Minocycline inhibits 5-lipoxygenase activation and brain inflammation after focal cerebral ischemia in rats

Aim: To determine whether the anti-inflammatory effect of minocycline on postis-chemic brain injury is mediated by the inhibition of 5-lipoxygenase (5-LOX) expression and enzymatic activation in rats. Methods: Focal cerebral ischemia was induced for 30 min with middle cerebral artery occlusion, followed by reperfusion. The ischemic injuries, endogenous IgG exudation, the accumulation of neutrophils and macrophage/microglia, and 5-LOX mRNA expression were determined 72 h after reperfusion. 5-LOX metabolites (leukotriene B-4 and cysteinyl leukotrienes) were measured 3 h after reperfusion. Results: Minocycline (22.5 and 45 mg/kg, ip, for 3 d) attenuated ischemic injuries, IgG exudation, and the accumulation of neutrophils and macrophage/microglia 72 h after reperfusion. It also inhibited 5-LOX expression 72 h after reperfusion and the production of leukotrienes 3 h after reperfusion. Conclusion: Minocycline inhibited postischemic brain inflammation, which might be partly mediated by the inhibition of 5-LOX expression and enzymatic activation.