Phase I and Phase II Therapies for Acute Ischemic Stroke: An Update on Currently Studied Drugs in Clinical Research

Unveiling the Multifaceted Pharmacological Actions of Indole-3-Carbinol and Diindolylmethane: A Comprehensive Review

Cruciferae family vegetables are remarkably high in phytochemicals such as Indole-3-carbinol (I3C) and Diindolylmethane (DIM), which are widely known as nutritional supplements. I3C and DIM have been studied extensively in different types of cancers like breast, prostate, endometrial, colorectal, gallbladder, hepatic, and cervical, as well as cancers in other tissues. In this review, we summarized the protective effects of I3C and DIM against cardiovascular, neurological, reproductive, metabolic, bone, respiratory, liver, and immune diseases, infections, and drug- and radiation-induced toxicities. Experimental evidence suggests that I3C and DIM offer protection due to their antioxidant, anti-inflammatory, antiapoptotic, immunomodulatory, and xenobiotic properties. Apart from the beneficial effects, the present review also discusses the possible toxicities of I3C and DIM that are reported in various preclinical investigations. So far, most of the reports about I3C and DIM protective effects against various diseases are only from preclinical studies; this emphasizes the dire need for large-scale clinical trials on these phytochemicals against human diseases. Further, in-depth research is required to improve the bioavailability of these two phytochemicals to achieve the desirable protective effects. Overall, our review emphasizes that I3C and DIM may become potential drug candidates for combating dreadful human diseases.

Sustaining Brain Youth by Neural Stem Cells: Physiological and Therapeutic Perspectives

In the last two decades, stem cells (SCs) have attracted considerable interest for their research value and therapeutic potential in many fields, namely in neuroscience. On the other hand, the discovery of adult neurogenesis, the process by which new neurons are generated in the adult brain, challenged the traditional view that the brain is a static structure after development. The recent findings showing that adult neurogenesis has a significant role in brain plasticity, learning and memory, and emotional behavior, together with the fact that it is strongly dependent on several external and internal factors, have sparked more interest in this area. The mechanisms of adult neural stem cell (NSC) regulation, the physiological role of NSC-mediated neuroplasticity throughout life, and the most recent NSC-based therapeutic applications will be concisely reviewed. Noteworthy, due to their multipotency, self-renewal potential, and ability to secrete growth and immunomodulatory factors, NSCs have been mainly suggested for (1) transplantation, (2) neurotoxicology tests, and (3) drug screening approaches. The clinical trials of NSC-based therapy for different neurologic conditions are, nonetheless, mostly in the early phases and have not yet demonstrated conclusive efficacy or safety. Here, we provide an outlook of the major challenges and limitations, as well as some promising directions that could help to move toward stem cell widespread use in the treatment and prevention of several neurological disorders.

Pathophysiology of cerebral ischemia-reperfusion injury: An overview of oxidative stress and plant-based therapeutic approaches

Stroke is a debilitating neurological disorder that causes substantial morbidity and mortality on a global scale. Ischemic stroke, the most common type, occurs when the brain's blood supply is interrupted. Oxidative stress is a key factor in stroke pathology, contributing to inflammation and neuronal cell death. As a result, there is increasing interest in the potential of plant extracts, which have been used in traditional medicine for centuries and are generally considered safe, to serve as alternative or complementary treatments for stroke. The plant extracts can target multiple pathological processes, including oxidative stress, offering neuroprotective effects. The development of highly efficient, low-toxicity, and cost-effective natural products is crucial for enhancing stroke treatment options. In this review, we examine 60 plant extracts that have been focused on the studies published from year 2000 to 2024 along with the studies' experimental models, dosages, and results. The plant extracts hold promise in modulating cerebral ischemia-reperfusion injury through counteraction of relevant pathophysiologic processes such as oxidative stress.

Stem cell therapies for neurological disorders: current progress, challenges, and future perspectives

Stem cell-based therapies have emerged as a promising approach for treating various neurological disorders by harnessing the regenerative potential of stem cells to restore damaged neural tissue and circuitry. This comprehensive review provides an in-depth analysis of the current state of stem cell applications in primary neurological conditions, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, spinal cord injury (SCI), and other related disorders. The review begins with a detailed introduction to stem cell biology, discussing the types, sources, and mechanisms of action of stem cells in neurological therapies. It then critically examines the preclinical evidence from animal models and early human trials investigating the safety, feasibility, and efficacy of different stem cell types, such as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), neural stem cells (NSCs), and induced pluripotent stem cells (iPSCs). While ESCs have been studied extensively in preclinical models, clinical trials have primarily focused on adult stem cells such as MSCs and NSCs, as well as iPSCs and their derivatives. We critically assess the current state of research for each cell type, highlighting their potential applications and limitations in different neurological conditions. The review synthesizes key findings from recent, high-quality studies for each neurological condition, discussing cell manufacturing, delivery methods, and therapeutic outcomes. While the potential of stem cells to replace lost neurons and directly reconstruct neural circuits is highlighted, the review emphasizes the critical role of paracrine and immunomodulatory mechanisms in mediating the therapeutic effects of stem cells in most neurological disorders. The article also explores the challenges and limitations associated with translating stem cell therapies into clinical practice, including issues related to cell sourcing, scalability, safety, and regulatory considerations. Furthermore, it discusses future directions and opportunities for advancing stem cell-based treatments, such as gene editing, biomaterials, personalized iPSC-derived therapies, and novel delivery strategies. The review concludes by emphasizing the transformative potential of stem cell therapies in revolutionizing the treatment of neurological disorders while acknowledging the need for rigorous clinical trials, standardized protocols, and multidisciplinary collaboration to realize their full therapeutic promise.

[Place of oligopeptide H-Met-Glu-His-Phe-Pro-Gly-Pro-OH in the therapy and rehabilitation of patients with ischemic stroke]

Cerebrovascular diseases (CVDs) are one of the leading causes of death and disability In Russia: they rank second in the structure of mortality from diseases of the circulatory system and in the overall mortality of the population. Successful treatment of CVD involves an integrated approach to the problem, taking into account the compensation of cardiovascular disorders, the elimination of neurological and psychopathological syndromes, the improvement of cerebral circulation and the use of neuroprotective agents that increase the resistance of brain tissue to hypoxia and ischemia. Insufficient clinical efficacy of neuroprotectors is due to a number of objective reasons, of which only two are universal. The first of these reasons is the timing of the start of therapy in the clinic, as a rule, is outside the «therapeutic window»; the second reason is the fact that disturbance of the patency of the cerebral vessels in the affected area makes it difficult or impossible to deliver the drug to the penumbra area. The way out of this situation is the intranasal route of drug administration, which is characteristic for the analogs of regulatory peptides such as for H-Met-Glu-His-Phe-Pro-Gly-Pro-OH (MGHPPGP). The review of clinical studies indicates that MGHPPGP is clinically effective in the treatment of ischemic stroke both in the acute period of stroke and in the recovery period. The clinical efficacy of MGHPPGP was shown both in atherothrombotic and cardioembolic subtypes of stroke, against the background of blood flow disturbances in both the carotid and vertebrobasilar systems.

Astragaloside IV promotes angiogenesis by targeting SIRT7/VEGFA signaling pathway to improve brain injury after cerebral infarction in rats

Cerebral infarction (CI) has become one of the leading causes of death and acquired disability worldwide. Astragaloside IV (AST IV), one of the basic components of Astragalus membranaceus, has a protective effect on CI. However, the underlying mechanism has not been conclusively elucidated. Therefore, this study aims to explore the underlying mechanism of AST IV improving brain injury after CI. Middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation/reoxygenation (OGD/R) were used to simulate cerebral infarction injury in SD rats and HUVECs cells. Neurologic score, Evans blue, TTC and HE staining were used to observe brain injury in rats. Cell viability and migration were measured in vitro. Angiogenesis was detected by immunofluorescence and tube formation assay, and cell cycle was detected by flow cytometry. Western blot was used to find the expression of related proteins. Molecular docking, virtual mutation, site-directed mutagenesis, MST, and lentivirus silencing were used for target validation. The results showed that AST IV alleviated neurological impairment and promoted angiogenesis after CI. Moreover, AST IV greatly increased the transcription levels of SIRT6 and SIRT7, but had no effect on SIRT1-SIRT5, and promoted cell viability, migration, angiogenesis and S phase ratio in OGD/R-induced HUVECs. Furthermore, AST IV up-regulated the protein expressions of CDK4, cyclin D1, VEGFA and VEGF2R. Interestingly, AST IV not only bound to SIRT7, but also increased the expression of SIRT7. Silencing SIRT7 by lentivirus neutralizes the positive effects of AST IV. Taken together, the present study revealed that AST IV may improve brain tissue damage after CI by targeting SIRT7/VEGFA signaling pathway to promote angiogenesis.

Neurovascular Inflammation and Complications of Thrombolysis Therapy in Stroke

Intravenous thrombolysis via tPA (tissue-type plasminogen activator) is the only approved pharmacological treatment for acute ischemic stroke, but its benefits are limited by hemorrhagic transformation. Emerging evidence reveals that tPA swiftly mobilizes immune cells which extravasate into the brain parenchyma via the cerebral vasculature, augmenting neurovascular inflammation, and tissue injury. In this review, we summarize the pronounced alterations of immune cells induced by tPA in patients with stroke and experimental stroke models. We argue that neuroinflammation, triggered by ischemia-induced cell death and exacerbated by tPA, compromises neurovascular integrity and the microcirculation, leading to hemorrhagic transformation. Finally, we discuss current and future approaches to attenuate thrombolysis-associated hemorrhagic transformation via uncoupling immune cells from the neurovascular unit.

Glutamate-releasing BEST1 channel is a new target for neuroprotection against ischemic stroke with wide time window

Many efforts have been made to understand excitotoxicity and develop neuroprotectants for the therapy of ischemic stroke. The narrow treatment time window is still to be solved. Given that the ischemic core expanded over days, treatment with an extended time window is anticipated. Bestrophin 1 (BEST1) belongs to a bestrophin family of calcium-activated chloride channels. We revealed an increase in neuronal BEST1 expression and function within the peri-infarct from 8 to 48 h after ischemic stroke in mice. Interfering the protein expression or inhibiting the channel function of BEST1 by genetic manipulation displayed neuroprotective effects and improved motor functional deficits. Using electrophysiological recordings, we demonstrated that extrasynaptic glutamate release through BEST1 channel resulted in delayed excitotoxicity. Finally, we confirmed the therapeutic efficacy of pharmacological inhibition of BEST1 during 6-72 h post-ischemia in rodents. This delayed treatment prevented the expansion of infarct volume and the exacerbation of neurological functions. Our study identifies the glutamate-releasing BEST1 channel as a potential therapeutic target against ischemic stroke with a wide time window.

Cerebroprotection in the endovascular era: an update

Despite advances in clinical diagnosis and increasing numbers of patients eligible for revascularisation, ischaemic stroke remains a significant public health concern accounting for 3.3 million deaths annually. In addition to recanalisation therapy, patient outcomes could be improved through cerebroprotection, but all translational attempts have remained unsuccessful. In this narrative review, we discuss potential reasons for those failures. We then outline the diverse, multicellular effects of ischaemic stroke and the complex temporal sequences of the pathophysiological cascade during and following ischaemia, reperfusion, and recovery. This evidence is linked with findings from prior cerebroprotective trials and interpreted for the modern endovascular era. Future cerebroprotective agents that are multimodal and multicellular, promoting cellular and metabolic health to different targets at time points that are most responsive to treatment, might prove more successful.

Stimuli-Responsive Nanotherapeutics for Treatment and Diagnosis of Stroke

Stroke is the second most common medical emergency and constitutes a significant cause of global morbidity. The conventional stroke treatment strategies, including thrombolysis, antiplatelet therapy, endovascular thrombectomy, neuroprotection, neurogenesis, reducing neuroinflammation, oxidative stress, excitotoxicity, hemostatic treatment, do not provide efficient relief to the patients due to lack of appropriate delivery systems, large doses, systemic toxicity. In this context, guiding the nanoparticles toward the ischemic tissues by making them stimuli-responsive can be a turning point in managing stroke. Hence, in this review, we first outline the basics of stroke, including its pathophysiology, factors affecting its development, current treatment therapies, and their limitations. Further, we have discussed stimuli-responsive nanotherapeutics used for diagnosing and treating stroke with challenges ahead for the safe use of nanotherapeutics.

[Results of a multicenter observational program to evaluate the effectiveness of complex therapy of patients with chronic cerebrovascular pathology with cognitive impairment with Cortexin and Neuromexol (CORNELia study)]

OBJECTIVE

To evaluate the effectiveness of complex therapy with Cortexin and Neuromexol in patients with chronic cerebral ischemia (CCI) and cognitive impairment (CI).

MATERIAL AND METHODS

We examined 801 patients with CCI on the background of arterial hypertension and atherosclerosis with confirmed CI: 329 (41.1%) men and 472 (58.9%) women aged 30 to 80 years (mean age 64±10 years), who were examined. Cortexin and Neuromexol. Examination - Mini-Mental State Examination (MMSE) scale, hour-long drawing test (HDT) and severity of depressive states (Brief Geriatric Depression Scale, Mini Geriatric Depression Scal, MGDS). In 30 patients receiving Cortexin and Neuromexol (main group, MG) and 30 patients in the comparison group (CG), biomarkers of ischemic brain damage (NSE, antibodies to NR2, VEGFA) were determined. The examination was carried out before the start of treatment and after 30 days.

RESULTS

During therapy with Cortexin and Neuromexol, characteristic signs of a decrease in the severity of CI were noted (p<0.05). A positive correlation was revealed between the performance indicators of the MMSE and TFC tests, both before and after treatment (r=0.5 and r=0.6, respectively; p<0.05). A positive effect of therapy on the emotional background of patients was noted, in particular, a decrease in the severity of depressive symptoms on the MGDS scale. During therapy, a 2-fold decrease in the NSE level (p<0.05) was detected in the MG, which indicates a decrease in the structural and functional parameters of biomembrane neurons in the brain. The concentration of antibodies to NR2 decreased compared to the baseline level in both groups (p<0.05), and VEGFA decreased only in the MG (p<0.05).

CONCLUSION

The results of the study allow us to recommend the complex prescription of Cortexin 10 mg/day for 10 days and Neuromexol tablets 125 mg (375-750 mg/day) for 30 days for chronic CVD. Complex therapy with Cortexin and Neuromexol is effective and safe in patients with CCI and CI.

Mechanistic Insight on Autophagy Modulated Molecular Pathways in Cerebral Ischemic Injury: From Preclinical to Clinical Perspective

Cerebral ischemia is one of the most devastating brain injuries and a primary cause of acquired and persistent disability worldwide. Despite ongoing therapeutic interventions at both the experimental and clinical levels, options for stroke-related brain injury are still limited. Several evidence suggests that autophagy is triggered in response to cerebral ischemia, therefore targeting autophagy-related signaling pathways can provide a new direction for the therapeutic implications in the ischemic injury. Autophagy is a highly conserved lysosomal-dependent pathway that degrades and recycles damaged or non-essential cellular components to maintain neuronal homeostasis. But, whether autophagy activation promotes cell survival against ischemic injury or, on the contrary, causes neuronal death is still under debate. We performed an extensive literature search from PubMed, Bentham and Elsevier for various aspects related to molecular mechanisms and pathobiology involved in autophagy and several pre-clinical studies justifiable further in the clinical trials. Autophagy modulates various downstream molecular cascades, i.e., mTOR, NF-κB, HIF-1, PPAR-γ, MAPK, UPR, and ROS pathways in cerebral ischemic injury. In this review, the various approaches and their implementation in the translational research in ischemic injury into practices has been covered. It will assist researchers in finding a way to cross the unbridgeable chasm between the pre-clinical and clinical studies.

Myrtenol improves brain damage and promotes angiogenesis in rats with cerebral infarction by activating the ERK1/2 signalling pathway

CONTEXT

Cerebral ischaemia/reperfusion (I/R) injury has a high disability and fatality worldwide. Myrtenol has protective effects on myocardial I/R injury through antioxidant and anti-apoptotic effects.

OBJECTIVE

This study investigated the effect of myrtenol on cerebral ischaemia/reperfusion (I/R) injury and the underlying mechanism.

MATERIALS AND METHODS

Cerebral I/R injury was induced in adult Sprague-Dawley rats by middle cerebral artery occlusion (MCAO) for 90 min. MCAO rats were treated with or without myrtenol (10, 30, or 50 mg/kg/day) or/and U0126 (10 μL) intraperitoneally for 7 days.

RESULTS

In the present study, myrtenol had no toxicity at concentrations up to 1.3 g/kg. Myrtenol treatment improved neurological function of MCAO rats, with significantly (p < 0.05) improved neurological deficits (4.31 ± 1.29 vs. 0.00) and reduced brain edoema (78.95 ± 2.27% vs. 85.48 ± 1.24%). Myrtenol extenuated brain tissue injury and neuronal apoptosis, with increased Bcl-2 expression (0.48-fold) and decreased Bax expression (2.02-fold) and caspase-3 activity (1.36-fold). Myrtenol promoted angiogenesis in the brain tissues of MCAO rats, which was reflected by increased VEGF (0.86-fold) and FGF2 (0.51-fold). Myrtenol promoted the phosphorylation of MEK1/2 (0.80-fold) and ERK1/2 (0.97-fold) in MCAO rats. U0126, the inhibitor of ERK1/2 pathway, reversed the protective effects of myrtenol on brain tissue damage and angiogenesis in MCAO rats.

DISCUSSION AND CONCLUSIONS

Myrtenol reduced brain damage and angiogenesis through activating the ERK1/2 signalling pathway, which may provide a novel alternative strategy for preventing cerebral I/R injury. Further in vitro work detailing its mechanism-of-action for improving ischaemic cerebral infarction is needed.

YTHDC1 mitigates ischemic stroke by promoting Akt phosphorylation through destabilizing PTEN mRNA

YTH Domain Containing 1 (YTHDC1) is one of the m⁶A readers that is essential for oocyte development and tumor progression. The role of YTHDC1 in neuronal survival and ischemic stroke is unknown. Here, we found that YTHDC1 was unregulated in the early phase of ischemic stroke. Knockdown of YTHDC1 exacerbated ischemic brain injury and overexpression of YTHDC1 protected rats against brain injury. Mechanistically, YTHDC1 promoted PTEN mRNA degradation to increase Akt phosphorylation, thus facilitating neuronal survival in particular after ischemia. These data identify YTHDC1 as a novel regulator of neuronal survival and modulating m⁶A reader YTHDC1 may provide a potential therapeutic target for ischemic stroke.

Materials to Promote Recovery After Stroke

Stroke is the leading cause of long-term disability with no current treatment addressing post-stroke disability. The complex pathophysiology of stroke and the brain's limited potential for regeneration prevents sufficient endogenous repair for complete recovery. While engineered materials provide an exciting opportunity to augment endogenous repair in conjunction with other therapies that address post-stroke disability, much of the preclinical work in this arena is still in its infancy. Biomaterials can be used to enhance drug- or stem cell-sustained and targeted delivery. Moreover, materials can act as extracellular matrix-mimics and augment a pro-repair environment by addressing astrogliosis, inflammation, neurogenesis, axonal sprouting, and angiogenesis. Lastly, there is a growing need to elucidate stroke repair mechanisms to identify novel targets to inform material design for brain repair after stroke.

Nanoparticle Delivery of CD147 Antagonistic Peptide-9 Protects against Acute Ischemic Brain Injury and tPA-Induced Intracerebral Hemorrhage in Mice

CD147 has emerged as a potential therapeutic target in many human diseases. We have demonstrated that inhibition of CD147 using its function-blocking antibody ameliorates acute ischemic brain injury and promotes long-term functional recovery in mice. Recently, peptide-nanoparticle conjugates have emerged as powerful tools for biomedical applications. The present study aimed to investigate the therapeutic potential of CD147 antagonist peptide-9 (AP9) in acute ischemic stroke in mice using nanomaterial as the drug delivery vehicles. AP9-conjugated nanoparticles (APN), with an average size of about 40 nm, were fabricated by maleimide linkage and characterized using dynamic light scattering and transmission electron microscopy. We found that APN specifically bound to CD147 in cultured mouse brain endothelial cells (bEnd.3) and to ischemia-induced CD147 in mouse cerebral microvessels. Using a mouse model of transient middle cerebral artery occlusion (tMCAO), we demonstrated, for the first time, that systemic delivery of APN (2.5 mg/kg, I.V.) initiated at 1 h after tMCAO significantly reduced brain infarct size, improved functional outcome, and attenuated delayed (5 h after tMCAO) tPA-induced intracerebral hemorrhage in acute ischemic stroke. These protective effects were associated with profound inhibition of MMP-9 and MMP-3 in both ischemic brain and plasma. In conclusion, the CD147 antagonist peptide-9 represents a potentially promising therapeutic candidate for the treatment of ischemic stroke.

Post-Ischaemic Immunological Response in the Brain: Targeting Microglia in Ischaemic Stroke Therapy

Microglia, the major endogenous immune cells of the central nervous system, mediate critical degenerative and regenerative responses in ischaemic stroke. Microglia become "activated", proliferating, and undergoing changes in morphology, gene and protein expression over days and weeks post-ischaemia, with deleterious and beneficial effects. Pro-inflammatory microglia (commonly referred to as M1) exacerbate secondary neuronal injury through the release of reactive oxygen species, cytokines and proteases. In contrast, microglia may facilitate neuronal recovery via tissue and vascular remodelling, through the secretion of anti-inflammatory cytokines and growth factors (a profile often termed M2). This M1/M2 nomenclature does not fully account for the microglial heterogeneity in the ischaemic brain, with some simultaneous expression of both M1 and M2 markers at the single-cell level. Understanding and regulating microglial activation status, reducing detrimental and promoting repair behaviours, present the potential for therapeutic intervention, and open a longer window of opportunity than offered by acute neuroprotective strategies. Pharmacological modulation of microglial activation status to promote anti-inflammatory gene expression can increase neurogenesis and improve functional recovery post-stroke, based on promising preclinical data. Cell-based therapies, using preconditioned microglia, are of interest as a method of therapeutic modulation of the post-ischaemic inflammatory response. Currently, there are no clinically-approved pharmacological options targeting post-ischaemic inflammation. A major developmental challenge for clinical translation will be the selective suppression of the deleterious effects of microglial activity after stroke whilst retaining (or enhancing) the neurovascular repair and remodelling responses of microglia.

Nanocarriers for Stroke Therapy: Advances and Obstacles in Translating Animal Studies

The technology of drug delivery systems (DDS) has expanded into many applications, such as for treating neurological disorders. Nanoparticle DDS offer a unique strategy for targeted transport and improved outcomes of therapeutics. Stroke is likely to benefit from the emergence of this technology though clinical breakthroughs are yet to manifest. This review explores the recent advances in this field and provides insight on the trends, prospects and challenges of translating this technology to clinical application. Carriers of diverse material compositions are presented, with special focus on the surface properties and emphasis on the similarities and inconsistencies among in vivo experimental paradigms. Research attention is scattered among various nanoparticle DDS and various routes of drug administration, which expresses the lack of consistency among studies. Analysis of current literature reveals lipid- and polymer-based DDS as forerunners of DDS for stroke; however, cell membrane-derived vesicles (CMVs) possess the competitive edge due to their innate biocompatibility and superior efficacy. Conversely, inorganic and carbon-based DDS offer different functionalities as well as varied capacity for loading but suffer mainly from poor safety and general lack of investigation in this area. This review supports the existing literature by systematizing presently available data and accounting for the differences in drugs of choice, carrier types, animal models, intervention strategies and outcome parameters.

Pre-clinical to Clinical Translational Failures and Current Status of Clinical Trials in Stroke Therapy: A Brief Review

In stroke (cerebral ischemia), despite continuous efforts both at the experimental and clinical level, the only approved pharmacological treatment has been restricted to tissue plasminogen activator (tPA). Stroke is the leading cause of functional disability and mortality throughout worldwide. Its pathophysiology starts with energy pump failure, followed by complex signaling cascade that ultimately ends in neuronal cell death. Ischemic cascade involves excessive glutamate release followed by raised intracellular sodium and calcium influx along with free radicals' generation, activation of inflammatory cytokines, NO synthases, lipases, endonucleases and other apoptotic pathways leading to cell edema and death. At the pre-clinical stage, several agents have been tried and proven as an effective neuroprotectant in animal models of ischemia. However, these agents failed to show convincing results in terms of efficacy and safety when the trials were conducted in humans following stroke. This article highlights the various agents which have been tried in the past but failed to translate into stroke therapy along with key points that are responsible for the lagging of experimental success to translational failure in stroke treatment.

Neural Stem Cell Extracellular Vesicles Disrupt Midline Shift Predictive Outcomes in Porcine Ischemic Stroke Model

Magnetic resonance imaging (MRI) is a clinically relevant non-invasive imaging tool commonly utilized to assess stroke progression in real time. This study investigated the utility of MRI as a predictive measure of clinical and functional outcomes when a stroke intervention is withheld or provided, in order to identify biomarkers for stroke functional outcome under these conditions. Fifteen MRI and ninety functional parameters were measured in a middle cerebral artery occlusion (MCAO) porcine ischemic stroke model. Multiparametric analysis of correlations between MRI measurements and functional outcome was conducted. Acute axial and coronal midline shift (MLS) at 24 h post-stroke were associated with decreased survival and recovery measured by modified Rankin scale (mRS) and were significantly correlated with 52 measured acute (day 1 post) and chronic (day 84 post) gait and behavior impairments in non-treated stroked animals. These results suggest that MLS may be an important non-invasive biomarker that can be used to predict patient outcomes and prognosis as well as guide therapeutic intervention and rehabilitation in non-treated animals and potentially human patients that do not receive interventional treatments. Neural stem cell–derived extracellular vesicle (NSC EV) was a disruptive therapy because NSC EV administration post-stroke disrupted MLS correlations observed in non-treated stroked animals. MLS was not associated with survival and functional outcomes in NSC EV–treated animals. In contrast to untreated animals, NSC EVs improved stroked animal outcomes regardless of MLS severity.

Anti-edema and antioxidant combination therapy for ischemic stroke via glyburide-loaded betulinic acid nanoparticles

Stroke is a deadly disease without effective pharmacotherapies, which is due to two major reasons. First, most therapeutics cannot efficiently penetrate the brain. Second, single agent pharmacotherapy may be insufficient and effective treatment of stroke requires targeting multiple complementary targets. Here, we set to develop single component, multifunctional nanoparticles (NPs) for targeted delivery of glyburide to the brain for stroke treatment. Methods: To characterize the brain penetrability, we radiolabeled glyburide, intravenously administered it to stroke- bearing mice, and determined its accumulation in the brain using positron emission tomography-computed tomography (PET/CT). To identify functional nanomaterials to improve drug delivery to the brain, we developed a chemical extraction approach and tested it for isolation of nanomaterials from E. ulmoides, a medicinal herb. To assess the therapeutic benefits, we synthesized glyburide-loaded NPs and evaluated them in stroke- bearing mice. Results: We found that glyburide has a limited ability to penetrate the ischemic brain. We identified betulinic acid (BA) capable of forming NPs, which, after intravenous administration, efficiently penetrate the brain and significantly reduce ischemia-induced infarction as an antioxidant agent. We demonstrated that BA NPs enhance delivery of glyburide, leading to therapeutic benefits significantly greater than those achieved by either glyburide or BA NPs. Conclusion: This study suggests a new direction to identify functional nanomaterials and a simple approach to achieving anti-edema and antioxidant combination therapy. The resulting glyburide- loaded BA NPs may be translated into clinical applications to improve clinical management of stroke.

Delayed recanalization at 3 days after permanent MCAO attenuates neuronal apoptosis through FGF21/FGFR1/PI3K/Caspase-3 pathway in rats

Reperfusion exceeded time window may induce ischemia/reperfusion injury, increase hemorrhagic transformation, and deteriorate neurological outcomes in ischemic stroke models. However, the increasing clinical evidences supported that reperfusion even within 6-24 h may salvage ischemic tissue and improve neurological outcomes in selected large vessel occlusion patients, without inducing serious ischemia/reperfusion injury and hemorrhagic transformation. The underlying molecular mechanisms are less clear. In present study, we demonstrated that delayed recanalization at 3 days after permanent middle cerebral artery occlusion (MCAO) decreased infarct volumes and improved neurobehavioral deficits in rats, with no increasing animal mortality and intracerebral hemorrhage. Meanwhile, we observed that endogenous neuroprotective agent fibroblast growth factor 21 (FGF21) significantly increased in serum after MCAO, but which did not synchronously increase in penumbra due to permanent MCAO. Recanalization dramatically increased the endogenous FGF21 expression on neurons in penumbra after MCAO. We confirmed that FGF21 activated the FGFR1/PI3K/Caspase-3 signaling pathway, which attenuated neuronal apoptosis in penumbra. Conversely, knockdown of FGFR1 via FGFR1 siRNA abolished the anti-apoptotic effects of FGF21, and in part abrogated beneficial effects of recanalization on neurological outcomes. These findings suggested that delayed recanalization at 3 days after MCAO improved neurological outcomes in rats via increasing endogenous FGF21 expression and activating FGFR1/PI3K/Caspase-3 pathway to attenuate neuronal apoptosis in penumbra. Delayed recanalization at 3 days after ischemic stroke onset may be a promising treatment strategy in selected patients.

Selenium nanoparticles for targeted stroke therapy through modulation of inflammatory and metabolic signaling

Ischemic cerebral stroke is a major cause of death and morbidity. Currently, no neuroprotective agents have been shown to impact the clinical outcomes in cerebral stroke cases. Here, we report therapeutic effects of Se nanoparticles on ischemic stroke in a murine model. Anti-transferrin receptor monoclonal antibody (OX26)-PEGylated Se nanoparticles (OX26-PEG-Se NPs) were designed and synthesized and their neuroprotective effects were measured using in vitro and in vivo approaches. We demonstrate that administration of the biodegradable nanoparticles leads to resolution of brain edema, protection of axons in hippocampus region, and myelination of hippocampal area after cerebral ischemic stroke. Our nanoparticle design ensures efficient targeting and minimal side effects. Hematological and biochemical analyses revealed no undesired NP-induced changes. To gain mechanistic insights into the therapeutic effects of these particles, we characterized the changes to the relevant inflammatory and metabolic signaling pathways. We assessed metabolic regulator mTOR and related signaling pathways such as hippo, Ubiquitin-proteasome system (ERK5), Tsc1/Tsc2 complex, FoxO1, wnt/β-catenine signaling pathway. Moreover, we examined the activity of jak2/stat3 signaling pathways and Adamts1, which are critically involved in inflammation. Together, our study provides a promising treatment strategy for cerebral stroke based on Se NP induced suppression of excessive inflammation and oxidative metabolism.

Synthesis and biological evaluation of 2,2-dimethylbenzopyran derivatives as potent neuroprotection agents

The development of novel neuroprotection agents is of great significance for the treatment of ischemic stroke. In this study, a series of compounds comprising 2,2-dimethylbenzopyran groups and cinnamic acid groups have been synthesized. Preferential combination principles and bioisostere that improved the neuroprotective effect of the compounds were identified for this series via biological activity assay in vitro. Meanwhile, a functional reversal group of the acrylamide amide resulted in the most active compounds. Among them, BN-07 significantly improved the morphology of neurons and obviously increased cell survival rate of primary neurons induced by oxygen glucose deprivation (OGD), superior to clinically used anti-ischemic stroke drug edaravone (Eda). Overall, our findings may provide an alternative strategy for the design of novel anti-ischemic stroke agents with more potency than Eda.

Novel compounds comprising 2,2-dimethylbenzopyran and cinnamic acid were synthesized. BN-07 significantly increased survival rate of primary neurons, superior to edaravone.

[The efficacy of recognan in the early stage of ischemic stroke]

AIM

To assess the efficacy and safety of recognan in patients with acute ischemic stroke (IS).

MATERIAL AND METHODS

Seventy-nine patients, aged from 30 to 80 years, were examined in the early stage of IS. All patients received recognan (citicoline) in dose of 1000 mg/daily during 15 days. The recovery of cognitive functions (MMSE), level of consciousness (Glasgow Coma Scale), severity of focal neurological deficit (NIHSS) and functional recovery (Rankin scale, Barthel index, Rivermead Mobility Index) were assessed.

RESULTS AND CONCLUSION

A decrease of cognitive impairment, improvement of memory, regression of neurological symptoms and increase in the motor activity were observed. Recognan used in dose of 1000 mg/daily during 15 days in the complex treatment of patients with IS promotes the recovery of cognitive function, reduces neurological symptoms and improves the recovery of motor activity.

[Multicenter observational program for evaluation of the effectiveness of the recognan (citicoline) in the correction of cognitive impairment in patients with chronic cerebrovascular pathology]

AIM

To study the efficacy and safety of recognan (citicoline) in the treatment of cognitive and depressive disorders in chronic cerebrovascular pathology (chronic brain ischemia) developed in patients with arterial hypertension and/or atherosclerosis.

MATERIAL AND METHODS

Seven hundred and thirty-six patients with cerebrovascular pathology, cognitive impairment and mild dementia were examined. The sample included 279 (37.9%) men and 457 (62.1%) women aged from 35 to 80 years (mean age 64.5±8.7 years). The drug recognan ('Gerofarm', Russia) was administered in the dose of 1000 mg daily during 30 days. Recovery of cognitive functions was assessed with MSSE, correction of visual/spatial coordination with CDT, depression severity with MGDS.

RESULTS

The improvement of cognitive function, memory and visual/spatial coordination, decrease in depression severity were observed during the treatment.

CONCLUSION

Recognan reduced cognitive dysfunction and disturbances of visual/spatial coordinationas well as had a positive effect on the emotional sphere decreasing the level of depression.

Hemopexin promotes angiogenesis via up-regulating HO-1 in rats after cerebral ischemia-reperfusion injury

BACKGROUND

Ischemia-reperfusion (I/R) is a critical pathophysiological change of ischemic stroke. Heme-oxygenase-1 (HO-1) is a rate-limiting enzyme of eliminating excessive free heme by combining with hemopexin (HPX), a plasma protein contributing to alleviating infarct size due to ischemia stroke. This study was to investigate whether HPX could improve angiogenesis after cerebral ischemia-reperfusion via up-regulating HO-1.

METHODS

Rats were randomly divided into five groups: sham, MCAO, MCAO + Vehicle, MCAO + HPX and MCAO + HPX + protoporphyrin IX (ZnPPIX, an HO-1 inhibitor). Cerebral I/R was induced by MCAO. Saline, vehicle, HPX and HPX + ZnPPIX were respectively given to MCAO group, MCAO + Vehicle group, MCAO + HPX group and MCAO + HPX + ZnPPIX group at the moment after reperfusion by intracerebroventricular injection. Neurological behavioral scores(NBS) was assessed at 24 h and 7d after I/R. Real-time polymerase chain reaction (RT-PCR) was used to analyze the mRNA level of HO-1. Angiogenesis in penumbra area was assessed by immunofluorescence detection at 7d after I/R. Serum endothelial nitric oxide synthase (eNOS) was assessed by enzyme linked immunosorbent assay (ELISA) at 24 h and 7d after I/R.

RESULTS

Compared with sham group, the NBS and the mRNA levels of HO-1 at 24 h and 7d after I/R in MCAO group decreased notably (P < 0.05), the new vessel density in ischemia penumbra increased notably at 7d after I/R (P < 0.05), the serum eNOS level increased at 24 h and 7d after I/R (P < 0.05). MCAO group and MCAO + Vehicle group showed no significant differences (P > 0.05). In the MCAO + HPX group, compared with MCAO + Vehicle group, the NBS and the mRNA levels of HO-1 increased drastically at 24 h and 7d after I/R (P < 0.05), the new vessel density in ischemia penumbra increased significantly at 7d after I/R (P < 0.05), the serum eNOS level at 24 h and 7d after I/R ascended notably (P < 0.05). Compared with MCAO + HPX group, the NBS assessment, new vessel density and serum eNOS level decreased at corresponding time points after I/R in MCAO + HPX+ ZnPPIX group (P < 0.05).

CONCLUSION

HPX can promote angiogenesis after cerebral ischemia-reperfusion injury in rats via up-regulating HO-1.

Condition-specific transcriptional regulation of neuronal ion channel genes in brain ischemia

In the context of seeking novel therapeutic targets for treating ischemic stroke, the preconditioning ischemia-induced brain ischemic tolerance has been used as a model of endogenously operative, broad-based neuroprotective mechanisms. Targeting such mechanisms is considered potentially less prone to adverse side effects, as those seen in many failed clinical trials that focus on single targets using exogenous compounds. Results from previous studies have revealed an overall decrease in potassium channel activity in tolerance development. The objective of this study is to identify ion channel genes that are differentially regulated under different brain ischemic conditions, as a mean to identify those ion channels that are associated with ischemic brain injury and ischemic tolerance. In mice in vivo, transient focal cerebral ischemia was induced by middle cerebral artery occlusion. In cultured neuronal cells in vitro, simulated ischemia was modeled by oxygen-glucose deprivation. For both in vivo and in vitro studies, three principal ischemic conditions were included: ischemic-preconditioned, injured and tolerant, respectively, plus appropriate controls. In these model systems, transcript levels of a panel of 84 neuronal ion channels genes were analyzed with a quantitative real-time PCR mini-array. The results showed that, both in vivo and in vitro, there was a predominant down regulation in neuronal ion channel genes under ischemic-tolerant conditions, and an up regulation in ischemic injury. Similar changes were observed among potassium, sodium and calcium channel genes. A number of regulated genes exhibited opposing changes under ischemic-injured and ischemic-tolerant conditions. This subset of ion channel genes exemplifies potentially novel leads for developing multi-factorial therapeutic targets for treating ischemic stroke.

[Possibilities of cavinton therapy regimen for infusions and cavinton comforte in acute and early recovery periods after ischemic stroke]

AIM

To study the efficacy of a current regimen of treatment with cavinton for infusions and cavinton comforte in patients with ischemic stroke in acute and early recovery periods and to evaluate an impact of treatment on erythrocyte deformity using atomic power microscopy.

MATERIAL AND METHODS

One hundred and sixty-four patients with hemispheric ischemic stroke, aged from 30 to 79 years, were randomized into main (n=100) and control (n=64) groups. Patients of the main group received complex treatment (basic therapy and cavinton R for drop infusions (10 intravenously during 10 days) followed by cavinton R comforte in dose 10 mg, 1 tablet 3 times a day during 90 days). Patients of the control group received basic therapy only. NIHSS, the Rankin scale, the Barthel index, MMSE, MоCA, the Rivermead scale, Beck depression scale, HADS were used to measure the severity of patient's state. To study the erythrocyte membrane by estimating Young's modulus, dry preparations were made with the following scanning of erythrocytes using atomic power microscopy.

RESULTS

Positive changes on all scales were observed in both groups. Higher scores on NIHSS, Rankin, Barthel, MоCA, MMSE, Rivermead mobility index were found in the main group compared to the controls. There were no differences in scores on the Beck depression scale and HADS. A decrease in Young's modulus was found in the main group while in the control group this index remained unchanged.

CONCLUSION

More rapid and complete regression of neurological deficit, better recovery of self-care function, cognitive function and social activity, an increase in erythrocyte membrane elasticity were found in the main group compared to the control one. These results indicate the efficacy of cavinton R and cavinton R comforte in the regimen used in complex treatment in acute and early recovery periods after ischemic stroke.

(-)-Phenserine inhibits neuronal apoptosis following ischemia/reperfusion injury

Stroke commonly leads to adult disability and death worldwide. Its major symptoms are spastic hemiplegia and discordant motion, consequent to neuronal cell death induced by brain vessel occlusion. Acetylcholinesterase (AChE) is upregulated and allied with inflammation and apoptosis after stroke. Recent studies suggest that AChE inhibition ameliorates ischemia-reperfusion injury and has neuroprotective properties. (-)-Phenserine, a reversible AChE inhibitor, has a broad range of actions independent of its AChE properties, including neuroprotective ones. However, its protective effects and detailed mechanism of action in the rat middle cerebral artery occlusion model (MCAO) remain to be elucidated. This study investigated the therapeutic effects of (-)-phenserine for stroke in the rat focal cerebral ischemia model and oxygen-glucose deprivation/reperfusion (OGD/RP) damage model in SH-SY5Y neuronal cultures. (-)-Phenserine mitigated OGD/PR-induced SH-SY5Y cell death, providing an inverted U-shaped dose-response relationship between concentration and survival. In MCAO challenged rats, (-)-phenserine reduced infarction volume, cell death and improved body asymmetry, a behavioral measure of stoke impact. In both cellular and animal studies, (-)-phenserine elevated brain-derived neurotrophic factor (BDNF) and B-cell lymphoma 2 (Bcl-2) levels, and decreased activated-caspase 3, amyloid precursor protein (APP) and glial fibrillary acidic protein (GFAP) expression, potentially mediated through the ERK-1/2 signaling pathway. These actions mitigated neuronal apoptosis in the stroke penumbra, and decreased matrix metallopeptidase-9 (MMP-9) expression. In synopsis, (-)-phenserine significantly reduced neuronal damage induced by ischemia/reperfusion injury in a rat model of MCAO and cellular model of OGD/RP, demonstrating that its anti-apoptotic/neuroprotective/neurotrophic cholinergic and non-cholinergic properties warrant further evaluation in conditions of brain injury.

MODULATION OF KEY BIOCHEMICAL MARKERS RELEVANT TO STROKE BY ANTIARIS AFRICANA LEAF EXTRACT FOLLOWING CEREBRAL ISCHEMIA/REPERFUSION INJURY

BACKGROUND

Oxidative stress plays a significant role in stroke pathogenesis. Hence, plants rich in antioxidant phytochemicals have been suggested as effective remedies for prevention and treatment of stroke and other neurological diseases. Antiaris africana Engl. (Moraceae) is traditionally used for the management of brain-related problems but there is paucity of data on its anti-stroke potential.

MATERIALS AND METHODS

Ischemia/reperfusion injury was induced by a 30 min bilateral common carotid artery occlusion/ 2 h reperfusion (BCCAO/R) in the brain of male Wistar rats. A sham-operated group which was not subjected to BCCAO/R and a group subjected to BCCAO/R without treatment with MEA served as controls. The ameliorative effect of 14 days of pretreatment with 50 mg/kg or 100 mg/kg A. africana methanol leaf extract (MEA) on BCCAO/R-mediated alterations to key markers of oxidative stress (malondialdehyde, reduced glutathione, xanthine oxidase, superoxide dismutase, catalase and glutathione peroxidase) and neurochemical disturbances and excitotoxicity (myeloperoxidase, glutamine synthetase, Na⁺/K⁺ ATPase, acetylcholinesterase and tyrosine hydroxylase), was evaluated and compared with the effect produced by treatment with 20 mg/kg quercetin as a reference standard.

RESULTS

Results show that pretreatment with MEA significantly mitigated or reversed BCCAO/R-induced changes in the level or activity of the evaluated biochemical markers of oxidative stress, neurochemical dysfunction and excitotoxicity compared with the BCCAO/R untreated control group (p < 0.05). The effect produced by 100 mg/kg MEA was similar to that of the reference standard, quercetin.

CONCLUSION

These results revealed the neuroprotective potential of A. africana in stroke and other ischemia-related pathologies.