lignans and Infarction--Middle-Cerebral-Artery

Neuroprotective agents can rescue ischemic penumbra in cerebral ischemia. However, the clinically effective neuroprotective agents for cerebral ischemic injury remain deficient in clinic so far. This study was undertaken to investigate the brain protective effect of 002C-3 and its potential mechanisms in rats, and its preliminary toxicity in mice. A transient middle cerebral artery occlusion (tMCAO) model in rats was used to evaluate its effect and mechanism, a dose limited experiment was used to evaluate its preliminary toxicity. 10-50μg/kg of 002C-3 (single iv bolus after reperfusion) significantly reduced neurological scores, infarct volumes and brain water contents, and the effect was more potent than that of magnolol under the same mole dose; 50μg/kg of 002C-3 significantly decreased the number of TUNEL-positive cells, reduced the activity of caspase-3, and lowered the autophagy-related proteins LC3-II and Beclin-1 level in I-R cerebral tissue. At 1000 times' dose of high effective dose (ip) 002C-3 failed to show evident toxicity in mice, and the mean body weight of mice treated with 002C-3 was almost the same as that of the vehicle control, but magnolol caused evident toxicity and death. In conclusion, 002C-3 has significant protective effect against cerebral ischemia-reperfusion injury; the effect is more potent than magnolol; this effect is maybe associated with its inhibition of both apoptosis and autophagy; its toxicity is greatly reduced compared to magnolol. These results provided data for its further research and development.

Topics: Animals; Apoptosis; Autophagy; Biphenyl Compounds; Brain; Brain Infarction; Caspase 3; Infarction, Middle Cerebral Artery; Lignans; Male; Mice; Neuroprotective Agents; Rats, Sprague-Dawley; Reperfusion Injury

SMXZF is a combination of Rb1, Rg1, schizandrin, and DT-13 (6:9:5:4) derived from Sheng-mai San, a widely used Chinese traditional medicine for the treatment of cardiovascular and cerebral diseases. The present study explores the inhibitory effects and signaling pathways of SMXZF on autophagy induced by cerebral ischemia-reperfusion injury. Male C57BL/6 mice were subjected to ischemia-reperfusion insult by right middle cerebral artery occlusion (MCAO) for 1 hr with subsequent 24 hr reperfusion. Three doses of SMXZF (4.5, 9, and 18 mg/kg) were administered intraperitoneally (i.p.) after ischemia for 1 hr. An autophagic inhibitor, 3-methyladenine (3-MA; 300 μg/kg), was administered i.p. 20 min before ischemia as a positive drug. We found that SMXZF significantly increased cerebral blood flow and reduced the infarct volume, brain water content, and the neurological deficits in a dose-dependent manner. Similar to the positive control, SMXZF at 18 mg/kg also significantly inhibited autophagosome formation. Immunofluorescence staining and Western blotting demonstrated that SMXZF could significantly decrease the expression levels of beclin1 and microtubule-associated protein 1 light chain 3. SMXZF also remarkably inhibited the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) as well as the expression of c-Jun N-terminal kinase (JNK) and its phosphorylation induced by 24 hr reperfusion. Finally, we demonstrated that the optimal administration time of SMXZF was at the early period of reperfusion. This study reveals that SMXZF displays neuroprotective effect against focal ischemia-reperfusion injury, possibly associated with autophagy inactivation through AMPK/mTOR and JNK pathways.

Topics: Adenine; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Animals; Autophagy; Brain; Brain Infarction; Cyclooctanes; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Combinations; Drugs, Chinese Herbal; Ginsenosides; Infarction, Middle Cerebral Artery; Lignans; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Polycyclic Compounds; Renal Circulation; Reperfusion Injury; Saponins; Time Factors; TOR Serine-Threonine Kinases

Stroke is a severe neurological disorder characterized by the abrupt loss of blood circulation into the brain resulting into wide ranging brain and behavior abnormalities. The present study was designed to evaluate molecular mechanism by which sesamin (SES) induces neuroprotection in mouse model of ischemic stroke. The results of this study demonstrate that SES treatment (30 mg/kg bwt) significantly reduced infarction volume, lipid per-oxidation, cleaved-caspase-3 activation, and increased GSH activity following MCAO in adult male mouse. SES treatment also diminished iNOS and COX-2 protein expression, and significantly restored SOD activity and protein expression level in the ischemic cortex of the MCAO animals. Furthermore, SES treatment also significantly reduced inflammatory and oxidative stress markers including Iba1, Nox-2, Cox-2, peroxynitrite compared to placebo MCAO animals. Superoxide radical production, as studied by DHE staining method, was also significantly reduced in the ischemic cortex of SES treated compared to placebo MCAO animals. Likewise, downstream effects of superoxide free radicals i.e. MAPK/ERK and P38 activation was also significantly attenuated in SES treated compared to placebo MCAO animals. In conclusion, these results suggest that SES induces significant neuroprotection, by ameliorating many signaling pathways activated/deactivated following cerebral ischemia in adult mouse.

Topics: Animals; Brain Ischemia; Dioxoles; Disease Models, Animal; Encephalitis; Infarction, Middle Cerebral Artery; Lignans; Male; Mice; Mice, Inbred C57BL; Microglia; Neuroprotective Agents; Oxidative Stress; Signal Transduction; Stroke

Honokiol, a major bioactive constituent of the bark of Magnolia officinalis has been confirmed to have the neuroprotective effect on ischemic stroke in rats. This study was designed to observe the therapeutic time window of honokiol microemulsion on cerebral ischemia-reperfusion injury to support its potential for future clinical trials and further explore the underlying mechanisms. Honokiol microemulsion (50μg/kg, i.v. at 0, 1 or 3h after reperfusion) significantly reduced neurological deficit, infarct volume and brain water content in rats subjected to cerebral ischemia-reperfusion, and honokiol (0.1-10μM) significantly attenuated oxygen-glucose deprivation- or glutamate-induced injury of fetal rat cortical neurons. In co-immunoprecipitation and western blot test, honokiol decreased the intensity of nNOS related to PSD95 but failed to affect that of PSD95 related to NR2B in NR2B-PSD95-nNOS complex, and it also inhibited the translocation of nNOS from cytosol to membrane without affecting total nNOS expression, and then markedly decreased NO production in cortical neurons. Besides, the results of whole-cell patch-clamp recordings showed that honokiol reversibly inhibited the NMDA current by about 64%. In conclusion, honokiol has a therapeutic window of at least 5h after the onset of cerebral ischemia or 3h after reperfusion in rats, which may be in part ascribed to the disruption of the PSD95-nNOS interaction leading to the inhibition of neurotoxic NO production.

Topics: Animals; Biphenyl Compounds; Bisbenzimidazole; Blotting, Western; Cell Hypoxia; Cells, Cultured; Central Nervous System Depressants; Cerebral Cortex; Coloring Agents; Cytosol; Disks Large Homolog 4 Protein; Glucose; Glutamic Acid; Immunoprecipitation; In Vitro Techniques; Infarction, Middle Cerebral Artery; Intracellular Signaling Peptides and Proteins; L-Lactate Dehydrogenase; Lignans; Male; Membrane Proteins; Nitric Oxide; Nitric Oxide Synthase Type I; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Reperfusion Injury; Translocation, Genetic

Honokiol, a constituent of Magnolia obovata, has various pharmacological effects, including protection against cerebral ischemia. However, few studies have been conducted to evaluate the possible neuroprotective effects of honokiol against cerebral ischemia. We recently reported that cerebral ischemic neuronal damage could be triggered by glucose intolerance that develops after the onset of ischemic stress (i.e., post-ischemic glucose intolerance). In addition, suppression of post-ischemic glucose intolerance significantly ameliorated ischemic neuronal damage. Here, we investigated the effects of honokiol on the development of post-ischemic glucose intolerance and neuronal damage. Mice were subjected to middle cerebral artery occlusion (MCAO) for 2 h. The development of post-ischemic glucose intolerance on day 1 and neuronal damage on day 3 after MCAO were significantly reduced by intraperitoneal administration of honokiol (10 mg/kg) compared with the vehicle-treated group. Honokiol did not affect serum insulin or adiponectin levels. However, honokiol significantly decreased the expression of phosphoenolpyruvate carboxykinase and increased the expression of 5'-AMP-activated protein kinase (AMPK) on day 1 after MCAO, compared with the vehicle-treated MCAO group. The results of this study suggest that honokiol could prevent post-ischemic glucose intolerance in an AMPK-dependent manner, which may be involved in the neuroprotective effects of honokiol against cerebral ischemia.

Topics: Adiponectin; AMP-Activated Protein Kinases; Animals; Biphenyl Compounds; Brain Ischemia; Glucose Intolerance; Infarction, Middle Cerebral Artery; Insulin; Lignans; Male; Mice; Phosphoenolpyruvate Carboxykinase (ATP)

Neuroprotective efficacy of magnolol, 5,5'-dially-2,2'-dihydroxydiphenyl, was investigated in a model of stroke and cultured neurons exposed to glutamate-induced excitotoxicity. Rats were subjected to permanent middle cerebral artery occlusion (pMCAO). Magnolol or vehicle was administered intraperitoneally, at 1 hr pre-insult or 1-6 hrs post-insult. Brain infarction was measured upon sacrifice. Relative to controls, animals pre-treated with magnolol (50-200 mg/kg) had significant infarct volume reductions by 30.9-37.8% and improved neurobehavioral outcomes (P<0.05, respectively). Delayed treatment with magnolol (100 mg/kg) also protected against ischemic brain damage and improved neurobehavioral scores, even when administered up to 4 hrs post-insult (P<0.05, respectively). Additionally, magnolol (0.1 µM) effectively attenuated the rises of intracellular Ca(2+) levels, [Ca(2+)](i), in cultured neurons exposed to glutamate. Consequently, magnolol (0.1-1 µM) significantly attenuated glutamate-induced cytotoxicity and cell swelling (P<0.05). Thus, magnolol offers neuroprotection against permanent focal cerebral ischemia with a therapeutic window of 4 hrs. This neuroprotection may be, partly, mediated by its ability to limit the glutamate-induced excitotoxicity.

Topics: Animals; Biphenyl Compounds; Brain; Calcium; Cells, Cultured; Cerebral Infarction; Dose-Response Relationship, Drug; Glutamic Acid; Infarction, Middle Cerebral Artery; Injections, Intraperitoneal; Lignans; Male; Neurons; Neuroprotective Agents; Neuropsychological Tests; Rats; Rats, Sprague-Dawley; Time Factors

Stroke is the third leading cause of death in industrialized countries and the most important cause of acquired adult disability. Many evidences suggest that inflammation accounts for the progression of cerebral ischemic injury. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignin isolated from certain plants, has shown anti-inflammatory activity against diabetes and Alzheimer's disease. In this study, we tested whether arctigenin can protect middle cerebral artery occluded (MCAO) rats. Male Sprague-Dawley rats were pretreated with arctigenin or vehicle for 7 d before being subjected to transient occlusion of middle cerebral artery and reperfusion. Rats were evaluated at 24 h after MCAO for neurological deficit scoring. Furthermore, the mechanism of the anti-inflammatory effect of arctigenin was investigated with a focus on inflammatory cells, proinflammatory cytokines, and transcriptional factors. Arctigenin significantly reduced cerebral infarction and improved neurological outcome. Arctigenin suppressed the activation of microglia and decreased the expression of interleukin (IL)- 1β and tumor necrosis factor (TNF)-α. These results revealed that arctigenin has a promising therapeutic effect in ischemic stroke treatment through an anti-inflammatory mechanism.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Arctium; Furans; Infarction, Middle Cerebral Artery; Inflammation; Interleukin-1beta; Lignans; Macrophages; Male; Microglia; Neuroprotective Agents; Phytotherapy; Rats; Rats, Sprague-Dawley; Seeds; Tumor Necrosis Factor-alpha

Restoration of blood flow to an ischemic brain region is associated with generation of reactive oxygen species (ROS) with consequent reperfusion injury. ROS cause lipid peroxidation, protein oxidation, and DNA damage, all of which are deleterious to cells. So diminishing the production of free radicals and scavenging them may be a successful therapeutic strategy for the protection of brain tissue in cerebral stroke. The present study investigated the neuroprotective effect of sesamin (Sn) to reduce brain injury after middle cerebral artery occlusion (MCAO). The middle cerebral artery (MCA) of adult male Wistar rat was occluded for 2h and reperfused for 22h. Sesamin is the most abundant lignan in sesame seed oil is a potent antioxidant. Sesamin (30 mg/kg) was given orally twice, 30 min before the onset of ischemia and 12h after reperfusion. The initial investigations revealed that sesamin reduced the neurological deficits in terms of behavior and reduced the level of thiobarbituric acid reactive species (TBARS), and protein carbonyl (PC) in the different areas of the brain when compared with the MCAO group. A significantly depleted level of glutathione and its dependent enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]) in MCAO group were protected significantly in MCAO group treated with sesamin. The present study suggests that sesamin may be able to attenuate the ischemic cell death and plays a crucial role as a neuroprotectant in regulating levels of reactive oxygen species in the rat brain. Thus, sesamin may be a potential compound in stroke therapy.

Topics: Animals; Antioxidants; Behavior, Animal; Dioxoles; Glutathione; Glutathione Peroxidase; Glutathione Reductase; Infarction, Middle Cerebral Artery; Lignans; Male; Motor Activity; Neuroprotective Agents; Protein Carbonylation; Rats; Rats, Wistar; Reactive Oxygen Species; Sodium-Potassium-Exchanging ATPase; Thiobarbituric Acid Reactive Substances

Acute neuroprotective effects of cinnamophilin (CINN; (8R, 8'S)-4, 4'-dihydroxy-3, 3'-dimethoxy-7-oxo-8, 8'-neolignan), a novel antioxidant and free radical scavenger, were studied in a mouse model of transient middle cerebral artery (MCA) occlusion. CINN was administered intraperitoneally either 15 min before (pretreatment) or 2 h after the onset of MCA occlusion (postischemic treatment). Relative to vehicle-treated controls, animals pretreated with CINN, at 20-80 mg/kg, had significant reductions in brain infarction by 33-46% and improvements in neurobehavioral outcome. Postischemic administration with CINN (80 mg/kg) also significantly reduced brain infarction by 43% and ameliorated neurobehavioral deficits. Additionally, CINN administration significantly attenuated in situ accumulation of superoxide anions (O2-) in the boundary zones of infarct at 4 h after reperfusion. Consequently, CINN-treated animals exhibited significantly decreased levels of oxidative damage, as assessed by immunopositive reactions for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE), and the resultant inflammatory reactions at 24 h post-insult. It is concluded that CINN effectively reduced brain infarction and improved neurobehavioral outcome following a short-term recovery period after severe transient focal cerebral ischemia in mice. The finding of a decreased extent of reactive oxygen species and oxidative damage observed with CINN treatment highlights that its antioxidant and radical scavenging ability is contributory.

Topics: Animals; Antioxidants; Brain Ischemia; Cerebral Cortex; Cerebrovascular Circulation; Free Radical Scavengers; Guaiacol; Infarction, Middle Cerebral Artery; Lignans; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Time Factors

Honokiol, a constituent extracted from Magnolia officinalis, had been shown be an antioxidant and an anti-platelet agent in biological systems with an anti-arrhythmic effect and a myocardial protective effect on ischemia-reperfusion injury. We examined the neuroprotective effect of honokiol in rats subjected to focal cerebral ischemia. Honokiol was administered intravenously either at fifteen minutes before right middle cerebral artery occlusion (pretreatment groups) or when both common carotid arteries clips were removed (treatment groups). The results showed that there was no significant hemodynamic change after intravenous infusion of honokiol at the dosages of 10(-8), 10(-7) and 10(-6) g/kg in both groups. However, honokiol significantly reduced the total volume of infarction at the doses of 10(-7) or 10(-6) g/kg in both pretreatment and treatment groups. This study suggests that honokiol is a potent neuroprotective agent in focal cerebral ischemia. This beneficial effect may be related to its antioxidant effect and anti-platelet aggregation activity.

Topics: Animals; Antioxidants; Biphenyl Compounds; Brain Ischemia; Dose-Response Relationship, Drug; Infarction, Middle Cerebral Artery; Infusions, Intravenous; Lignans; Magnolia; Male; Phytotherapy; Platelet Aggregation Inhibitors; Random Allocation; Rats; Rats, Long-Evans

The effects of (-)clausenamide (clau) on long-term potentiation (LTP) and neuronal DNA damage were investigated in a rat model of middle cerebral artery (MCA) occlusion. Four days after reperfusion, electrophysiology records revealed reduced LTP in the ipsilateral dentate gyrus of ischemic rats, while treatment with clau (10 mg kg-1 p.o. once daily) improved LTP impairment. The fractional increase of population spike amplitude 20-50 min after tetanus was significantly larger in ischemic rats treated with clau than vehicle treated animals. Terminal deoxynucleotidyltransferase mediated dUTP end labeling (TUNEL) assay revealed occurrence of apoptosis in the ipsilateral striatum. The numbers of TUNEL-positive particles were significantly reduced after treatment with clau compared with vehicle group (78.8 +/- 17.9 versus 105.8 +/- 27.2). Mitochondrial rhodamine 123 accumulation showed that clau treatment (55.0 +/- 8.5) elevated numbers of rhodamine 123-positive particles in the ipsilateral striatum compared with vehicle group (40.4 +/- 7.5) These results demonstrate that clau can improve LTP impairment in the ipsilateral dentate gyrus and enhance cell survival in the striatum compared to the vehicle-treated rats four days following ischemic damage and its protective effect on mitochondria may partially underlie its action.

Topics: Animals; Apoptosis; Drugs, Chinese Herbal; Infarction, Middle Cerebral Artery; Lactams; Lignans; Long-Term Potentiation; Male; Rats; Rats, Wistar

We have previously shown that honokiol, an active component of Magnolia officinalis, displayed protective effect against focal cerebral ischemia-reperfusion (FCI/R) injury in rats. Production of reactive oxygen species (ROS) and infiltration of neutrophils to injured tissue play deleterious roles during cerebral ischemia. To study the mechanism(s) in mediating neuroprotective effect of honokiol, FCI/R-induced neutrophil infiltration and lipid peroxidation in brain tissue, and activation of neutrophils in-vitro were examined. Intravenous administration of honokiol (0.01-1.0 microg/kg) 15 min before (pretreatment) or 60 min after (post-treatment) middle cerebral artery occlusion reduced the total infarcted volume by 20-70% in dose-dependent manner. Pretreatment or post-treatment of honokiol at concentration of 0.1 and 1.0 microg/kg significantly decreased the neutrophil infiltration in the infarcted brain. Time course of neutrophil infiltration was performed in parallel with the lipid peroxidation in infracted brain tissue during FCI/R injury. The results indicate that honokiol can protect brain tissue against lipid peroxidation and neutrophil infiltration during FCI/R injury and cerebral infarction induced by FCI/R is accompanied with a prominent neutrophil infiltration to the infarcted area during FCI/R course. In-vitro, honokiol (0.1-10 microM) significantly diminished fMLP (N-formyl-methionyl-leucyl-phenylalanine)- or PMA (phorbol-12-myristate-13-acetate)-induced neutrophil firm adhesion, a prerequisite step behind neutrophil infiltration, and ROS production in neutrophils. Intracellular calcium overloading activates calcium-stimulated enzymes and further exaggerates FCI/R injury. Honokiol (0.1-10 microM) impeded the calcium influx induced by fMLP (a receptor agonist), AlF(4)(-) (a G-protein activator) or thapsigargin (an intracellular calcium pool releaser). Therefore, we conclude that the amelioration of FCI/R injury by honokiol can be attributed to its anti-oxidative and anti-inflammatory actions through, at least in part, limiting lipid peroxidation and reducing neutrophil activation/infiltration by interfering firm adhesion, ROS production, and calcium overloading that may be primed/activated during FCI/R injury.

Topics: Animals; Biphenyl Compounds; Brain Ischemia; Calcium; Calcium Signaling; Cell Adhesion; Cerebral Infarction; Chemotaxis, Leukocyte; Dose-Response Relationship, Drug; Infarction, Middle Cerebral Artery; Lignans; Lipid Peroxidation; Male; N-Formylmethionine Leucyl-Phenylalanine; Neuroprotective Agents; Neutrophils; Rats; Rats, Long-Evans; Reactive Oxygen Species; Reperfusion Injury; Tetradecanoylphorbol Acetate

The effects of (-)clausenamide (clau) on spatial cognitive functions and hippocampal long-term potentiation (LTP) after transient focal cerebral ischemia in rats were investigated. Four weeks after middle cerebral artery occlusion, Morris water maze tasks demonstrated that 2 h of transient forebrain ischemia resulted in a significant decrease in spatial discrimination performance. The escape latency at 4 and 5 days of acquisition trial was lower in the ischemic rats than in sham-operated rats (33.8+/-6.7 sec and 26.8+/-5 sec versus 12.2+/-4.0 sec and 10.4+/-3.6 sec), chronic treatment with clau (10 mg kg(-1) p.o. once daily) significantly improved the impairment (12.4+/-4.1 sec and 15.2+/-3.1 sec). After Morris water maze, the changes in population spike (PS) amplitude were recorded as an index of LTP in the perforant path-dentate gyrus synapses. There was no difference in PS amplitude between the sham-operated and vehicle-treated animals, whereas the fractional increase of PS 20-50 min after tetanus was significantly larger in clau-treated group. Histopathological analysis revealed that clau could protect against neuron loss in the regions of cortex and striatum. In conclusion, these data indicate a beneficial effect of clau for synaptic plasticity and cognitive function impaired by transient focal cerebral ischemia.

Topics: Action Potentials; Animals; Brain; Brain Ischemia; Cognition Disorders; Drugs, Chinese Herbal; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Lactams; Lignans; Male; Maze Learning; Nerve Degeneration; Neurons; Rats; Rats, Wistar; Recovery of Function; Reperfusion Injury; Treatment Outcome