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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antioxidants have been the focus of studies for developing neuroprotective agents to be used in the therapy for stroke, which is an acute and progressive neurodegenerative disorder and is the second leading cause of death throughout the world. In fact, many herbal antioxidants have been developed in in vitro and in vivo experiments and some of these have been tested in clinical studies of stroke. Embelia ribes have been reported to have antioxidant and antidiabetic effects. In addition to these effects, this study was designed to investigate the neuroprotective effect of ethanolic extract of E. ribes Burm fruits on middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia in rats. Male Wistar albino rats were fed ethanolic E. ribes extract (100 and 200 mg/kg body weight; p.o.) for 30 days. After 30 days of feeding, all animals were anaesthetized with chloral hydrate (400 mg/kg, i.p.). The right middle cerebral artery was occluded with a 4-0 suture for 2 h. The suture was removed after 2 h to allow reperfusion injury. Ischemia followed by reperfusion in ischemic group rats significantly (P < 0.001) reduced the grip strength activity and non-enzymatic (reduced glutathione, GSH) and enzymatic [glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)] antioxidant levels in hippocampus and frontal cortex compared to sham-operated rats. Further, serum lactate dehydrogenase (LDH) and thiobarbituric acid reactive substance (TBARS) levels in hippocampus and frontal cortex were significantly increased in ischemic group compared to sham-operated rats. Furthermore, ethanolic E. ribes extracts pretreatment significantly (P < 0.001) increased the grip strength activity, and GSH, GPx, GR and GST levels in hippocampus and frontal cortex with significant decrease in LDH levels in serum and TBARS levels in hippocampus and frontal cortex compared to MCAO + vehicle group rats. The data from this study suggest that chronic treatment with ethanolic E. ribes extract enhances the antioxidant defense against MCAO- induced focal cerebral ischemia in rats and exhibits neuroprotective activity.
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PMID:Evaluation of antioxidant and neuroprotective effect of ethanolic extract of Embelia ribes Burm in focal cerebral ischemia/reperfusion-induced oxidative stress in rats. 1848 49

Hibernating mammals exhibit oxidative stress resistance in brain, liver and other tissues. In many animals, cellular oxidative stress resistance is associated with enhanced expression of intracellular antioxidant enzymes. Intracellular antioxidant capacity may be upregulated during hibernation to protect against oxidative damage associated with the ischemia-reperfusion that occurs during transitions between torpor and arousal. We tested the hypothesis that the 13-lined ground squirrel (Spermophilus tridecemlineatus), upregulates intracellular antioxidant enzymes in major oxidative tissues during hibernation. The two major intracellular isoforms of superoxide dismutase (MnSOD and CuZnSOD), which catalyze the first step in superoxide detoxification, were quantified in heart, brain and liver tissue using immunodetection and an in-gel activity assay. However, no differences in SOD protein expression or activity were found between active and hibernating squirrels. Measurements of glutathione peroxidase and glutathione reductase, which catalyze hydrogen peroxide removal, were not broadly upregulated during hibernation. The activity of catalase, which catalyzes an alternative hydrogen peroxide detoxification pathway, was higher in heart and brain of torpid squirrels, but lower in liver. Taken together, these data do not support the hypothesis that hibernation is associated with enhanced oxidative stress resistance due to an upregulation of intracellular antioxidant enzymes in the major oxidative tissues.
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PMID:Intracellular antioxidant enzymes are not globally upregulated during hibernation in the major oxidative tissues of the 13-lined ground squirrel Spermophilus tridecemlineatus. 1894 23

The primary cause of morbidity and mortality in renal transplantation is cardiovascular disease. Increased oxidative stress implies a greater degree of atherogenesis in these patients. N-acetylcysteine (NAC) which has a thiol group that is the source of l-cysteine and reduced glutathione, acts against atherosclerosis via a decrease in apoptosis, vasoconstriction, and endothelial dysfunction. Experimental models have examined the antioxidant effects of NAC during and after ischemia-reperfusion, but few studies have shown an effect in renal transplantation in human beings. In 8 months, we studied the effect of NAC treatment on oxidative stress, lipids, and renal function in 25 patients with stable renal function and no diabetes after transplantation. Data were collected on oxidative parameters: malondialdehyde, glutathione peroxidase, catalase, superoxide dismutase, glutathione reductase, lipid profile, and renal function (creatinine concentration, Cockroft-Gault formula, and Modified Diet in Renal Disease study). There were no significant differences in oxidative profile before and after treatment with NAC. The mean serum high-density lipoprotein cholesterol fraction increased after treatment and showed a significant positive correlation with glutathione peroxidase (r = 0.495). Serum creatinine concentration decreased, and Cockroft-Gault and Modified Diet in Renal Disease study estimates of renal function increased in the treatment period. In conclusion, NAC treatment in patients with stable renal function after transplantation increased high-density lipoprotein cholesterol and antioxidant molecules in relation to glutathione peroxidase, with a positive influence on renal function.
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PMID:Treatment with N-acetylcysteine in stable renal transplantation. 1901 Jan 40

Recent studies suggest that intermittent and prolonged normobaric hyperoxia results in ischemic tolerance to reduce ischemia brain injury. In this research attempts were made to see the changes in antioxidant enzyme activities following prolonged and intermittent normobaric hyperoxia preconditioning. Rats were divided into four experimental groups, each of 21 animals. The first two were exposed to 95% inspired normobaric hyperoxia for 4 h/day for 6 consecutive days (intermittent normobaric hyperoxia) or for 24 h continuous (prolonged normobaric hyperoxia). The second two groups acted as controls, and were exposed to 21% oxygen in the same chamber. Each main group was subdivided to middle cerebral artery occlusion-operated, sham-operated (without middle cerebral artery occlusion), and intact (without any surgery) subgroups. After 24 h, middle cerebral artery occlusion-operated subgroups were subjected to 60 min of right middle cerebral artery occlusion. After 24 h reperfusion, neurologic deficit score, infarct volume were measured in middle cerebral artery occlusion-operated subgroups. Antioxidant enzyme activities were assessed in sham-operated and intact subgroups. Preconditioning with prolonged and intermittent normobaric hyperoxia decreased neurologic deficit score and infarct volume, and increased antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) significantly. Although further studies are needed to clarify the mechanisms of ischemic tolerance, the intermittent and prolonged normobaric hyperoxia seems to partly exert their effects via increase antioxidant enzymes activities.
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PMID:In vivo normobaric hyperoxia preconditioning induces different degrees of antioxidant enzymes activities in rat brain tissue. 1930 5

Myocardial reperfusion is believed to be associated with free radical injury. The present study evaluates the effect of aqueous extract of D. gangeticum (DG) on lipid peroxides and antioxidants in ischemic reperfused (IR) Wistar albino male rats. Significant elevation in lipid peroxide products (thiobarbituric acid reactive substances) and decreased activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) were observed in the rat hearts during ischemia reperfusion phase. Pre treatment of rats with aqueous extract of DG orally for 30 days showed significantly improved preservation of antioxidant enzymes and subsequent reduction in lipid peroxidation. But 2,3,5 triphenyl tetrazolium chloride (TTC) stained rat heart did not show much significant antioxidant enzyme activities and lipid peroxidation. On the other hand, TTC unstained rat heart showed significant improvement in the antioxidant activities indicating cardio protective effect of aqueous extract of DG in myocardium affected by ischemia reperfusion insult. The administration of DG to normal rats did not have any significant effect on any of the parameter studied. These results indicate that DG improves the antioxidant capacity of heart and attenuate the degree of lipid peroxidation after IR.
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PMID:Administration of aqueous extract of Desmodium gangeticum (L) root protects rat heart against ischemic reperfusion injury induced oxidative stress. 1937 68

Free radical induced neural damage is implicated in cerebral ischemia-reperfusion (IR) injury and antioxidants are reported to have neuroprotective activity. The present study was designed to assess the neuroprotective role of rutin (Vitamin P), and mechanism of action. The middle cerebral artery (MCA) of an adult male Wistar rat was occluded for 2 h and reperfused for 22 h. The administration of rutin (25 mg/kg bwt., orally) once daily for 21 days before middle cerebral artery occlusion (MCAO) showed marked reduction in infarct size, reduced the neurological deficits in terms of behaviors, suppressed neuronal loss and diminished the p53 expression in MCAO rats. A significantly depleted activity of antioxidant enzymes, glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD) and content of glutathione (GSH) in MCAO group were protected significantly in MCAO group pretreated with rutin. Conversely, the elevated level of thiobarbituric acid reactive species (TBARS), H(2)O(2) and protein carbonyl (PC) in MCAO group was attenuated significantly in rutin-pretreated group when compared with MCAO group. These results indicate that rutin attenuates ischemic neural apoptosis by reducing the expression of p53, preventing morphological changes and increasing endogenous antioxidant enzymatic activities. Thus, rutin treatment may represent a novel approach in lowering the risk or improving the function of ischemia-reperfusion brain injury-related disorders.
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PMID:Rutin protects the neural damage induced by transient focal ischemia in rats. 1963 Nov 95

The purpose of this study was to assess the effects of the addition of Nitroglycerin or Nicorandil to University of Wisconsin solution in long-term myocardial preservation. In a model of heterotopic heart transplantation in pigs, the donor heart was preserved for 24 hours by means of continuous perfusion in this solution, in the presence or absence of these drugs. During this period, the oxygenation and pH of the solution were measured, as were lactate concentrations and enzyme release. At regular intervals following reperfusion we measured the concentrations of enzymes, antioxidants, glutathione peroxidase, glutathione reductase, malondialdehyde, endothelin and nitrite, and, two hours later, samples of both ventricles were taken for a morphological study. In the treated groups there was a higher lactate production during preservation and, during reperfusion, the signs of contracture and the elevation of enzyme levels were more marked than in the untreated groups. In contrast, the glutathione reductase concentrations did not decrease during the first phase of reperfusion and were directly correlated with those of antioxidants, endothelin levels increased less than in the untreated groups and, in the case of nitroglycerin, the nitrite concentration was significantly greater than in the remaining groups. We conclude that nitroglycerin and nicorandil improved the oxidative state and endothelial function and did not produce substantial morphological changes, but increased cell necrosis and contracture, possibly due to the duration of ischemia.
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PMID:Supplementation of University of Wisconsin solution with Nitroglycerin and Nicorandil in long-term myocardial preservation: effects on the oxidative state, endothelial function and morphology. 1979 47

Restoration of blood flow to an ischemic brain region is associated with generation of reactive oxygen species (ROS) with consequent reperfusion injury. ROS cause lipid peroxidation, protein oxidation, and DNA damage, all of which are deleterious to cells. So diminishing the production of free radicals and scavenging them may be a successful therapeutic strategy for the protection of brain tissue in cerebral stroke. The present study investigated the neuroprotective effect of sesamin (Sn) to reduce brain injury after middle cerebral artery occlusion (MCAO). The middle cerebral artery (MCA) of adult male Wistar rat was occluded for 2h and reperfused for 22h. Sesamin is the most abundant lignan in sesame seed oil is a potent antioxidant. Sesamin (30 mg/kg) was given orally twice, 30 min before the onset of ischemia and 12h after reperfusion. The initial investigations revealed that sesamin reduced the neurological deficits in terms of behavior and reduced the level of thiobarbituric acid reactive species (TBARS), and protein carbonyl (PC) in the different areas of the brain when compared with the MCAO group. A significantly depleted level of glutathione and its dependent enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]) in MCAO group were protected significantly in MCAO group treated with sesamin. The present study suggests that sesamin may be able to attenuate the ischemic cell death and plays a crucial role as a neuroprotectant in regulating levels of reactive oxygen species in the rat brain. Thus, sesamin may be a potential compound in stroke therapy.
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PMID:Sesamin attenuates behavioral, biochemical and histological alterations induced by reversible middle cerebral artery occlusion in the rats. 1983 51

This study assesses the effects of a vitamin E analogue, Trolox, on the oxidative state, endothelial function and morphology in experimental heart transplantation. Heterotopic heart transplantation was carried out in pigs: untreated after 2 and 24 hours of ischemia and treated with Trolox after 24 hours of ischemia. Prolonged preservation of donor hearts was achieved with continuous perfusion and University of Wisconsin solution, in which acid-base balance and enzymes were determined during the procedure. In recipients, hemodynamic and biochemical parameters were determined at baseline and during reperfusion. Trolox diminished the pH of the preservation solution (p<0.01), the left ventricle of the transplanted heart recovered a systolic pressure equaling that of the 2h group and higher than that of the untreated 24h group (p<0.01), the antioxidant levels were not decreased and the glutathione reductase level was maintained throughout the first part of reperfusion. In this group also there was a direct correlation between the concentration of this enzyme and the antioxidant levels (p<0.001). Although the endothelin concentrations increased, the change was less marked in the Trolox group than in the untreated 24h group (p<0.01). Morphologically, mitochondria and myocardial vessels presented a normal structure in the Trolox group, and interstitial edema, inflammatory infiltrate and contraction bands were less prominent than in the untreated group. All these effects indicate that Trolox protected the transplanted heart, at least partially, against ischemia-reperfusion injury.
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PMID:Vitamin E action on oxidative state, endothelial function and morphology in long-term myocardial preservation. 2023 96

Experimental studies indicate that oxidative stress during and after laparoscopic surgery may cause liver ischemia-reperfusion injury. The aim of the study was to assess the effect of ischemic preconditioning against liver damage during pneumoperitoneum on oxidative stress. Twenty one New Zealand rabbits were divided into three groups of seven animals. Control group (C) rabbits received anesthesia for 60 min alone; 15 mm Hg intra-abdominal pressure with CO2 for 60 min was used in the pneumoperitoneum group animals (PNP); and 15-min insufflation and 10-min desuflation followed by 60-min pneumoperitoneum were used in the ischemic preconditioning group animals (IP). Venous blood samples were obtained at different time points to measure lipid hydroperoxide, glutathione reductase and total antioxidant status as indicators of increased oxidative stress. Aspartate transaminase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were evaluated as indicators of hepatocellular injury. The Kruskal-Wallis and Mann-Whitney U tests were used on statistical analysis. Elevated intra-abdominal pressure was found to produce significant increase in lipid hydroperoxide at the end of pneumoperitoneum and 30 min after desuflation in comparison with pre-insufflation period, and with both C and IP groups at the same time points. Total antioxidant status level decreased significantly in the PNP group at 24 h of desuflation. At 24h of desuflation, the AST, ALT and LDH levels were significantly increased in the PNP group in comparison with the levels measured before induction of anesthesia, and with the C and IP groups. Study results demonstrated that ischemic preconditioning prevented hepatocyte injury and oxidative stress during CO2 pneumoperitoneum.
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PMID:Ischemic preconditioning decreases laparoscopy induced oxidative stress in the liver. 2069 31


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