Effect of Low-Dose Alcohol Consumption on Inflammation Following Transient Focal Cerebral Ischemia in Rats

Increasing evidence suggest that low-dose alcohol consumption (LAC) reduces the incidence and improves the functional outcome of ischemic stroke. We determined the influence of LAC on post-ischemic inflammation. Male Sprague-Dawley rats were divided into 3 groups, an ethanol (13.5% alcohol) group, a red wine (Castle Rock Pinot Noir, 13.5% alcohol) group, and a control group. The amount of alcohol given to red wine and ethanol groups was 1.4 g/kg/day. After 8 weeks, the animals were subjected to a 2-hour middle cerebral artery occlusion (MCAO) and sacrificed at 24 hours of reperfusion. Cerebral ischemia/reperfusion (I/R) injury, expression of adhesion molecules and pro- and anti-inflammatory cytokines/chemokines, microglial activation and neutrophil infiltration were evaluated. The total infarct volume and neurological deficits were significantly reduced in red wine- and ethanol-fed rats compared to control rats. Both red wine and ethanol suppressed post-ischemic expression of adhesion molecules and microglial activation. In addition, both red wine and ethanol upregulated expression of tissue inhibitor of metalloproteinases 1 (TIMP-1), downregulated expression of proinflammatory cytokines/chemokines, and significantly alleviated post-ischemic expression of inflammatory mediators. Furthermore, red wine significantly reduced post-ischemic neutrophil infiltration. Our findings suggest that LAC may protect the brain against its I/R injury by suppressing post-ischemic inflammation.