Edaravone, a free radical scavenger, protects neuronal cells’ mitochondria from ischemia by inactivating another new critical factor of the 5-lipoxygenase pathway affecting the arachidonic acid metabolism

The protective role of vagus nerve stimulation in ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) encompasses the damage resulting from the restoration of blood supply following tissue ischemia. This phenomenon commonly occurs in clinical scenarios such as hemorrhagic shock, severe trauma, organ transplantation, and thrombolytic therapy. Despite its prevalence, existing treatments exhibit limited efficacy against IRI. Vagus nerve stimulation (VNS) is a widely utilized technique for modulating the autonomic nervous system. Numerous studies have demonstrated that VNS significantly reduces IRI in various organs, including the heart, brain, and liver. This article reviews the pathological processes during IRI and summarizes the role and possible mechanisms of VNS in IRI of different organs. Furthermore, this review addresses the current challenges of VNS clinical applications, providing a novel perspective on IRI treatment.

The WMI Rat of Premature Cognitive Aging Presents Intrinsic Vulnerability to Oxidative Stress in Primary Neurons and Astrocytes Compared to Its Nearly Isogenic WLI Control

The primary neuronal and astrocyte culture described here is from the stress-hyperreactive Wistar Kyoto (WKY) More Immobile (WMI) rat with premature aging-related memory deficit, and its nearly isogenic control, the Less Immobile (WLI) strain. Primary WMI hippocampal neurons and cortical astrocytes are significantly more sensitive to oxidative stress (OS) generated by administration of H2O2 compared to WLI cells as measured by the trypan blue cell viability assay. Intrinsic genetic vulnerability is also suggested by the decreased gene expression in WMI neurons of catalase (Cat), and in WMI cortical astrocytes of insulin-like growth factor 2 (Igf2), synuclein gamma (Sncg) and glutathione peroxidase 2 (Gpx2) compared to WLI. The expressions of several mitochondrial genes are dramatically increased in response to H2O2 treatment in WLI, but not in WMI cortical astrocytes. We propose that the vulnerability of WMI neurons to OS is due to the genetic differences between the WLI and WMI. Furthermore, the upregulation of mitochondrial genes may be a compensatory response to the generation of free radicals by OS in the WLIs, and this mechanism is disturbed in the WMIs. Thus, this pilot study suggests intrinsic vulnerabilities in the WMI hippocampal neurons and cortical astrocytes, and affirm the efficacy of this bimodal in vitro screening system for finding novel drug targets to prevent oxidative damage in illnesses.

Loss of larger hypoglossal motor neurons in aged Fischer 344 rats

The intrinsic (longitudinal, transversalis and verticalis) and extrinsic (genioglossus, styloglossus, hyoglossus and geniohyoid) tongue muscles are innervated by hypoglossal motor neurons (MNs). Tongue muscle activations occur during many behaviors: maintaining upper airway patency, chewing, swallowing, vocalization, vomiting, coughing, sneezing and grooming/sexual activities. In the tongues of the elderly, reduced oral motor function and strength contribute to increased risk of obstructive sleep apnoea. Tongue muscle atrophy and weakness is also described in rats, yet hypoglossal MN numbers are unknown. In young (6-months, n=10) and old (24-months, n=8) female and male Fischer 344 (F344) rats, stereological assessment of hypoglossal MN numbers and surface areas were performed on 16µm Nissl-stained brainstem cryosections. We observed a robust loss of ~15% of hypoglossal MNs and a modest ~8% reduction in their surface areas with age. In the larger size tertile of hypoglossal MNs, age-associated loss of hypoglossal MNs approached ~30% These findings uncover a potential neurogenic locus of pathology for age-associated tongue dysfunctions.

Size-dependent differences in mitochondrial volume density in phrenic motor neurons

Neuromotor control of diaphragm muscle (DIAm) motor units is dependent on an orderly size-dependent recruitment of phrenic motor neurons (PhMNs). Slow (type S) and fast, fatigue resistant (type FR) DIAm motor units, which are frequently recruited to sustain ventilation, comprise smaller PhMNs that innervate type I and IIa DIAm fibers. More fatigable fast (type FF) motor units, which are infrequently recruited for higher force, expulsive behaviors, comprise larger PhMNs that innervate more type IIx/IIb DIAm fibers. We hypothesize that due to the more frequent activation and thus higher energy demand of type S and FR motor units, the mitochondrial volume density (MVD) of smaller PhMNs is greater compared with larger PhMNs. In eight adult (6 mo old) Fischer 344 rats, PhMNs were identified via intrapleural injection of Alexa488-conjugated cholera toxin B (CTB). Following retrograde CTB labeling, mitochondria in PhMNs were labeled by transdural infusion of MitoTracker Red. PhMNs and mitochondria were imaged using multichannel confocal microscopy using a ×60 oil objective. Following optical sectioning and three-dimensional (3-D) rendering, PhMNs and mitochondria were analyzed volumetrically using Nikon Elements software. Analysis of MVD in somal and dendritic compartments was stratified by PhMN somal surface area. Smaller PhMNs (likely S and FR units) had greater somal MVDs compared with larger PhMNs (likely FF units). By contrast, proximal dendrites or larger PhMNs had higher MVD compared with dendrites of smaller PhMNs. We conclude that more active smaller PhMNs have a higher mitochondrial volume density to support their higher energy demand in sustaining ventilation.NEW & NOTEWORTHY Type S and FR motor units, comprising smaller phrenic motor neurons (PhMNs) are regularly activated to perform indefatigable ventilatory requirements. By contrast, type FF motor units, comprising larger PhMNs, are infrequently activated to perform expulsive straining and airway defense maneuvers. This difference in activation history is mirrored in the mitochondrial volume density (MVD), with smaller PhMNs having higher MVD than larger PhMNs. In proximal dendrites, this trend was reversed, with larger PhMNs having higher MVD than smaller PhMNs, likely due to the maintenance requirements for the larger dendritic arbor of FF PhMNs.

Propofol Protects Against Erastin-Induced Ferroptosis in HT-22 Cells

Propofol is a short-acting intravenous anesthetic that is widely used in clinical treatment. Previous articles have indicated that propofol is a therapeutic target for anti-apoptosis, anti-inflammation, anti-lipid peroxidation, and anti-reactive oxygen species (ROS). Moreover, cell ferroptosis is strongly correlated with cellular ROS, inflammatory responses, and lipid peroxidation. However, the mechanisms by which propofol attenuates neuronal injury by reducing ferroptosis remain unknown. Hence, we hypothesized that propofol could protect neurons by reducing ferroptosis. To test this hypothesis, HT-22 cells were treated with a specific ferroptosis activator (erastin) in the presence of propofol (50 μM). We found that propofol reduced erastin-induced high Fe²⁺ concentrations, lipid peroxides, and excess ROS. Western blotting results also suggested that propofol could rescue erastin-induced low expression of GXP4 and system Xc^-. Further experiments indicated that propofol attenuated p-ALOX5 expression at Ser663 independent of ERK. In addition, we built two transient transfection cell lines, ALOX5 OE and Ser663Ala-ALOX5 OE, to confirm the target of propofol. We found that the Ser663 point is the critical role of propofol in rescuing erastin-induced cell injury/lipid peroxidation. In conclusion, propofol may help attenuate ferroptosis, which may provide a new therapeutic method to treat neuronal injury or the brain inflammatory response.

Edaravone Modulates Neuronal GPX4/ACSL4/5-LOX to Promote Recovery After Spinal Cord Injury

The FDA-approved drug edaravone has a neuroprotective effect on spinal cord injury (SCI) and many other central nervous system diseases. However, its molecular mechanism remains unclear. Since edaravone is a lipid peroxidation scavenger, we hypothesize that edaravone exerts its neuroprotective effect by inhibiting ferroptosis in SCI. Edaravone treatment after SCI upregulates glutathione peroxidase 4 (GPX4) and system Xc-light chain (xCT), which are anti-ferroptosis proteins. It downregulates pro-ferroptosis proteins Acyl-CoA synthetase long-chain family member 4 (ACSL4) and 5-lipoxygenase (5-LOX). The most significant changes in edaravone treatment occur in the acute phase, two days post injury. Edaravone modulates neuronal GPX4/ACSL4/5-LOX in the spinal segment below the lesion, which is critical for maintaining locomotion. Moreover, the GPX4/ACSL4/5-LOX in motor neuron is also modulated by edaravone in the spinal cord. Therefore, secondary injury below the lesion site is reversed by edaravone via ferroptosis inhibition. The cytokine array revealed that edaravone upregulated some anti-inflammatory cytokines such as IL-10, IL-13, and adiponectin. Edaravone reduced microgliosis and astrogliosis, indicating reduced neuroinflammation. Edaravone has a long-term effect on neuronal survival, spinal cord tissue sparing, and motor function recovery. In summary, we revealed a novel mechanism of edaravone in inhibiting neuronal ferroptosis in SCI. This mechanism may be generalizable to other neurological diseases.

Therapeutic Implications of Caffeic Acid in Cancer and Neurological Diseases

Caffeic acid (CA) is found abundantly in fruits, vegetables, tea, coffee, oils, and more. CA and its derivatives have been used for many centuries due to their natural healing and medicinal properties. CA possesses various biological and pharmacological activities, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. The potential therapeutic effects of CA are mediated via repression and inhibition of transcription and growth factors. CA possesses potential anticancer and neuroprotective effects in human cell cultures and animal models. However, the biomolecular interactions and pathways of CA have been described highlighting the target binding proteins and signaling molecules. The current review focuses on CA’s chemical, physical, and pharmacological properties, including antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. We further described CA’s characteristics and therapeutic potential and its future directions.

Effects of the Edaravone, a Drug Approved for the Treatment of Amyotrophic Lateral Sclerosis, on Mitochondrial Function and Neuroprotection

Edaravone, the first known free radical scavenger, has demonstrated cellular protective properties in animals and humans. Owing to its antioxidant activity, edaravone modulates oxidative damage in various diseases, especially neurodegenerative diseases. In 2015, edaravone was approved in Japan to treat amyotrophic lateral sclerosis. The distinguishing pathogenic features of neurodegenerative diseases include high reactive oxygen species levels and mitochondrial dysfunction. However, the correlation between mitochondria and edaravone has not been elucidated. This review highlights recent studies on novel therapeutic perspectives of edaravone in terms of its effect on oxidative stress and mitochondrial function.

Dengzhanxixin Injection Ameliorates Cognitive Impairment Through a Neuroprotective Mechanism Based on Mitochondrial Preservation in Patients With Acute Ischemic Stroke

Acute ischemic stroke (AIS) is a global health burden and cognitive impairment is one of its most serious complication. Adequate interventions for AIS may have the potential to improve cognitive outcomes. In the present study, we selected Erigeron breviscapus (Vaniot) Hand.-Mazz. injection (Dengzhanxixin injection, DZXI), a widely used Chinese herbal injection, in contrast to edaravone as the positive control drug to test its potential to ameliorates neurological and cognitive impairments caused by AIS. We performed a 2-week randomized trial with these two drugs in AIS patients presenting mild to moderate cognitive impairments. Neuropsychological tests and MRI examinations showed that DZXI attenuated the neurological and cognitive impairments of patients and protected the grey matter in specific regions from ischemic damage. Notably, DZXI exerted better effects than edaravone in some neuropsychological tests, probably due to the protective effect of DZXI on grey matter. To explore the therapeutic mechanisms, we carried out an experiment with a middle cerebral artery occlusion rat model. We found that DZXI decreased the infarct volume and increased the survival of neuronal cells in the ischemic penumbra; furthermore, DZXI modulated the mitochondrial respiratory chain process and preserved the mitochondrial structure in the brain tissue. Overall, our data suggested that the administration of DZXI is effective at ameliorating neurological and cognitive impairments in AIS, and the underlying mechanisms are related to the protective effects of DZXI on cerebral neurons and neuronal mitochondria.

Protective Effect of Piceatannol Against Cerebral Ischaemia-Reperfusion Injury Via Regulating Nrf2/HO-1 Pathway In Vivo and Vitro

Piceatannol is a natural plant-derived compound with protective effects against cardiovascular diseases. However, its effect on cerebral ischaemia-reperfusion injury (CIRI) induced by oxidative stress remains unclear. This study aimed to investigate piceatannol's antioxidation in CIRI. An in vitro oxygen-glucose deprivation followed by reoxygenation model was used and cell viability was measured. A middle cerebral artery occlusion followed by reperfusion model was used in vivo. Neurological function, encephalisation quotient, oedema, and volume of the cerebral infarction were then evaluated. The effects of piceatannol on histopathological findings, as well as the ultrastructure of the cortex, were analysed. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and lactate dehydrogenase (LDH) and the malondialdehyde (MDA) content was measured both in vitro and in vivo. Finally, the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), hemeoxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 (NQO1) in cerebral tissue was detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. Our results demonstrated that cell viability in the piceatannol groups was increased. The SOD, GSH-Px activities were increased as LDH activity and MDA content decreased in the piceatannol groups both in vitro and in vivo, reflecting a decrease in oxidative stress. The neurological severity score and infarction volume in the piceatannol groups at doses of 10 and 20 mg/kg were lower than those of the model group. Furthermore, the damage seen on histopathological examination was partially attenuated by piceatannol. RT-qPCR and western blot analysis indicated that the expression of Nrf2, HO-1, and NQO1 were significantly increased by piceatannol. The results of the study demonstrate that piceatannol exerts a protective effect against CIRI.

Impact of edaravone on serum CXC chemokine ligand-13 levels and perioperative neurocognitive disorders in elderly patients with hip replacement

BACKGROUND

Perioperative neurocognitive disorders (PND) are a series of severe complications in the perioperative and anesthetic periods with a decline in memory, execution ability, and information processing speed as the primary clinical manifestation. This study aimed to evaluate the impact of edaravone (EDA) on PND and peripheral blood C-X-C motif chemokine ligand 13 (CXCL13) levels in elderly patients with hip replacement.

METHODS

A total of 160 elderly patients undergoing hip arthroplasty in Affiliated Dongguan People's Hospital of Southern Medical University (from March 2016 to March 2018) were randomly and double-blindly categorized into an EDA group and a control group (CON). Group EDA was administered intravenously EDA 30 min before surgery, and group CON was administered intravenously saline. The cognitive function of the two groups was evaluated 1-day before the operation and at 1 and 12 months after surgery, and the incidence of post-operative delirium was tested on days 1, 3, and 7 after surgery using the Chinese version of the confusion assessment method. Serum CXCL13 and interleukin (IL)-6 concentrations were measured before anesthesia, during surgery (30 min after skin incision), and on days 1, 3, and 7 after surgery. The continuous variables in accordance with normal distribution were tested using the Student's t test, the continuous variables without normal distribution using the Mann-Whitney U test, and categorical variables by the χ2 test or Fisher exact test.

RESULTS

The incidence of post-operative delirium within 7 days after surgery was significantly higher in group CON than that in group EDA (31.3% vs. 15.0%, t = -5.6, P < 0.001). The modified telephone interview for cognitive status and activities of daily life scores were significantly higher in the group EDA than those in the group CON at 1 month (39.63 ± 4.35 vs. 33.63 ± 5.81, t = -2.13, P < 0.05 and 74.3 ± 12.6 vs. 61.2 ± 13.1, t = -1.69, P < 0.05) and 12 months (40.13 ± 5.93 vs. 34.13 ± 5.36, t = -3.37, P < 0.05 and 79.6 ± 11.7 vs. 65.6 ± 16.6, t = -2.08, P < 0.05) after surgery; and the incidence of neurocognitive dysfunction was significantly lower in the group EDA than that in the group CON (P < 0.05). Serum CXCL13 and IL-6 concentrations were significantly lower in the group EDA than those in the group CON during and after surgery (P < 0.05).

CONCLUSION

EDA can significantly reduce the serum concentrations of CXCL13 and IL-6 and improve the PND of patients.

The Discovery of Novel ACA Derivatives as Specific TRPM2 Inhibitors that Reduce Ischemic Injury Both In Vitro and In Vivo

The transient receptor potential melastatin 2 (TRPM2) channel is associated with ischemia/reperfusion injury, inflammation, cancer, and neurodegenerative diseases. However, the limit of specific inhibitors impedes the development of TRPM2-targeted therapeutic agents. To discover more potent and selective TRPM2 inhibitors, 59 N-(p-amylcinnamoyl) anthranilic acid (ACA) derivatives were synthesized and evaluated using calcium imaging and electrophysiology approaches. Systematic structure-activity relationship studies resulted in some potent compounds inhibiting the TRPM2 channel with sub-micromolar half-maximal inhibitory concentration values. Among them, the preferred compound A23 exhibited TRPM2 selectivity over TRPM8 and TRPV1 channels as well as phospholipase A2 and showed neuroprotective activity in vitro. Following pharmacokinetic studies, A23 was further evaluated in a transient middle cerebral artery occlusion model in vivo, which significantly reduced cerebral infarction. These data indicate that A23 might serve as a useful tool for TRPM2-related research as well as a lead compound for the development of therapeutic agents for ischemic injury.

Neuroprotective effects of Myricetin on Epoxiconazole-induced toxicity in F98 cells

Epoxiconazole is one of the most commonly used fungicides in the world. The exposition of humans to pesticides is mainly attributed to its residue in food or occupational exposure in agricultural production. Because of its lipophilic character, Epoxiconazole can accumulate in the brain Heusinkveld et al. (2013) [1]. Consequently, it is urgent to explore efficient strategies to prevent or treat Epoxiconazole-related brain damages. The use of natural molecules commonly found in our diet represents a promising avenue. Flavonoids belong to a major sub-group compounds possessing powerful antioxidant activities based on their different structural and sterical properties [2]. We choose to evaluate Myricetin, a flavonoid with a wide spectrum of pharmacological effects, for its possible protective functions against Epoxiconazole-induced toxicities. The cytotoxicity induced by this fungicide was evaluated by the cell viability, cell cycle arrest, ROS generation, antioxidant enzyme activities, and Malondialdehyde production, as previously described in Hamdi et al., 2019 [3]. The apoptosis was assessed through the evaluation of the mitochondrial transmembrane potential (ΔΨm), caspases activation, DNA fragmentation, cytoskeleton disruption, nuclear condensation, appearance of sub-G0/G1 peak (fragmentation of the nucleus) and externalization of Phosphatidylserine. This study indicates that pre-treatment of F98 cells with Myricetin during 2 h before Epoxiconazole exposure significantly increased the survival of cells, restored DNA synthesis of the S phase, abrogated the ROS generation, regulated the activities of Catalase (CAT) and Superoxide Dismutase (SOD), and reduced the MDA level. The loss of mitochondrial membrane potential, DNA fragmentation, cytoskeleton disruption, chromatin condensation, Phosphatidylserine externalization, and Caspases activation were also reduced by Myricetin. Together, these findings indicate that Myricetin is a powerful natural product able to protect cells from Epoxiconazole-induced cytotoxicity and apoptosis.

Neuroprotective Effects of Coffee Bioactive Compounds: A Review

Coffee is one of the most widely consumed beverages worldwide. It is usually identified as a stimulant because of a high content of caffeine. However, caffeine is not the only coffee bioactive component. The coffee beverage is in fact a mixture of a number of bioactive compounds such as polyphenols, especially chlorogenic acids (in green beans) and caffeic acid (in roasted coffee beans), alkaloids (caffeine and trigonelline), and the diterpenes (cafestol and kahweol). Extensive research shows that coffee consumption appears to have beneficial effects on human health. Regular coffee intake may protect from many chronic disorders, including cardiovascular disease, type 2 diabetes, obesity, and some types of cancer. Importantly, coffee consumption seems to be also correlated with a decreased risk of developing some neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, and dementia. Regular coffee intake may also reduce the risk of stroke. The mechanism underlying these effects is, however, still poorly understood. This review summarizes the current knowledge on the neuroprotective potential of the main bioactive coffee components, i.e., caffeine, chlorogenic acid, caffeic acid, trigonelline, kahweol, and cafestol. Data from both in vitro and in vivo preclinical experiments, including their potential therapeutic applications, are reviewed and discussed. Epidemiological studies and clinical reports on this matter are also described. Moreover, potential molecular mechanism(s) by which coffee bioactive components may provide neuroprotection are reviewed.

Targeting Oxidative Stress and Inflammation to Prevent Ischemia-Reperfusion Injury

The cerebral ischemia injury can result in neuronal death and/or functional impairment, which leads to further damage and dysfunction after recovery of blood supply. Cerebral ischemia/reperfusion injury (CIRI) often causes irreversible brain damage and neuronal injury and death, which involves many complex pathological processes including oxidative stress, amino acid toxicity, the release of endogenous substances, inflammation and apoptosis. Oxidative stress and inflammation are interactive and play critical roles in ischemia/reperfusion injury in the brain. Oxidative stress is important in the pathological process of ischemic stroke and is critical for the cascade development of ischemic injury. Oxidative stress is caused by reactive oxygen species (ROS) during cerebral ischemia and is more likely to lead to cell death and ultimately brain death after reperfusion. During reperfusion especially, superoxide anion free radicals, hydroxyl free radicals, and nitric oxide (NO) are produced, which can cause lipid peroxidation, inflammation and cell apoptosis. Inflammation alters the balance between pro-inflammatory and anti-inflammatory factors in cerebral ischemic injury. Inflammatory factors can therefore stimulate or exacerbate inflammation and aggravate ischemic injury. Neuroprotective therapies for various stages of the cerebral ischemia cascade response have received widespread attention. At present, neuroprotective drugs mainly include free radical scavengers, anti-inflammatory agents, and anti-apoptotic agents. However, the molecular mechanisms of the interaction between oxidative stress and inflammation, and their interplay with different types of programmed cell death in ischemia/reperfusion injury are unclear. The development of a suitable method for combination therapy has become a hot topic.

Carvacryl acetate, a semisynthetic monoterpenic ester obtained from essential oils, provides neuroprotection against cerebral ischemia reperfusion-induced oxidative stress injury via the Nrf2 signalling pathway

Carvacryl acetate (CA) is a semisynthetic monoterpenic ester obtained from essential oils, and it exerts an antioxidation effect.

JLX001 Ameliorates Ischemia/Reperfusion Injury by Reducing Neuronal Apoptosis via Down-Regulating JNK Signaling Pathway

JLX001, a novel compound with similar structure with cyclovirobuxine D (CVB-D), has been proved to exert therapeutical effects on permanent focal cerebral ischemia. However, the protective effects of JLX001 on cerebral ischemia/reperfusion (I/R) injury and its anti-apoptotic effects have not been reported. We investigated the efficacy of JLX001 in two pharmacodynamic tests (pre-treatment test and post-treatment) with rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The pharmacodynamic tests demonstrated that JLX001 ameliorated I/R injury by reducing infarct sizes and brain edema. The results of Morris water maze, neurological scores, cylinder test and posture reflex test implied that JLX001 improved the learning, memory and motor ability after MCAO/R in the long term. Anti-apoptotic effects of JLX001 and its regulation of cytosolic c-Jun N-terminal Kinases (JNKs) signal pathway were confirmed in vivo by co-immunofluorescence staining and western immunoblotting. Furthermore, primary cortical neuron cultures were prepared and exposed to oxygen glucose deprivation/reoxygenation (OGD/R) for in vitro studies. Cytotoxicity test and mitochondrial membrane potential (MMP) test showed that JLX001 enhanced cell survival rate and maintained MMP. Flow cytometry and TdT-mediated dUTP-X nick end labeling (TUNEL) staining demonstrated the anti-apoptotic effects of JLX001 in vitro. Likewise, JLX001 regulated JNK signal pathway in vivo, which was also confirmed by western immunoblotting. Collectively, this study presents the first evidence that JLX001 exerted protective effects against I/R injury by reducing neuronal apoptosis via down-regulating JNK signaling pathway.

Nrf2 mediates the protective effect of edaravone after chlorpyrifos-induced nervous system toxicity

We aim to confirm the impairment of chlorpyrifos (CPF) in PC12 cells, evaluate the protective effect of edaravone on CPF-induced injury, and try to unravel its underlying mechanism perspective from Nrf2 signaling pathway. Viability of PC12 cells treated with CPF and edaravone (Ed) were evaluated by MTT assay. Cell apoptosis was observed by the Hoechst 33342 stain. The level of reactive oxygen species (ROS), the content of malondialdehyde (MDA), and the activity of superoxide dismutase (SOD) were detected to evaluate the oxidative stress injury. The expression of Nrf2 was detected by Western blot; profoundly, RNA interference was conducted to construct Nrf2 gene knockdown PC12 cells and to uncover its underlying mechanism. MTT results showed CPF injured PC12 cells in a concentration-dependent manner. Increased ROS and MDA content, decreased total SOD activity, or even apoptosis were occurred in PC12 cells when treated with CPF. Interestingly, CPF-induced cell injury was conspicuously reversed after Ed administration. Nrf2 signaling pathway was activated after Ed treatment and the neuroprotective effect of Ed was not significant in cells after Nrf2 gene knockdown. In conclusion, Ed exerts neuroprotective effect on CPF-induced oxidative stress injury and its mechanism was correlated with the Nrf2 signaling pathway.

Edaravone inhibits autophagy after neuronal oxygen-glucose deprivation/recovery injury

PURPOSE OF THE STUDY

Edaravone is an oxygen free radical scavenger that is widely used to treat ischemic injury to the nervous system. This study investigated the effect of edaravone pretreatment on neurons subjected to oxygen-glucose deprivation/recovery (OGD/R) injury.

MATERIALS AND METHODS

Common neurons were subjected to oxygen and glucose deprivation for 1 h, followed by oxygen and glucose recovery for 0.5, 2, 6 and 12 h to establish the OGD/R model. Autophagy was assessed by electron microscope observation of autophagosomes, cell immunofluorescence, mRFP-GFP-LC3 virus cell fluorescence and western blotting analyses of the autophagy-related proteins. The findings showed that at OGD/R 2 h autophagy was high. Next, neurons were pretreated with different concentrations of edaravone (0, 5, 10, 25, 50 and 100 μM) before establishing the OGD/R model. Western blotting was used to analyze the expression of autophagy-related proteins. The CCK-8 assay was used to analyze cell viability after pretreatment with different concentrations of edaravone. Optimal inhibition of autophagy was achieved with the concentration of edaravone 50 μM. Neurons pretreated with 50 μM edaravone and established OGD/R model were analyzed for autophagy levels.

RESULTS

At every OGD/R time point autophagy was lower in neurons pretreated with edaravone than in those not pretreated with the drug. The difference was statistically significant without OGD/R 12 h.

CONCLUSIONS

Pretreatment with edaravone may reduce the level of autophagy in neurons subjected to OGD/R injury.

A novel therapeutic potential of cysteinyl leukotrienes and their receptors modulation in the neurological complications associated with Alzheimer's disease

Cysteinyl leukotrienes (cysLTs) are member of eicosanoid inflammatory lipid mediators family produced by oxidation of arachidonic acid by action of the enzyme 5-lipoxygenase (5-LOX). 5-LOX is activated by enzyme 5-Lipoxygenase-activating protein (FLAP), which further lead to production of cysLTs i.e. leukotriene C4 (LTC4), leukotriene D4 (LTD4) and leukotriene E4 (LTE4). CysLTs then produce their potent inflammatory actions by activating CysLT1 and CysLT2 receptors. Inhibitors of cysLTs are indicated in asthma, allergic rhinitis and other inflammatory disorders. Earlier studies have associated cysLTs and their receptors in several neurodegenerative disorders diseases like, multiple sclerosis, Parkinson's disease, Huntington's disease, epilepsy and Alzheimer's disease (AD). These inflammatory lipid mediators have previously shown effects on various aggravating factors of AD. However, not much data has been elucidated to test their role against AD clinically. Herein, through this review, we have provided the current and emerging information on the role of cysLTs and their receptors in various neurological complications responsible for the development of AD. In addition, literature evidences for the effect of cysLT inhibitors on distinct aspects of abnormalities in AD has also been reviewed. Promising advancement in understanding on the role of cysLTs on the various neuromodulatory processes and mechanisms may contribute to the development of newer and safer therapy for the treatment of AD in future.