Combinatorial Effect of Probucol and Cilostazol in Focal Ischemic Mice with Hypercholesterolemia

Abstract

Hypercholesterolemia may increase stroke risk by accelerating atherosclerosis, narrowing the luminal diameter in cerebral vessels, and disrupting both vascular endothelial and smooth muscle function. In the present study, we investigated the beneficial effects of combinatorial therapy with probucol and cilostazol on focal cerebral ischemia with hypercholesterolemia. Apolipoprotein E (ApoE) knockout (KO) mice were fed a high-fat diet with or without 0.5% probucol and/or 0.2% cilostazol for 10 weeks. Probucol alone and probucol and cilostazol significantly decreased total, low-density lipoprotein, and high-density lipoprotein cholesterol, whereas cilostazol did not affect the plasma cholesterol levels in ApoE KO mice. Administration of probucol alone and cilostazol alone significantly decreased atherosclerotic lesion area in the aorta, with a significant decrease evident using combinatorial administration. Middle cerebral artery occlusion resulted in significantly larger infarct volumes in ApoE KO mice fed 10 weeks of high-fat diet compared with those in ApoE KO mice fed a regular diet. The infarct volume was reduced significantly using probucol alone or cilostazol alone and even was reduced significantly by their combinatorial administration. Consistent with a larger infarct size, the combinatorial therapy prominently improved neurological function. The combinatorial administration increased cerebral blood flow during ischemia. Expression of endothelial nitric oxide synthase and adiponectin in the cortex were decreased by high-fat diet but were elevated by combinatorial treatment. Adiponectin expression colocalized within the cerebral vascular endothelium. The data suggest that the combination of probucol and cilostazol prevents cerebrovascular damage in focal cerebral ischemic mice with hypercholesterolemia by up-regulation of endothelial nitric oxide synthase and adiponectin.

Probucol inhibits LPS-induced microglia activation and ameliorates brain ischemic injury in normal and hyperlipidemic mice

“…Probucol has also been demonstrated to prevent atherogenesis via the induction of the anti-inflammatory enzyme heme oxygenase-1 independently of lipid oxidation and cholesterol reduction in models of atherosclerosis, restenosis and type 2 diabetes [32] . Most recently, we found that probucol and probucol plus cilostazol decrease microglial activation in the ischemic cortices of hyperlipidemic mice [8,9] . Therefore, we investigated the effects of probucol on the expression of inflammation-related genes in LPS-stimulated microglia.…”

“…Therefore, the identification of novel agents that regulate neuroinflammation by inhibiting microglial activation is regarded as a significant strategy for the treatment of ischemic stroke. Several animal studies have demonstrated that probucol exerts beneficial effects via anti-inflammation mechanisms in aging mice [19,20] , focal cerebral ischemic mice [8,9] , heart failure rats [21,22] , diabetic rabbits [23] and atherosclerotic rabbits [24] . Probucol has also been demonstrated to prevent atherogenesis via the induction of the anti-inflammatory enzyme heme oxygenase-1 independently of lipid oxidation and cholesterol reduction in models of atherosclerosis, restenosis and type 2 diabetes [32] .…”

“…It is well known that hyperlipidemia induces inflammation in the brain [5][6][7] and that hyperlipidemia exacerbates the ischemic brain damage that is linked to neuroinflammation [8,9] . There is also considerable evidence that hyperlipidemia contributes to the disruption of cerebrovascular reflexes and the breakdown of the blood-brain barrier [45,46] .…”

“…Probucol also dramatically retards atherosclerosis in hyperlipidemic animals [16][17][18] . Furthermore, probucol has been demonstrated to posse the capacity to attenuate inflammation in animal models of aging [19,20] , focal cerebral ischemia [8,9] and ischemic myocardial injury [21,22] , as well as in diabetic [23] and atherosclerotic rabbits [24] . Based on these reports, probucol may be useful for the treatment of ischemic stroke with hyperlipidemia via reductions in cholesterol and neuroinflammation.…”

“…Although hyperlipidemia is not a direct predictor of stroke, half of stroke patients have hyperlipidemia [4] . Hyperlipidemia induces inflammation in the brain [5][6][7] and exacerbates ischemic brain damage [8,9] . Therefore, decreasing cholesterol and inflammation may be an effective therapeutic strategy for reducing the influences of both hyperlipidemia and ischemic stroke.…”