trans-2-3--4-5--tetrahydroxystilbene and Brain-Ischemia

Oxyresveratrol is a potent antioxidant and free-radical scavenger found in mulberry wood (Morus alba L.) with demonstrated protective effects against cerebral ischemia. We analyzed the neuroprotective ability of oxyresveratrol using an in vitro model of stretch-induced trauma in co-cultures of neurons and glia, or by exposing cultures to high levels of glutamate. Cultures were treated with 25 μM, 50 μM or 100 μM oxyresveratrol at the time of injury. Trauma produced marked neuronal death when measured 24 h post-injury, and oxyresveratrol significantly inhibited this death. Microscopic examination of glia suggested signs of toxicity in cultures treated with 100 μM oxyresveratrol, as demonstrated by elevated S-100B protein release and a high proportion of cells with condensed nuclei. Cultures exposed to glutamate (100 μM) for 24 h exhibited ~ 37% neuronal loss, which was not inhibited by oxyresveratrol. These results show that the two pathologies of high glutamate exposure and trauma are differentially affected by oxyresveratrol treatment in vitro. Further studies using oxyresveratrol in trauma models are warranted, as toxicity to glia could be beneficial by inhibiting reactive gliosis, which often occurs after trauma.

Topics: Animals; Antioxidants; Brain Ischemia; Cell Death; Cells, Cultured; Cerebral Cortex; Coculture Techniques; Free Radical Scavengers; Glutamic Acid; Mice; Nerve Growth Factors; Neuroglia; Neurons; Neuroprotective Agents; Plant Extracts; Rats; S100 Calcium Binding Protein beta Subunit; S100 Proteins; Stilbenes; Wounds and Injuries

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