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

Abstract

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.

Figure 1

Effect of low-dose red wine or ethanol consumption on brain injury following a 2-hour MCAO/24-hour reperfusion. (A) Representative brain sections stained with TTC. (B) Total infarct volume. (C) Neurological score. Values are means ± SE for 4 rats in each group. *P < 0.05 vs. Control.

Figure 2

Effect of low-dose red wine or ethanol consumption on expression of ICAM-1 (A), VCAM-1 (B), E-selectin (C) and P-selectin (D) following a 2-hour MCAO/24-hour reperfusion. Values are means ± SE for 4 rats in each group. Data shown are representative blots for each group. Ethanol and red wine groups were run on separate gels with two samples from control group as internal control. *P < 0.05 vs Control Baseline. ^#P < 0.05 vs Control I/R. **P < 0.05 vs Red Wine Baseline.

Figure 3

Effect of low-dose red wine or ethanol consumption on expression of IL-1 (A), L-selectin (B), CCL3 (C), MIP-3α (D) and TIMP-1 (E) following a 2-hour MCAO/24-hour reperfusion. Values are means ± SE for 4 rats in each group. *P < 0.05 vs Control Baseline. ^#P < 0.05 vs Control I/R. **P < 0.05 vs Ethanol Baseline. ***P < 0.05 vs Red Wine Baseline.

Figure 4

Effect of low-dose red wine or ethanol consumption on neutrophil infiltration following a 2-hour MCAO/24-hour reperfusion. (A) Representative MPO staining. (B) Values are mean ± SE for 4 rats in each group. *P < 0.05 vs. control.

Figure 5

Effect of low-dose red wine or ethanol consumption on microglial activation following a 2-hour MCAO/24-hour reperfusion. (A) Representative lba1 staining. (B) Values are mean ± SE for 4 rats in each group. *P < 0.05 vs. control.