trans-2-3--4-5--tetrahydroxystilbene and Infarction--Middle-Cerebral-Artery

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.

Topics: Animals; Calcium; Cell Death; Cells, Cultured; Cerebral Cortex; Disease Models, Animal; Dose-Response Relationship, Drug; Excitatory Amino Acid Agonists; Infarction, Middle Cerebral Artery; Male; N-Methylaspartate; Neurons; Neuroprotective Agents; Plant Extracts; Plant Preparations; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Resveratrol; Rhizome; Smilax; Stilbenes; Time Factors

Oxidative stress is one of the major pathological factors in the cascade that leads to cell death in cerebral ischemia. Here, we investigated the neuroprotective effect of a naturally occurring antioxidant, oxyresveratrol, to reduce brain injury after cerebral stroke. We used the transient rat middle cerebral artery occlusion (MCAO) model of brain ischemia to induce a defined brain infarction. Oxyresveratrol was given twice intraperitoneally: immediately after occlusion and at the time of reperfusion. Oxyresveratrol (10 or 20 mg/kg) significantly reduced the brain infarct volume by approximately 54% and 63%, respectively, when compared to vehicle-treated MCAO rats. Also, the neurological deficits as assessed by different scoring methods improved in oxyresveratrol-treated MCAO rats. Histological analysis of apoptotic markers in the ischemic brain area revealed that oxyresveratrol treatment diminished cytochrome c release and decreased caspase-3 activation in MCAO rats. Also, staining for apoptotic DNA showed that the number of apoptotic nuclei in ischemic brain was reduced after oxyresveratrol treatment as compared to the vehicle-treated MCAO rats. This dose-dependent neuroprotective effect of oxyresveratrol in an in vivo stroke model demonstrates that this drug may prove to be beneficial for a therapeutic strategy to limit brain injury in acute brain ischemia.

Topics: Analysis of Variance; Animals; Brain Ischemia; Cell Death; Cerebral Cortex; Cerebral Infarction; Cytochromes c; Disease Models, Animal; DNA Fragmentation; Dose-Response Relationship, Drug; Epoprostenol; Immunohistochemistry; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Male; Microtubule-Associated Proteins; Mitochondria; Neurologic Examination; Neurons; Neuroprotective Agents; Phosphopyruvate Hydratase; Plant Extracts; Rats; Rats, Wistar; Stilbenes; Time Factors