lignans and Ischemic-Attack--Transient

Magnolol is isolated from the herb Magnolia officinalis, which has been demonstrated to exert pharmacological effects. Our aim was to investigate whether magnolol is able to act as an anti-inflammatory agent that brings about neuroprotection using a global ischemic stroke model and to determine the mechanisms involved. Rats were treated with and without magnolol after ischemia reperfusion brain injury by occlusion of the two common carotid arteries. The inflammatory cytokine production in serum and the volume of infarction in the brain were measured. The proteins present in the brains obtained from the stroke animal model (SAM) and control animal groups with and without magnolol treatment were compared. Magnolol reduces the total infarcted volume by 15% and 30% at dosages of 10 and 30mg/kg, respectively, compared to the untreated SAM group. The levels of acute inflammatory cytokines, including interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 were attenuated by magnolol. Magnolol was also able to suppress the production of nitrotyrosine, 4-hydroxy-2-nonenal (4-HNE), inducible NO synthase (iNOS), various phosphorylated p38 mitogen-activated protein kinases and various C/EBP homologues. Furthermore, this modulation of ischemia injury factors in the SAM model group treated with magnolol seems to result from a suppression of reactive oxygen species production and the upregulation of p-Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings confirm the anti-oxidative properties of magnolol, including the inhibition of ischemic injury to neurons; this protective effect seems to involve changes in the in vivo activity of Akt, GSK3β and NF-κB.

Topics: Animals; Biphenyl Compounds; Blotting, Western; Brain; Brain Ischemia; Cell Death; Endoplasmic Reticulum Stress; Immunohistochemistry; Indicators and Reagents; Ischemic Attack, Transient; Lignans; Male; Neurons; Neuroprotective Agents; NF-kappa B; Nitric Oxide Synthase Type II; Oncogene Protein v-akt; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Stroke; Transcription Factor CHOP; Tyrosine

Fruits of Schisandra have been traditionally used in East Asia for the treatment of dyspnea, cough, dysentery, insomnia, tonic-clonic seizures, and amnesia. Schisandrin B, a dibenzocyclooctadiene derivative isolated from Fructus Schisandrae, has been shown to produce antioxidant effect on rodent liver and heart. In the present study, we investigated the neuroprotective effects of Schisandrin B, a constituent drug of the fruit of Schisandra, against focal cerebral ischemia in rats. Schisandrin B (10, 30 mg/kg, i.p.) was twice administered 30 min before the onset of ischemia and 2h after reperfusion. Schisandrin B 10 and 30 mg/kg treated groups showed infarct volumes reduced by 25.7% and 53.4%, respectively, 2h after occlusion. Also, Schisandrin B treated animal treatment abrogated protein expression of TNF-α and IL-1β and degradation of MMP-2 and MMP-9 in ischemic hemispheres. These results suggest that Schisandrin B treatment provides a neuroprotective effect to rats after transient focal cerebral ischemia by inhibiting inflammation and by protecting against metalloproteinase degradation.

Topics: Animals; Antioxidants; Cerebral Infarction; Cyclooctanes; Drugs, Chinese Herbal; Inflammation; Interleukin-1beta; Ischemic Attack, Transient; Lignans; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Neuroprotective Agents; Plant Extracts; Polycyclic Compounds; Rats; Rats, Sprague-Dawley; Reperfusion; Schisandra; Tumor Necrosis Factor-alpha

We have previously shown that cinnamophilin ([8R, 8'S]-4, 4'-dihydroxy-3, 3'-dimethoxy-7-oxo-8, 8'-neolignan) exhibited potent antioxidant, radical-scavenging, and anti-inflammatory actions and reduced acute ischemic brain damage, even when it was given up to 6 hrs postinsult. Here, we characterized the long-lasting neuroprotection of cinnamophilin against gray and white matter damage and its beneficial effects on electrophysiological and functional outcomes in a model of stroke.. Prospective laboratory animal study.. Research laboratory in a university teaching hospital.. Adult male Sprague-Dawley rats (240-290 g).. Under controlled conditions of normoxia, normocarbia, and normothermia, spontaneously breathing, halothane-anesthetized (1.0-1.5%) rats were subjected to transient middle cerebral artery occlusion for 90 mins. Cinnamophilin (80 mg/kg) or vehicle was given intravenously at reperfusion onset.. Physiological parameters, including arterial blood gases and cortical blood perfusion, somatosensory-evoked potentials, and neurobehavioral outcomes, were serially examined. Animals were euthanized at 7 days or 21 days postinsult. Gray matter and white matter (axonal and myelin) damage were then evaluated by quantitative histopathology and immunohistochemistry against phosphorylated component-H neurofilaments and myelin basic protein, respectively. After the follow-up period of 7 and 21 days, our results showed that cinnamophilin significantly decreased gray matter damage by 31.6% and 34.9% (p < .05, respectively) without notable adverse effects. Additionally, cinnamophilin effectively reduced axonal and myelin damage by 46.3-68.6% (p < .05) and 25.2-28.1% (p < .05), respectively. Furthermore, cinnamophilin not only improved the ipsilateral field potentials (p < .05, respectively), but also reduced the severity of contralateral electrophysiological diaschisis (p < .05). Consequently, cinnamophilin improved sensorimotor outcomes up to 21 days postinsult (p < .05, respectively).. Administration with cinnamophilin provides long-lasting neuroprotection against gray and white matter damage and improves functional and electrophysiological outcomes after ischemic stroke. The results suggest a need for further studies to characterize the potential of cinnamophilin in the field of ischemic stroke.

Topics: Animals; Antioxidants; Behavior, Animal; Body Weight; Brain; Cerebral Cortex; Confidence Intervals; Disease Models, Animal; Electrophysiology; Evoked Potentials, Somatosensory; Guaiacol; Ischemic Attack, Transient; Lignans; Male; Nerve Fibers, Myelinated; Nerve Fibers, Unmyelinated; Neuroprotective Agents; Oxidative Stress; Random Allocation; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Statistics, Nonparametric; Survival Rate

Cinnamophilin (CINN, (8R, 8'S)-4, 4'-dihydroxy-3, 3'-dimethoxy-7-oxo-8, 8'-neolignan) protects against ischemic stroke in mice. While some anti-oxidative effects of CINN have been characterized, its therapeutic window and molecular basis for neuroprotection remain unclear. We evaluated antioxidant and anti-inflammatory properties and therapeutic window of CINN against brain ischemia using a panel of in vitro and in vivo assays. Data from lipid peroxidation and radical scavenging assays showed that CINN was a robust antioxidant and radical scavenger. CINN effectively inhibited the production of tumor necrosis factor alpha (TNF-alpha), nitrite/nitrate, interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW 264.7 and BV2 cells (P<0.05, respectively). Relative to controls, CINN, administrated at 80 mg/kg, 2, 4, or 6 h postinsult, but not 12 h, significantly reduced brain infarction by 34-43% (P<0.05) and improved neurobehavioral outcome (P<0.05) following transient focal cerebral ischemia in rats. CINN (10-30 microM) also significantly reduced oxygen-glucose deprivation-induced neuronal damage (P<0.05) in rat organotypic hippocampal slices, even when it was administrated 2, 4, or 6 h postinsult. Together, CINN protects against ischemic brain damage with a therapeutic window up to 6 h in vivo and in vitro, which may, at least in part, be attributed by its direct antioxidant and anti-inflammatory effects.

Topics: Analysis of Variance; Animals; Animals, Newborn; Antioxidants; Benzothiazoles; Body Weight; Cell Line, Transformed; Disease Models, Animal; Dose-Response Relationship, Drug; Glucose; Guaiacol; Hippocampus; Hypoxia; Interleukin-6; Ischemic Attack, Transient; Lignans; Lipid Peroxidation; Microglia; Nitrates; Nitrites; Organ Culture Techniques; Peroxidase; Phenethylamines; Polysaccharides; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfonic Acids; Time Factors; Tumor Necrosis Factor-alpha

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