Resveratrol attenuates ischemic brain damage in the delayed phase after stroke and induces messenger RNA and protein express for angiogenic factors.

BACKGROUND: It has been reported recently that resveratrol preconditioning can protect the brain from ischemia-reperfusion injury. However, it was unclear whether resveratrol administration after stroke was beneficial to the delayed phases after focal cerebral ischemia injury. This study investigated the effects and possible protective mechanism of resveratrol on the delayed phase after focal cerebral ischemia injury in mice.
METHODS: Mice were randomly assigned to five groups according to the time of administration of resveratrol. Control group mice received a corresponding volume of saline solution (0.9% NaCl) containing 20% hydroxypropyl h-cyclodextrin by gavage and were exposed to middle cerebral artery (MCA) occlusion and reperfusion injury. The treatment groups received resveratrol (50 mg/kg/d, gavage) until day 7. Ischemia group mice received their first dose 5 minutes before MCA ischemia, reperfusion group mice received their first dose 5 minutes before MCA reperfusion, first-day, group mice received their first dose 24 hours after MCA reperfusion, and third-day group mice received their first dose at 72 hours after MCA reperfusion. Brain injury was evaluated by triphenyltetrazolium chloride staining and neurologic examination 7 days after reperfusion. The microvascular cell number was examined with immunohistochemistry staining. Effect of resveratrol on matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) gene expression was investigated with reverse transcriptase-polymerase chain reaction and Western blot.
RESULTS: The mean neurologic scores and infarct volumes of the ischemia and reperfusion groups were lower than that of the control group at 7 days after MCA reperfusion (P < .05). Immunohistochemistry staining showed significantly less reduction in the number of microvessels in the cortical area of mice of the ischemia and reperfusion groups compared with controls. The ischemic hemispheres of the ischemia and reperfusion groups showed significantly (P < .05) elevated levels of protein of MMP-2 and VEGF.
CONCLUSIONS: Resveratrol administration by gavage provided an important neuroprotective effect on focal cerebral ischemic injury in the delayed phase. The elevated MMP-2 and VEGF levels might be important in the neuroprotective effect of resveratrol administration by inducing angiogenesis.