How is edaravone effective against acute ischemic stroke and amyotrophic lateral sclerosis?

Controlling redox state by edaravone at transplantation site enhances bone regeneration

In cell-based bone augmentation, transplanted cell dysfunction and apoptosis can occur due to oxidative stress caused by the overproduction of reactive oxygen species (ROS). Edaravone (EDA) is a potent free radical scavenger with potential medical applications. This study aimed to investigate the effect of controlling oxidative stress on bone regeneration using EDA. Bone marrow-derived cells were collected from 4-week-old rats, and EDA effects on cell viability and osteogenic differentiation were evaluated. Collagen gels containing PKH26-prelabeled cells were implanted into the calvarial defects of 12-week-old rats, followed by daily subcutaneous injections of normal saline or 500 μM EDA for 4 d. Bone formation was examined using micro-computed tomography and histological staining. Immunofluorescence staining was performed for markers of oxidative stress, macrophages, osteogenesis, and angiogenesis. EDA suppressed ROS production and hydrogen peroxide-induced apoptosis, recovering cell viability and osteoblast differentiation. EDA treatment in vivo increased new bone formation. EDA induced the transition of the macrophage population toward the M2 phenotype. The EDA group also exhibited stronger immunofluorescence for vascular endothelial growth factor and CD31. In addition, more PKH26-positive and PKH26-osteocalcin-double-positive cells were observed in the EDA group, indicating that transplanted cell survival was prolonged, and they differentiated into bone-forming cells. This could be attributed to oxidative stress suppression at the transplantation site by EDA. Collectively, local administration using EDA facilitates bone regeneration by improving the local environment and angiogenesis, prolonging survival, and enhancing the osteogenic capabilities of transplanted cells.

Hypoxic-Ischemic Encephalopathy: Pathogenesis and Promising Therapies

Hypoxic-ischemic encephalopathy (HIE) is a brain lesion caused by inadequate blood supply and oxygen deprivation, often occurring in neonates. It has emerged as a grave complication of neonatal asphyxia, leading to chronic neurological damage. Nevertheless, the precise pathophysiological mechanisms underlying HIE are not entirely understood. This paper aims to comprehensively elucidate the contributions of hypoxia-ischemia, reperfusion injury, inflammation, oxidative stress, mitochondrial dysfunction, excitotoxicity, ferroptosis, endoplasmic reticulum stress, and apoptosis to the onset and progression of HIE. Currently, hypothermia therapy stands as the sole standard treatment for neonatal HIE, albeit providing only partial neuroprotection. Drug therapy and stem cell therapy have been explored in the treatment of HIE, exhibiting certain neuroprotective effects. Employing drug therapy or stem cell therapy as adjunctive treatments to hypothermia therapy holds great significance. This article presents a systematic review of the pathogenesis and treatment strategies of HIE, with the goal of enhancing the effect of treatment and improving the quality of life for HIE patients.

Sodium Phenylbutyrate and Tauroursodeoxycholic Acid: A Story of Hope Turned to Disappointment in Amyotrophic Lateral Sclerosis Treatment

The absence of a definitive cure for amyotrophic lateral sclerosis (ALS) emphasizes the crucial need to explore new and improved treatment approaches for this fatal, progressive, and disabling neurodegenerative disorder. As at the end of 2023, five treatments - riluzole, edaravone, dextromethorphan hydrobromide + quinidine sulfate (DHQ), tofersen, and sodium phenylbutyrate-tauroursodeoxycholic acid (PB-TUDCA) - were FDA approved for the treatment of patients with ALS. Among them PB-TUDCA has been shown to impact DNA processing impairments, mitochondria dysfunction, endoplasmic reticulum stress, oxidative stress, and pathologic folded protein agglomeration defects, which have been associated with ALS pathophysiology. The Phase 2 CENTAUR trial demonstrated significant impact of PB-TUDCA on the ALS Functional Rating Scale-Revised (ALSFRS-R) risk of death, hospitalization, and the need for tracheostomy or permanent assisted ventilation in patients with ALS based on post hoc analyses. More recently, contrasting with the CENTAUR trial results, results from the Phase 3 PHOENIX trial (NCT05021536) showed no change in ALSFRS-R total score at 48 weeks. Consequently, the sponsor company initiated the process with the US FDA and Health Canada to voluntarily withdraw the marketing authorizations for PB-TUDCA. In the present article, we review ALS pathophysiology, with a focus on PB-TUDCA's proposed mechanisms of action and recent clinical trial results and discuss the implications of conflicting trial data for ALS and other neurological disorders.

Current therapy in amyotrophic lateral sclerosis (ALS): A review on past and future therapeutic strategies

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects the first and second motoneurons (MNs), associated with muscle weakness, paralysis and finally death. The exact etiology of the disease still remains unclear. Currently, efforts to develop novel ALS treatments which target specific pathomechanisms are being studied. The mechanisms of ALS pathogenesis involve multiple factors, such as protein aggregation, glutamate excitotoxicity, oxidative stress, mitochondrial dysfunction, apoptosis, inflammation etc. Unfortunately, to date, there are only two FDA-approved drugs for ALS, riluzole and edavarone, without curative treatment for ALS. Herein, we give an overview of the many pathways and review the recent discovery and preclinical characterization of neuroprotective compounds. Meanwhile, drug combination and other therapeutic approaches are also reviewed. In the last part, we analyze the reasons of clinical failure and propose perspective on the treatment of ALS in the future.

Natural products in the management of neurodegenerative diseases

Neurodegenerative diseases represent one of the utmost imperative well-being health issues and apprehensions due to their escalating incidence of mortality. Natural derivatives are more efficacious in various preclinical models of neurodegenerative illnesses. These natural compounds include phytoconstituents in herbs, vegetables, fruits, nuts, and marine and freshwater flora, with remarkable efficacy in mitigating neurodegeneration and enhancing cognitive abilities in preclinical models. According to the latest research, the therapeutic activity of natural substances can be increased by adding phytoconstituents in nanocarriers such as nanoparticles, nanogels, and nanostructured lipid carriers. They can enhance the stability and specificity of the bioactive compounds to a more considerable extent. Nanotechnology can also provide targeting, enhancing their specificity to the respective site of action. In light of these findings, this article discusses the biological and therapeutic potential of natural products and their bioactive derivatives to exert neuroprotective effects and some clinical studies assessing their translational potential to treat neurodegenerative disorders.

Edaravone Oral Suspension: A Neuroprotective Agent to Treat Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is characterized by loss of motor neurons due to degeneration of nerve cells within the brain and spinal cord. Early symptoms include limb weakness, twitching or muscle cramping, and slurred speech. As the disease progresses, difficulty breathing, swallowing, and paralysis can lead to death. Currently, there are no medications that cure ALS, and guidelines recommend treatments focused on symptom management. Intravenous (IV) edaravone was approved by the US Food and Drug Administration (FDA) in 2017 as a treatment to slow the progression of ALS. In May 2022, the FDA approved an oral suspension (ORS) formulation of edaravone.

MECHANISM OF ACTION

The mechanism of action of edaravone is not well defined. However, its neuroprotective effects are thought to result from antioxidant properties occurring through elimination of free radicals.

PHARMACOKINETICS

Edaravone ORS (105 mg) has a bioavailability of 57% when compared with edaravone IV (60 mg). The ORS should be taken on an empty stomach in the morning, with water and no food or beverages, for 1 hour. Edaravone is bound to albumin (92%), has a mean volume of distribution of 63.1 L, a half-life of 4.5-9 hours, and a total clearance of 35.9 L/h after intravenous administration. Edaravone is metabolized into nonactive sulfate and glucuronide conjugates.

CLINICAL TRIALS

The FDA approval was based on studies of the pharmacokinetics, safety, tolerability, and bioavailability of edaravone ORS. A phase III, global, multicenter, open-label safety study was conducted on edaravone ORS in 185 patients with ALS over 48 weeks. The most reported treatment-emergent adverse events were falls, muscular weakness, and constipation. Serious treatment-emergent adverse events included disease worsening, dysphagia, dyspnea, and respiratory failure.

THERAPEUTIC ADVANCE

Oral edaravone is an ALS treatment that can be self-administered or administered by a caregiver, precluding the need for administration by a health care professional in an institutional setting.

Oxidative Metabolism in Brain Ischemia and Preconditioning: Two Sides of the Same Coin

Brain ischemia is one of the major causes of chronic disability and death worldwide. It is related to insufficient blood supply to cerebral tissue, which induces irreversible or reversible intracellular effects depending on the time and intensity of the ischemic event. Indeed, neuronal function may be restored in some conditions, such as transient ischemic attack (TIA), which may be responsible for protecting against a subsequent lethal ischemic insult. It is well known that the brain requires high levels of oxygen and glucose to ensure cellular metabolism and energy production and that damage caused by oxygen impairment is tightly related to the brain's low antioxidant capacity. Oxygen is a key player in mitochondrial oxidative phosphorylation (OXPHOS), during which reactive oxygen species (ROS) synthesis can occur as a physiological side-product of the process. Indeed, besides producing adenosine triphosphate (ATP) under normal physiological conditions, mitochondria are the primary source of ROS within the cell. This is because, in 0.2-2% of cases, the escape of electrons from complex I (NADPH-dehydrogenase) and III of the electron transport chain occurring in mitochondria during ATP synthesis leads to the production of the superoxide radical anion (O2•-), which exerts detrimental intracellular effects owing to its high molecular instability. Along with ROS, reactive nitrosative species (RNS) also contribute to the production of free radicals. When the accumulation of ROS and RNS occurs, it can cause membrane lipid peroxidation and DNA damage. Here, we describe the intracellular pathways activated in brain tissue after a lethal/sub lethal ischemic event like stroke or ischemic tolerance, respectively, highlighting the important role played by oxidative stress and mitochondrial dysfunction in the onset of the two different ischemic conditions.

Edaravone Dexborneol mitigates pathology in animal and cell culture models of Alzheimer's disease by inhibiting neuroinflammation and neuronal necroptosis

BACKGROUND

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease with limited disease-modifying treatments. Drug repositioning strategy has now emerged as a promising approach for anti-AD drug discovery. Using 5×FAD mice and Aβ-treated neurons in culture, we tested the efficacy of Y-2, a compounded drug containing the antioxidant Edaravone (Eda), a pyrazolone and (+)-Borneol, an anti-inflammatory diterpenoid from cinnamon, approved for use in amyotrophic lateral sclerosis patients.

RESULTS

We examined effects of Y-2 versus Eda alone by i.p. administered in 8-week-old 5×FAD mice (females) for 4 months by comparing cognitive function, Aβ pathologies, neuronal necroptosis and neuroinflammation. Using primary neurons and astrocytes, as well as neuronal and astrocytic cell lines, we elucidated the molecular mechanisms of Y-2 by examining neuronal injury, astrocyte-mediated inflammation and necroptosis. Here, we find that Y-2 improves cognitive function in AD mice. Histopathological data show that Y-2, better than Eda alone, markedly ameliorates Aβ pathologies including Aβ burden, astrogliosis/microgliosis, and Tau phosphorylation. In addition, Y-2 reduces Aβ-induced neuronal injury including neurite damage, mitochondrial impairment, reactive oxygen species production and NAD+ depletion. Notably, Y-2 inhibits astrocyte-mediated neuroinflammation and attenuates TNF-α-triggered neuronal necroptosis in cell cultures and AD mice. RNA-seq further demonstrates that Y-2, compared to Eda, indeed upregulates anti-inflammation pathways in astrocytes.

CONCLUSIONS

Our findings infer that Y-2, better than Eda alone, mitigates AD pathology and may provide a potential drug candidate for AD treatment.

Luteolin-7-O-β-d-glucuronide Ameliorates Cerebral Ischemic Injury: Involvement of RIP3/MLKL Signaling Pathway

Luteolin-7-O-β-d-glucuronide (LGU) is a major active flavonoid glycoside compound that is extracted from Ixeris sonchifolia (Bge.) Hance, and it is a Chinese medicinal herb mainly used for the treatment of coronary heart disease, angina pectoris, cerebral infarction, etc. In the present study, the neuroprotective effect of LGU was investigated in an oxygen glucose deprivation (OGD) model and a middle cerebral artery occlusion (MCAO) rat model. In vitro, LGU was found to effectively improve the OGD-induced decrease in neuronal viability and increase in neuronal death by a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) leakage rate assay, respectively. LGU was also found to inhibit OGD-induced intracellular Ca2+ overload, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) decrease. By Western blotting analysis, LGU significantly inhibited the OGD-induced increase in expressions of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). Moreover, molecular docking analysis showed that LGU might bind to RIP3 more stably and firmly than the RIP3 inhibitor GSK872. Immunofluorescence combined with confocal laser analyses disclosed that LGU inhibited the aggregation of MLKL to the nucleus. Our results suggest that LGU ameliorates OGD-induced rat primary cortical neuronal injury via the regulation of the RIP3/MLKL signaling pathway in vitro. In vivo, LGU was proven, for the first time, to protect the cerebral ischemia in a rat middle cerebral artery occlusion (MCAO) model, as shown by improved neurological deficit scores, infarction volume rate, and brain water content rate. The present study provides new insights into the therapeutic potential of LGU in cerebral ischemia.

The Antioxidant Drug Edaravone Binds to the Aryl Hydrocarbon Receptor (AHR) and Promotes the Downstream Signaling Pathway Activation

A considerable effort has been spent in the past decades to develop targeted therapies for the treatment of demyelinating diseases, such as multiple sclerosis (MS). Among drugs with free radical scavenging activity and oligodendrocyte protecting effects, Edaravone (Radicava) has recently received increasing attention because of being able to enhance remyelination in experimental in vitro and in vivo disease models. While its beneficial effects are greatly supported by experimental evidence, there is a current paucity of information regarding its mechanism of action and main molecular targets. By using high-throughput RNA-seq and biochemical experiments in murine oligodendrocyte progenitors and SH-SY5Y neuroblastoma cells combined with molecular docking and molecular dynamics simulation, we here provide evidence that Edaravone triggers the activation of aryl hydrocarbon receptor (AHR) signaling by eliciting AHR nuclear translocation and the transcriptional-mediated induction of key cytoprotective gene expression. We also show that an Edaravone-dependent AHR signaling transduction occurs in the zebrafish experimental model, associated with a downstream upregulation of the NRF2 signaling pathway. We finally demonstrate that its rapid cytoprotective and antioxidant actions boost increased expression of the promyelinating Olig2 protein as well as of an Olig2:GFP transgene in vivo. We therefore shed light on a still undescribed potential mechanism of action for this drug, providing further support to its therapeutic potential in the context of debilitating demyelinating conditions.

Exploring antioxidant strategies in the pathogenesis of ALS

The central nervous system is essential for maintaining homeostasis and controlling the body's physiological functions. However, its biochemical characteristics make it highly vulnerable to oxidative damage, which is a common factor in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). ALS is a leading cause of motor neuron disease, characterized by a rapidly progressing and incurable condition. ALS often results in death from respiratory failure within 3-5 years from the onset of the first symptoms, underscoring the urgent need to address this medical challenge. The aim of this study is to present available data supporting the role of oxidative stress in the mechanisms underlying ALS and to discuss potential antioxidant therapies currently in development. These therapies aim to improve the quality of life and life expectancy for patients affected by this devastating disease.

Edaravone alleviated allergic airway inflammation by inhibiting oxidative stress and endoplasmic reticulum stress

Oxidative stress and endoplasmic reticulum stress (ERS) was associated with the development of asthma. Edaravone (EDA) plays a classical role to prevent the occurrence and development of oxidative stress-related diseases. Herein, we investigated the involvement and signaling pathway of EDA in asthma, with particular emphasis on its impact on type 2 innate lymphoid cells (ILC2) and CD4+T cells, and then further elucidated whether EDA could inhibit house dust mite (HDM)-induced allergic asthma by affecting oxidative stress and ERS. Mice received intraperitoneally injection of EDA (10 mg/kg, 30 mg/kg), dexamethasone (DEX) and N-acetylcysteine (NAC), with the latter two used as positive control drugs. DEX and high dose of EDA showed better therapeutic effects in alleviating airway inflammation and mucus secretion in mice, along with decreasing eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) than NAC. Further, the protein levels of IL-33 in lung tissues were inhibited by EDA, leading to reduced activation of ILC2s in the lung. EDA treatment alleviated the activation of CD4+ T cells in lung tissues of HDM-induced asthmatic mice and reduced Th2 cytokine secretion in BALF. ERS-related markers (p-eIF2α, IRE1α, CHOP, GRP78) were decreased after treatment of EDA compared to HDM group. Malondialdehyde (MDA), glutathione (GSH), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) were detected to evaluate the oxidant stress in lung tissues. EDA showed a protective effect against oxidant stress. In conclusion, our findings demonstrated that EDA could suppress allergic airway inflammation by inhibiting oxidative stress and ERS, suggesting to serve as an adjunct medication for asthma in the future.

Development of a Semi-Dry Method for Measuring Drug Permeation into Skin Using an Electric Facial Care Device and Iontophoresis

INTRODUCTION

Percutaneous drug delivery systems are attractive not only as a therapeutic strategy but also for cosmetic treatment. Iontophoresis is a well-recognized method for promoting transdermal absorption of ionized compounds. Franz cells are generally used to estimate drug permeation of skin by iontophoresis. However, methods using Franz cells are less versatile; for instance, the method is unsuited for use with a portable electric facial care device having a working probe of a certain size and weight. In this study, we constructed a semi-dry apparatus for use with an electric facial care device.

METHODS

The apparatus has a multilayer structure consisting of mouse skin and 3 filter papers, modeled after the Franz cell. The skin permeation of the drug edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) was then measured using this apparatus.

RESULTS

Edaravone permeation depended on working time, drug concentration, and ionization ratio of edaravone when iontophoresis was carried out with an electric facial care device. Furthermore, glycyrrhizic acid, α-tocopheryl phosphate, retinoic acid, and ascorbyl palmitate, which are recognized as functional cosmetic materials, also permeated the skin by applying iontophoresis with the device.

CONCLUSION

These results suggest that the developed measuring apparatus is applicable for use with a portable electric facial care device and that iontophoresis using a portable electric facial care device is potentially useful in the cosmetic field.

Enhanced the treatment of ischemic stroke through intranasal temperature-sensitive hydrogels of edaravone and borneol inclusion complex

Since ischemic stroke occurs by a combination of multiple mechanisms, therapies that modulate multiple mechanisms are required for its treatment. The combination of edaravone (EDA) and borneol can significantly ameliorate the symptoms of neurological deficits in cerebral ischemia-reperfusion model in rats. In this study, the solubility of borneol and edaravone was improved by hydroxypropyl-β-cyclodextrin and PEG400. Furthermore, a nasal temperature-sensitive hydrogel containing both edaravone and borneol inclusion complex (EDA-BP TSGS) was developed to overcome the obstacles of ischemic stroke treatment including the obstruction of the blood-brain barrier (BBB) and the unavailability and untimely of intravenous injection. The effectiveness of the thermosensitive hydrogel was investigated in transient middle cerebral artery occlusion/reperfusion model rats (MCAO/R). The results showed that EDA-BP TSGS could significantly alleviate the symptoms of neurological deficits and decrease the cerebral infarct area and the degree of brain damage. In summary, nasal EDA-BP TSGS is a secure and effective brain-targeting formulation that may provide a viable option for the clinical prophylaxis and treatment of ischemic stroke.

Hybrids of selective COX-2 inhibitors and active derivatives of edaravone as COX-2 selective NSAIDs with free radical scavenging activity: Design, synthesis and biological activities

Novel hybrids of selective COX-2 inhibitors (coxibs) and active derivatives of free radical scavenger edaravone were designed to overcome the risk of cardiovascular events and stroke increased by NSAIDs (nonsteroidal anti-inflammatory drugs) in this study. All the hybrids were assayed for the COX-2 inhibitory and DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging activities in vitro. Finally, we found a series of hybrids with good inhibitory activity and selectivity of COX-2 and excellent free radical scavenging activity in vitro. The most promising compound 6a (WYZ90) exhibited very potent COX-2 inhibitory activity (COX-2, IC50 = 75 nM), weak COX-1 inhibitory activity (COX-1, IC50 = 5734 nM), better free radical scavenging activity (DPPH, IC50 = 19.9 μM) than edaravone, moderate drug-likeness and ADME properties in silico, acceptable pharmacokinetic properties (T1/2 = 4.16 h, 10 mg/kg, o.p.) and oral bioavailability (F% = 36.03 %) in mice. In addition, compound WYZ90 showed similar analgesic activity to the selective COX-2 inhibitor celecoxib in acetic acid-induced mice and better antioxidant activity in Fe2+-induced lipid peroxidation in mouse liver tissue homogenate than edaravone. In conclusion, this study provided a novel class of coxibs containing edaravone moiety as COX-2 selective NSAIDs with free radical scavenging activity and the candidate compound WYZ90 showed not only similar selective COX-2 inhibitory and analgesic activity to celecoxib but also better free radical scavenging and antioxidant activity than edaravone.

Edaravone: A Novel Possible Drug for Cancer Treatment?

Despite significant advancements in understanding the causes and progression of tumors, cancer remains one of the leading causes of death worldwide. In light of advances in cancer therapy, there has been a growing interest in drug repurposing, which involves exploring new uses for medications that are already approved for clinical use. One such medication is edaravone, which is currently used to manage patients with cerebral infarction and amyotrophic lateral sclerosis. Due to its antioxidant and anti-inflammatory properties, edaravone has also been investigated for its potential activities in treating cancer, notably as an anti-proliferative and cytoprotective drug against side effects induced by traditional cancer therapies. This comprehensive review aims to provide updates on the various applications of edaravone in cancer therapy. It explores its potential as a standalone antitumor drug, either used alone or in combination with other medications, as well as its role as an adjuvant to mitigate the side effects of conventional anticancer treatments.

A Critical Appraisal of the Protective Activity of Polyphenolic Antioxidants against Iatrogenic Effects of Anticancer Chemotherapeutics

Polyphenolic compounds, encompassing flavonoids (e.g., quercetin, rutin, and cyanidin) and non-flavonoids (e.g., gallic acid, resveratrol, and curcumin), show several health-related beneficial effects, which include antioxidant, anti-inflammatory, hepatoprotective, antiviral, and anticarcinogenic properties, as well as the prevention of coronary heart diseases. Polyphenols have also been investigated for their counteraction against the adverse effects of common anticancer chemotherapeutics. This review evaluates the outcomes of clinical studies (and related preclinical data) over the last ten years, with a focus on the use of polyphenols in chemotherapy as auxiliary agents acting against oxidative stress toxicity induced by antitumor drugs. While further clinical studies are needed to establish adequate doses and optimal delivery systems, the improvement in polyphenols' metabolic stability and bioavailability, through the implementation of nanotechnologies that are currently being investigated, could improve therapeutic applications of their pharmaceutical or nutraceutical preparations in tumor chemotherapy.

Neuroprotective Effects of Probucol against Rotenone-Induced Toxicity via Suppression of Reactive Oxygen Species Production in SH-SY5Y Cells

Probucol is a hyperlipidemic drug with antioxidant properties. It has been reported to prevent mitochondrial dysfunction, reduce oxidative stress, and suppress neurotoxicity in neurodegenerative disease models, including Parkinson's disease models. However, the molecular mechanisms underlying the neuroprotective effects of probucol have been not examined yet. Thus, in this study, we investigated whether probucol can alleviate the effects of a mitochondrial complex I inhibitor, rotenone, on a human neuroblastoma cell line (SH-SY5Y). We evaluated the cell viability and cytotoxicity and apoptosis rates of SH-SY5Y cells treated with rotenone and probucol or edaravone, a known free-radical scavenger. Subsequently, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) levels in the cells were evaluated to determine the effects of probucol on mitochondrial function. We found that rotenone caused cytotoxicity, cell apoptosis, and mitochondrial dysfunction, enhanced ROS generation, and impaired MMP. However, probucol could inhibit this rotenone-induced decrease in cell viability, MMP loss, intracellular ROS generation, and apoptosis. These results suggest that probucol exerts neuroprotective effects via MMP stabilization and the inhibition of ROS generation. Additionally, this effect of probucol was equal to or greater than and more persistent than that of edaravone. Thus, we believe probucol may be a promising drug for the treatment of neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases.

Neurodegenerative Diseases: New Hopes and Perspectives

Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, Huntington's disease, and Friedrich ataxia are all incurable neurodegenerative diseases defined by the continuous progressive loss of distinct neuronal subtypes. Despite their rising prevalence among the world's ageing population, fewer advances have been made in the concurrent massive efforts to develop newer drugs. Recently, there has been a shift in research focus towards the discovery of new therapeutic agents for neurodegenerative diseases. In this review, we have summarized the recently developed therapies and their status in the management of neurodegenerative diseases.

Development of Pharmacological Strategies with Therapeutic Potential in Ischemic Stroke

Acute ischemic stroke constitutes a health challenge with great social impact due to its high incidence, with the social dependency that it generates being an important source of inequality. The lack of treatments serving as effective neuroprotective therapies beyond thrombolysis and thrombectomy is presented as a need. With this goal in mind, our research group's collaborative studies into cerebral ischemia and subsequent reperfusion concluded that there is a need to develop compounds with antioxidant and radical scavenger features. In this review, we summarize the path taken toward the identification of lead compounds as potential candidates for the treatment of acute ischemic stroke. Evaluations of the antioxidant capacity, neuroprotection of primary neuronal cultures and in vivo experimental models of cerebral ischemia, including neurological deficit score assessments, are conducted to characterize the biological efficacy of the various neuroprotective compounds developed. Moreover, the initial results in preclinical development, including dose-response studies, the therapeutic window, the long-term neuroprotective effect and in vivo antioxidant evaluation, are reported. The results prompt these compounds for clinical trials and are encouraging regarding new drug developments aimed at a successful therapy for ischemic stroke.

Edaravone Confers Neuroprotective, Anti-inflammatory, and Antioxidant Effects on the Fetal Brain of a Placental-ischemia Mouse Model

Reduced uterine perfusion pressure (RUPP) is a well-established model which mimics many clinical features of preeclampsia (PE). Edaravone is a free radical scavenger with neuroprotective, antioxidant and anti-inflammatory effects against different models of cerebral ischemia. Therefore, we aimed to elucidate the different potential mechanisms through which PE affects fetal brain development using our previously established RUPP-placental ischemia mouse model. In addition, we investigated the neuroprotective effect of edaravone against the RUPP-induced fetal brain development alterations. On gestation day (GD) 13, pregnant mice were divided into four groups; sham (SV), edaravone (SE), RUPP (RV), and RUPP+edaravone (RE). SV and SE groups underwent sham surgeries, however, RV and RE groups were subjected to RUPP surgery via bilateral uterine ligation. Edaravone (3mg/kg) was injected via tail i.v. injection from GD 14-18. The fetal brains from different groups were collected on GD 18 and subjected to further investigations. The results showed that RUPP altered the structure of fetal brain cortex, induced neurodegeneration, increased the expression of the investigated pro-inflammatory markers; TNF-α, IL-6, IL-1β, and MMP-9. RUPP resulted in microglial and astrocyte activation in the fetal brains, in addition to upregulation of Hif-1α and iNOS. Edaravone conferred a neuroprotective effect via alleviating the inflammatory response, restoring the neuronal structure and decreasing oxidative stress in the developing fetal brain. In conclusion, RUPP-placental ischemia mouse model could be a useful tool to further understand the underlying mechanisms of PE-induced child neuronal alterations. Edaravone could be a potential adjuvant therapy during PE to protect the developing fetal brain. The current study investigated the effects of a placenta-induced ischemia mouse model using reduced uterine perfusion pressure (RUPP) surgery on the fetal brain development and the potential neuroprotective effects of the drug edaravone. The study found that the RUPP model caused neurodegeneration and a pro-inflammatory response in the developing fetal brain, as well as hypoxia and oxidative stress. However, maternal injection of edaravone showed a strong ability to protect against these detrimental effects and target multiple pathways associated with neuronal damage. The current study suggests that the RUPP model could be useful for further study of the impact of preeclampsia on fetal brain development and that edaravone may have potential as a therapy for protecting against this damage.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Attenuation of LPS-Induced Lung Injury by Benziodarone via Reactive Oxygen Species Reduction

As overproduction of reactive oxygen species (ROS) causes various diseases, antioxidants that scavenge ROS, or inhibitors that suppress excessive ROS generation, can be used as therapeutic agents. From a library of approved drugs, we screened compounds that reduced superoxide anions produced by pyocyanin-stimulated leukemia cells and identified benzbromarone. Further investigation of several of its analogues showed that benziodarone possessed the highest activity in reducing superoxide anions without causing cytotoxicity. In contrast, in a cell-free assay, benziodarone induced only a minimal decrease in superoxide anion levels generated by xanthine oxidase. These results suggest that benziodarone is an inhibitor of NADPH oxidases in the plasma membrane but is not a superoxide anion scavenger. We investigated the preventive effect of benziodarone on lipopolysaccharide (LPS)-induced murine lung injury as a model of acute respiratory distress syndrome (ARDS). Intratracheal administration of benziodarone attenuated tissue damage and inflammation via its ROS-reducing activity. These results indicate the potential application of benziodarone as a therapeutic agent against diseases caused by ROS overproduction.

Current State and Future Directions in the Therapy of ALS

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder affecting upper and lower motor neurons, with death resulting mainly from respiratory failure three to five years after symptom onset. As the exact underlying causative pathological pathway is unclear and potentially diverse, finding a suitable therapy to slow down or possibly stop disease progression remains challenging. Varying by country Riluzole, Edaravone, and Sodium phenylbutyrate/Taurursodiol are the only drugs currently approved in ALS treatment for their moderate effect on disease progression. Even though curative treatment options, able to prevent or stop disease progression, are still unknown, recent breakthroughs, especially in the field of targeting genetic disease forms, raise hope for improved care and therapy for ALS patients. In this review, we aim to summarize the current state of ALS therapy, including medication as well as supportive therapy, and discuss the ongoing developments and prospects in the field. Furthermore, we highlight the rationale behind the intense research on biomarkers and genetic testing as a feasible way to improve the classification of ALS patients towards personalized medicine.

Development of Edaravone Ionic Liquids and Their Application for the Treatment of Cerebral Ischemia/Reperfusion Injury

Preparation of the ionic liquid (IL) form of active pharmaceutical ingredients (APIs), termed API-IL, has attracted attention because it can improve upon certain disadvantages of APIs, such as poor water solubility and low stability. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) is a clinically approved cerebroprotective agent against ischemic stroke and amyotrophic lateral sclerosis, while new formulations that enable improvement of its physicochemical properties and biodistribution are desired. Herein, we report a newly developed API-IL of edaravone (edaravone-IL), in which edaravone is used as an anionic molecule. We investigated the physicochemical properties of edaravone-IL and its therapeutic effect against cerebral ischemia/reperfusion (I/R) injury, a secondary injury after an ischemic stroke. Among the cationic molecules used for edaravone-IL preparation, the IL prepared with tetrabutylphosphonium cation existed as a liquid at room temperature, and significantly increased the water solubility of edaravone without decreasing its antioxidative activity. Importantly, edaravone-IL formed negatively charged nanoparticles upon suspension in water. Intravenous administration of edaravone-IL showed significantly higher blood circulation time and lower distribution in the kidney compared with edaravone solution. Moreover, edaravone-IL significantly suppressed brain cell damage and motor functional deficits in model rats of cerebral I/R injury and showed comparable cerebroprotective effect to edaravone. Taken together, these results suggest that edaravone-IL could be a new form of edaravone with superior physicochemical properties and could be useful for the treatment of cerebral I/R injury.

Acute and Sub-chronic Anticonvulsant Effects of Edaravone on Seizure Induced by Pentylenetetrazole or Electroshock in Mice, Nitric Oxide Involvement

Background

Edaravone is an anti-stroke medication that may have nitric oxide (NO) modulating properties. This study evaluated the role of NO in the acute and sub-chronic anticonvulsant effects of edaravone in murine models of seizures induced by intraperitoneal (IP) or intravenous (IV) injections of pentylenetetrazole (PTZ) or electroshock (maximal electroshock seizure [MES]).

Methods

132 male albino mice were randomly divided into 22 groups (n=6) and given IP injections of vehicle or edaravone either acutely or for eight days (sub-chronically). The seizure was induced by electroshock or PTZ (IP or IV). The following edaravone doses were used: 7.5, 10, 12.5 (acute); 5, 7.5, 10 (sub-chronic) in IP PTZ model; 5, 7.5, 10 in IV PTZ model; and 5, 10 mg/Kg in the MES. To evaluate NO involvement, 216 mice were randomly divided into 36 groups (n=6) and pretreated with vehicle, edaravone, a non-specific nitric oxide synthase (NOS) inhibitor: N(ω)-nitro-L-arginine methyl ester (L-NAME) (5 mg/Kg), a specific nNOS inhibitor: 7-nitroindazole (7-NI) (60 mg/Kg), or a combination of edaravone plus L-NAME or 7-NI, either acutely or for eight days before seizure induction. Doses of edaravone were as follows: in IP PTZ model: 12.5 (acute) and 10 (sub-chronic); in IV PTZ model: 10; and in the MES: 5 mg/Kg. Data were analyzed using the one-way analysis of variance (ANOVA) followed by Tukey's test (SPSS 18). P≤0.05 was considered statistically significant.

Results

In the IP PTZ model, edaravone increased time latencies to seizures (P<0.001), prevented tonic seizures, and death. Edaravone increased the seizure threshold (P<0.001) in the IV PTZ model and shortened the duration of tonic hind-limb extension (THE) in the MES model (P<0.001). In comparison to mice treated with edaravone alone, adding L-NAME or 7-NI reduced seizure time latencies (P<0.001), reduced seizure threshold (P<0.001), and increased THE duration (P<0.001).

Conclusion

Edaravone (acute or sub-chronic) could prevent seizures by modulating NO signaling pathways.

Defense systems to avoid ferroptosis caused by lipid peroxidation-mediated membrane damage

The presence of hydrogen peroxide along with ferrous iron produces hydroxyl radicals that preferably oxidize polyunsaturated fatty acids (PUFA) to alkyl radicals (L•). The reaction of L• with an oxygen molecule produces lipid peroxyl radical (LOO•) that collectively trigger chain reactions, which results in the accumulation of lipid peroxidation products (LOOH). Oxygenase enzymes, such as lipoxygenase, also stimulate the peroxidation of PUFA. The production of phospholipid hydroperoxides (P-LOOH) can result in the destruction of the architecture of cell membranes and ultimate cell death. This iron-dependent regulated cell death is generally referred to as ferroptosis. Radical scavengers, which include tocopherol and nitric oxide (•NO), react with lipid radicals and terminate the chain reaction. When tocopherol reductively detoxifies lipid radicals, the resultant tocopherol radicals are recycled via reduction by coenzyme Q or ascorbate. CoQ radicals are reduced back by the anti-ferroptotic enzyme FSP1. •NO reacts with lipid radicals and produces less reactive nitroso compounds. The resulting P-LOOH is reductively detoxified by the action of glutathione peroxidase 4 (GPX4) or peroxiredoxin 6 (PRDX6). The hydrolytic removal of LOOH from P-LOOH by calcium-independent phospholipase A2 leads the preservation of membrane structure. While the expression of such protective genes or the presence of these anti-oxidant compounds serve to maintain a healthy condition, tumor cells employ them to make themselves resistant to anti-tumor treatments. Thus, these defense mechanisms against ferroptosis are protective in ordinary cells but are also potential targets for cancer treatment.

Critical Roles of the Cysteine-Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System

γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys-GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys-GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.

Masitinib: The promising actor in the next season of the Amyotrophic Lateral Sclerosis treatment series

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease with high mortality and morbidity rate affecting both upper and lower motor neurons (MN). Muscle force reduction, behavioral change, pseudobulbar affect, and cognitive impairments are the most common clinical manifestations of ALS. The main physiopathology of ALS is still unclear, though several studies have identified that oxidative stress, proteinopathies, glutamate-related excitotoxicity, microglial activation, and neuroinflammation may be involved in the pathogenesis of ALS. From 1995 until October 2022, only Riluzole, Dextromethorphan Hydrobromide (DH) with Quinidine sulfate (Q), Edaravone, and Sodium phenylbutyrate with Taurursodiol (PB/TUDCO) have achieved FDA approval for ALS treatment. Despite the use of these four approved agents, the survival rate and quality of life of ALS patients are still low. Thus, finding novel treatments for ALS patients is an urgent requirement. Masitinib, a tyrosine kinase inhibitor, emphasizes the neuro-inflammatory activity of ALS by targeting macrophages, mast cells, and microglia cells. Masitinib downregulates the proinflammatory cytokines, indirectly reduces inflammation, and induces neuroprotection. Also, it was effective in phase 2/3 and 3 clinical trials (CTs) by increasing overall survival and delaying motor, bulbar, and respiratory function deterioration. This review describes the pathophysiology of ALS, focusing on Masitinib's mechanism of action and explaining why Masitinib could be a promising actor in the treatment of ALS patients. In addition, Masitinib CTs and other competitor drugs in phase 3 CTs have been discussed.

Enhancing the Neuroprotection Potential of Edaravone in Transient Global Ischemia Treatment with Glutathione- (GSH-) Conjugated Poly(methacrylic acid) Nanogel as a Promising Carrier for Targeted Brain Drug Delivery

Ischemic stroke is the most common among various stroke types and the second leading cause of death, worldwide. Edaravone (EDV) is one of the cardinal antioxidants that is capable of scavenging reactive oxygen species, especially hydroxyl molecules, and has been already used for ischemic stroke treatment. However, poor water solubility, low stability, and bioavailability in aqueous media are major EDV drawbacks. Thus, to overcome the aforementioned drawbacks, nanogel was exploited as a drug carrier of EDV. Furthermore, decorating the nanogel surface with glutathione as targeting ligands would potentiate the therapeutic efficacy. Nanovehicle characterization was assessed with various analytical techniques. Size (199 nm, hydrodynamic diameter) and zeta potential (-25 mV) of optimum formulation were assessed. The outcome demonstrated a diameter of around 100 nm, sphere shape, and homogenous morphology. Encapsulation efficiency and drug loading were determined to be 99.9% and 37.5%, respectively. In vitro drug release profile depicted a sustained release process. EDV and glutathione presence in one vehicle simultaneously made the possibility of antioxidant effects on the brain in specific doses, which resulted in elevated spatial memory and learning along with cognitive function in Wistar rats. In addition, significantly lower MDA and PCO and higher levels of neural GSH and antioxidant levels were observed, while histopathological improvement was approved. The developed nanogel can be a suited vehicle for drug delivery of EDV to the brain and improve ischemia-induced oxidative stress cell damage.

Ultrasmall iron-gallic acid coordination polymer nanodots with antioxidative neuroprotection for PET/MR imaging-guided ischemia stroke therapy

Oxidative stress from reactive oxygen species (ROS) is a reperfusion injury factor that can lead to cell damage and death. Here, ultrasmall iron-gallic acid coordination polymer nanodots (Fe-GA CPNs) were developed as antioxidative neuroprotectors for ischemia stroke therapy guided by PET/MR imaging. As proven by the electron spin resonance spectrum, the ultrasmall Fe-GA CPNs with ultrasmall size, scavenged ROS efficiently. In vitro experiments revealed that Fe-GA CPNs could protect cell viability after being treated with hydrogen peroxide (H2O2) and displayed the effective elimination of ROS by Fe-GA CPNs, which subsequently restores oxidation balance. When analyzing the middle cerebral artery occlusion model, the neurologic damage displayed by PET/MR imaging revealed a distinct recovery after treatment with Fe-GA CPNs, which was proved by 2,3,5-triphenyl tetrazolium chloride staining. Furthermore, immunohistochemistry staining indicated that Fe-GA CPNs inhibited apoptosis through protein kinase B (Akt) restoration, whereas western blot and immunofluorescence indicated the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) pathway following Fe-GA CPNs application. Therefore, Fe-GA CPNs exhibit an impressive antioxidative and neuroprotective role via redox homeostasis recovery by Akt and Nrf2/HO-1 pathway activation, revealing its potential for clinical ischemia stroke treatment.

Signature-Based Computational Drug Repurposing for Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease characterized by progressive loss of the upper and lower motor neurons. There are currently limited approved drugs for the disorder, and for this reason the strategy of repositioning already approved therapeutics could exhibit a successful outcome. Herein, we used CMAP and L1000CDS2 databases which include gene expression profiles datasets (genomic signatures) to identify potent compounds and classes of compounds which reverse disease's signature which could in turn reverse its phenotype. ALS signature was obtained by comparing gene expression of muscle biopsy specimens between diseased and healthy individuals. Statistical analysis was conducted to explore differentially transcripts in patients' samples. Then, the list of upregulated and downregulated genes was used to query both databases in order to determine molecules which downregulate the genes which are upregulated by ALS and vice versa. These compounds, based on their chemical structure along with known treatments, were clustered to reveal drugs with novel and potentially more effective mode of action with most of them predicted to affect pathways heavily involved in ALS. This evidence suggests that these compounds are strong candidates for moving to the next phase of the drug repurposing pipeline which is in vitro and in vivo experimental evaluation.

Application of regulation of reactive oxygen species and lipid peroxidation to disease treatment

Although many diseases in which reactive oxygen species (ROS) and free radicals are involved in their pathogenesis are known, and antioxidants that effectively capture ROS have been identified and developed, there are only a few diseases for which antioxidants have been used for treatment. Here, we discuss on the following four concepts regarding the development of applications for disease treatment by regulating ROS, free radicals, and lipid oxidation with the findings of our research and previous reports. Concept 1) Utilization of antioxidants for disease treatment. In particular, the importance of the timing of starting antioxidant will be discussed. Concept 2) Therapeutic strategies using ROS and free radicals. Methods of inducing ferroptosis, which has been advocated as an iron-dependent cell death, are mentioned. Concept 3) Treatment with drugs that inhibit the synthesis of lipid mediators. In addition to the reduction of inflammatory lipid mediators by inhibiting cyclooxygenase and leukotriene synthesis, we will introduce the possibility of disease treatment with lipoxygenase inhibitors. Concept 4) Disease treatment by inducing the production of useful lipid mediators for disease control. We describe the treatment of inflammatory diseases utilizing pro-resolving mediators and propose potential compounds that activate lipoxygenase to produce these beneficial mediators.

Versatile and Sustainable Approach to Access Biologically Relevant Chromeno[2,3-b]pyridine and Benzylpyrazolyl Coumarin Derivatives Using Graphitic Carbon Nitride as a Reusable Heterogeneous Catalyst

Herein, the synthesis of graphitic carbon nitride (g-C₃N₄) via the simple heating of cheap and readily available urea as the starting material has been reported. The catalytic activity of the prepared g-C₃N₄ was investigated for the synthesis of chromeno[2,3-b]pyridine and benzylpyrazolyl coumarin derivatives in an ethanol medium. The reactions were performed under mild conditions to achieve widely functionalized target products in a one-pot operation. The as-synthesized g-C₃N₄, being a heterogeneous catalyst, demonstrates excellent recyclability up to the 5th consecutive run without a significant decrease in its catalytic activity and yield of the product. A gram-scale reaction was performed to demonstrate the industrial applications of the present protocol. The green chemistry metrics such as environmental factor (E-factor), atom economy (AE), carbon efficiency (CE), and reaction mass efficiency (RME) were calculated and found to be very close to the ideal values. Additionally, operation simplicity, wide substrate scope, easy reusability of the catalyst, and avoidance of metal contamination in the products drive the process toward green and sustainable development.

Food Effect Study to Assess the Impact on Edaravone Pharmacokinetic Profiles in Healthy Participants

PURPOSE

The safety and efficacy of intravenous edaravone, a neuroprotectant used for the treatment of amyotrophic lateral sclerosis (ALS), have been shown in clinical trials. An oral suspension of edaravone has been developed, but the food effect on its pharmacokinetic profile has not been evaluated. This study aimed to assess the food effect on the pharmacokinetic profile of edaravone after oral administration and to investigate dosing regimens and administration instructions with different meal intake and timing.

METHODS

Data from 3 Phase I clinical studies were used to evaluate the effect of food on the pharmacokinetic profiles of a single dose of edaravone oral suspension. In all 3 studies, participants received a single dose of edaravone with various meal conditions. Healthy Japanese adult male participants (Studies 1, 2, and 3) or female participants (Study 3) aged 20 to 45 years at the time of informed consent were included.

FINDINGS

In Study 1, 6 participants were enrolled and 5 completed the study. Nine and 16 participants were treated in Studies 2 and 3, respectively, and all completed the study. The C_max and AUC_0-∞ of edaravone were lower when administered 30 minutes after a high-fat meal compared with those in a fasted condition (Study 1). Lower plasma edaravone concentrations (approximately within the first hour) and subsequent lower C_max and AUC_0-∞ were observed after administration of edaravone 4 hours after a high-fat meal (Study 2) or 2 hours after a low-fat meal (Study 3). The C_max and AUC_0-∞ of oral edaravone were generally similar and not affected when administered 8 hours after a high-fat meal, 4 hours after a low-fat meal, or 2 hours after a light meal relative to the fasted condition. Administration of edaravone 1 hour before a high-fat meal resulted in no effect on C_max or AUC_0-∞ relative to the fasted condition. Administration of edaravone in the fed or fasted conditions resulted in a similar urine pharmacokinetic profile.

IMPLICATIONS

Oral administration of edaravone with a meal decreased the plasma concentration of edaravone. Oral administration of edaravone 8 hours after a high-fat meal, 4 hours after a low-fat meal, 2 hours after a light meal, and 1 hour before a high-fat meal showed no effect of food on the PK profile of unchanged edaravone compared with that observed under a fasted condition.

CLINICALTRIALS

gov identifiers: NCT04481750, NCT04481789, and NCT05342597.

Cerebral Malaria and Neuronal Implications of Plasmodium Falciparum Infection: From Mechanisms to Advanced Models

Reorganization of host red blood cells by the malaria parasite Plasmodium falciparum enables their sequestration via attachment to the microvasculature. This artificially increases the dwelling time of the infected red blood cells within inner organs such as the brain, which can lead to cerebral malaria. Cerebral malaria is the deadliest complication patients infected with P. falciparum can experience and still remains a major public health concern despite effective antimalarial therapies. Here, the current understanding of the effect of P. falciparum cytoadherence and their secreted proteins on structural features of the human blood-brain barrier and their involvement in the pathogenesis of cerebral malaria are highlighted. Advanced 2D and 3D in vitro models are further assessed to study this devastating interaction between parasite and host. A better understanding of the molecular mechanisms leading to neuronal and cognitive deficits in cerebral malaria will be pivotal in devising new strategies to treat and prevent blood-brain barrier dysfunction and subsequent neurological damage in patients with cerebral malaria.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

Exploring the effects of edaravone in rats with contrast-induced acute kidney injury

AIMS

Oxidative stress and inflammatory response play a vital role in the pathogenesis of contrast-induced acute kidney injury (CI-AKI). This study investigated the effects of edaravone in rats with CI-AKI.

MAIN METHODS

Male Sprague Dawley rats were randomly assigned into four groups (n = 11-14/group): control, edaravone (30 mg/kg/day intraperitoneally (IP)), CI-AKI, and edaravone with CI-AKI. The induction of CI-AKI was performed by dehydration and the administration of contrast media (iohexol) and inhibitors of prostaglandin (indomethacin) and nitric oxide synthesis (L-NAME: N-nitro L-arginine methyl ester). Edaravone was administered for two weeks before the induction of CI-AKI. Serum creatinine and urea, renal oxidative stress and inflammatory biomarkers, and histopathological alterations were evaluated after 48 h of contrast exposure.

KEY FINDINGS

Rats with CI-AKI showed a significant increase in serum creatinine and urea. The levels of antioxidant biomarkers including glutathione peroxidase, superoxide dismutase and reduced glutathione were significantly decreased in CI-AKI group versus control. Pre-treatment of rats with edaravone normalized kidney function and protected the kidney from oxidative damage as demonstrated by normalization of previous biomarkers. Furthermore, edaravone partially ameliorated renal histopathological alterations relative to the CI-AKI group, notably in the nephrons. No changes were observed in inflammatory biomarkers including tumour necrosis factor-alpha and interleukin-6 among all groups.

SIGNIFICANCE

The current findings suggest that edaravone could be a potential strategy to ameliorate developing CI-AKI possibly by improving renal antioxidant capacity. Further studies are warranted to expand the current understanding of the use of edaravone in the various models of AKI.

Therapeutic Effect of Icaritin on Cerebral Ischemia-Reperfusion-Induced Senescence and Apoptosis in an Acute Ischemic Stroke Mouse Model

An ischemic stroke is brain damage caused by interruption of blood supply to the brain that can cause death and long-term disability. New medical strategies or therapies are urgently needed for ischemic stroke. Icaritin (ICT) is a metabolite of icariin (ICA), which are two active flavonoid components extracted from Herba epimedii and considered neuroprotective agents in animal models of Alzheimer’s disease and ischemic stroke. The therapeutic effect of ICT on ischemic still remains to be clarified. The aim of this study was to investigate the therapeutic effect of ICT on cerebral ischemia-reperfusion-associated senescence and apoptosis in a middle cerebral artery occlusion (MCAO) mouse model (ischemia for 50 min and reperfusion for 24 h). Administration of ICT after ischemia significantly reduced MCAO-induced neurological damage, infarct volume, and histopathological changes in the brain of acute ischemic stroke mice. ICT treatment could also reduce neuronal apoptosis and senescence and reversed the expression of apoptosis- and senescence-related signaling proteins. These findings suggest that ICT may have therapeutic potential to ameliorate acute ischemic stroke.

Edaravone Dexborneol Alleviates Cerebral Ischemic Injury via MKP-1-Mediated Inhibition of MAPKs and Activation of Nrf2

The edaravone and dexborneol concentrated solution for injection (edaravone-dexborneol) is a medication used clinically to treat neurological impairment induced by ischemic stroke. This study was aimed at investigating the preventive effects and the underlying mechanisms of edaravone-dexborneol on cerebral ischemic injury. A rat four-vessel occlusion (4-VO) model was established, and the neuronal injury and consequent neurological impairment of rats was investigated. Brain tissue malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) levels were determined. The levels of proteins in mitogen-activated protein kinases (MAPKs), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-κB (NF-κB) signaling pathways were determined by western immunoblotting. The function of mitogen-activated protein kinase phosphatase 1 (MKP-1) was investigated using both western blot and immunofluorescence methods, and the effect of the MKP-1 inhibitor, (2E)-2-benzylidene-3-(cyclohexylamino)-3H-inden-1-one (BCI), was investigated. The results indicated that edaravone-dexborneol alleviated neurological deficiency symptoms and decreased apoptosis and neuron damage in the hippocampal CA1 area of the ischemic rats. Edaravone-dexborneol increased the MKP-1 level; decreased the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK); inhibited NF-κB p65 activation; and boosted Nrf2 activation, all of which were partially reversed by the MKP-1 inhibitor, BCI. The above results indicated that the upregulation of MKP-1 contributed to the protective effects of edaravone-dexborneol against ischemic brain injury. Our findings support the hypothesis that edaravone-dexborneol can alleviate cerebral ischemic injury via the upregulation of MKP-1, which inhibits MAPKs and activates Nrf2.

Pharmacotherapy for Amyotrophic Lateral Sclerosis: A Review of Approved and Upcoming Agents

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder involving loss of upper and lower motor neurons, with most cases ending in death within 3-5 years of onset. Several molecular and cellular pathways have been identified to cause ALS; however, treatments to stop or reverse disease progression are yet to be found. Riluzole, a neuroprotective agent offering only a modest survival benefit, has long been the sole disease-modifying therapy for ALS. Edaravone, which demonstrated statistically significant slowing of ALS disease progression, is gaining approval in an increasing number of countries since its first approval in 2015. Sodium phenylbutyrate and taurursodiol (PB-TURSO) was conditionally approved in Canada in 2022, having shown significant slowing of disease progression and prolonged survival. Most clinical trials have focused on testing small molecules affecting common cellular pathways in ALS: targeting glutamatergic, apoptotic, inflammatory, and oxidative stress mechanisms among others. More recently, clinical trials utilizing stem cell transplantation and other biologics have emerged. This rich and ever-growing pipeline of investigational products, along with innovative clinical trial designs, collaborative trial networks, and an engaged ALS community', provide renewed hope to finding a cure for ALS. This article reviews existing ALS therapies and the current clinical drug development pipeline.

Edaravone Dexborneol Downregulates Neutrophil Extracellular Trap Expression and Ameliorates Blood-Brain Barrier Permeability in Acute Ischemic Stroke

Background

Our previous work has shown that inflammatory processes play a detrimental role in the pathophysiology of acute ischemic stroke (AIS). Neutrophil extracellular traps (NETs) have been recognized as a key contributor to the proinflammatory response in AIS and could aggravate blood-brain barrier (BBB) damage. Recently, experimental and clinical researches showed that Edaravone Dexborneol (Eda.B), which is comprised of two active ingredients, Edaravone and (+)-Borneol, was effective in treatment of AIS. However, it is not clear whether the effects of Eda.B against AIS are related to NETs and BBB permeability.

Methods

Experiment 1 was to detect the effects of Eda.B in AIS patients. Serum samples of volunteers and AIS patients were collected before and 3 days after Edaravone Dexborneol treatment. Markers of NETs and occludin were detected by ELISA kit. Experiment 2 was to explore the effects of Eda.B on experimental stroke mice. Male C57BL/6 mice were subjected to distal middle cerebral artery occlusion (MCAO) and treated with vehicle, Eda.B, or DeoxyribonueleaseI (DNase I). After stroke, the neurobehavioral tests, infarct volume, and cerebral blood flow evaluation were determined. Leakage of Evans blue was to assess the integrity of BBB. Western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence were used to examine the expression of NETs and tight junction- (TJ-) associated proteins.

Results

Eda.B significantly improved neurological function and cerebral blood flow but reduced infarct volume after experimental stroke. Eda.B downregulated level of NETs in serum samples of AIS patients and tissue samples of MCAO mouse cortex. Eda.B and DNase I alleviated BBB permeability by upregulating TJ-associated proteins.

Conclusion

NETs are related to the early stage of AIS. Eda.B exerted neuroprotective effects and ameliorated BBB permeability after AIS.

Edaravone Attenuated Angiotensin II-Induced Atherosclerosis and Abdominal Aortic Aneurysms in Apolipoprotein E-Deficient Mice

Background: The aim of the study was to define whether edaravone, a free-radical scavenger, influenced angiotensin II (AngII)-induced atherosclerosis and abdominal aortic aneurysms (AAAs) formation. Methods: Male apolipoprotein E-deficient mice (8–12 weeks old) were fed with a normal diet for 5 weeks. Either edaravone (10 mg/kg/day) or vehicle was injected intraperitoneally for 5 weeks. After 1 week of injections, mice were infused subcutaneously with either AngII (1000 ng/kg/min, n = 16–17 per group) or saline (n = 5 per group) by osmotic minipumps for 4 weeks. Results: AngII increased systolic blood pressure equivalently in mice administered with either edaravone or saline. Edaravone had no effect on plasma total cholesterol concentrations and body weights. AngII infusion significantly increased ex vivo maximal diameters of abdominal aortas and en face atherosclerosis but was significantly attenuated by edaravone administration. Edaravone also reduced the incidence of AngII-induced AAAs. In addition, edaravone diminished AngII-induced aortic MMP-2 activation. Quantitative RT-PCR revealed that edaravone ameliorated mRNA abundance of aortic MCP-1 and IL-1β. Immunostaining demonstrated that edaravone attenuated oxidative stress and macrophage accumulation in the aorta. Furthermore, edaravone administration suppressed thioglycolate-induced mice peritoneal macrophages (MPMs) accumulation and mRNA abundance of MCP-1 in MPMs in male apolipoprotein E-deficient mice. In vitro, edaravone reduced LPS-induced mRNA abundance of MCP-1 in MPMs. Conclusions: Edaravone attenuated AngII-induced AAAs and atherosclerosis in male apolipoprotein E-deficient mice via anti-oxidative action and anti-inflammatory effect.

Chromatographic measurement of 3-hydroxyanthranilate 3,4-dioxygenase activity reveals that edaravone can mitigate the formation of quinolinic acid through a direct enzyme inhibition

Herein it is reported the development and application of two chromatographic assays for the measurement of the activity of 3-Hydroxyanthranilate-3,4-dioxygenase (3HAO). Such an enzyme converts 3-Hydroxyanthranilic acid (3HAA) to 2-amino-3-carboxymuconic semialdehyde (ACMS), which undergo a spontaneous, non-enzymatic cyclization to produce quinolinic acid (QUIN). The enzyme activity was measured by quantitation of the substrate consumption over time either with spectrophotometric (UV) or mass spectrometric (MS) detection upon reversed-phase chromatographic separation. MS detection resulted more selective and sensitive, but less accurate and precise. However, both methods have sufficient sensitivity to allow the measurement of enzyme activity with consistent results compared to literature data. Since MS detection allowed less sample consumption it was used to calculate the kinetics parameters (i.e., Vmax and Kd) of recombinant 3HAO. Another MS-based method was then developed to measure the amount of QUIN produced, revealing an incomplete conversion of 3HAA to QUIN. As suggested by previous studies, the enzyme activity was apparently sensitive to the redox state of the enzyme thiols. In fact, thiol reducing agents such as dithiothreitol (DTT) and glutathione (GSH), can alter the enzyme activity although the investigation on the exact mechanism involved in such effect was beyond the scope of the research. Interestingly, edaravone (EDA) induced an in vitro suppression of QUIN production through direct, competitive 3HAO inhibition. EDA is a molecule approved for the treatment of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with an increase of QUIN concentrations in both serum and cerebrospinal fluid. Although EDA was reported to mitigate ALS progression its mode of action is still largely unknown. Some studies reported antioxidant and radical scavenger properties of EDA, but none confirm a direct activity as 3HAO enzyme inhibitor. Since QUIN is reported to be a neurotoxic metabolite, 3HAO inhibition can contribute to the beneficial effect of EDA in ALS, although such a mechanism must be then confirmed in vivo. However, EDA might be a convenient scaffold for the design of selective 3HAO inhibitors with potential applications in ALS treatment.

The Protective Effect of Edaravone on TDP-43 Plus Oxidative Stress-Induced Neurotoxicity in Neuronal Cells: Analysis of Its Neuroprotective Mechanisms Using RNA Sequencing

Edaravone is a free-radical scavenger drug that was recently approved for the treatment of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease. A pathological hallmark of ALS is the accumulation of ubiquitinated or phosphorylated aggregates of the 43-kDa transactive response DNA binding protein (TDP-43) within the cytoplasm of motor neurons. This study revealed the efficacy of edaravone in preventing neuronal cell death in a TDP-43 proteinopathy model and analyzed the molecular changes associated with the neuroprotection. The viability of the neuronal cells expressing TDP-43 was reduced by oxidative stress, and edaravone (≥10 μmol/L) protected in a concentration-dependent manner against the neurotoxic insult. Differential gene expression analysis revealed changes among pathways related to nuclear erythroid 2-related-factor (Nrf2)-mediated oxidative stress response in cells expressing TDP-43. In edaravone-treated cells expressing TDP-43, significant changes in gene expression were also identified among Nrf2-oxidative response, unfolded protein response, and autophagy pathways. In addition, the expression of genes belonging to phosphatidylinositol metabolism pathways was modified. These findings suggest that the neuroprotective effect of edaravone involves the prevention of TDP-43 misfolding and enhanced clearance of pathological TDP-43 in TDP-43 proteinopathy.

Isolated pulmonary recovery in a veteran with late stage bulbar ALS following edaravone treatment and cessation

CONTEXT

Amyotrophic lateral sclerosis (ALS) is a group of rare neurological diseases which cause progressive loss of upper and lower motor neurons at the spinal or bulbar level. ALS affects voluntary muscles of the body which control eating, talking, and moving. Individuals with ALS manifest difficulty breathing on their own due to weakness of the respiratory system. The average life expectancy of individuals with ALS is 2-5 years from the time of diagnosis, with death resulting from respiratory failure. There is no cure for ALS. At present, riluzole and edaravone are the only FDA-approved treatments that impact survival. Adverse reactions to edaravone include hypoxia and respiratory failure. To date, there are no published reports describing isolated dramatic respiratory improvement in ALS with continued global clinical worsening including limb and face function, particularly following edaravone use.

FINDINGS

We present a case report of late stage bulbar ALS, in which a dramatic respiratory improvement is seen following edaravone use, and subsequent cessation.

CONCLUSION/CLINICAL RELEVANCE

Isolated pulmonary decline and subsequent recovery following cessation of edaravone in the setting of continued systemic neurologic decline has not yet been described and may suggest potential for reversibility of edaravone-related pulmonary decline. Research is needed to evaluate this possibility further, and this case report may lead to further investigation to evaluate this possibility. Alternatively, although less likely, it is possible the observed that pulmonary improvement may either be beneficially attributed to edaravone, or unrelated to edaravone entirely - representing an undescribed phenomenon of isolated pulmonary decline and improvement in the setting of systemic continued ALS progression, possibly related to the bulbar subtype. Further investigation is warranted to evaluate both the role of edaravone in causing in a potentially reversible pulmonary decline upon cessation of the medication, and the possibility of other undefined variables including various subtypes of ALS contributing to this phenomenon.