 mg/kg SSTF via intragastric ad- ministration for 1 week prior to the establishment of focal cerebral ischemia/reperfusion injury. The results showed that pretreatment with SSTF effectively improved neurological function, reduced brain water content and the permeability of blood vessels, ameliorated ischemia-induced morphology changes in hippocampal microvessels, down-regulated Fas and FasL protein expression, elevated the activity of superoxide dismutase and glutathione peroxidase, and decreased malondialdehyde content. In contrast to low-dose SSTF pretreatment, the above changes were most obvious after pretreatment with moderateand high-doses of SSTF. Experimental findings indicate that SSTF pretreatment can exert protective effects on the brain against cerebral ischemia/reperfusion injury. The underlying mechanisms may involve reducing brain water content, increasing microvascular recanalization, inhibiting the apoptosis of hippocampal neurons, and attenuating free radical damage.     

Protective effects of dl-3n-butylphthalide against diffuse brain injury

Dl-3n-butylphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders fol owing diffuse brain injury remain ...     

Acute renal failure potentiates brain energy dysfunction elicited by methylmalonic acid

The influence of acute renal failure induced by gentamicin administration on the effects of MMA on mitochondrial respiratory chain complexes, citrate synthase, succinate dehydrogenase and creatine kinase activities in cerebral cortex and kidney of young rats were investigated. Animals received one intraperitoneal injection of saline or gentamicin (70 mg/kg). One hour after, the animals received three consecutive subcutaneous injections of MMA (1.67 μmol/g) or saline (11 h interval between injections) and 60 min after the last injection the animals were killed. Acute MMA administration decreased creatine kinase activity in both tissues and increased complexes I–III activity in cerebral cortex. Creatine kinase activity was also inhibited by gentamicin administration. Simultaneous administration of MMA and gentamicin increased the activities of citrate synthase in cerebral cortex and kidney and complexes II–III in cerebral cortex. The other enzyme activities in cerebral cortex and kidney of animals receiving MMA plus gentamicin did not significantly differ from those observed in animals receiving only MMA. Our present data is line with the hypothesis that MMA acts as a toxin in brain and kidney of rats and suggest that renal injury potentiates the toxicity of MMA on the Krebs cycle and respiratory chain in brain and peripheral tissues.