Edaravone ameliorates oxidative stress associated cholinergic dysfunction and limits apoptotic response following focal cerebral ischemia in rat

Therapeutic effect and psychological impact of aspirin plus edaravone on patients with cerebral infarction

BACKGROUND

Cerebral infarction (CI) is characterized by a high prevalence, disability, and mortality. Timely or improper treatment greatly affects patient prognosis.

AIM

To explore the drug efficacy of aspirin plus edaravone and to explore their effect on quality of life (QOL), anxiety and depression in CI patients.

METHODS

We retrospectively analyzed the records of 124 CI patients treated between June 2019 and February 2021 who were assigned to an observation group (OG) (combination therapy of aspirin and edaravone, 65 patients) or a control group (CG) (aspirin monotherapy, 59 patients). The therapeutic effects, pre- and posttreatment National Institutes of Health Stroke Scale (NIHSS) scores, activities of daily living, degree of cognitive impairment, protein levels of glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE) and S-100B, occurrence of adverse reactions, and serum high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6 and tumor necrosis factor (TNF)-α were evaluated, detected and compared between the two groups. Finally, posttreatment QOL, anxiety, and depression were assessed by the Medical Outcomes Study 36- Item Short Form Health Survey Scale, Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS), respectively.

RESULTS

Compared with the CG, the OG had markedly better therapeutic effects, greater improvements in activities of daily living, and better alleviation in cognitive dysfunction after treatment, as well as lower posttreatment NIHSS scores and serum NSE, GFAP, S-100B, hs-CRP, IL-6, and TNF-α levels; the OG was similar to the CG in terms of adverse reactions but was better than the CG in terms of posttreatment QOL; and the OG also had lower SDS and SAS scores than the CG after treatment.

CONCLUSION

Aspirin plus edaravone had a good curative effect on CI. It can reverse cranial nerve damage in patients, improve neurological function and prognosis, and alleviate inflammation, anxiety, and depression; thus, it is considered safe and worthy of clinical application.

Therapeutic management of ischemic stroke

Stroke is the third leading cause of years lost due to disability and the second-largest cause of mortality worldwide. Most occurrences of stroke are brought on by the sudden occlusion of an artery (ischemic stroke), but sometimes they are brought on by bleeding into brain tissue after a blood vessel has ruptured (hemorrhagic stroke). Alteplase is the only therapy the American Food and Drug Administration has approved for ischemic stroke under the thrombolysis category. Current views as well as relevant clinical research on the diagnosis, assessment, and management of stroke are reviewed to suggest appropriate treatment strategies. We searched PubMed and Google Scholar for the available therapeutic regimes in the past, present, and future. With the advent of endovascular therapy in 2015 and intravenous thrombolysis in 1995, the therapeutic options for ischemic stroke have expanded significantly. A novel approach such as vagus nerve stimulation could be life-changing for many stroke patients. Therapeutic hypothermia, the process of cooling the body or brain to preserve organ integrity, is one of the most potent neuroprotectants in both clinical and preclinical contexts. The rapid intervention has been linked to more favorable clinical results. This study focuses on the pathogenesis of stroke, as well as its recent advancements, future prospects, and potential therapeutic targets in stroke therapy.

C60 adduct with L-arginine as a promising nanomaterial for treating cerebral ischemic stroke

The work aimed to investigate the biocompatibility and biological activity of the water-soluble fullerene adduct C60-Arg. It was found that the material is haemocompatible, is not cyto- and genotoxic, possesses pronounced antioxidant activity. Additionally, this paper outlines the direction of application of water-soluble fullerene adducts in the creation of neuroprotectors. It has been suggested that a putative mechanism of the protective action of the C60-Arg adduct is associated with its antioxidant properties, the ability to penetrate the blood-brain barrier, and release nitrogen monoxide as a result of the catabolism of L-arginine residues, which promote vascular relaxation. The action of the C60-Arg adduct was compared with the action of such an antioxidant as Edaravone, which is approved in Japan for the treatment of ischemic and haemorrhagic strokes.

Combination of Radix Astragali and Safflower Promotes Angiogenesis in Rats with Ischemic Stroke via Silencing PTGS2

Promotion of angiogenesis and restoration of the blood flow in the ischemic penumbra is an effective treatment for patients with ischemic stroke (IS). Radix astragali-safflower (AS), a classic herbal pair for accelerating blood circulation and dispersing blood stasis, has been used for thousands of years to treat patients with IS in China. Even so, the mechanism of the treatment of IS by AS is still undecipherable. In the current study, network pharmacology was firstly employed to unveil the mechanism of AS in treating IS, which showed that AS might promote angiogenesis associated with PTGS2 silence. Middle cerebral artery occlusion/reperfusion (MCAO/R) model rats were then used as the experimental animals to verify the prediction result. The experimental results revealed that treatment with AS improved the cerebral infarct volume, neurological damage, and cerebral histopathological damage; inhibited cell apoptosis; increased the contents of PDGF-BB, EPO, and TGF-β1; and reduced the levels of PF4, Ang-2, and TIMP-1 in serum. Immunohistochemical staining demonstrated that the expression of PTGS2 was dramatically increased in the hippocampus and cerebral cortex of rats with MCAO/R, and this trend was reversed by the treatment of AS. Immunofluorescent staining expressed that AS reversed the down-regulation of VEGF and further promoted the expression of CD31, which indicated that AS promoted angiogenesis in MCAO/R rats. The abnormal protein or mRNA expression of PTGS2, PGI2, bFGF, TSP-1, and VEGF in the penumbra were transposed by AS or Celecoxib (an inhibitor of PTGS2). In conclusion, the protective mechanism of AS for IS promoted angiogenesis and was involved with PTGS2 silence.

Discovery of 1,2,4-triazole derivatives as novel neuroprotectants against cerebral ischemic injury by activating antioxidant response element

Acute ischemic stroke is an important cause of death and long-term disability worldwide. In this work, we have synthesized a series of derivatives with 3,5‑diaryl substituent triazole scaffolds. The derivatives showed favorable protective effective in SNP-induced oxidative stress model, of which compound 5 was the most active. In vivo experiments showed that compound 5 could ameliorate neurological deficits, attenuate infarction sizes, reduce malonaldehyde (MDA) level and increase superoxide dismutase (SOD) level in middle cerebral artery occlusion (MCAO) rats. Preliminary safety evaluation showed that compound 5 exhibited low acute toxicity in BALB/c mice (LD₅₀ greater than 1000 mg/kg). Further investigation indicated that compound 5 was able to scavenge ROS, restore mitochondrial membrane potential and protect PC12 cells from SNP-induced apoptosis. Moreover, compound 5 could initiate transcription of antioxidant response element (ARE) and induced expressions of antioxidative enzymes. Collectively, compound 5 might have the potency of treating acute ischemic stroke.

Oxidative Stress in the Brain: Basic Concepts and Treatment Strategies in Stroke

The production of free radicals is inevitably associated with metabolism and other enzymatic processes. Under physiological conditions, however, free radicals are effectively eliminated by numerous antioxidant mechanisms. Oxidative stress occurs due to an imbalance between the production and elimination of free radicals under pathological conditions. Oxidative stress is also associated with ageing. The brain is prone to oxidative damage because of its high metabolic activity and high vulnerability to ischemic damage. Oxidative stress, thus, plays a major role in the pathophysiology of both acute and chronic pathologies in the brain, such as stroke, traumatic brain injury or neurodegenerative diseases. The goal of this article is to summarize the basic concepts of oxidative stress and its significance in brain pathologies, as well as to discuss treatment strategies for dealing with oxidative stress in stroke.

Modulatory effect of ursolic acid on neurodegenerative activities in oxidative brain injury: An ex vivo study

Natural products-based antioxidants have been well reported for their therapeutic benefits in the treatment and management of neurodegenerative diseases. The neuroprotective effect of ursolic acid (UA) against oxidative injury was investigated in isolated rat brain. Induction of oxidative injury in isolated rat brains with 0.1 mM FeSO4 led to depleted levels of glutathione, superoxide dismutase, catalase, and ENTPDase activities, with concomitant exacerbation of malondialdehyde and nitric oxide levels, α-chymotrypsin, ATPase, and acetylcholinesterase activities. These levels and activities were significantly reversed following treatment of the brain tissues with UA. Molecular docking studies revealed strong molecular interactions between UA, catalase, and ATPase. Overall, these results indicate the neuroprotective effect of UA against oxidative injury in isolated rat brains as depicted by their ability to mitigate oxidative stress, purinergic, and cholinergic dysfunctions, with concomitant suppression of proteolytic activity. PRACTICAL APPLICATIONS: Neurodegenerative diseases are among the common diseases associated with aging and has been implicated as oxidative mediated. Natural products have received increasing recognition in their use as treatment remedy for various oxidative-mediated diseases including neurodegeneration. These natural products include plant secondary metabolites commonly known as phytochemicals. Ursolic acid is a phytochemical usually present in leafy vegetables and fruits. The present study describes the possible therapeutic mechanism of ursolic acid in the amelioration of complications linked to neurodegeneration in oxidative-mediated brain injury. These findings thus give insights into the use of natural products of plant origin in treating and managing neurodegenerative diseases, which may have little or no side effects.

Edaravone protects from memory impairment induced by chronic L-methionine administration

Hyperhomocysteinemia is a well-known cause of cognitive impairment and neurodegeneration. Increased oxidative stress in the brain has a major possible role in hyperhomocysteinemia-induced pathogenesis. Edaravone is a potent free radical scavenger that has a neuroprotective effect against memory impairment in several experimental models. The current study investigated the possible protective effect of edaravone in L-methionine-induced vascular dementia in a rat model. L-methionine was given (1.7 mg/kg/day) through oral gavage, while edaravone was given (6 mg/kg/day) intraperitoneally. The administration of methionine and edaravone started concomitantly and continued for a total of 9 weeks. Spatial learning and memory were assessed using the radial arm water maze (RAWM). Changes in the oxidative stress-related biomarkers in the hippocampus were assessed using enzymatic assays. Chronic L-methionine administration resulted in short-term and long-term memory impairment, whereas edaravone prevented such effect. Furthermore, edaravone ameliorated L-methionine induced decrease in the activity of the antioxidant enzymes catalase and glutathione peroxidase as well as the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG ratio). Edaravone also prevented increase in the oxidized glutathione (GSSG) secondary to chronic L-methionine administration. In conclusion, the current study suggests that memory impairment and oxidative stress secondary to chronic L-methionine administration can be prevented by edaravone, probably via enhancing antioxidant mechanisms in the hippocampus.

Therapeutic Role of a Cysteine Precursor, OTC, in Ischemic Stroke Is Mediated by Improved Proteostasis in Mice

Oxidative stress aggravates brain injury following ischemia/reperfusion (I/R). We previously showed that ubiquilin-1 (Ubqln1), a ubiquitin-like protein, improves proteostasis and protects brains against oxidative stress and I/R-induced brain injury. Here, we demonstrate that a small molecule compound, L-2-oxothiazolidine-4-carboxylic acid (OTC) that functions as a precursor of cysteine, upregulated Ubqln1 and protected cells against oxygen-glucose deprivation-induced cell death in neuronal cultures. Further, the administration of OTC either at 1 h prior to ischemia or 3 h after the reperfusion significantly reduced brain infarct injury and improved behavioral outcomes in a stroke model. Administration of OTC also increased glutathione (GSH) level and decreased superoxide production, oxidized protein, and neuroinflammation levels in the penumbral cortex after I/R in the stroke mice. Furthermore, I/R reduced both Ubqln1 and the glutathione S-transferase protein levels, whereas OTC treatment restored both protein levels, which was associated with reduced ubiquitin-conjugated protein level. Interestingly, in the Ubqln1 knockout (KO) mice, OTC treatment showed reduced neuroprotection and increased ubiquitin-conjugated protein level when compared to the similarly treated non-KO mice following I/R, suggesting that OTC-medicated neuroprotection is, at least partially, Ubqln1-dependent. Thus, OTC is a potential therapeutic agent for stroke and possibly for other neurological disorders and its neuroprotection involves enhanced proteostasis.

Edaravone attenuates neuronal apoptosis in hypoxic-ischemic brain damage rat model via suppression of TRAIL signaling pathway

BACKGROUND AND OBJECTIVES

Edaravone is a new type of oxygen free radical scavenger and able to attenuate various brain damage including hypoxic-ischemic brain damage (HIBD). This study was aimed at investigating the neuroprotective mechanism of edaravone in rat hypoxic-ischemic brain damage model and its correlation with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling pathway.

MATERIALS AND METHODS

75 seven-day-old Sprague-Dawley neonatal rats were equally divided into three groups: sham-operated group (sham), HIBD group and HIBD rats injected with edaravone (HIBD + EDA) group. Neurological severity and space cognitive ability of rats in each group were evaluated using Longa neurological severity score and Morris water maze testing. TUNEL assay and flow cytometry were used to determine brain cell apoptosis. Western blot was used to estimate the expression level of death receptor-5 (DR5), Fas-associated protein with death domain (FADD), caspase 8, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax). In addition, immunofluorescence was performed to detect caspase 3.

RESULTS

Edaravone reduced neurofunctional damage caused by HIBD and improved the cognitive capability of rats. The above experiment results suggested that edaravone could down-regulate the expression of active caspase 3 protein, thereby relieving neuronal apoptosis.

CONCLUSION

Taken together, edaravone could attenuate neuronal apoptosis in rat hypoxic-ischemic brain damage model via suppression of TRAIL signaling pathway, which also suggested that edaravone might be an effective therapeutic strategy for HIBD clinical treatment.

Glucose-6-phosphate dehydrogenase a novel hope on a blood-based diagnosis of Alzheimer's disease

Alzheimer's disease (AD) is a multi-factorial neurodegenerative disorder that numerous factors have key properties in the development of this proteopathy. Glucose-6-phosphate dehydrogenase (G6PD) is the most common form of enzymopathy. We have examined G6PD enzyme activity levels in the serum of newly diagnosed AD patients compared with control subjects without dementia from the both sexes. Serum G6PD levels were found to be significantly higher (approximately two times) in AD patients compared to control geriatric subjects in both sexes. We have concluded that G6PD seems to play an integral role in the progress and/or prevention of AD.

A free radical scavenger edaravone suppresses systemic inflammatory responses in a rat transient focal ischemia model

A free radical scavenger edaravone is clinically used in Japan for acute stroke, and several basic researches have carefully examined the mechanisms of edaravone's protective effects. However, its actions on pro-inflammatory responses under stroke are still understudied. In this study, we subjected adult male Sprague-Dawley rats to 90-min middle cerebral artery (MCA) occlusion followed by reperfusion. Edaravone was treated twice via tail vein; after MCA occlusion and after reperfusion. As expected, edaravone-treated group showed less infarct volume and edema formation compared with control group at 24-h after an ischemic onset. Furthermore, edaravone reduced the levels of plasma interleukin (IL)-1β and matrix metalloproteinase-9 at 3-h after ischemic onset. Several molecules besides IL-1β and MMP-9 are involved in inflammatory responses under stroke conditions. Therefore, we also examined whether edaravone treatment could decrease a wide range of pro-inflammatory cytokines/chemokines by testing rat plasma samples with a rat cytokine array. MCAO rats showed elevations in plasma levels of CINC-1, Fractalkine, IL-1α, IL-1ra, IL-6, IL-10, IP-10, MIG, MIP-1α, and MIP-3α, and all these increases were reduced by edaravone treatment. These data suggest that free radical scavengers may reduce systemic inflammatory responses under acute stroke conditions, and therefore, oxidative stress can be still a viable target for acute stroke therapy.

Analysis of treatment effect of urinary kallidinogenase combined with edaravone on massive cerebral infarction

The aim of the study was to investigate the clinical effect of urinary kallidinogenase combined with edaravone in the treatment of massive cerebral infarction. A total of 58 patients with massive cerebral infarction were admitted to hospital between January 2013 and January 2014. There were 34 male and 24 female patients. The patients were randomly divided into the observation and control groups (n=29 cases per group). The patients in the control group received edaravone treatment, while patients in the observation group were treated with urinary kallidinogenase and edaravone. The clinical effects of the two groups were then compared. The results showed that the National Institutes of Health Stroke Scale score and serum C-reactive protein level of the patients in the two groups were significantly decreased following treatment. The decreased degree in the observation group was significantly smaller than that in the control group. The difference was statistically significant [(11.03±3.75) vs. (16.58±7.43) scores, P<0.05; (9.88±4.82) vs. (11.98±4.69) mmol/l, P<0.05]. The serum levels of vascular endothelial growth factor were significantly increased in patients of the two groups after treatment. The increased degree in the observation group was significantly higher than that in the control group. The difference was statistically significant [(268.51±77.34) vs. (188.82±57.33) ng/l, P<0.05]. The total effective rate of the observation group was significantly higher than that of the control group and the difference was statistically significant (89.66 vs. 62.07%, P<0.05). In conclusion, urinary kallidinogenase combined with edaravone treatment has a certain clinical curative effect on massive cerebral infarction.

Rutin protects against cognitive deficits and brain damage in rats with chronic cerebral hypoperfusion

BACKGROUND AND PURPOSE

Chronic cerebral hypoperfusion is a critical causative factor for the development of cognitive decline and dementia in the elderly, which involves many pathophysiological processes. Consequently, inhibition of several pathophysiological pathways is an attractive therapeutic strategy for this disorder. Rutin, a biologically active flavonoid, protects the brain against several insults through its antioxidant and anti-inflammatory properties, but its effect on cognitive deficits and brain damage caused by chronic cerebral hypoperfusion remains unknown. Here, we investigated the neuroprotective effect of rutin on cognitive impairments and the potential mechanisms underlying its action in rats with chronic cerebral hypoperfusion.

EXPERIMENTAL APPROACH

We used Sprague-Dawley rats with permanent bilateral common carotid artery occlusion (BCCAO), a well-established model of chronic cerebral hypoperfusion. After rutin treatment for 12 weeks, the neuroprotective effect of rutin in rats was evaluated by behavioural tests, biochemical and histopathological analyses.

KEY RESULTS

BCCAO rats showed marked cognitive deficits, which were improved by rutin treatment. Moreover, BCCAO rats exhibited central cholinergic dysfunction, oxidative damage, inflammatory responses and neuronal damage in the cerebral cortex and hippocampus, compared with sham-operated rats. All these effects were significantly alleviated by treatment with rutin.

CONCLUSION AND IMPLICATIONS

Our results provide new insights into the pharmacological actions of rutin and suggest that rutin has multi-targeted therapeutical potential on cognitive deficits associated with conditions with chronic cerebral hypoperfusion such as vascular dementia and Alzheimer's disease.

Edaravone offers neuroprotection for acute diabetic stroke patients

INTRODUCTION

Edaravone, a novel free-radical scavenger, has been shown to alleviate cerebral ischemic injury and protect against vascular endothelial dysfunction. However, the effects of edaravone in acute diabetic stroke patients remain undetermined.

METHODS

A randomized, double-blind, placebo-controlled study was performed to prospectively evaluate the effects of edaravone on acute diabetic stroke patients admitted to our hospital within 24 h of stroke onset. The edaravone group received edaravone (30 mg twice per day) diluted with 100 ml of saline combined with antiplatelet drug aspirin and atorvastatin for 14 days. The non-edaravone group was treated only with 100 ml of saline twice per day combined with aspirin and atorvastatin. Upon admission, and on days 7, 14 post-stroke onset, neurological deficits and activities of daily living were assessed using the National Institutes of Health Stroke Scale (NIHSS) and the Barthel Index (BI), respectively. The occurrence of hemorrhage transformation, pulmonary infection, progressive stroke and epilepsy was also evaluated on day 14 post-treatment.

RESULTS

A total of 65 consecutive acute diabetic stroke patients were enrolled, of whom 35 were allocated to the edaravone group and 30 to the non-edaravone group. There was no significant group difference in baseline clinical characteristics, but mean NIHSS scores were lower (60 %), and BI scores were 1.7-fold higher, in edaravone-treated patients vs. controls on day 14. Furthermore, the incidence of hemorrhage transformation, pulmonary infection, progressive stroke and epilepsy was markedly reduced in the edaravone vs. non-edaravone group.

CONCLUSION

Edaravone represents a promising neuroprotectant against cerebral ischemic injury in diabetic patients.

Phase II anti-inflammatory and immune-modulating drugs for acute ischaemic stroke

INTRODUCTION

Stroke is the second leading cause of death worldwide and the leading cause of adult neurological disability. Despite advances in stroke unit care, and increasing use of thrombolysis, there remains an urgent need for safe and effective treatments for acute ischaemic stroke. However, this is against a backdrop of multiple failures in translational drug development. Cerebral ischaemia initiates a complex cascade of immune and inflammatory pathways in the brain microvasculature and periphery, which contribute to the evolution of cerebral injury, resolution and repair. Targeting specific inflammatory or immune pathways, therefore, represents an attractive treatment strategy in acute ischaemic stroke. Although anti-inflammatory drugs have already failed in clinical trial development, several are currently at the Phase II developmental stage.

AREAS COVERED

The authors highlight several candidate drugs, which modulate a range of inflammatory and immune pathways, and have been investigated in pre-clinical and Phase II studies to date.

EXPERT OPINION

Drugs targeting inflammatory and immune pathways offer theoretical advantages including potentially longer therapeutic time windows and effects complementary to thrombolysis (ameliorating reperfusion injury). Fundamental changes in the approach to pre-clinical and clinical drug development are required to facilitate successful translation of promising candidate drugs into clinical practice.

The neuroprotective properties of the superoxide dismutase mimetic tempol correlate with its ability to reduce pathological glutamate release in a rodent model of stroke

The contribution of oxidative stress to ischemic brain damage is well established. Nevertheless, for unknown reasons, several clinically tested antioxidant therapies have failed to show benefits in human stroke. Based on our previous in vitro work, we hypothesized that the neuroprotective potency of antioxidants is related to their ability to limit the release of the excitotoxic amino acids glutamate and aspartate. We explored the effects of two antioxidants, tempol and edaravone, on amino acid release in the brain cortex, in a rat model of transient occlusion of the middle cerebral artery (MCAo). Amino acid levels were quantified using a microdialysis approach, with the probe positioned in the ischemic penumbra as verified by a laser Doppler technique. Two-hour MCAo triggered a dramatic increase in the levels of glutamate, aspartate, taurine, and alanine. Microdialysate delivery of 10mM tempol reduced the amino acid release by 60-80%, whereas matching levels of edaravone had no effect. In line with these data, an intracerebroventricular injection of tempol but not edaravone (500 nmol each, 15 min before MCAo) reduced infarction volumes by ~50% and improved neurobehavioral outcomes. In vitro assays showed that tempol was superior at removing superoxide anion, whereas edaravone was more potent at scavenging hydrogen peroxide, hydroxyl radical, and peroxynitrite. Overall, our data suggest that the neuroprotective properties of tempol are probably related to its ability to reduce tissue levels of the superoxide anion and pathological glutamate release and, in such a way, limit progression of brain infarction within ischemic penumbra. These new findings may be instrumental in developing new antioxidant therapies for treatment of stroke.

The radical scavenger edaravone improves neurologic function and perihematomal glucose metabolism after acute intracerebral hemorrhage

Oxidative injury caused by reactive oxygen species plays an important role in the progression of intracerebral hemorrhage (ICH)-induced secondary brain injury. Previous studies have demonstrated that the free radical scavenger edaravone may prevent neuronal injury and brain edema after ICH. However, the influence of edaravone on cerebral metabolism in the early stages after ICH and the underlying mechanism have not been fully investigated. In the present study, we investigated the effect of edaravone on perihematomal glucose metabolism using (18)F-fluorordeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Additionally, the neurologic deficits, brain edemas, and cell death that followed ICH were quantitatively analyzed. After blood infusion, the rats treated with edaravone showed significant improvement in both forelimb placing and corner turn tests compared with those treated with vehicle. Moreover, the brain water content of the edaravone-treated group was significantly decreased compared with that of the vehicle group on day 3 after ICH. PET/CT images of ICH rats exhibited obvious decreases in FDG standardized uptake values in perihematomal region on day 3, and the lesion-to-normal ratio of the edaravone-treated ICH rats was significantly increased compared with that of the control rats. Calculation of the brain injury volumes from the PET/CT images revealed that the volumes of the blood-induced injuries were significantly smaller in the edaravone group compared with the vehicle group. Terminal Deoxynucleotidyl Transferase-mediated dUTP Nick End Labeling assays performed 3 days after ICH revealed that the numbers of apoptotic cells in perihematomal region of edaravone-treated ICH rats were decreased relative to the vehicle group. Thus, the present study demonstrates that edaravone has scavenging properties that attenuate neurologic behavioral deficits and brain edema in the early period of ICH. Additionally, edaravone may improve cerebral metabolism around the hematoma by attenuating apoptotic cell death after ICH.

Edaravone's free radical scavenging mechanisms of neuroprotection against cerebral ischemia: review of the literature

Free radicals and oxidative stress play key roles in cerebral ischemic pathogenesis and represent pharmacological targets for treatment. Edaravone (Edv), one of antioxidant agents that have been used in acute ischemic stroke in both clinical settings and animal experiments, exerts neuroprotective effect on ischemic injured brains. This review is aimed to elaborate the latest molecular mechanisms of the neuroprotection of Edv on cerebral ischemia and provide reasonable evidence in its clinical application. It is found that Edv has neuroprotective influence on cerebral ischemia, which is closely related to the facets of scavenging reactive oxygen species (ROS), hydroxyl radical (ċOH) and reactive nitrogen species (RNS). And it is a good antioxidant agent that can be safely used in the treatment of cerebral ischemia and chronic neurodegenerative disorders as well as other ischemia/reperfusion (I/R)-related diseases. The combination of Edv with thrombolytic therapy also can be applied in clinical settings and will be greatly beneficial to patients with stroke.

Perillyl alcohol improves functional and histological outcomes against ischemia-reperfusion injury by attenuation of oxidative stress and repression of COX-2, NOS-2 and NF-κB in middle cerebral artery occlusion rats

Perillyl alcohol (PA) is a monoterpene found in essential oils of mints, cherries, citreous fruits and lemon grass, reported to have antioxidant and anti-inflammatory properties. However, the role of PA in stroke is still illusive. Since oxidative stress and inflammation play a pivotal role in ischemia-reperfusion (I-R) injury, this study was designed to elucidate the potential effects of PA against I-R induced pathology in rat׳s brain. Middle cerebral artery occlusion (MCAO) for 2h followed by 22h reperfusion in Wistar male rats (250-280g, 14-16 weeks old) induced the behavioral and histological alterations along with exhausted antioxidant status and enhanced inflammatory mediators. However, PA administration (25, 50 and 100mg/kg b.wt orally once daily for 7 days) prior to MCAO significantly attenuated neurological deficits related to flexion test and spontaneous motor activity, improved grip strength and motor coordination in a dose dependent manner. PA treatment also inhibited oxidative stress in MCAO rats as evident from decreased lipid peroxidation and augmented level of reduced glutathione and restored activities of catalase, glutathione peroxidase, and glutathione reductase and thus, reduced infarct volume and protected the brain histology after I-R injury. Furthermore, PA markedly suppressed the level of proinflammatory cytokines (IL-1β, TNF α and IL-6) and down regulated expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (NOS-2) and nuclear factor κB (NF-κB) in MCAO group. In conclusion, PA mediates neuroprotection against I-R injury via mitigation of oxidative stress and inflammation and thus, may be a good therapeutic approach in stroke prone patient.

Fetal umbilical vein transplantation for the repair of middle cerebral artery injury

It is necessary to investigate the longitudinal tensile mechanical characteristics of the middle cerebral artery and the fetal umbilical vein prior to applying fetal umbilical vein transplantation for repair of injured middle cerebral artery. Fifteen fresh fetal umbilical vein specimens and 15 normal human fresh cadaver middle cerebral artery specimens were collected for longitudinal tensile testing at the speed of 0.5 mm/min and at normal human temperature. The results showed that under 16.0 kPa physiological stress, the strain value of fetal umbilical vein specimens was larger, while the maximal stress and elastic modulus values were less than those of middle cerebral artery specimens. Our findings indicate that fetal umbilical vein has good elastic properties and the stress-strain curve of the fetal umbilical vein is similar to that of the middle cerebral artery. Fetal umbilical vein transplantation can, therefore, potentially repair the injured middle cerebral artery.

Effect of edaravone on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma after radiotherapy: a randomized controlled trial

Excessive generation of free radicals plays a critical role in the pathogenesis of radiation-induced brain injury. This study was designed to evaluate the protective effect of edaravone, a free radical scavenger, on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma. Eligible patients were randomized 1:1 to the control group and the edaravone group (intravenous 30 mg twice per day for 2 weeks). Both groups received intravenous conventional steroid therapy and were monitored by brain MRI and LENT/SOMA scales prior to the entry of the trial and at 3-months after completing the trial. The primary end point was a 3-month response rate of the proportional changes determined by MRI. The trial is registered at Clinicaltrials.gov Identifier: NCT01865201. Between 2009 and 2012, we enrolled 154 patients. Of whom 137 were eligible for analysis. The volumes of necrosis estimated on T₂-weighted image showed that 55.6 % edaravone-treated patients (40 out of 72) showed edema decreases ≥25 %, which was significantly higher than that in the control group (35.4 %, 23 out of 65, p = 0.025). Forty-four patients treated with edaravone (61.1 %) reported improvement in neurologic symptoms and signs evaluated by LENT/SOMA scales, while the rate was 38.5 % in the control group (p = 0.006). MRI of the edaravone group showed a significant decrease in area of T₁-weighted contrast enhancement (1.67 ± 4.69 cm², p = 0.004) and the T₂-weighted edema (5.08 ± 10.32 cm², p = 0.000). Moreover, compared with those in control group, patients with edaravone exhibited significantly better radiological improvement measured by T₂-weighted image (p = 0.042). Administration of edaravone, in adjunct to steroid regimen, might provide a better outcome in patients with radiation-induced brain necrosis.

Viscoelastic evaluation of fetal umbilical vein for reconstruction of middle cerebral artery

The transplantation of artificial blood vessels with < 6 mm inner diameter as substitutes for human arterioles or veins has not achieved satisfactory results. Umbilical vein has been substituted for ar-tery in vascular transplantation, but it remains unclear whether the stress relaxation and creep tween these vessels are consistent. In this study, we used the fetal umbilical vein and middle cere-bral artery from adult male cadavers to make specimens 15 mm in length, 0.196–0.268 mm in nica media thickness, and 2.82–2.96 mm in outer diameter. The results demonstrated that the stress decrease at 7 200 seconds was similar between the middle cerebral artery and fetal umbilical vein specimens, regardless of initial stress of 18.7 kPa or 22.5 kPa. However, the strain increase at 7 200 seconds of fetal umbilical veins was larger than that of middle cerebral arteries. Moreover, the stress relaxation experiment showed that the stress decrease at 7 200 seconds of the fetal umbilical vein and middle cerebral artery specimens under 22.5 kPa initial stress was less than the decrease in these specimens under 18.7 kPa initial stress. These results indicate that the fetal umbilical vein has appropriate stress relaxation and creep properties for transplantation. These properties are advantageous for vascular reconstruction, indicating that the fetal umbilical vein can be transplanted to repair middle cerebral artery injury.

Congenital hypothyroidism alters the oxidative status, enzyme activities and morphological parameters in the hippocampus of developing rats

Congenital hypothyroidism is associated with delay in cell migration and proliferation in brain tissue, impairment of synapse formation, misregulation of neurotransmitters, hypomyelination and mental retardation. However, the mechanisms underlying the neuropsychological deficits observed in congenital hypothyroidism are not completely understood. In the present study we proposed a mechanism by which hypothyroidism leads to hippocampal neurotoxicity. Congenital hypothyroidism induces c-Jun-N-terminal kinase (JNK) pathway activation leading to hyperphosphorylation of the glial fibrillary acidic protein (GFAP), vimentin and neurofilament subunits from hippocampal astrocytes and neurons, respectively. Moreover, hyperphosphorylation of the cytoskeletal proteins was not reversed by T3 and poorly reversed by T4. In addition, congenital hypothyroidism is associated with downregulation of astrocyte glutamate transporters (GLAST and GLT-1) leading to decreased glutamate uptake and subsequent influx of Ca(2+) through N-methyl-D-aspartate (NMDA) receptors. The Na(+)-coupled (14)C-α-methyl-amino-isobutyric acid ((14)C-MeAIB) accumulation into hippocampal cells also might cause an increase in the intracellular Ca(2+) concentration by opening voltage-dependent calcium channels (VDCC). The excessive influx of Ca(2+) through NMDA receptors and VDCCs might lead to an overload of Ca(2+) within the cells, which set off glutamate excitotoxicity and oxidative stress. The inhibited acetylcholinesterase (AChE) activity might also induce Ca(2+) influx. The inhibited glucose-6-phosphate dehydrogenase (G6PD) and gamma-glutamyl transferase (GGT) activities, associated with altered glutamate and neutral amino acids uptake could somehow affect the GSH turnover, the antioxidant defense system, as well as the glutamate-glutamine cycle. Reduced levels of S100B and glial fibrillary acidic protein (GFAP) take part of the hypothyroid condition, suggesting a compromised astroglial/neuronal neurometabolic coupling which is probably related to the neurotoxic damage in hypothyroid brain.

Neurodegenerative evidence in mice brains with cecal ligation and puncture-induced sepsis: preventive effect of the free radical scavenger edaravone

Sepsis is a major clinical challenge and septic encephalopathy is its nasty complication. The pathogenesis and underlying mechanisms of septic encephalopathy are not well understood. This study sought to fully characterize sepsis-associated biochemical and histopathological changes in brains of mice after cecal ligation and puncture, regarded as a highly clinically relevant animal model of polymicrobial sepsis. Real-time PCR analysis showed that gene expression levels of proinflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, were significantly up-regulated in brain tissues from septic mice, but to a much lesser extent when compared with those in peripheral tissues such as lungs. Blood-brain barrier (BBB) permeability was significantly increased in septic mice, as determined by the measurement of sodium fluorescein and Evans blue content. Sepsis resulted in increases in NADPH oxidase activity and expression of p47^phox and p67^phox and up-regulation of inducible nitric oxide (NO) synthase in brains, indicating that superoxide, produced by NADPH oxidase, reacts with NO to form peroxynitrite, that maybe lead to the loss of BBB integrity. Light and electron microscopic examination of septic mouse brain showed serious neuronal degeneration, as indicated by hyperchromatic, shrunken, pyknotic, and electron-dense neurons. These histopathogical changes were prevented by treatment with the free radical scavenger edaravone. Together, these results suggest that sepsis can lead to rapid neurodegenerative changes in brains via free radical species production and possibly subsequent injury to the BBB. We may also provide a potentially useful therapeutic tool for treating septic encephalopathy.