Reactive oxygen species and the central nervous system

A Cross-Sectional Study Comparing Oxidative Stress in Patients with Epilepsy Treated with Old and New Generation Antiseizure Medications

Background and Objectives: Oxidative stress resulting from a disturbance of the endogenous redox system is suspected in numerous diseases of the central nervous system, including epilepsy. In addition, antiseizure medications (ASMs), especially those of the old generation, may further increase oxidative stress. To evaluate the effects of ASM generation on oxidative stress, we conducted a cross-sectional study in patients with epilepsy treated with old, new, and polytherapy. Materials and Methods: The antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, as well as the concentrations of malondialdehyde, protein carbonyl, nitrate, nitrite, and glutathione in reduced and oxidized forms, were measured in 49 patients with epilepsy and 14 healthy controls. In addition, the plasma concentrations of ASMs and metabolites of carbamazepine and valproic acid were measured in the patients. Results: Patients with epilepsy showed increased activities of superoxide dismutase and catalase (p < 0.001), concentrations of glutathione disulfide and markers of nitric oxide metabolism (p < 0.001), and decreased activities of glutathione peroxidase, glutathione reductase, glutathione, and nitrite concentrations (p ≤ 0.005) compared to healthy controls. A comparison of ASM generations revealed increased levels of superoxide dismutase and catalase (p ≤ 0.007) and decreased levels of glutathione peroxidase and glutathione reductase (p ≤ 0.01) in patients treated with old ASMs compared to those treated with new generation ASMs. In addition, an increase in protein carbonyl and nitric oxide metabolites (p ≤ 0.002) was observed in patients treated with old generation ASMs compared to those treated with new generation ASMs. Most oxidative stress parameters in patients receiving polytherapy with ASMs were intermediate between the results of patients treated with the old and new generations of ASMs. Conclusions: An increase in oxidative stress markers and modulation of antioxidant enzyme activities was observed in patients with epilepsy compared to controls. The results of our study showed significantly higher oxidative stress in patients treated with old ASMs compared to those treated with new generation ASMs.

Neuronal GPCR NMUR-1 regulates energy homeostasis in response to pathogen infection

A key question in current immunology is how the innate immune system generates high levels of specificity. Our previous study in Caenorhabditis elegans revealed that NMUR-1, a neuronal G protein-coupled receptor homologous to mammalian receptors for the neuropeptide neuromedin U (NMU), regulates distinct innate immune responses to different bacterial pathogens. Here, by using quantitative proteomics and functional assays, we discovered that NMUR-1 regulates F1FO ATP synthase and ATP production in response to pathogen infection, and that such regulation contributes to NMUR-1-mediated specificity of innate immunity. We further demonstrated that ATP biosynthesis and its contribution to defense is neurally controlled by the NMUR-1 ligand CAPA-1 and its expressing neurons ASG. These findings indicate that NMUR-1 neural signaling regulates the specificity of innate immunity by controlling energy homeostasis as part of defense against pathogens. Our study provides mechanistic insights into the emerging roles of NMU signaling in immunity across animal phyla.

Centella asiatica improves memory and executive function in middle-aged rats by controlling oxidative stress and cholinergic transmission

ETHNOPHARMACOLOGICAL RELEVANCE

Centella asiatica (L.) Urban, is a medicinal herb with rich history of traditional use in Indian subcontinent. This herb has been valued for its diverse range of medicinal properties including memory booster, and also as a folk treatment for skin diseases, wound healing and mild diuretic.

AIM OF STUDY

Aging is a gradual and continuous process of natural decay in the biological systems, including the brain. This work aims to evaluate the effectiveness of ethanolic extract of Centella asiatica (CAE) on age-associated cognitive impairments in rats, as well as the underlying mechanism.

MATERIAL AND METHODS

Rats were allocated into five distinct groups of 5 animals each: Young rats (3 months old rats), middle-aged (m-aged) rats (13-14 months old), and the remaining three groups were comprised of m-aged rats treated with different concentrations of CAE, viz., 150, 300, and 450 mg/kg b. w., orally for 42 days. Y-maze, open field, novel object recognition, and elevated plus maze tests were used to assess animal behavior. The malondialdehyde (MDA), superoxide dismutase (SOD), and acetylcholinesterase (AChE) assays; and H&E staining were done in the rat brain to assess the biochemical and structural changes. CAE was also subjected to HPLC analysis, in vitro antioxidant and anti-cholinergic activity. The active compounds of CAE were docked with AChE and BuChE in molecular docking study.

RESULTS

The results showed that CAE treatment improves behavioral performance; attenuates the age-associated increase in MDA content, SOD, and AChE activity; and reduces neuronal loss. In vitro study showed that CAE has concentration-dependent antioxidant and anti-AChE activity. Furthermore, the presence of Asiatic acid and Madecassic acid in CAE and their good binding with cholinergic enzymes (in silico) also suggest the anticholinergic effect of CAE.

CONCLUSION

The findings of the current study show that the anticholinergic and antioxidant effects of CAE are attributable to the presence of Asiatic acid and Madecassic acid, which not only provide neuroprotection against age-associated cognitive decline but also reverse it.

Anti-Parkinson potential of hesperetin nanoparticles: in vivo and in silico investigations

Parkinson's disease (PD) is characterised by the gradual demise of dopaminergic neurons. In recent years, there has been significant interest in herbal treatments. In this study, hesperetin nanoparticles (HTN) were developed and compared their anti-PD potential with hesperetin (HT) on rotenone induced PD rats. Molecular docking was also performed to evaluate the binding affinity of hesperetin on pathological protein, i.e. D2 dopamine receptors (DR2), using Auto Dock Vina tools. The results showed a higher binding relationship of HTN on dopamine receptors (-7.2 kcal/mol) compared to L-dopa (-6.4 kcal/mol), supporting their potential as drug candidates for PD therapy. HTN was effectively synthesised using the fabrication technique and characterised by zeta potential and SEM analysis. HTN had favourable characteristics, including a size of 249.8 ± 14.9 nm and a Z-potential of -32.9 mV. After being administered orally, HTN demonstrated a notable anti-Parkinsonian effects, indicated by the significant improvement in motor function as assessed by the rota rod test (p < .001***), pole test (p < .001***), stair test (p < .01**), wood walk test (p < .01**) and an increase in substantia nigra (SN) antioxidant levels, CAT (p < .001***), SOD (p < .001***), GSH (p < .01**). Additionally, HTN led to increased dopamine levels (p < .01**) and a decrease in the oxidant system, MDA levels (p < .01**). Furthermore, histopathological examination revealed decreased SN neuronal necrosis in diseased animals treated with HTN compared to those treated with HT in a rat model of Parkinson's disease. Therefore, HTN can be regarded as a viable platform for efficient therapy of PD.

Current and further outlook on the protective potential of Antrodia camphorata against neurological disorders

Prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and stroke are increasingly becoming a global burden as society ages. It is well-known that degeneration and loss of neurons are the fundamental underlying processes, but there are still no effective therapies for these neurological diseases. In recent years, plenty of studies have focused on the pharmacology and feasibility of natural products as new strategies for the development of drugs that target neurological disorders. Antrodia camphorata has become one of the most promising candidates, and the crude extracts and some active metabolites of it have been reported to play various pharmacological activities to alleviate neurological symptoms at cellular and molecular levels. This review highlights the current evidence of Antrodia camphorata against neurological disorders, including safety evaluation, metabolism, blood-brain barrier penetration, neuroprotective activities, and the potential on regulating the gut-microbiome-brain axis. Furthermore, potential strategies to resolve problematic issues identified in previous studies are also discussed. We aim to provide an overview for the ongoing development and utilization of Antrodia camphorata in cerebral neuropathology.

Nuclear translocation of STAT5 initiates iron overload in huntington's disease by up-regulating IRP1 expression

Mutant huntingtin (mHtt) proteins interact to form aggregates, disrupting cellular functions including transcriptional dysregulation and iron imbalance in patients with Huntington's disease (HD) and mouse disease models. Previous studies have indicated that mHtt may lead to abnormal iron homeostasis by upregulating the expression of iron response protein 1 (IRP1) in the striatum and cortex of N171-82Q HD transgenic mice, as well as in HEK293 cells expressing the N-terminal fragment of mHtt containing 160 CAG repeats. However, the mechanism underlying the upregulation of IRP1 remains unclear. We investigated the levels and phosphorylation status of signal transducer and activator of transcription 5 (STAT5) in the brains of N171-82Q HD transgenic mice using immunohistochemistry staining. We also assessed the nuclear localization of STAT5 protein through western blot and immunofluorescence, and measured the relative RNA expression levels of STAT5 and IRP1 using RT-PCR in both N171-82Q HD transgenic mice and HEK293 cells expressing the N-terminal fragment of huntingtin. Our findings demonstrate that the transcription factor STAT5 regulates the transcription of the IPR1 gene in HEK293 cells. Notably, both the brains of N171-82Q mice and 160Q HEK293 cells exhibited increased nuclear content of STAT5, despite unchanged total STAT5 expression. These results suggest that mHtt promotes the nuclear translocation of STAT5, leading to enhanced expression of IRP1. The nuclear translocation of STAT5 initiates abnormal iron homeostatic pathways, characterized by elevated IRP1 expression, increased levels of transferrin and transferrin receptor, and iron accumulation in the brains of HD mice. These findings provide valuable insights into potential therapeutic strategies targeting iron homeostasis in HD.

Modulation of thioredoxin by chlorogenic acid in an ischemic stroke model and glutamate-exposed neurons

Ischemic stroke increases the production of reactive oxygen species (ROS), which can eventually lead to neuronal death. Thioredoxin is a small reductase protein that acts as an eliminator of ROS and protects neurons from brain damage. Chlorogenic acid is known as a phenolic compound that has a neuroprotective effect. We investigated the change of thioredoxin expression by chlorogenic acid in a middle cerebral artery occlusion (MCAO) animal model. Adult rats were injected intraperitoneally with phosphate buffered saline or chlorogenic acid (30 mg/kg) 2 h after MCAO. MCAO damage induced neurological defects and increased ROS and lipid peroxidation levels, however, chlorogenic acid mitigated these changes. MCAO damage reduced thioredoxin expression, which was mitigated by chlorogenic acid treatment. The interaction between thioredoxin and apoptosis signal-regulating kinase 1 (ASK1) was decreased in MCAO animals, chlorogenic acid treatment prevented this decrease. In cultured neurons, chlorogenic acid dose-dependently attenuated glutamate-induced decreases in cell viability and thioredoxin expression. Glutamate toxicity downregulated bcl-2 and upregulated bax, cytochrome c, and caspase-3, however, chlorogenic acid attenuated these changes. The mitigating effect of chlorogenic acid was lower in thioredoxin siRNA-transfected cells than in non-transfected cells. These results provide evidence that chlorogenic acid exerts potent antioxidant and neuroprotective effects through regulation of thioredoxin and modulation of ASK1 and thioredoxin binding in ischemic brain injury. These findings indicate that chlorogenic acid exerts a neuroprotective effect by regulating thioredoxin expression in cerebral ischemia and glutamate exposure conditions.

Development and application of novel ELISA-based analytical tools for assessing nitroxidative distress biomarkers in ischemic stroke: implications for improved diagnosis and clinical management

Ischemic cerebrovascular accident (iCVA) is a public health issue, whose subjacent events involve the development of nitroxidative distress. Identifying biomarkers that assist in the diagnosis of this disease has clinically relevant implications. The aim of this study was to develop an analytic tool for measuring nitroxidative distress biomarkers, intended for application in clinical practice to enhance patient healthcare. Three enzyme linked immunosorbent assays (ELISA) were developed, with different detection objectives. One of them, in a sandwich format, quantifies the amount of fibrinogen in human plasma, an important glycoprotein involved in the blood coagulation process, contributing to thrombus formation and thereby participating in the mechanism of ischemic stroke. Another ELISA, also in a sandwich format, detects the presence of nitrotyrosine residues in fibrinogen from human plasma, a nitroxidative posttranslational modification resulting from the attack of peroxynitrite by-products on tyrosine residues present in proteins. The third one, in inhibition format, determines human plasma nitrotyrosine total content and was used to analyze human plasma samples from control and iCVA patients. Those two groups of plasma samples were analyzed using inhibition ELISA, revealing statistically significant differences in their nitrotyrosine content and molar ratios of nitrotyrosine to fibrinogen, which were higher in the iCVA group. This study provides evidence that nitroxidative distress occurs in ischemic stroke, as indicated by the detection of the biomarker nitrotyrosine. This finding supports other studies that also identified nitrotyrosine in ischemic stroke, through several different methods. This specific ELISA method is applicable for the rapid analysis of clinical samples, making it a potential clinical tool for assessing iCVA patients.

Cardiovascular benefits of SGLT2 inhibitors and GLP-1 receptor agonists through effects on mitochondrial function and oxidative stress

Overloaded glucose levels in several metabolic diseases such as type 2 diabetes (T2D) can lead to mitochondrial dysfunction and enhanced production of reactive oxygen species (ROS). Oxidative stress and altered mitochondrial homeostasis, particularly in the cardiovascular system, contribute to the development of chronic comorbidities of diabetes. Diabetes-associated hyperglycemia and dyslipidemia can directly damage vascular vessels and lead to coronary artery disease or stroke, and indirectly damage other organs and lead to kidney dysfunction, known as diabetic nephropathy. The new diabetes treatments include Na+-glucose cotransporter 2 inhibitors (iSGLT2) and glucagon-like 1 peptide receptor agonists (GLP-1RA), among others. The iSGLT2 are oral anti-diabetic drugs, whereas GLP-1RA are preferably administered through subcutaneous injection, even though GLP-1RA oral formulations have recently become available. Both therapies are known to improve both carbohydrate and lipid metabolism, as well as to improve cardiovascular and cardiorenal outcomes in diabetic patients. In this review, we present an overview of current knowledge on the relationship between oxidative stress, mitochondrial dysfunction, and cardiovascular therapeutic benefits of iSGLT2 and GLP-1RA. We explore the benefits, limits and common features of the treatments and remark how both are an interesting target in the prevention of obesity, T2D and cardiovascular diseases, and emphasize the lack of a complete understanding of the underlying mechanism of action.

Luminescent Radicals

Organic radicals are attracting increasing interest as a new class of molecular emitters. They demonstrate electronic excitation and relaxation dynamics based on their doublet or higher multiplet spin states, which are different from those based on singlet-triplet manifolds of conventional closed-shell molecules. Recent studies have disclosed luminescence properties and excited state dynamics unique to radicals, such as highly efficient electron-photon conversion in OLEDs, NIR emission, magnetoluminescence, an absence of heavy atom effect, and spin-dependent and spin-selective dynamics. These are difficult or sometimes impossible to achieve with closed-shell luminophores. This review focuses on luminescent organic radicals as an emerging photofunctional molecular system, and introduces the material developments, fundamental properties including luminescence, and photofunctions. Materials covered in this review range from monoradicals, radical oligomers, and radical polymers to metal complexes with radical ligands demonstrating radical-involved emission. In addition to stable radicals, transiently formed radicals generated in situ by external stimuli are introduced. This review shows that luminescent organic radicals have great potential to expand the chemical and spin spaces of luminescent molecular materials and thus broaden their applicability to photofunctional systems.

Dopamine oxidation promoted by human telomeric DNA models in the presence of a Cu(II) terpyridine chelate

We found that under oxidative stress conditions, the coexistence of human telomeric DNA (HT-DNA) and a copper-terpyridine metallodrug can accelerate dopamine oxidation. The unwinding of HT-DNA from a duplex to cytosine-rich (C-rich) and guanine-rich (G-rich) single strands promotes dopamine oxidation in a general order of C-rich > G-rich > duplex. Along with dopamine oxidation, HT-DNA also undergoes severe damage.

Oxidative damage in neurodegeneration: roles in the pathogenesis and progression of Alzheimer disease

Alzheimer disease (AD) is associated with multiple etiologies and pathological mechanisms, among which oxidative stress (OS) appears as a major determinant. Intriguingly, OS arises in various pathways regulating brain functions, and it seems to link different hypotheses and mechanisms of AD neuropathology with high fidelity. The brain is particularly vulnerable to oxidative damage, mainly because of its unique lipid composition, resulting in an amplified cascade of redox reactions that target several cellular components/functions ultimately leading to neurodegeneration. The present review highlights the "OS hypothesis of AD," including amyloid beta-peptide-associated mechanisms, the role of lipid and protein oxidation unraveled by redox proteomics, and the antioxidant strategies that have been investigated to modulate the progression of AD. Collected studies from our groups and others have contributed to unraveling the close relationships between perturbation of redox homeostasis in the brain and AD neuropathology by elucidating redox-regulated events potentially involved in both the pathogenesis and progression of AD. However, the complexity of AD pathological mechanisms requires an in-depth understanding of several major intracellular pathways affecting redox homeostasis and relevant for brain functions. This understanding is crucial to developing pharmacological strategies targeting OS-mediated toxicity that may potentially contribute to slow AD progression as well as improve the quality of life of persons with this severe dementing disorder.

Potential Role of Oxidative Stress in the Pathophysiology of Neurodegenerative Disorders

Neurodegeneration causes premature death in the peripheral and central nervous system. Neurodegeneration leads to the accumulation of oxidative stress, inflammatory responses, and the generation of free radicals responsible for nervous disorders like amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disorders. Therefore, focus must be diverted towards treating and managing these disorders, as it is very challenging. Furthermore, effective therapies are also lacking, so the growing interest of the global market must be inclined towards developing newer therapeutic approaches that can intercept the progression of neurodegeneration. Emerging evidences of research findings suggest that antioxidant therapy has significant potential in modulating disease phenotypes. This makes them promising candidates for further investigation. This review focuses on the role of oxidative stress and reactive oxygen species in the pathological mechanisms of various neurodegenerative diseases, amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disorders and their neuroprotection. Additionally, it highlights the potential of antioxidant-based therapeutics in mitigating disease severity in humans and improving patient compliance. Ongoing extensive global research further sheds light on exploring new therapeutic targets for a deeper understanding of disease mechanisms in the field of medicine and biology targeting neurogenerative disorders.

Tramadol induces apoptosis, inflammation, and oxidative stress in rat choroid plexus

BACKGROUND

The choroid plexus (CP) is the principal source of cerebrospinal fluid (CSF). It can produce and release a wide range of materials, including growth and neurotrophic factors which have a crucial role in the maintenance and proper functioning of the brain. Tramadol is a synthetic analog of codeine, mainly prescribed to alleviate mild to moderate pains. Nevertheless, it causes several side effects, such as emotional instability and anxiety.

METHODS

In this study, we focused on alterations in the expression of inflammatory and apoptotic genes in the CP under chronic tramadol exposure. Herein, rats were treated daily with tramadol at 50 mg/kg doses for three weeks. CSF samples were collected, with superoxide dismutase (SOD) and glutathione (GSH) measured in the CSF.

RESULTS

We found that tramadol reduced the SOD and GSH levels in the CSF. Furthermore, the stereological analysis revealed a significant increase in the CP volume, epithelial cells, and capillary number upon tramadol administration. Tramadol elevated the number of blob mitochondria in CP. Also, we observed the upregulation of inflammatory and apoptosis genes following tramadol administration in the CP.

CONCLUSIONS

Our findings indicate that tramadol induces neurotoxicity in the CP via apoptosis, inflammation, and oxidative stress.

Protective Effect of Topiramate against Diabetic Retinopathy and Computational Approach Recognizing the Role of NLRP3/IL-1β/TNF-α Signaling

The possible impact of topiramate against diabetic retinopathy (DREN) and its molecular mechanisms in relation to the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome has not been studied before. Thus, in the present study, we aimed to utilize a computational approach to investigate the possible protective effect of topiramate on experimental DREN and explore its impact on NLRP3/interlukin-1β signaling and brain-derived neurotrophic factor (BDNF) expression. Male albino mice were distributed to four experimental groups and assigned the following categorizations: (i) saline, (ii) diabetic, (iii) diabetic + topiramate 10 mg/kg and (iv) diabetic + topiramate 30 mg/kg. We observed shrinkage of total retinal thickness and elevation in retinal glutamate, malondialdehyde, NLRP3 and interlukin-1β but decreased glutathione (GSH) levels in the diabetic mice. Additionally, retinal ultra-structures in the diabetic group showed abnormalities and vacuolations in the pigmented epithelium, the photoreceptor segment, the outer nuclear layer, the inner nuclear layer and the ganglion cell layer (GCL). Mice treated with topiramate 10 or 30 mg/kg showed downregulation in retinal malondialdehyde, NLRP3 and interlukin-1β levels; improvements in the retinal pathologies; enhanced immunostaining for BDNF and improved ultra-structures in different retinal layers. Overall, the current results suggest topiramate as a neuroprotective agent for DREN, and future studies are warranted to further elucidate the mechanism of its protective action.

Interactions of amyloidogenic proteins with mitochondrial protein import machinery in aging-related neurodegenerative diseases

Most mitochondrial proteins are targeted to the organelle by N-terminal mitochondrial targeting sequences (MTSs, or "presequences") that are recognized by the import machinery and subsequently cleaved to yield the mature protein. MTSs do not have conserved amino acid compositions, but share common physicochemical properties, including the ability to form amphipathic α-helical structures enriched with basic and hydrophobic residues on alternating faces. The lack of strict sequence conservation implies that some polypeptides can be mistargeted to mitochondria, especially under cellular stress. The pathogenic accumulation of proteins within mitochondria is implicated in many aging-related neurodegenerative diseases, including Alzheimer's, Parkinson's, and Huntington's diseases. Mechanistically, these diseases may originate in part from mitochondrial interactions with amyloid-β precursor protein (APP) or its cleavage product amyloid-β (Aβ), α-synuclein (α-syn), and mutant forms of huntingtin (mHtt), respectively, that are mediated in part through their associations with the mitochondrial protein import machinery. Emerging evidence suggests that these amyloidogenic proteins may present cryptic targeting signals that act as MTS mimetics and can be recognized by mitochondrial import receptors and transported into different mitochondrial compartments. Accumulation of these mistargeted proteins could overwhelm the import machinery and its associated quality control mechanisms, thereby contributing to neurological disease progression. Alternatively, the uptake of amyloidogenic proteins into mitochondria may be part of a protein quality control mechanism for clearance of cytotoxic proteins. Here we review the pathomechanisms of these diseases as they relate to mitochondrial protein import and effects on mitochondrial function, what features of APP/Aβ, α-syn and mHtt make them suitable substrates for the import machinery, and how this information can be leveraged for the development of therapeutic interventions.

Daytime-Restricted Feeding Ameliorates Oxidative Stress by Increasing NRF2 Transcriptional Factor in the Rat Hippocampus in the Pilocarpine-Induced Acute Seizure Model

Seizure-mediated oxidative stress is a crucial mechanism in the pathophysiology of epilepsy. This study evaluated the antioxidant effects of daytime-restricted feeding (DRF) and the role of the Nrf2 signaling pathway in a lithium-pilocarpine model seizure model that induces status epilepticus (SE). We performed a lipoperoxidation assay and dihydroethidium fluorescence to measure oxidative stress markers in the hippocampus (malondialdehyde and reactive oxygen species). The protein content of Nrf2 and its downstream protein SOD2 was evaluated using Western blotting. The cellular distribution of the Nrf2 and SOD2 proteins in the pyramidal cell layer of both the CA1 and CA3 hippocampal subfields and astrocytes (GFAP marker) were quantified using immunofluorescence and immunohistochemistry, respectively. Our results indicate that DRF reduced the malondialdehyde levels and the production of reactive oxygen species. Furthermore, a significant increase in Nrf2 and SOD2 protein content was observed in animals subjected to restrictive diet. In addition, DRF increased the relative intensity of the Nrf2 fluorescence in the perinuclear and nuclear compartments of pyramidal neurons in the CA1 subfield. Nrf2 immunoreactivity and the astrocyte marker GFAP also increased their colocalization under DRF conditions. Additionally, SOD2 immunoreactivity was increased in CA1 pyramidal neurons but not in the CA3 region. Our findings suggest that DRF partially prevents oxidative stress by increasing the Nrf2 transcriptional factor and the SOD2 enzyme during the development of SE.

Vascular multiple sclerosis: addressing the pathogenesis, genetics, pro-angiogenic factors, and vascular abnormalities, along with the role of vascular intervention

Dysfunction in the epithelium, breakdown of the blood-brain barrier, and consequent leukocyte and T-cell infiltration into the central nervous system define Vascular Multiple Sclerosis. Multiple sclerosis (MS) affects around 2.5 million individuals worldwide, is the leading cause of neurological impairment in young adults, and can have a variety of progressions and consequences. Despite significant discoveries in immunology and molecular biology, the root cause of MS is still not fully understood, as do the immunological triggers and causative pathways. Recent research into vascular anomalies associated with MS suggests that a vascular component may be pivotal to the etiology of MS, and there can be actually a completely new entity in the already available classification of MS, which can be called 'vascular multiple sclerosis'. Unlike the usual other causes of MS, vascular MS is not dependent on autoimmune pathophysiologic mechanisms, instead, it is caused due to the blood vessels pathology. This review aims to thoroughly analyze existing information and updates about the scattered available findings of genetics, pro-angiogenetic factors, and vascular abnormalities in this important spectrum, the vascular facets of MS.

Urolithins: A Prospective Alternative against Brain Aging

The impact of host-microbiome interactions on cognitive health and disease has received increasing attention. Microbial-derived metabolites produced in the gut are one of crucial mechanisms of the gut-brain axis interaction, showing attractive perspectives. Urolithins (Uros) are gut microbial-derived metabolites of ellagitannins and ellagic acid, whose biotransformation varies considerably between individuals and decreases greatly with age. Recently, accumulating evidence has suggested that Uros may have specific advantages in preventing brain aging including favorable blood-brain barrier permeability, selective brain distribution, and increasingly supporting data from preclinical and clinical studies. However, the usability of Uros in diagnosis, prevention, and treatment of neurodegenerative diseases remains elusive. In this review, we aim to present the comprehensive achievements of Uros in age-related brain dysfunctions and neurodegenerative diseases and discuss their prospects and knowledge gaps as functional food, drugs, or biomarkers against brain aging.

Cationic starch: A functionalized polysaccharide based polymer for advancement of drug delivery and health care system - A review

Research and development in health care industry is in persistence progression. To make it more patient-friendly or to get maximum benefits from it, special attention to different advanced drug delivery system (ADDS) is employed that delivers the drug at the target site and will be able to sustain/control release of drugs. ADDS should be non-toxic, biodegradable, biocompatible along with desirable showing physicochemical and functional properties. These drug delivery systems can be totally based on polymers, either with natural or synthetic polymers. The molecular weight of polymer can be tuned and different groups of polymers can be modified or substituted with other functional groups. Degree of substitution is also tailored. Cationic starch in recent years is exploited in drug delivery, tissue engineering and biomedicine. Due to their abundant availability, low cost, easy chemical modification, low toxicity, biodegradability and biocompatibility, extensive research is now being carried out. Our present discussion will shed light on the usage of cationic starch in health care system.

Involvement of antioxidant enzymes in Parkinson's disease

Similar to many other diseases, the etiology of Parkinson's disease (PD) is multifactorial and includes both genetic and environmental factors. Exposure to pesticides and the production of reactive oxygen species (ROS) in the body, mainly in electron transporter complexes 1 and 2 in the inner mitochondrial membrane, are two primary environmental risk factors for this disease. Increased accumulation of ROS and oxidative stress (OS) trigger a series of reactions that can lead to the aggregation of misfolded proteins, DNA damage, autophagy, and apoptosis, which may adversely affect cell function. These processes cause diseases such as coronary artery disease (CAD), Alzheimer's disease (AD), and PD. As indicated in previous studies, ROS is considered a critical regulator in the progression of PD. The human body contains several antioxidant molecules, such as vitamin A, vitamin C, bilirubin, and uric acid, as well as antioxidant enzymes including paraoxonase (PON), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). Therefore, based on the canonical function of the antioxidant enzymes in PD, In the present review, we attempted to examine the function of antioxidant enzymes in PD.

Inhibiting NLRP3 inflammasome signaling pathway promotes neurological recovery following hypoxic-ischemic brain damage by increasing p97-mediated surface GluA1-containing AMPA receptors

BACKGROUND

The nucleotide-binding oligomeric domain (NOD)-like receptor protein 3 (NLRP3) inflammasome is believed to be a key mediator of neuroinflammation and subsequent secondary brain injury induced by ischemic stroke. However, the role and underlying mechanism of the NLRP3 inflammasome in neonates with hypoxic-ischemic encephalopathy (HIE) are still unclear.

METHODS

The protein expressions of the NLRP3 inflammasome including NLRP3, cysteinyl aspartate specific proteinase-1 (caspase-1) and interleukin-1β (IL-1β), the α-amino-3-hydroxy-5-methyl-4-isoxazole-propionicacid receptor (AMPAR) subunit, and the ATPase valosin-containing protein (VCP/p97), were determined by Western blotting. The interaction between p97 and AMPA glutamate receptor 1 (GluA1) was determined by co-immunoprecipitation. The histopathological level of hypoxic-ischemic brain damage (HIBD) was determined by triphenyltetrazolium chloride (TTC) staining. Polymerase chain reaction (PCR) and Western blotting were used to confirm the genotype of the knockout mice. Motor functions, including myodynamia and coordination, were evaluated by using grasping and rotarod tests. Hippocampus-dependent spatial cognitive function was measured by using the Morris-water maze (MWM).

RESULTS

We reported that the NLRP3 inflammasome signaling pathway, such as NLRP3, caspase-1 and IL-1β, was activated in rats with HIBD and oxygen-glucose deprivation (OGD)-treated cultured primary neurons. Further studies showed that the protein level of the AMPAR GluA1 subunit on the hippocampal postsynaptic membrane was significantly decreased in rats with HIBD, and it could be restored to control levels after treatment with the specific caspase-1 inhibitor AC-YVAD-CMK. Similarly, in vitro studies showed that OGD reduced GluA1 protein levels on the plasma membrane in cultured primary neurons, whereas AC-YVAD-CMK treatment restored this reduction. Importantly, we showed that OGD treatment obviously enhanced the interaction between p97 and GluA1, while AC-YVAD-CMK treatment promoted the dissociation of p97 from the GluA1 complex and consequently facilitated the localization of GluA1 on the plasma membrane of cultured primary neurons. Finally, we reported that the deficits in motor function, learning and memory in animals with HIBD, were ameliorated by pharmacological intervention or genetic ablation of caspase-1.

CONCLUSION

Inhibiting the NLRP3 inflammasome signaling pathway promotes neurological recovery in animals with HIBD by increasing p97-mediated surface GluA1 expression, thereby providing new insight into HIE therapy.

The Unfolded Protein Response: A Double-Edged Sword for Brain Health

Efficient brain function requires as much as 20% of the total oxygen intake to support normal neuronal cell function. This level of oxygen usage, however, leads to the generation of free radicals, and thus can lead to oxidative stress and potentially to age-related cognitive decay and even neurodegenerative diseases. The regulation of this system requires a complex monitoring network to maintain proper oxygen homeostasis. Furthermore, the high content of mitochondria in the brain has elevated glucose demands, and thus requires a normal redox balance. Maintaining this is mediated by adaptive stress response pathways that permit cells to survive oxidative stress and to minimize cellular damage. These stress pathways rely on the proper function of the endoplasmic reticulum (ER) and the activation of the unfolded protein response (UPR), a cellular pathway responsible for normal ER function and cell survival. Interestingly, the UPR has two opposing signaling pathways, one that promotes cell survival and one that induces apoptosis. In this narrative review, we discuss the opposing roles of the UPR signaling pathways and how a better understanding of these stress pathways could potentially allow for the development of effective strategies to prevent age-related cognitive decay as well as treat neurodegenerative diseases.

Metabolic partitioning in the brain and its hijacking by glioblastoma

The different cell types in the brain have highly specialized roles with unique metabolic requirements. Normal brain function requires the coordinated partitioning of metabolic pathways between these cells, such as in the neuron-astrocyte glutamate-glutamine cycle. An emerging theme in glioblastoma (GBM) biology is that malignant cells integrate into or "hijack" brain metabolism, co-opting neurons and glia for the supply of nutrients and recycling of waste products. Moreover, GBM cells communicate via signaling metabolites in the tumor microenvironment to promote tumor growth and induce immune suppression. Recent findings in this field point toward new therapeutic strategies to target the metabolic exchange processes that fuel tumorigenesis and suppress the anticancer immune response in GBM. Here, we provide an overview of the intercellular division of metabolic labor that occurs in both the normal brain and the GBM tumor microenvironment and then discuss the implications of these interactions for GBM therapy.

Biosynthesized Selenium Nanoparticles Using Epigallocatechin Gallate Protect against Pentylenetetrazole-Induced Acute Epileptic Seizures in Mice via Antioxidative, Anti-Inflammatory, and Anti-Apoptotic Activities

Several negative outcomes are associated with current anti-epileptic medications. Epigallocatechin gallate (EGCG) is a plant-derived compound called catechin and has many medicinal activities, such as anti-inflammatory and antioxidant activities. Biosynthesized selenium nanoparticles are also showing their neuroprotective effect. The anti-epileptic effect of EGCG, alone or with SeNPs, is still debated. Here, we aimed to investigate the potential anti-seizure effect of biosynthesized SeNPs using EGCG (EGCG-SeNPs) against epileptic seizures and hippocampal damage, which is enhanced by pentylenetetrazole (PTZ) injection in mice. Mice were grouped as follows: control; PTZ-exposed group (epileptic model); EGCG + PTZ-treated group; sodium selenite (Na₂SeO₃) + PTZ-treated group; EGCG-SeNPs + PTZ-treated group; and valproic acid (VPA) + PTZ-treated group. EGCG-SeNPs administration showed anti-epileptic activity by increasing the latency time and reducing the seizure duration following the PTZ injection. Additionally, EGCG-SeNPs counteracted the PTZ-induced changes in oxidants and antioxidants. Moreover, EGCG-SeNPs inhibited the inflammatory response by suppressing the release of pro-inflammatory cytokines and decreasing the immunoreactivity of the glial fibrillary acidic protein and mRNA expression of glutamate receptor subunit zeta-1 (NMDAR; Grin1), showing their inhibitory effect on epilepsy-associated inflammation. Moreover, EGCG-SeNPs reduced PTZ-induced neuronal apoptosis, as indicated by a reduction in the levels of pro-apoptotic proteins and an elevation of the anti-apoptotic protein. Moreover, EGCG-SeNPs administration significantly modulated the PTZ-induced changes in monoamine levels and acetylcholinesterase activity in the hippocampal tissue. The obtained findings suggest the anti-seizure activity of EGCG-SeNPs via their antioxidant, anti-inflammatory, and anti-apoptotic effects, along with their neuromodulatory effect.

Plasma and cerebrospinal fluid nonenzymatic protein damage is sustained in Alzheimer's disease

BACKGROUND

Oxidative stress is considered to play an important role in the pathogenesis of Alzheimer's disease (AD). It has been observed that oxidative damage to specific protein targets affecting particular functional networks is one of the mechanisms by which oxidative stress contributes to neuronal failure and consequently loss of cognition and AD progression. Studies are lacking in which oxidative damage is measured at both systemic and central fluid levels and in the same cohort of patients. We aimed to determine the levels of both plasma and cerebrospinal fluid (CSF) nonenzymatic protein damage in patients in the continuum of AD and to evaluate the relation of this damage with clinical progression from mild cognitive impairment (MCI) to AD.

METHODS

Different markers of nonenzymatic post-translational protein modification, mostly from oxidative processes, were detected and quantified in plasma and CSF by isotope dilution gas chromatography‒mass spectrometry using selected ion monitoring (SIM-GC/MS) for 289 subjects: 103 AD, 92 MCI, and 94 control subjects. Characteristics of the study population such as age, sex, Mini-mental state examination, CSF AD biomarkers, and APOE ϵ4, were also considered.

RESULTS

Forty-seven (52.8%) MCI patients progressed to AD during follow-up (58 ± 12.5 months). After controlling for age, sex, and APOE ϵ4 allele, plasma and CSF concentrations of protein damage markers were not associated with either diagnosis of AD or MCI. The CSF levels of nonenzymatic protein damage markers were associated with none of the CSF AD biomarkers. In addition, neither in CSF nor in plasma were the levels of protein damage associated with the MCI to AD progression.

CONCLUSION

The lack of association between both CSF and plasma concentrations of nonenzymatic protein damage markers and AD diagnosis and progression suggests that oxidative damage in AD is a pathogenic mechanism specifically expressed at the cell-tissue level, not in extracellular fluids.

Amelioration of Hepatotoxic and Neurotoxic Effect of Cartap by Aloe vera in Wistar Rats

Pesticide exposure can pose a serious risk to nontarget animals. Cartap is being broadly used in agricultural fields. The toxic effects of cartap on the levels of hepatotoxicity and neurotoxicity have not been properly studied in mammalian systems. Therefore, the present work focused on the effect of cartap on the liver and brain of Wistar rats and made an assessment of the ameliorating potential of A. vera. The experimental animals were divided into 4 groups, comprising six rats in each: Group 1-Control; Group 2-A. vera; Group 3-Cartap; and Group 4-A. vera + Cartap. The animals orally given cartap and A. vera were sacrificed after 24 h of the final treatment and histological and biochemical investigations were conducted in liver and brain of Wistar rats. Cartap at sublethal concentrations caused substantial decreases in CAT, SOD, and GST levels in the experimental rats. The activity levels of transaminases and phosphatases in cartap group were also found to be substantially altered. The AChE activity was recorded as decreasing in RBC membrane and brain of the cartap-treated animals. The TNF-α and IL-6 level in serum were increased expressively in the cartap challenged groups. Histological investigation of liver showed disorganized hepatic cords and severely congested central veins due to cartap. However, the A. vera extract was observed to significantly protect against the effects of cartap toxicity. The protective impact of A. vera against cartap toxicity may be due to the existence of antioxidants in it. These findings suggest that A. vera may be developed as a potential supplement to the appropriate medication in the treatment of cartap toxicity.

Analysis of Phenolic Acids and Flavonoids in Rabbiteye Blueberry Leaves by UPLC-MS/MS and Preparation of Nanoemulsions and Extracts for Improving Antiaging Effects in Mice

Rabbiteye blueberry leaves, a waste produced after harvest of blueberry, are rich in polyphenols. This study aims to analyze phenolic acids and flavonoids in blueberry leaves by UPLC-MS/MS and prepare nanoemulsions for determining anti-aging activity in mice. Overall, 30% ethanol was the most suitable extraction solvent for total phenolic acids and total flavonoids. A total of four phenolic acids and four flavonoids were separated within seven minutes for further identification and quantitation by UPLC-MS/MS in selective reaction monitoring (SRM) mode, with 3-O-caffeoylquinic acid being present in the highest amount (6474.2 μg/g), followed by quercetin-3-O-galactoside (1943.9 μg/g), quercetin-3-O-rutinoside (1036.6 μg/g), quercetin-3-O-glucoside (867.2 μg/g), 5-O-caffeoylquinic acid (815.8 μg/g), kaempferol-3-O-glucoside (309.7 μg/g), 3,5-dicaffeoylquinic acid (195.3 μg/g), and 4,5-dicaffeoylquinic acid (60.8 μg/g). The blueberry nanoemulsion was prepared by using an appropriate ratio of soybean oil, Tween 80, glycerol, ethanol, and water at 1.2%, 8%, 2%, 2%, and 86.8%, respectively, and mixing with dried blueberry extract, with the mean particle size and zeta potential being 16 nm and -54 mV, respectively. A high stability was observed during storage of nanoemulsion for 90 days at 4 °C and heated at 100 °C for 2 h. An animal study revealed that this nanoemulsion could elevate dopamine content in mice brain as well as superoxide dismutase, glutathione peroxidase, and catalase activities in mice liver while reducing the contents of malondialdehyde and protein carbonyl in mice brains. Collectively, the high-dose nanoemulsion possessed the highest efficiency in improving mice aging with a promising potential for development into a health food.

Central Facial Nervous System Biomolecules Involved in Peripheral Facial Nerve Injury Responses and Potential Therapeutic Strategies

Peripheral facial nerve injury leads to changes in the expression of various neuroactive substances that affect nerve cell damage, survival, growth, and regeneration. In the case of peripheral facial nerve damage, the injury directly affects the peripheral nerves and induces changes in the central nervous system (CNS) through various factors, but the substances involved in these changes in the CNS are not well understood. The objective of this review is to investigate the biomolecules involved in peripheral facial nerve damage so as to gain insight into the mechanisms and limitations of targeting the CNS after such damage and identify potential facial nerve treatment strategies. To this end, we searched PubMed using keywords and exclusion criteria and selected 29 eligible experimental studies. Our analysis summarizes basic experimental studies on changes in the CNS following peripheral facial nerve damage, focusing on biomolecules that increase or decrease in the CNS and/or those involved in the damage, and reviews various approaches for treating facial nerve injury. By establishing the biomolecules in the CNS that change after peripheral nerve damage, we can expect to identify factors that play an important role in functional recovery from facial nerve damage. Accordingly, this review could represent a significant step toward developing treatment strategies for peripheral facial palsy.

Cell Proliferation, Viability, Differentiation, and Apoptosis of Iron Oxide Labeled Stem Cells Transfected with Lipofectamine Assessed by MRI

To assess in vitro and in vivo tracking of iron oxide labeled stem cells transfected by lipofectamine using magnetic resonance imaging (MRI), rat dental pulp stem cells (DPSCs) were characterized, labeled with iron oxide nanoparticles, and then transfected with lipofectamine to facilitate the internalization of these nanoparticles. Cell proliferation, viability, differentiation, and apoptosis were investigated. Prussian blue staining and MRI were used to trace transfected labeled cells. DPSCs were a morphologically spindle shape, adherent to culture plates, and positive for adipogenic and osteogenic inductions. They expressed CD73 and CD90 markers and lacked CD34 and CD45. Iron oxide labeling and transfection with lipofectamine in DPSCs had no toxic impact on viability, proliferation, and differentiation, and did not induce any apoptosis. In vitro and in vivo internalization of iron oxide nanoparticles within DPSCs were confirmed by Prussian blue staining and MRI tracking. Prussian blue staining and MRI tracking in the absence of any toxic effects on cell viability, proliferation, differentiation, and apoptosis were safe and accurate to track DPSCs labeled with iron oxide and transfected with lipofectamine. MRI can be a useful imaging modality when treatment outcome is targeted.

WDR45 mutation dysregulates iron homeostasis by promoting the chaperone-mediated autophagic degradation of ferritin heavy chain in an ER stress/p38 dependent mechanism

Ferritin is the main iron storage protein that plays a pivotal role in the regulation of iron homeostasis. Mutations in the autophagy protein WD repeat domain 45 (WDR45) that lead to iron overload is associated with the human β-propeller protein-associated neurodegeneration (BPAN). Previous studies have demonstrated that ferritin was decreased in WDR45 deficient cells, but the mechanism remains unclear. In this study, we have demonstrated that the ferritin heavy chain (FTH) could be degraded via chaperone-mediated autophagy (CMA) in ER stress/p38-dependent pathway. In HeLa cells, inducing the ER stress activated CMA, therefore facilitated the degradation of FTH, and increased the content of Fe²⁺. However, the increased CMA activity and Fe²⁺ as well as the decreased FTH by ER stress inducer were restored by pre-treatment with p38 inhibitor. Overexpression of a mutant WDR45 activated CMA thus promoted the degradation of FTH. Furthermore, inhibition of ER stress/p38 pathway resulted in reduced activity of CMA, which consequently elevated the protein level of FTH but reduced the Fe²⁺ level. Our results revealed that WDR45 mutation dysregulates iron homeostasis by activating CMA, and promotes FTH degradation through ER stress/p38 signaling pathway.

Anticancer Activity of Nano-formulated Orlistat-Dopamine Conjugates Through Self-Assembly

Orlistat, an FDA-approved fatty acid inhibitor for obesity treatment, demonstrates certain low and greatly varied anticancer abilities. In a previous study, we revealed a synergistic effect between orlistat and dopamine in cancer treatment. Here, orlistat-dopamine conjugates (ODCs) with defined chemical structures were synthesized. The ODC by design underwent polymerization and self-assembly in the presence of oxygen to form nano-sized particles (Nano-ODCs) spontaneously. The resulted Nano-ODCs of partial crystalline structures demonstrated good water dispersion to form stable Nano-ODC suspensions. Because of the bioadhesive property of the catechol moieties, once administered, Nano-ODCs were quickly accumulated on cell surfaces and efficiently uptaken by cancer cells. In the cytoplasm, Nano-ODC experienced biphasic dissolution followed by spontaneous hydrolysis to release intact orlistat and dopamine. Besides elevated levels of intracellular reactive oxygen species (ROS), the co-localized dopamine also induced mitochondrial dysfunctions through monoamine oxidases (MAOs)-catalyzed dopamine oxidation. The strong synergistic effects between orlistat and dopamine determined a good cytotoxicity activity and a unique cell lysis mechanism, explaining the distinguished activity of Nano-ODC to drug-sensitive and -resistant cancer cells. This new technology-enabled orlistat repurposing will contribute to overcoming drug resistance and the improvement of cancer chemotherapy.

Selenium homeostasis in human brain cells: Effects of copper (II) and Se species

BACKGROUND

Both essential trace elements selenium (Se) and copper (Cu) play an important role in maintaining brain function. Homeostasis of Cu, which is tightly regulated under physiological conditions, seems to be disturbed in Alzheimer´s (AD) and Parkinson´s disease (PD) patients. Excess Cu promotes the formation of oxidative stress, which is thought to be a major cause for development and progression of neurological diseases (NDs). Most selenoproteins exhibit antioxidative properties and may counteract oxidative stress. However, expression of selenoproteins is altered under conditions of Se deficiency. Serum Se levels are decreased in AD and PD patients suggesting Se as an important factor in the development and progression of NDs. The aim of this study was to elucidate the interactions between Cu and Se in human brain cells particularly with respect to Se homeostasis.

METHODS

Firstly, modulation of Se status by selenite or SeMet were assessed in human astrocytes and human differentiated neurons. Therefore, cellular total Se content, intra- and extracellular selenoprotein P (SELENOP) content, and glutathione peroxidase (GPX) activity were quantified. Secondly, to investigate the impact of Cu on these markers, cells were exposed to copper(II)sulphate (CuSO₄) for 48 h. In addition, putative protective effects of Se on Cu-induced toxicity, as measured by cell viability, DNA damage, and neurodegeneration were investigated.

RESULTS

Modulation of cellular Se status was strongly dependent on Se species. In detail, SeMet increased total cellular Se and SELENOP content, whereas selenite led to increased GPX activity and SELENOP excretion. Cu treatment resulted in 133-fold higher cellular Cu concentration with a concomitant decrease in Se content. Additionally, SELENOP excretion was suppressed in both cell lines, while GPX activity was diminished only in astrocytes. These effects of Cu could be partially prevented by the addition of Se depending on the cell line and Se species used. While Cu-induced oxidative DNA damage could not be prevented by addition of Se regardless of chemical species, SeMet protected against neurite network degeneration triggered by Cu.

CONCLUSION

Cu appears to negatively affect Se status in astrocytes and neurons. Especially with regard to an altered homeostasis of those trace elements during aging, this interaction is of high physiological relevance. Increasing Cu concentrations associated with decreased selenoprotein expression or functionality might be a promoting factor for the development of NDs.

Opioid induces increased DNA damage in prefrontal cortex and nucleus accumbens

Opioid use disorder (OUD) is a chronic disease characterized by compulsive opioid taking and seeking, affecting millions of people worldwide. The high relapse rate is one of the biggest challenges in treating opioid addiction. However, the cellular and molecular mechanisms underlying relapse to opioid seeking are still unclear. Recent studies have shown that DNA damage and repair processes are implicated in a broad spectrum of neurodegenerative diseases as well as in substance use disorders. In the present study, we hypothesized that DNA damage is related to relapse to heroin seeking. To test our hypothesis, we aim to examine the overall DNA damage level in prefrontal cortex (PFC) and nucleus accumbens (NAc) after heroin exposure, as well as whether manipulating DNA damage levels can alter heroin seeking. First, we observed increased DNA damage in postmortem PFC and NAc tissues from OUD individuals compared to healthy controls. Next, we found significantly increased levels of DNA damage in the dorsomedial PFC (dmPFC) and NAc from mice that underwent heroin self-administration. Moreover, increased accumulation of DNA damage persisted after prolonged abstinence in mouse dmPFC, but not in NAc. This persistent DNA damage was ameliorated by the treatment of reactive oxygen species (ROS) scavenger N-acetylcysteine, along with attenuated heroin-seeking behavior. Furthermore, intra-PFC infusions of topotecan and etoposide during abstinence, which trigger DNA single-strand breaks and double-strand breaks respectively, potentiated heroin-seeking behavior. These findings provide direct evidence that OUD is associated with the accumulation of DNA damage in the brain (especially in the PFC), which may lead to opioid relapse.

Effects of Sideritis scardica Extract on Scopolamine-Induced Learning and Memory Impairment in Mice

BACKGROUND

The neurodegenerative process in Alzheimer's disease, one of the most common types of dementia worldwide, mostly affects the cholinergic neurotransmitter system and, to a lesser extent, the monoaminergic one. The antioxidant acetylcholinesterase (AChE) and triple monoamine reuptake inhibitory activity of Sideritis scardica (S. scardica) and other Sideritis species has already been reported.

OBJECTIVE

To investigate the effects of S. scardica water extracts on the learning and memory processes, anxiety-like behavior, and locomotor activities in scopolamine (Sco)-induced dementia in mice.

METHODS

Male Albino IRC mice were used. The plant extract was administered for 11 consecutive days in the presence or absence of Sco (1 mg/kg, i.p). The behavioural performance of the animals was evaluated by passive avoidance, T-maze, and hole-board tests. The effects of extract on AChE activity, brain noradrenalin (NA), and serotonin (Sero) content, and antioxidant status were also monitored.

RESULTS

Our experimental data revealed that the S. scardica water extract caused a reduction in degree of memory impairment and anxiety-like behaviour in mice with scopolamine-induced dementia. The extract did not affect changed by the Sco AChE activity but impact reduced brain NA and Sero levels and demonstrated moderate antioxidant activity. In healthy mice we did not confirm the presence of anxiolytic-like and AChE inhibitory effects of the S. scardica water extract. The extract did not change the control Sero brain levels and reduce those of NA.

CONCLUSION

S. scardica water extract demonstrated memory preserving effect in mice with scopolamine-induced dementia and deserve further attention.

[The role of the phenosanic acid in the combined treatment of patients with epilepsy]

Epilepsy is one of the most studied chronic neurological disorders in the world. Despite significant progress in epilepsy research, some patients continue to experience recurrent seizures. It has been proven that oxidative stress plays an important role in epilepsy. Targeting oxidative stress may provide a novel therapeutic intervention to attenuate epileptogenesis as well as cognitive and psychiatric impairment in patients with epilepsy. One of the promising directions in the search for new strategies for the treatment of epilepsy is the combined use of antiepileptic drugs with antioxidants that affect the pathogenetic links of this disease. The new Russian antiepileptic drug fenosanoic acid (Dibufelon) has an anticonvulsant effect due to the inhibition of lipid peroxidation of brain cells and the reconstruction of cell membranes. This mechanism of action also paves the way for an increase in the effectiveness of co-administered drugs with phenosanoic acid. The effect of the drug on the cognitive and mental functions of patients, the regression of asthenia phenomena is also observed. The clinical efficacy and safety of the combination of this drug with other antiepileptic drugs in epilepsy has been demonstrated in experimental and clinical studies.

Quantum Mimicry With Inorganic Chemistry

Quantum objects, such as atoms, spins, and subatomic particles, have important properties due to their unique physical properties that could be useful for many different applications, ranging from quantum information processing to magnetic resonance imaging. Molecular species also exhibit quantum properties, and these properties are fundamentally tunable by synthetic design, unlike ions isolated in a quadrupolar trap, for example. In this comment, we collect multiple, distinct, scientific efforts into an emergent field that is devoted to designing molecules that mimic the quantum properties of objects like trapped atoms or defects in solids. Mimicry is endemic in inorganic chemistry and featured heavily in the research interests of groups across the world. We describe a new field of using inorganic chemistry to design molecules that mimic the quantum properties (e.g. the lifetime of spin superpositions, or the resonant frequencies thereof) of other quantum objects, "quantum mimicry." In this comment, we describe the philosophical design strategies and recent exciting results from application of these strategies.

The potential neuroprotective effects of stingless bee honey

Tropical Meliponini bees produce stingless bee honey (SBH). Studies have shown beneficial properties, including antibacterial, bacteriostatic, anti-inflammatory, neurotherapeutic, neuroprotective, wound, and sunburn healing capabilities. High phenolic acid and flavonoid concentrations offer SBH its benefits. SBH can include flavonoids, phenolic acids, ascorbic acid, tocopherol, organic acids, amino acids, and protein, depending on its botanical and geographic origins. Ursolic acid, p-coumaric acid, and gallic acid may diminish apoptotic signals in neuronal cells, such as nuclear morphological alterations and DNA fragmentation. Antioxidant activity minimizes reactive oxygen species (ROS) formation and lowers oxidative stress, inhibiting inflammation by decreasing enzymes generated during inflammation. Flavonoids in honey reduce neuroinflammation by decreasing proinflammatory cytokine and free radical production. Phytochemical components in honey, such as luteolin and phenylalanine, may aid neurological problems. A dietary amino acid, phenylalanine, may improve memory by functioning on brain-derived neurotrophic factor (BDNF) pathways. Neurotrophin BDNF binds to its major receptor, TrkB, and stimulates downstream signaling cascades, which are crucial for neurogenesis and synaptic plasticity. Through BDNF, SBH can stimulate synaptic plasticity and synaptogenesis, promoting learning and memory. Moreover, BDNF contributes to the adult brain's lasting structural and functional changes during limbic epileptogenesis by acting through the cognate receptor tyrosine receptor kinase B (TrkB). Given the higher antioxidants activity of SBH than the Apis sp. honey, it may be more therapeutically helpful. There is minimal research on SBH's neuroprotective effects, and the related pathways contribute to it is unclear. More research is needed to elucidate the underlying molecular process of SBH on BDNF/TrkB pathways in producing neuroprotective effects.

Analysis of the time-dependent changes of phospholipids in the brain regions of a mouse model of Alzheimer's disease

Phospholipid levels are reported to be decreased in Alzheimer's disease (AD). For a better understanding, we investigated the time-dependent changes of phospholipids species in a mouse model of AD. The levels of phospholipids in the hippocampus and prefrontal cortex of wild-type and APP-Tg (J20) mice were measured by LC-ESI-MS/MS. Compared to wild-type, total phosphatidylcholine (PC), phosphatidylethanolamine (PE), and lysophosphatidylcholine (LPC) were Increased at 3 months but decreased at 6 months in the cortex of J20 mice. Total lysophosphatidylethanolamine (LPE) was decreased both at 3 and 6 months. PC was decreased and LPC was increased at 6 months, resulting in an increased LPC/PC ratio in the hippocampus of J20 mice. At species levels, PCA analysis could discriminate wild-type and J20 based on PC and LPC distribution at 6 months. At 6 months, several highly abundant PC including PC (16:0/16:0), PC (16:0/18:0), PC (16:0/18:1), and PC (18:0/18:1) were decreased in the cortex and hippocampus of J20. Conversely, LPC species including LPC 16:0, LPC 18:1, and LPC 20:4 were increased especially in the hippocampal area. Increased activation of phospholipid-metabolizing enzyme cPLA2 was seen in the hippocampus and cortex of J20 mice at 9 months. On the other hand, ROS levels started to increase as early as 3 months. Compared to 3 months, ROS levels were higher at 6 months in J20 mice. Thus, we demonstrated here a time- and area-dependent alteration of phospholipid composition during the early stage of AD, which could be important in understanding the pathological process.

Ether Lipid-Mediated Antioxidant Defense in Alzheimer's Disease

One of the richest tissues in lipid content and diversity of the human body is the brain. The human brain is constitutively highly vulnerable to oxidative stress. This oxidative stress is a determinant in brain aging, as well as in the onset and progression of sporadic (late-onset) Alzheimer's disease (sAD). Glycerophospholipids are the main lipid category widely distributed in neural cell membranes, with a very significant presence for the ether lipid subclass. Ether lipids have played a key role in the evolution of the human brain compositional specificity and functionality. Ether lipids determine the neural membrane structural and functional properties, membrane trafficking, cell signaling and antioxidant defense mechanisms. Here, we explore the idea that ether lipids actively participate in the pathogenesis of sAD. Firstly, we evaluate the quantitative relevance of ether lipids in the human brain composition, as well as their role in the human brain evolution. Then, we analyze the implications of ether lipids in neural cell physiology, highlighting their inherent antioxidant properties. Finally, we discuss changes in ether lipid content associated with sAD and their physiopathological implications, and propose a mechanism that, as a vicious cycle, explains the potential significance of ether lipids in sAD.

Lipid Adaptations against Oxidative Challenge in the Healthy Adult Human Brain

It is assumed that the human brain is especially susceptible to oxidative stress, based on specific traits such as a higher rate of mitochondrial free radical production, a high content in peroxidizable fatty acids, and a low antioxidant defense. However, it is also evident that human neurons, although they are post-mitotic cells, survive throughout an entire lifetime. Therefore, to reduce or avoid the impact of oxidative stress on neuron functionality and survival, they must have evolved several adaptive mechanisms to cope with the deleterious effects of oxidative stress. Several of these antioxidant features are derived from lipid adaptations. At least six lipid adaptations against oxidative challenge in the healthy human brain can be discerned. In this work, we explore the idea that neurons and, by extension, the human brain is endowed with an important arsenal of non-pro-oxidant and antioxidant measures to preserve neuronal function, refuting part of the initial premise.

Quantifying Intraparenchymal Hemorrhage after Traumatic Spinal Cord Injury: A Review of Methodology

Intraparenchymal hemorrhage (IPH) after a traumatic injury has been associated with poor neurological outcomes. Although IPH may result from the initial mechanical trauma, the blood and its breakdown products have potentially deleterious effects. Further, the degree of IPH has been correlated with injury severity and the extent of subsequent recovery. Therefore, accurate evaluation and quantification of IPH following traumatic spinal cord injury (SCI) is important to define treatments' effects on IPH progression and secondary neuronal injury. Imaging modalities, such as magnetic resonance imaging (MRI) and ultrasound (US), have been explored by researchers for the detection and quantification of IPH following SCI. Both quantitative and semiquantitative MRI and US measurements have been applied to objectively assess IPH following SCI, but the optimal methods for doing so are not well established. Studies in animal SCI models (rodent and porcine) have explored US and histological techniques in evaluating SCI and have demonstrated the potential to detect and quantify IPH. Newer techniques using machine learning algorithms (such as convolutional neural networks [CNN]) have also been studied to calculate IPH volume and have yielded promising results. Despite long-standing recognition of the potential pathological significance of IPH within the spinal cord, quantifying IPH with MRI or US is a relatively new area of research. Further studies are warranted to investigate their potential use. Here, we review the different and emerging quantitative MRI, US, and histological approaches used to detect and quantify IPH following SCI.

Protein Glutathionylation and Glutaredoxin: Role in Neurodegenerative Diseases

Oxidative stress has been implicated in the pathogenesis and progression of many neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. One of the major enzyme systems involved in the defense against reactive oxygen species are the tripeptide glutathione and oxidoreductase glutaredoxin. Glutathione and glutaredoxin system are very important in the brain because of the oxidative modification of protein thiols to protein glutathione mixed disulfides with the concomitant formation of oxidized glutathione during oxidative stress. Formation of Pr-SSG acts as a sink in the brain and is reduced back to protein thiols during recovery, thus restoring protein functions. This is unlike in the liver, which has a high turnover of glutathione, and formation of Pr-SSG is very minimal as liver is able to quickly quench the prooxidant species. Given the important role glutathione and glutaredoxin play in the brain, both in normal and pathologic states, it is necessary to study ways to augment the system to help maintain the protein thiol status. This review details the importance of glutathione and glutaredoxin systems in several neurodegenerative disorders and emphasizes the potential augmentation of this system as a target to effectively protect the brain during aging.

Ferroptosis increases obesity: Crosstalk between adipocytes and the neuroimmune system

Ferroptosis requires not only the accumulation of iron ions, but also changes in many ferroptosis-related regulators, including a decrease in GPX4 and inhibition of SLC7A11 for classical ferroptosis, a deletion of FSP1 or GCH1. Surprisingly, adipose tissue (AT) in the obesity conditions is also accompanied by iron buildup, decreased GSH, and increased ROS. On the neurological side, the pro-inflammatory factor released by AT may have first caused ferroptosis in the vagus nerve by inhibiting of the NRF2-GPX4 pathway, resulting in disorders of the autonomic nervous system. On the immune side, obesity may cause M2 macrophages ferroptosis due to damage to iron-rich ATMs (MFe^hi) and antioxidant ATMs (Mox), and lead to Treg cells ferroptosis through reductions in NRF2, GPX4, and GCH1 levels. At the same time, the reduction in GPX4 may also trigger the ferroptosis of B1 cells. In addition, some studies have also found the role of GPX4 in neutrophil autophagy, which is also worth pondering whether there is a connection with ferroptosis. In conclusion, this review summarizes the associations between neuroimmune regulation associated with obesity and ferroptosis, and on the basis of this, highlights their potential molecular mechanisms, proposing that ferroptosis in one or more cells in a multicellular tissue changes the fate of that tissue.

Stepping Further from Coupling Tools: Development of Functional Polymers via the Biginelli Reaction

Multicomponent reactions (MCRs) have been used to prepare polymers with appealing functions. The Biginelli reaction, one of the oldest and most famous MCRs, has sparked new scientific discoveries in polymer chemistry since 2013. Recent years have seen the Biginelli reaction stepping further from simple coupling tools; for example, the functions of the Biginelli product 3,4-dihydropyrimidin-2(1H)-(thi)ones (DHPM(T)) have been gradually exploited to develop new functional polymers. In this mini-review, we mainly summarize the recent progress of using the Biginelli reaction to identify polymers for biomedical applications. These polymers have been documented as antioxidants, anticancer agents, and bio-imaging probes. Moreover, we also provide a brief introduction to some emerging applications of the Biginelli reaction in materials and polymer science. Finally, we present our perspectives for the further development of the Biginelli reaction in polymer chemistry.

Hallmarks of neurodegenerative disease: A systems pharmacology perspective

Age-related central neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, are a rising public health concern and have been plagued by repeated drug development failures. The complex nature and poor mechanistic understanding of the etiology of neurodegenerative diseases has hindered the discovery and development of effective disease-modifying therapeutics. Quantitative systems pharmacology models of neurodegeneration diseases may be useful tools to enhance the understanding of pharmacological intervention strategies and to reduce drug attrition rates. Due to the similarities in pathophysiological mechanisms across neurodegenerative diseases, especially at the cellular and molecular levels, we envision the possibility of structural components that are conserved across models of neurodegenerative diseases. Conserved structural submodels can be viewed as building blocks that are pieced together alongside unique disease components to construct quantitative systems pharmacology (QSP) models of neurodegenerative diseases. Model parameterization would likely be different between the different types of neurodegenerative diseases as well as individual patients. Formulating our mechanistic understanding of neurodegenerative pathophysiology as a mathematical model could aid in the identification and prioritization of drug targets and combinatorial treatment strategies, evaluate the role of patient characteristics on disease progression and therapeutic response, and serve as a central repository of knowledge. Here, we provide a background on neurodegenerative diseases, highlight hallmarks of neurodegeneration, and summarize previous QSP models of neurodegenerative diseases.

Fluorine-Nitrogen-Codoped Carbon Dots as Fluorescent Switch Probes for Selective Fe(III) and Ascorbic Acid Sensing in Living Cells

High-quality fluorescent probes based on carbon dots (CDs) have promising applications in many fields owing to their good stability, low toxicity, high quantum yield, and low raw material price. The fluorine- and nitrogen-doped fluorescent CDs (NFCDs) with blue fluorescence was successfully synthesized using 3-aminophenol and 2,4-difluorobenzoic acid as the raw material by the hydrothermal method. The NFCDs as probe can be used to directly and indirectly detect Fe3+ (detection range: 0.1–150 μM and detection limit: 0.14 μM) and ascorbic acid (AA) (detection range: 10–80 μM and detection limit: 0.11 μM). The NFCDs-based probe shows exceptional selectivity and strong anti-interference for Fe3+ and ascorbic acid (AA). In addition, we examined the response of NFCDs to Fe3+ and AA in living cells, which showed that the timely use of AA can reduce the effects of iron poisoning. This has important biological significance. This means that using NFCDs as fluorescent probes is beneficial for Fe3+ and AA detection and observing their dynamic changes in living cells. Thus, this work may contribute to the study of Fe3+- and AA-related diseases.

Neurotoxicity induced by the pyrethroid lambda-cyhalothrin: Alterations in monoaminergic systems and dopaminergic and serotoninergic pathways in the rat brain

The effects of Type II pyrethroid lambda-cyhalothrin on dopamine (DA) and serotonin (5-HT) synthesis in rat brain regions (striatum, hippocampus, prefrontal cortex, hypothalamus and midbrain) were studied. Lambda-cyhalothrin (1, 4 and 8 mg/kg bw, oral gavage, 6 days) induced a decrease of DA, 5-HT and metabolites contents, in a brain regional- and dose-related manner. The major decreases in DA and 5-HT contents were observed in hippocampus and prefrontal cortex tissues. This research study also showed in hippocampus and prefrontal cortex, that lambda-cyhalothrin modified the mRNA levels of DA transporter gene (Dat1 up-regulation), 5-HT transporter gene (SERT down-regulation), DA receptor genes (Drd1and Drd2 down-regulation), 5-HT receptor genes (5-HT1A and 5-HT2A down-regulation/up-regulation), DA synthesis gene (TH down-regulation), 5-HT synthesis gene (TPH2 down-regulation), DA and 5-HT degradation genes (MAOA and MAOB up-regulation). These results reveal that lambda-cyhalothrin altered central nervous system (CNS) monoaminergic neurotransmitters. Lambda-cyhalothrin evoked a selective neurotoxic injury to dopaminergic and serotoninergic pathways. These findings may clarify on the pyrethroids-induced neurotoxicity mechanisms and could involve pyrethroids as environmental risk factors leading to the development of neurodegenerative diseases.