4-hydroxy-2-nonenal and Brain-Infarction

This study aims to determine if erythromycin provides neuroprotective effects against ischemic injury following permanent focal cerebral ischemia.. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO). Each animal received a single subcutaneous injection of erythromycin lactobionate (EM, 50 mg/kg) or vehicle immediately after ischemia. The infarct volume, edema index and neurological performance were evaluated at 24 and 72 h after MCAO. The cerebral blood flow (CBF) was measured with an MRI system at 30 min after MCAO. TUNEL staining and immunohistochemical analyses for oxidative stress (4-HNE, 8-OHdG) and inflammation (Iba-1, TNF-α) in the cortex were conducted at 24 and 72 h after MCAO.. The CBF did not differ between the EM-treated and vehicle-treated groups. The EM treatment significantly reduced the infarct volume (p < 0.01) at 24 and 72 h after MCAO and significantly reduced the edema index (p < 0.01) at 24 h. The EM treatment significantly improved the neurological deficit scores (p < 0.05) at 24 and 72 h. EM also significantly suppressed the accumulation of 4-HNE (p < 0.01) and 8-OHdG (p < 0.01) and markedly reduced Iba-1 (p < 0.01) and TNF-α expression (p < 0.05) at both time points. The EM treatment significantly reduced TUNEL-positive cells (p < 0.01) at both time points.. These findings suggest that EM can protect against the neuronal damage caused by cerebral ischemia by alleviating inflammation and reducing oxidant stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Blood Pressure; Body Temperature; Brain Edema; Brain Infarction; Brain Injuries; Calcium-Binding Proteins; Cerebrovascular Circulation; Deoxyguanosine; Disease Models, Animal; Erythromycin; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Magnetic Resonance Imaging; Microfilament Proteins; Neuroprotective Agents; Rats; Statistics, Nonparametric; Time Factors; Tumor Necrosis Factor-alpha

Long-chain n-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), have been shown to reduce ischemic neuronal injury. We investigated the effects of ethyl-EPA (EPA-E) on ischemic brain damage using a rat transient focal cerebral ischemia model. Male Sprague-Dawley rats (n=105) were subjected to 90 min of focal cerebral ischemia. EPA-E (100mg/kg/day) or vehicle was administered once a day for 3, 5 or 7 days prior to ischemia. Different withdrawal intervals of 3, 5, and 7 days prior to ischemia following 7-day pretreatment with EPA-E or vehicle were also examined. In addition, post-ischemic administration of EPA-E was investigated. Pretreatment with EPA-E for 7 and 5 days, but not 3 days, showed significant infarct volume reduction and neurological improvements when compared with vehicle pretreatment. In addition, withdrawal of EPA-E administration for 3 days, but not 5 and 7 days, also demonstrated significant infarct volume reduction and neurological improvements when compared with vehicle treatment. Post-ischemic treatment of EPA-E did not show any neuroprotection. Immunohistochemistry revealed that 7-day pretreatment with EPA-E significantly reduced cortical expression of 8-hydroxydeoxyguanosine (maker for oxidative DNA damage), 4-hydroxy-2-nonenal (maker for lipid peroxidation), phosphorylated adducin (marker for Rho-kinase activation) and von Willebrand factor (endothelial marker) when compared with vehicle pretreatment. In addition, phosphorylated adducin expression co-localized with von Willebrand factor immunoreactivity. The present study established the neuroprotective effect of EPA-E on ischemic brain damage following transient focal cerebral ischemia in rats, which may be involved in the suppression of oxidative stress and endothelial Rho-kinase activation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Analysis of Variance; Animals; Brain Infarction; Brain Injuries; Deoxyguanosine; Disease Models, Animal; Dose-Response Relationship, Drug; Eicosapentaenoic Acid; Ischemic Attack, Transient; Magnetic Resonance Imaging; Male; Neurologic Examination; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Time Factors; von Willebrand Factor

Despite extensive research to develop an effective neuroprotective strategy for the treatment of ischemic stroke, therapeutic options remain limited. Although caspase-dependent death is thought to play a prominent role in neuronal injury, direct evidence of active initiator caspases in stroke and the functional relevance of this activity have not previously been shown. Using an unbiased caspase-trapping technique in vivo, we isolated active caspase-9 from ischemic rat brain within 1 h of reperfusion. Pathogenic relevance of active caspase-9 was shown by intranasal delivery of a novel cell membrane-penetrating highly specific inhibitor for active caspase-9 at 4 h postreperfusion (hpr). Caspase-9 inhibition provided neurofunctional protection and established caspase-6 as its downstream target. The temporal and spatial pattern of expression demonstrates that neuronal caspase-9 activity induces caspase-6 activation, mediating axonal loss by 12 hpr followed by neuronal death within 24 hpr. Collectively, these results support selective inhibition of these specific caspases as an effective therapeutic strategy for stroke.

Topics: Administration, Intranasal; Aldehydes; Animals; Brain Infarction; Caspase 6; Caspase 9; Caspase Inhibitors; Cysteine Proteinase Inhibitors; Disease Models, Animal; Enzyme Inhibitors; Hippocampus; Humans; In Vitro Techniques; Infarction, Middle Cerebral Artery; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nerve Tissue Proteins; Nervous System Diseases; Neurons; PTEN Phosphohydrolase; Rats; Rats, Wistar; Time Factors

(2S)-1-(4-Amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl) phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate (SUN N8075) is a novel antioxidant with neuroprotective properties. We examined whether SUN N8075 inhibited the neuronal damage resulting from permanent focal cerebral ischemia, and examined its neuroprotective properties in vivo and in vitro mechanism. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion in mice, and the resulting infarction, brain swelling, and neurological deficits were evaluated after 24 h or 72 h. Brain damage was assessed histochemically using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining and antibody recognizing 4-hydroxynonenal histidine adduct (4-HNE). In the in vitro study, we examined the effects of SUN N8075 on 1) lipid peroxidation in mouse brain homogenates and 2) cell viability and caspase-3 protease activity under a hypoxic insult or FeSO(4) in rat cultured cerebrocortical neurons. SUN N8075 administered either 10 min before or at 1 h after the occlusion reduced both infarction size and neurological deficits. SUN N8075 reduced brain swelling when administered 10 min before, 1 h, or 3 h after occlusion. Furthermore, only pretreatment (administered 10 min before) decreased infarct volume and brain swelling at 72 h after middle cerebral artery occlusion. SUN N8075 reduced the number of TUNEL-positive cells and decreased the level of oxidative damage, as assessed by immunopositive staining to 4-HNE. SUN N8075 inhibited lipid peroxidation, leakage of lactate dehydrogenase, caspase-3 activation induced by in vitro hypoxia, and the neuronal damage induced by in vitro FeSO(4) exposure. These findings indicate that SUN N8075 has neuroprotective effects against acute ischemic neuronal damage in mice and may prove promising as a therapeutic drug for stroke.

Topics: Aldehydes; Analysis of Variance; Aniline Compounds; Animals; Brain Infarction; Brain Ischemia; Caspase 3; Cell Count; Cell Death; Cells, Cultured; Disease Models, Animal; Dose-Response Relationship, Drug; In Situ Nick-End Labeling; In Vitro Techniques; Iron; Lipid Peroxidation; Male; Mice; Neurons; Neuroprotective Agents; Piperazines; Time Factors

Free radical-induced oxidative damages of macromolecules and cell death are important factors in the pathogenesis of ischemia/reperfusion brain injury. In the present study, an investigation as to whether green tea extract reduces ischemia/reperfusion-induced brain injury in Mongolian gerbils was conducted. The effect of green tea on the ischemia/reperfusion-induced production of hydrogen peroxide, lipid peroxidation and oxidative DNA damage (formation of 8-hydroxydeoxyguanosine), and cell death in addition to locomotor activity was studied. Two doses (0.5 or 2%) of green tea extract were added into the drinking water and to be accessed by animals ad libitum for 3 weeks prior to the induction of ischemia. A global ischemia was induced by the bilateral occlusion of the common carotid arteries for 5 min. Reperfusion was achieved by releasing the occlusion and restoring blood circulation for 48 h. The infarction volumes were 112+/-31 mm(3) and 76+/-11 mm(3) in the 0.5 and 2% green tea pretreated animals compared to 189+/-12 mm(3) in the ischemia/reperfusion animals. Green tea extract also reduced the levels of ischemia/reperfusion-induced hydrogen peroxide (from 1470+/-170 to 1034+/-46 and 555+/-30 nmole/mg protein), lipid peroxidation products (from 1410+/-210 to 930+/-40 and 330+/-20 nmole/mg protein) and 8-oxodG (from 3.9+/-0.1 to 2.8+/-0.3 and1.9+/-0.3 ng/microg DNA, x10(-2)) by pretreatment of 0.5 or 2% green tea for 3 weeks, respectively. Moreover, green tea also reduced the number of ischemia/reperfusion-induced apoptotic cells (from 59+/-12 to 37+/-8, 15+/-11 apoptotic cells/high power field in the striatum region) and locomotor activity (from 15140+/-2940 to 3900+/-600 and 4100+/-1200). This study therefore suggests that green tea may be a useful agent for the prevention of cerebral ischemia damage.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Apoptosis; Beverages; Brain; Brain Infarction; Cerebrovascular Circulation; Cysteine Proteinase Inhibitors; Deoxyguanosine; DNA; Female; Gerbillinae; Hydrogen Peroxide; Ischemic Attack, Transient; Lipid Peroxidation; Malondialdehyde; Motor Activity; Neurons; Oxidative Stress; Plant Extracts; Reperfusion Injury