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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological studies indicate that the intake of flavonoids is inversely associated with risk of stroke, cardiovascular diseases and cancer. Isoliquiritigenin (ISL), a flavonoid constituent in the root of Glycyrrhiza glabra, is known to have vasorelaxant effect, antioxidant, anti-platelet, anti-tumor, anti-allergic, antiviral activities and estrogenic properties. However, there is no report on the effects of ISL in cerebral ischemia. Evidence demonstrate that the impaired energy metabolism and the excessive generation of reactive oxygen radicals (ROS) contribute to the brain injury associated with cerebral ischemia. In the present study, the protective effects of ISL were investigated in transient middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia-reperfusion injury in rats. Male Sprague-Dawley rats were divided into five groups: sham-operated group, vehicle-pretreated group, and three ISL-pretreated groups (5, 10 and 20 mg kg(-1), i.g.). ISL were administered once a day, for 7 days prior to ischemia. The rats were subjected to 2 h right MCAO via the intraluminal filament technique and 22 h reperfusion. Pretreatment with ISL significantly reduced the cerebral infarct volume and edema and produced significant reduction in neurological deficits. In this study, in order to clarify the mechanism of ISL's protection against cerebral ischemia damage, cerebral energy metabolism, brain Na+K+ATPase activity, malondialdehyde (MDA) content and antioxidant enzyme activities were measured. ISL pretreatment increased the brain ATP content, energy charge (EC) and total adenine nucleotides (TAN) in a dose-dependent manner. The brain Na+K+ATPase activity was protected significantly by pretreatment of ISL for 7 days. Pretreatment with ISL significantly inhibited the increases of brain MDA content and prevented the activities of brain superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) from declines caused by cerebral ischemia-reperfusion. All these findings indicate that ISL has the protective potential against cerebral ischemia injury and its protective effects may be due to the amelioration of cerebral energy metabolism and its antioxidant property.
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PMID:Protective effects of isoliquiritigenin in transient middle cerebral artery occlusion-induced focal cerebral ischemia in rats. 1645 97

As part of a basic study on the prevention of cerebral injury, ajoene (0.5 mg/d) and oil-macerated garlic extract (OMGE, containing 0.5 mg ajoene/d) were administrated to stroke-prone spontaneously hypertensive rats (SHRSP) among 8 weeks from 9 weeks of age. In the control group, 3 of 10 rats died (30%), whereas all SHRSP treated by ajoene or OMGE survived. Our results suggested that ajoene and OMGE-treatment reduced the mortality and cerebral injury in SHRSP. The levels of thiobarbituric acid reactive substance (TBARS) and the enzymatic activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) in the serum of stroke stage of SHRSP were measured. The results obtained were as follows; the TBARS level of the ajoene and OMGE-treated groups were lower than those of control groups. On the other hand, the GSH-Px and SOD activities of the ajoene and OMGE-treated groups were higher. Our results suggested that ajoene and OMGE were capable of having prophylactic effects on cerebral injury in SHRSP.
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PMID:Prophylactic effects of ajoene on cerebral injury in stroke-prone spontaneously hypertensive rats (SHRSP). 1659 90

Edaravone, a potent antioxidant, is currently being used in the management of acute ischemic stroke in relatively high-aged populations. Mitogen activated protein kinase (MAPK) pathways have been shown to play important roles in neuronal cell death. We examined the role of MAPK pathways and the effect of treatment with edaravone in the brain after cerebral ischemia-reperfusion (I/R) injury in a bilateral carotid artery occlusion (BCAO) model with ischemia for 85 min followed by reperfusion for 45 min in aged rats. Western immunoblotting, immunostaining, enzyme-linked immunosorbent assay (ELISA), spectrophotometry, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) and triphenyl tetrazolium chloride (TTC) staining were performed to evaluate various proteins in the homogenate, c-Jun NH2-terminal kinase (JNK) in the tissue sections, protein carbonyl, glutathione peroxidase (GSHPx), apoptosis and infarct size, respectively. Our results showed that I/R injury resulted in a reduction of GSHPx, but protein carbonyl content and inducible nitric oxide synthase were increased. The activation of JNK and its downstream molecule c-Jun was significantly increased after injury, whereas the activities of p38 MAPK and extracellular-regulated kinase 1/2 were slightly but not significantly increased. Edaravone (3 mg/kg, i.v.) treatment significantly reduced all of these changes. Our findings suggest that the JNK pathway differentially mediates neuronal injury in aged rats after BCAO, and edaravone treatment significantly reduces the neuronal damage after I/R injury by inhibiting oxidative stress and the JNK-c-Jun pathway with concomitant inhibition of overall MAPK activity in the brains of aged rats.
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PMID:Edaravone inhibits JNK-c-Jun pathway and restores anti-oxidative defense after ischemia-reperfusion injury in aged rats. 1659 5

The purpose of the present study was to assess the therapeutic effect of hypothermic retrograde jugular vein flush (HRJVF) on heatstroke. HRJVF was accomplished by infusion of 4 degrees C isotonic sodium chloride solution via the external jugular vein (1.7 mL/100 g of body weight over 5 min). Immediately after the onset of heatstroke, anesthetized rats were divided into 2 major groups and given the following: 36 degrees C or 4 degrees C isotonic sodium chloride solution, i.v. They were exposed to ambient temperature of 43 degrees C to induce heatstroke. Another group of rats was exposed to room temperature (24 degrees C) and used as normothermic controls. When the 36 degrees C saline-treated rats underwent heat exposure, their survival time values were found to be 23 to 28 min. Immediately after the onset of heatstroke, resuscitation with an i.v. dose of 4 degrees C saline significantly improved survival during heatstroke (208-252 min). All heat-stressed animals displayed systemic inflammation and activated coagulation, evidenced by increased tumor necrosis factor alpha, prothrombin time, activated partial thromboplastin time, and d-dimer, and decreased platelet count and protein C. Biochemical markers evidenced cellular ischemia and injury/dysfunction: plasma levels of blood urea nitrogen, creatinine, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and alkaline phosphatase; and striatal levels of glycerol, glutamate, and lactate/pyruvate; dihydroxy benzoic acid, lipid peroxidation, oxidized-form glutathione reduced-form glutathione, dopamine, and serotonin were all elevated during heatstroke. Core and brain temperatures and intracranial pressure were also increased during heatstroke. In contrast, the values of mean arterial pressure, cerebral perfusion pressure, and striatal levels of local blood flow, partial pressure of oxygen, superoxide dismutase, catalase, glutathione peroxidase, and glutathions reductase activities were all significantly lower during heatstroke. The circulatory dysfunction, systemic inflammation, hypercoagulable state, and cerebral oxidative stress, ischemia, and damage during heatstroke were all significantly suppressed by HRJVF. These findings demonstrate that brain cooling caused by HRJVF therapy may resuscitate persons who had a stroke by attenuating cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heatstroke.
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PMID:Brain cooling causes attenuation of cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heatstroke. 1687 31

Shengmai San (SMS) is a traditional Chinese medicine (TCM) comprising three different herbal components, Panax ginseng, Ohiopogon japonicus and Fructus schisandrae and has been used for treating coronary heart diseases (Bensky and Barolet, 1990). It was shown that SMS effectively prevented cerebral oxidative injury in rats when it administered into the duodenum before cerebral ischemia-reperfusion. In the present study, we examined whether post-ischemic administration of SMS can ameliorate cerebral ischemia-reperfusion injury in rats as well. Results showed that SMS injected immediately after ischemia also prevented the ischemia-reperfusion injury, when the effect was evaluated by the formation of protein carbonyl and thiobarbituric acid reactive substance (TBARS), and the loss of glutathione peroxidase (GPX). The preventative potential of SMS was decreased rapidly dependent on the time lag until SMS was injected after ischemia. However, it was noted that intravenously administered SMS protected the oxidative injury approximately 30% even after 60 min of reperfusion in terms of protein carbonyl formation. It is thus suggested that SMS injection might be useful for preventing the progression of injury in cerebral infarction after stroke.
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PMID:Prevention of cerebral oxidative injury by post-ischemic intravenous administration of Shengmai San. 1688 30

Plasma levels of the oxidants xanthine oxidase, nitric oxide and malondialdehyde and the antioxidants superoxide dismutase, glutathione peroxidase and glutathione reductase, together with total superoxide scavenger activity and non-enzymatic superoxide scavenger activity, were determined in 19 patients with acute ischaemic stroke and 20 controls. Compared with controls, superoxide dismutase, total superoxide scavenger activity, glutathione peroxidase and glutathione reductase activities were significantly lower, and nitric oxide and malondialdehyde levels significantly higher, in acute stroke patients. Xanthine oxidase showed a slight but non-significant increase in stroke patients compared with controls. There was no significant difference in non-enzymatic superoxide scavenger activity between the two groups. There was a positive correlation between glutathione reductase levels and Glasgow Coma Scale scores, and a negative correlation between malondialdehyde levels and non-enzymatic superoxide scavenger activity. These findings suggest that oxidative stress in patients with acute ischaemic stroke may be the result of an imbalance in oxidant/antioxidant homeostasis.
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PMID:Plasma oxidants and antioxidants in acute ischaemic stroke. 1698 98

Recent findings suggest that erythrocyte intracellular glutathione peroxidase-1 (GPX-1) activity is related inversely to future cardiovascular events. The aim of this study is to evaluate the association of GPX-1 activity to extent of atherosclerosis, as well as its long-term prognosis in context with atherosclerotic burden. In a prospective study, we included 508 patients before coronary angiography. Atherosclerosis of carotid and leg arteries was documented using sonographic methods. Blood samples were drawn after an overnight fasting period, and GPX-1 activity was determined in washed erythrocytes. GPX-1 activity tended to decrease with increasing numbers of atherosclerotic vascular beds, so that patients without clinically relevant atherosclerosis had GPX-1 activity of 49.3 U/g hemoglobin compared with 46.0 U/g hemoglobin in patients with prevalent atherosclerosis in all 3 vascular beds (p = NS). Follow-up data (median 6.5 years) were available for 504 patients (99.2%), and 96 patients (19.0%) experienced cardiovascular events (cardiovascular death, infarction, and stroke). The event rate was inversely associated with level of GPX-1 activity divided into tertiles (hazard ratio 2.3, 95% confidence interval 1.4 to 4.0 for lowest vs highest tertile of GPX-1 activity, p = 0.002, adjusted). The highest event rate was found in persons with low GPX-1 activity and multivascular atherosclerosis (event rate 36.9%, p <0.0001). In conclusion, decreased red blood cell GPX-1 activity is associated with increased cardiovascular risk according to the extent of atherosclerosis.
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PMID:Glutathione peroxidase-1 activity, atherosclerotic burden, and cardiovascular prognosis. 1735 Mar 71

In dyscirculatory encephalopathy and moderate ischemic stroke there are single changes of components of glutathione metabolism. In moderate and severe ischemic stroke frequent and considerable changes have been revealed. Changes in hemorrhagic stroke are also expressed. An increase of activities of glutathione peroxidase and glutathione transferase is the most typical, rarely the increase of glutathione reductase and GSH is observed. The increase of enzymes activity was absent at the delayed oneset of treatment (more than 3 days) and in severe cases patients who died later. Glutathione system is important in the tolerance to cerebral ischemia.
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PMID:[Glutathione system in erythrocytes and blood plasma in strokes and dyscirculatory encephalopathy]. 1803 26

This review focuses on the morphological features of atherosclerosis and the involvement of oxidative stress in the initiation and progression of this disease. There is now consensus that atherosclerosis represents a state of heightened oxidative stress characterized by lipid and protein in the vascular wall. Reactive oxygen species (ROS) are key mediators of signaling pathways that underlie vascular inflammation in atherogenesis, starting from the initiation of fatty streak development, through lesion progression, to ultimate plaque rupture. Plaque rupture and thrombosis result in the acute clinical complications of myocardial infarction and stroke. Many data support the notion that ROS released from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, myeloperoxidase (MPO), xanthine oxidase (XO), lipoxygenase (LO), nitric oxide synthase (NOS) and enhanced ROS production from dysfunctional mitochondrial respiratory chain, indeed, have a causatory role in atherosclerosis and other vascular diseases. Moreover, oxidative modifications in the arterial wall can contribute to the arteriosclerosis when the balance between oxidants and antioxidants shifts in favour of the former. Therefore, it is important to consider sources of oxidants in the context of available antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase and transferases thiol-disulfide oxidoreductases and peroxiredoxins. Here, we review also the mechanisms in which they are involved in order to accelerate the pace of the discovery and facilitate development of novel therapeutic approaches.
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PMID:Atherosclerosis and oxidative stress. 1807 94

Several reports suggest that consumption of red wine is associated with a lower risk of stroke. We investigated the chronic effect of red wine polyphenols (RWP) on the functional and structural characteristics of cerebral arterioles in chronic hypertension, which is an important risk factor of stroke. Spontaneous hypertensive rats (SHR) were treated with RWP extract (100 mg/kg/day in drinking water) for 10 weeks. We measured the effect of agonist- and hypotension-induced changes in internal diameter of cerebral arterioles using an open cranial window technique. Wall mechanical parameters were determined in deactivated cerebral arterioles. The activity of antioxidant enzymes in plasma was determined. Adenosine diphosphate-induced vasodilatation was decreased by 48% in SHR and normalized in SHR treated with RWP. RWP had no effect on hypotension-induced dilatation. RWP decreased the wall thickness/external diameter ratio by 13% and significantly shifted the stress-strain relationship of the arteriole wall to the left. There was a decrease in glutathione-S-transferase and glutathione peroxidase after treatment of RWP in SHR. In summary, chronic oral administration of RWP to SHR improved endothelium-dependent dilatation, normalized wall stress and diameter, and altered the systemic antioxidant state. These effects of RWP could be useful in the prevention of stroke in hypertensive patients.
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PMID:Impact of chronic treatment with red wine polyphenols (RWP) on cerebral arterioles in the spontaneous hypertensive rat. 1835 96


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