13 reasons why the brain is susceptible to oxidative stress

Exploring Neuroprotection against Radiation-Induced Brain Injury: A Review of Key Compounds

Brain radiation is a crucial tool in neuro-oncology for enhancing local tumor control, but it can lead to mild-to-profound and progressive impairments in cognitive function. Radiation-induced brain injury is a significant adverse effect of radiotherapy for cranioencephalic tumors, primarily caused by indirect cellular damage through the formation of free radicals. This results in late neurotoxicity manifesting as cognitive impairment due to free radical production. The aim of this review is to highlight the role of different substances, such as drugs used in the clinical setting and antioxidants such as ascorbate, in reducing the neurotoxicity associated with radiation-induced brain injury. Currently, there is mainly preclinical and clinical evidence supporting the benefit of these interventions, representing a cost-effective and straightforward neuroprotective strategy.

Nrf2 pathways in neuroprotection: Alleviating mitochondrial dysfunction and cognitive impairment in aging

Mitochondrial dysfunction and cognitive impairment are widespread phenomena among the elderly, being crucial factors that contribute to neurodegenerative diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important regulator of cellular defense systems, including that against oxidative stress. As such, increased Nrf2 activity may serve as a strategy to avert mitochondrial dysfunction and cognitive decline. Scientific data on Nrf2-mediated neuroprotection was collected from PubMed, Google Scholar, and Science Direct, specifically addressing mitochondrial dysfunction and cognitive impairment in older people. Search terms included "Nrf2", "mitochondrial dysfunction," "cognitive impairment," and "neuroprotection." Studies focusing on in vitro and in vivo models and clinical investigations were included to review Nrf2's therapeutic potential comprehensively. The relative studies have demonstrated that increased Nrf2 activity could improve mitochondrial performance, decrease oxidative pressure, and mitigate cognitive impairment. To a large extent, this is achieved through the modulation of critical cellular signalling pathways such as the Keap1/Nrf2 pathway, mitochondrial biogenesis, and neuroinflammatory responses. The present review summarizes the recent progress in comprehending the molecular mechanisms regarding the neuroprotective benefits mediated by Nrf2 through its substantial role against mitochondrial dysfunction and cognitive impairment. This review also emphasizes Nrf2-target pathways and their contribution to cognitive function improvement and rescue from mitochondria-related abnormalities as treatment strategies for neurodegenerative diseases that often affect elderly individuals.

Severe hypoxaemic hypercapnia compounds cerebral oxidative-nitrosative stress during extreme apnoea: Implications for cerebral bioenergetic function

We examined the extent to which apnoea-induced extremes of oxygen demand/carbon dioxide production impact redox regulation of cerebral bioenergetic function. Ten ultra-elite apnoeists (six men and four women) performed two maximal dry apnoeas preceded by normoxic normoventilation, resulting in severe end-apnoea hypoxaemic hypercapnia, and hyperoxic hyperventilation designed to ablate hypoxaemia, resulting in hyperoxaemic hypercapnia. Transcerebral exchange of ascorbate radicals (by electron paramagnetic resonance spectroscopy) and nitric oxide metabolites (by tri-iodide chemiluminescence) were calculated as the product of global cerebral blood flow (by duplex ultrasound) and radial arterial (a) to internal jugular venous (v) concentration gradients. Apnoea duration increased from 306 ± 62 s during hypoxaemic hypercapnia to 959 ± 201 s in hyperoxaemic hypercapnia (P ≤ 0.001). Apnoea generally increased global cerebral blood flow (all P ≤ 0.001) but was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose (P = 0.015-0.044). This was associated with a general net cerebral output (v > a) of ascorbate radicals that was greater in hypoxaemic hypercapnia (P = 0.046 vs. hyperoxaemic hypercapnia) and coincided with a selective suppression in plasma nitrite uptake (a > v) and global cerebral blood flow (P = 0.034 to <0.001 vs. hyperoxaemic hypercapnia), implying reduced consumption and delivery of nitric oxide consistent with elevated cerebral oxidative-nitrosative stress. In contrast, we failed to observe equidirectional gradients consistent with S-nitrosohaemoglobin consumption and plasma S-nitrosothiol delivery during apnoea (all P ≥ 0.05). Collectively, these findings highlight a key catalytic role for hypoxaemic hypercapnia in cerebral oxidative-nitrosative stress. KEY POINTS: Local sampling of blood across the cerebral circulation in ultra-elite apnoeists determined the extent to which severe end-apnoea hypoxaemic hypercapnia (prior normoxic normoventilation) and hyperoxaemic hypercapnia (prior hyperoxic hyperventilation) impact free radical-mediated nitric oxide bioavailability and global cerebral bioenergetic function. Apnoea generally increased the net cerebral output of free radicals and suppressed plasma nitrite consumption, thereby reducing delivery of nitric oxide consistent with elevated oxidative-nitrosative stress. The apnoea-induced elevation in global cerebral blood flow was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose. Cerebral oxidative-nitrosative stress was greater during hypoxaemic hypercapnia compared with hyperoxaemic hypercapnia and coincided with a lower apnoea-induced elevation in global cerebral blood flow, highlighting a key catalytic role for hypoxaemia. This applied model of voluntary human asphyxia might have broader implications for the management and treatment of neurological diseases characterized by extremes of oxygen demand and carbon dioxide production.

Aging abolishes circadian rhythms and disrupts temporal organization of antioxidant-prooxidant status, endogenous clock activity and neurotrophin gene expression in the rat temporal cortex

Disruption of circadian rhythms contributes to deficits in cognitive functions during aging. Up to date, the biochemical, molecular and chronobiological bases of such deterioration have not been completely elucidated. Here, we aim: 1) to investigate the endogenous nature of 24 h-rhythms of antioxidant defenses, oxidative stress, clocḱ's, and neurotrophic factors expression, in the rat temporal cortex (TC), and 2) to study the consequences of aging on the circadian organization of those factors. We observed a circadian organization of antioxidant enzymes activity, lipoperoxidation and the clock, BMAL1 and RORa, proteins, in the TC of young rats. Such temporal organization suggests the existence of a two-way communication among clock transcription factors and antioxidant defenses. This might generate the rhythmic and circadian expression of Bdnf and Rc3 genes involved in the TC-depending cognitive function. Noteworthy, such circadian organization disappears in the TC of aged rats. Aging also reduces glutathione peroxidase activity and expression, and it increases lipid peroxidation, throughout a 24 h-period. An increased oxidative stress makes the cellular redox environment change into an oxidative status which alters the endogenous clock activity and disrupts the circadian organization of, at least part, of the molecular basis of the synaptic plasticity in the TC.

Augmented Mitochondrial Transfer Involved in Astrocytic PSPH Attenuates Cognitive Dysfunction in db/db Mice

Diabetes-associated cognitive dysfunction (DACD) has ascended to become the second leading cause of mortality among diabetic patients. Phosphoserine phosphatase (PSPH), a pivotal rate-limiting enzyme in L-serine biosynthesis, has been documented to instigate the insulin signaling pathway through dephosphorylation. Concomitantly, CD38, acting as a mediator in mitochondrial transfer, is activated by the insulin pathway. Given that we have demonstrated the beneficial effects of exogenous mitochondrial supplementation on DACD, we further hypothesized whether astrocytic PSPH could contribute to improving DACD by promoting astrocytic mitochondrial transfer into neurons. In the Morris Water Maze (MWM) test, our results demonstrated that overexpression of PSPH in astrocytes alleviated DACD in db/db mice. Astrocyte specific-stimulated by PSPH lentivirus/ adenovirus promoted the spine density both in vivo and in vitro. Mechanistically, astrocytic PSPH amplified the expression of CD38 via initiation of the insulin signaling pathway, thereby promoting astrocytic mitochondria transfer into neurons. In summation, this comprehensive study delineated the pivotal role of astrocytic PSPH in alleviating DACD and expounded upon its intricate cellular mechanism involving mitochondrial transfer. These findings propose that the specific up-regulation of astrocytic PSPH holds promise as a discerning therapeutic modality for DACD.

Microglia and gut microbiota: A double-edged sword in Alzheimer's disease

The strong association between gut microbiota (GM) and brain functions such as mood, behaviour, and cognition has been well documented. Gut-brain axis is a unique bidirectional communication system between the gut and brain, in which gut microbes play essential role in maintaining various molecular and cellular processes. GM interacts with the brain through various pathways and processes including, metabolites, vagus nerve, HPA axis, endocrine system, and immune system to maintain brain homeostasis. GM dysbiosis, or an imbalance in GM, is associated with several neurological disorders, including anxiety, depression, and Alzheimer's disease (AD). Conversely, AD is sustained by microglia-mediated neuroinflammation and neurodegeneration. Further, GM and their products also affect microglia-mediated neuroinflammation and neurodegeneration. Despite the evidence connecting GM dysbiosis and AD progression, the involvement of GM in modulating microglia-mediated neuroinflammation in AD remains elusive. Importantly, deciphering the mechanism/s by which GM regulates microglia-dependent neuroinflammation may be helpful in devising potential therapeutic strategies to mitigate AD. Herein, we review the current evidence regarding the involvement of GM dysbiosis in microglia activation and neuroinflammation in AD. We also discuss the possible mechanisms through which GM influences the functioning of microglia and its implications for therapeutic intervention. Further, we explore the potential of microbiota-targeted interventions, such as prebiotics, probiotics, faecal microbiota transplantation, etc., as a novel therapeutic strategy to mitigate neuroinflammation and AD progression. By understanding and exploring the gut-brain axis, we aspire to revolutionize the treatment of neurodegenerative disorders, many of which share a common theme of microglia-mediated neuroinflammation and neurodegeneration.

Imidacloprid unique and repeated treatment produces cholinergic transmission disruption and apoptotic cell death in SN56 cells

Imidacloprid (IMI), the most widely used worldwide neonicotinoid biocide, produces cognitive disorders after repeated and single treatment. However, little was studied about the possible mechanisms that produce this effect. Cholinergic neurotransmission regulates cognitive function. Most cholinergic neuronal bodies are present in the basal forebrain (BF), regulating memory and learning process, and their dysfunction or loss produces cognition decline. BF SN56 cholinergic wild-type or acetylcholinesterase (AChE), β-amyloid-precursor-protein (βAPP), Tau, glycogen-synthase-kinase-3-beta (GSK3β), beta-site-amyloid-precursor-protein-cleaving enzyme 1 (BACE1), and/or nuclear-factor-erythroid-2-related-factor-2 (NRF2) silenced cells were treated for 1 and 14 days with IMI (1 μM-800 μM) with or without recombinant heat-shock-protein-70 (rHSP70), recombinant proteasome 20S (rP20S) and with or without N-acetyl-cysteine (NAC) to determine the possible mechanisms that mediate this effect. IMI treatment for 1 and 14 days altered cholinergic transmission through AChE inhibition, and triggered cell death partially through oxidative stress generation, AChE-S overexpression, HSP70 downregulation, P20S inhibition, and Aβ and Tau peptides accumulation. IMI produced oxidative stress through reactive oxygen species production and antioxidant NRF2 pathway downregulation, and induced Aβ and Tau accumulation through BACE1, GSK3β, HSP70, and P20S dysfunction. These results may assist in determining the mechanisms that produce cognitive dysfunction observed following IMI exposure and provide new therapeutic tools.

Chrysin mitigates neuronal apoptosis and impaired hippocampal neurogenesis in male rats subjected to D-galactose-induced brain aging

Oxidative stress-induced neuronal apoptosis is primarily involved in brain aging and impaired hippocampal neurogenesis. Long-term D-galactose administration increases oxidative stress related to brain aging. Chrysin, a subtype of flavonoids, exhibits neuroprotective effects, particularly its antioxidant properties. To elucidate the neuroprotection of chrysin on neuronal apoptosis and an impaired hippocampal neurogenesis relevant to oxidative damage in D-galactose-induced brain aging, male Sprague Dawley rats were allocated into vehicle control, D-galactose, chrysin, and cotreated rats. The rats received their respective treatments daily for 8 weeks. The reactions of scavenging enzymes, protein regulating endogenous antioxidant defense, and anti-apoptotic protein expression were significantly reduced in the hippocampus and prefrontal cortex of the animals receiving D-galactose. Conversely, product of oxidative damage and apoptotic protein expressions were significantly elevated in both cortical areas of the D-galactose group. In hippocampal neurogenesis, significant upregulation of cell cycle arrest and decrease in differentiated protein expression were detected after D-galactose administration. Nevertheless, chrysin supplementation significantly mitigated all negative effects in animals receiving D-galactose. This study demonstrates that chrysin likely attenuates brain aging induced by D-galactose by enhancing scavenging enzyme activities and reducing oxidative stress, neuronal apoptosis, and the impaired hippocampal neurogenesis.

L-Cysteine mitigates ROS-induced apoptosis and neurocognitive deficits by protecting against endoplasmic reticulum stress and mitochondrial dysfunction in mouse neuronal cells

Oxidative stress and mitochondrial dysfunction play critical roles in neurodegenerative diseases. Glutathione (GSH), a key brain antioxidant, helps to neutralize reactive oxygen species (ROS) and maintain redox balance. We investigated the effectiveness of L-cysteine (L-Cys) in preventing apoptosis induced by the ROS generator 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) in mouse hippocampal neuronal HT22 cells, as well as alleviating memory and cognitive impairments caused by the GSH synthesis inhibitor L-buthionine sulfoximine (BSO) in mice. DMNQ-induced apoptotic events in HT22 cells, including elevated cytosolic and mitochondrial ROS levels, DNA fragmentation, endoplasmic reticulum stress, and mitochondrial damage-mediated apoptotic pathways were dose-dependently abrogated by L-Cys (0.5-2 mM). The reduced intracellular GSH level, caused by DMNQ treatment, was restored by L-Cys cotreatment. Although L-Cys did not significantly restore GSH in the presence of BSO, it prevented DMNQ-induced ROS elevation, mitochondrial damage, and apoptosis. Furthermore, compared to N-acetylcysteine and GSH, L-Cys had higher 2,2-diphenyl-1-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical-scavenging activity. L-Cys also restored mitochondrial respiration capacity in DMNQ-treated HT22 cells by reversing mitochondrial fission-fusion dynamic balance. BSO administration (500 mg/kg/day) in mice led to neuronal deficits, including memory and cognitive impairments, which were effectively mitigated by oral L-Cys (15 or 30 mg/kg/day). L-Cys also reduced BSO-induced ROS levels in the mice hippocampus and cortex. These findings suggest that even though it does not contribute to intracellular GSH synthesis, exogenous L-Cys protects neuronal cells against oxidative stress-induced mitochondrial damage and apoptosis, by acting as a ROS scavenger, which is beneficial in ameliorating neurocognitive deficits caused by oxidative stress.

Benzopyrene represses mitochondrial fission factors and PINK1/Parkin-mediated mitophagy in primary astrocytes

Mitochondria are essential for various physiological functions in astrocytes in the brain, such as maintaining ion and pH homeostasis, regulating neurotransmission, and modulating neuroinflammation. Mitophagy, a form of autophagy specific to mitochondria, is essential for ensuring mitochondrial quality and function. Benzo[a]pyrene (BaP) accumulates in the brain, and exposure to it is recognized as an environmental risk factor for neurodegenerative diseases. However, while the toxic mechanisms of BaP have been investigated in neurons, their effects on astrocytes-the most prevalent glial cells in the brain-are not clearly understood. Therefore, this study aims to investigate the toxic effects of exposure to BaP on mitochondria in primary astrocytes. Fluorescent probes and genetically encoded indicators were utilized to visualize mitochondrial morphology and physiology, and regulatory factors involved in mitochondrial morphology and mitophagy were assessed. Additionally, the mitochondrial respiration rate was measured in BaP-exposed astrocytes. BaP exposure resulted in mitochondrial enlargement owing to the suppression of mitochondrial fission factors. Furthermore, BaP-exposed astrocytes demonstrated reduced mitophagy and exhibited aberrant mitochondrial function and physiology, such as altered mitochondrial respiration rates, increased mitochondrial superoxide, disrupted mitochondrial membrane potential, and dysregulated mitochondrial Ca2+. These findings offer insights into the underlying toxic mechanisms of BaP exposure in neurodegenerative diseases by inducing aberrant mitophagy and mitochondrial dysfunction in astrocytes.

Diabetes mellitus and Alzheimer's disease: Understanding disease mechanisms, their correlation, and promising dual activity of selected herbs

ETHNOPHARMACOLOGICAL RELEVANCE

This review explores the link between Type 2 Diabetes Mellitus (T2DM) and diabetes-induced Alzheimer's disease (AD). It emphasizes the shared pathophysiological links and mechanisms between the two conditions, focusing on reduced insulin levels and receptors, impaired glucose metabolism, insulin resistance, mitochondrial dysfunction, and oxidative damage in AD-affected brains-paralleling aspects of T2DM. The review suggests AD as a "diabetes of the brain," supported by cognitive enhancement through antidiabetic interventions. It focuses on the traditionally used Indian herbs as a means to manage both conditions while addressing developmental challenges.

AIM OF THE STUDY

This study explores the DM-AD connection, reviewing medicinal herbs with protective potential for both ailments, considering traditional uses and developmental challenges.

MATERIALS AND METHODS

Studied research, reviews, and ethnobotanical and scientific data from electronic databases and traditional books.

RESULTS

The study analyzes the pathophysiological links between DM and AD, emphasizing their interconnected factors. Eight Ayurvedic plants with dual protective effects against T2DM and AD are thoroughly reviewed with preclinical/clinical evidence. Historical context, phytoconstituents, and traditional applications are explored. Innovative formulations using these plants are examined. Challenges stemming from phytoconstituents' physicochemical properties are highlighted, prompting novel formulation development, including nanotechnology-based delivery systems. The study uncovers obstacles in formulating treatments for these diseases.

CONCLUSION

The review showcases the dual potential of chosen medicinal herbs against both diseases, along with their traditional applications, endorsing their use. It addresses formulation obstacles, proposing innovative delivery technologies for herbal therapies, while acknowledging their constraints. The review suggests the need for heightened investment and research in this area.

Bisphenol F-induced precocious genesis of aggressive neurobehavioral response is associated with heightened monoamine oxidase activity and neurodegeneration in zebrafish brain

The production and use of plastics and plastics products has increased dramatically in recent decades. Moreover, their unprotected disposal into ambient life sustaining environment poses a significant health risk. Bisphenol F (BPF) an alternative to bisphenol A (BPA) has been extensively employed for making of plastics. Recent reports have documented the neurotoxic potential of BPF through induction of altered neurochemical profile, microglia-astrocyte-mediated neuroinflammation, oxidative stress, transformed neurobehavioral response, cognitive dysfunction, etc. In the present study, our approach was to understand the underlying mechanism of BPF-persuaded genesis of aggressive neurobehavioral response in zebrafish. The basic findings advocated a temporal transformation in native explorative behaviour and progressive induction of aggressive behavioural response in zebrafish following exposure to BPF. Our neurobehavioral findings supported the argument of oxidative stress-mediated neuromorphological transformation in the periventricular grey zone (PGZ) of the zebrafish brain. In line with earlier reports, our findings also showed that heightened monoamine oxidase (MAO) activity and downregulation in tyrosine hydroxylase expression in the zebrafish brain is associated with the precocious genesis of aggressive neurobehavioral response in zebrafish brain. Our findings also shed light on BPF-instigated apoptotic neuronal death as revealed by augmented chromatin condensation and cleaved caspase-3 expression. Further observation showed that the downregulation of NeuN (a marker of post-mitotic mature neuron) expression provided substantial neurotoxicity, leading to neurodegeneration in the PGZ region of the zebrafish brain. These basic findings grossly advocate that BPF acts as a potent neurotoxicant in transmuting native neurobehavioral response through the induction of oxidative stress, heightened MAO activity and neuromorphological transformation in the zebrafish brain.

Unraveling the ozone impact and oxidative stress on the nervous system

Ozone (O₃), a potent oxidant, can penetrate the body through breathing, generating reactive oxygen species (ROS) and triggering inflammatory processes. Oxidative stress, an imbalance between the production of ROS and the body's antioxidant capacity, plays a crucial role in the pathophysiology of various neurodegenerative diseases. This phenomenon can negatively impact the Central Nervous System (CNS), inducing structural and functional alterations that contribute to the development of neurological pathologies. This review examines how O₃-induced oxidative stress affects the nervous system by analyzing existing literature on the involved molecular mechanisms and potential antioxidant systems to mitigate its effects. Through a comprehensive review of experimental studies, our objective is to shed light on the interaction between O₃ and the nervous system, as well as its signaling pathways and altered genes, providing a foundation for future research in this field. Several studies have demonstrated that prolonged exposure to O₃ leads to increased expression of reactive oxygen species, causing alterations in the blood-brain barrier and damage to astrocytes and microglia. These effects can lead to an increase in the production of proinflammatory cytokines, neurotoxins, and genes, exacerbating neuronal damage and accelerating the progression of neurodegenerative diseases such as Alzheimer's, Parkinson's, and other neurological disorders. The results of this review suggest that exposure to O₃ may induce oxidative damage to the nervous system, which could have significant implications for public health.

Investigating the mechanisms of inflammation and immune alterations in Parkinson's disease using spatial transcriptomics techniques

In recent years, overwhelming evidence has emphasized the crucial role of inflammation in the pathogenesis of PD. However, the exact mechanisms by which inflammation damages dopaminergic neurons in PD are still unclear. Therefore, we generated a MPTP-induced PD mouse model and performed spatial transcriptomic sequencing to provide more insight into the process of PD development at specific brain regions. Our results indicate that the pathological changes of PD are mainly manifested in the midbrain, especially in the substantia nigra region, with significant reductions in oligodendrocytes and Agt-labeled astrocytes and an increase in Gfap-labeled astrocytes. Macrophages displayed an increasing trend in the PD environment, indicating a pattern of immune modulation induced by PD. Moreover, pathway analysis revealed significant impairments in ion migration ability, abnormal Ca2+ channels, cAMP signaling, and synaptic damage in PD. Significant downregulation of Mt1 and Mt2 and upregulation of Atp1b2, Gpi1, and Cox6a1 in PD further underscored the occurrence of intense inflammation and immune alterations. On the basis of these findings, we have validated the significant accumulation of Ca2+ in the midbrain tissue in the PD environment by measuring its content. Additionally, we have demonstrated a close association between the reduction of dopaminergic neurons, represented by the midbrain region, and ferroptosis by evaluating the iron content, malondialdehyde (MDA) levels, and the protein expression of GPX4 and TH in the tissue. We propose the hypothesis that PD-related inflammation and immune changes can induce neuronal and oligodendrocyte damage through the induction of ferroptosis, thereby further accelerating the progression of PD.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Alpha-Lipoic Acid: Biological Mechanisms and Health Benefits

Alpha-lipoic acid (ALA) is a bioactive molecule with significant health effects. The biological action of ALA has been ascribed to the characteristic antioxidant properties of the oxidized form (ALA) and its reduced counterpart the dihydrolipoic acid (DHLA) system. The ALA/DHLA combination represents an ideal antioxidant since it can quench radicals, is able to chelate metals, is amphiphilic, and has no major adverse effects. This unique system is able to scavenge reactive oxygen species, exerting a major effect on tissue levels of reduced forms of other antioxidants, including glutathione. For this reason, ALA is also known as the "antioxidant of antioxidants". This review analyzes the antioxidant, anti-inflammatory, and neuroprotective effects of ALA and discusses its applications as an ameliorative tool for chronic diseases and those associated with oxidative stress. Results from in vitro and in vivo studies demonstrated that ALA modulates various oxidative stress pathways suggesting its application, alone or in combination with other functional substances, as a useful support in numerous conditions, in which the balance oxidant-antioxidant is disrupted, such as neurodegenerative disorders. Based on several successful clinical studies, it has been also established that oral ALA supplements are clinically useful in relieving the complications of diabetes and other disorders including cardiovascular diseases and nerve discomforts suggesting that ALA can be considered a useful approach to improving our health.

Regulation of glycolysis-derived L-lactate production in astrocytes rescues the memory deficits and Aβ burden in early Alzheimer's disease models

Aberrant energy metabolism in the brain is a common pathological feature in the preclinical Alzheimer's Disease (AD). Recent studies have reported the early elevations of glycolysis-involved enzymes in AD brain and cerebrospinal fluid according to a large-scale proteomic analysis. It's well-known that astrocytes exhibit strong glycolytic metabolic ability and play a key role in the regulation of brain homeostasis. However, its relationship with glycolytic changes and cognitive deficits in early AD patients is unclear. Here, we investigated the mechanisms by which astrocyte glycolysis is involved in early AD and its potential as a therapeutic target. Our results suggest that Aβ-activated microglia can induce glycolytic-enhanced astrocytes in vitro, and that these processes are dependent on the activation of the AKT-mTOR-HIF-1α pathway. In early AD models, the increase in L-lactate produced by enhanced glycolysis of astrocytes leads to spatial cognitive impairment by disrupting synaptic plasticity and accelerating Aβ aggregation. Furthermore, we find rapamycin, the mTOR inhibitor, can rescue the impaired spatial memory and Aβ burden by inhibiting the glycolysis-derived L-lactate in the early AD models. In conclusion, we highlight that astrocytic glycolysis plays a critical role in the early onset of AD and that the modulation of glycolysis-derived L-lactate by rapamycin provides a new strategy for the treatment of AD.

The Effect of Trientine on AlCl3-Induced Cognitive Dysfunction and Biochemical Changes in the Hippocampus of Rats

Cognitive impairments affect millions of people worldwide with an increasing prevalence. Research on their etiology and treatment is developing, nevertheless significant gaps remain. Trientine (TETA), as a copper chelator, has been shown to have beneficial effects in different human chronic diseases such as diabetic cardiomyopathy and neuropathy. Here, we examined the impact of TETA on AlCl3-induced neurocognitive dysfunctions and molecular changes in the hippocampus of rats.Thirty-six male Wistar rats (weighing 200-250 g) were randomly divided into four groups including control, TETA (100 mg/kg/day), AlCl3 (100 mg/kg/day), and AlCl3 (100 mg/kg/day)+TETA (100 mg/kg/day), and received chemicals by gavage for 30 days. At the end of the treatment, the open field maze, elevated plus maze, novel object recognition memory test, and shuttle box test were done. Then after, brain-derived neurotrophic factor (BDNF), glycogen synthase kinase-3 β (GSK-3β), acetylcholinesterase activity, oxidative stress markers, and inflammatory mediators were measured in the hippocampus.AlCl3 increased anxiety-like behaviors and impaired recognition and short-term memory. TETA was able to improve AlCl3-induced anxiety-like behaviors and short-term memory dysfunction. In the AlCl3-treated group, there was a significant increase in GSK-3β, oxidative stress, pro-inflammatory and pro-apoptotic markers, and decreased BDNF in the hippocampus. Co-administration of TETA was able to decrease lipid peroxidation, inflammation, GSK-3β, and acetylcholinesterase activity, and increase BDNF in the hippocampus compared with AlCl3-treated rats.It can be concluded that TETA was able to improve neurobehavioral and neurocognitive functions by alleviating oxidative stress, inflammation, and pro-apoptotic pathways leading to the normalization of BDNF and GSK-3β.

The effects of cannabidiol on behavioural and oxidative stress parameters induced by prolonged haloperidol administration

OBJECTIVES

We investigated the influence of oral cannabidiol (CBD) on vacuous chewing movements (VCM) and oxidative stress parameters induced by short- and long-term administration of haloperidol in a rat model of tardive dyskinesia (TD).

METHODS

Haloperidol was administered either sub-chronically via the intraperitoneal (IP) route or chronically via the intramuscular (IM) route to six experimental groups only or in combination with CBD. VCM and oxidative stress parameters were assessed at different time points after the last dose of medication.

RESULTS

Oral CBD (5 mg/kg) attenuated the VCM produced by sub-chronic administration of haloperidol (5 mg/kg) but had minimal effects on the VCM produced by chronic administration of haloperidol (50 mg/kg). In both sub-chronic and chronic haloperidol groups, there were significant changes in brain antioxidant parameters compared with CBD only and the control groups. The sub-chronic haloperidol-only group had lower glutathione activity compared with sub-chronic haloperidol before CBD and the control groups; also, superoxide dismutase, catalase, and 2,2-diphenyl-1-picrylhydrazyl activities were increased in the sub-chronic (IP) haloperidol only group compared with the CBD only and control groups. Nitric oxide activity was increased in sub-chronic haloperidol-only group compared to the other groups; however, the chronic haloperidol group had increased malondialdehyde activity compared to the other groups.

CONCLUSIONS

Our findings indicate that CBD ameliorated VCM in the sub-chronic haloperidol group before CBD, but marginally in the chronic haloperidol group before CBD. There was increased antioxidant activity in the sub-chronic group compared to the chronic group.

NRF2 Deficiency Promotes Ferroptosis of Astrocytes Mediated by Oxidative Stress in Alzheimer's Disease

Oxidative stress is involved in the pathogenesis of Alzheimer's disease (AD), which is linked to reactive oxygen species (ROS), lipid peroxidation, and neurotoxicity. Emerging evidence suggests a role of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a major source of antioxidant response elements in AD. The molecular mechanism of oxidative stress and ferroptosis in astrocytes in AD is not yet fully understood. Here, we aimed to investigate the mechanism by which Nrf2 regulates the ferroptosis of astrocytes in AD. We found decreased expression of Nrf2 and upregulated expression of the ROS marker NADPH oxidase 4 (NOX4) in the frontal cortex from patients with AD and in the cortex of 3×Tg mice compared to wildtype mice. We demonstrated that Nrf2 deficiency led to ferroptosis-dependent oxidative stress-induced ROS with downregulated heme oxygenase-1 and glutathione peroxidase 4 and upregulated cystine glutamate expression. Moreover, Nrf2 deficiency increased lipid peroxidation, DNA oxidation, and mitochondrial fragmentation in mouse astrocytes (mAS, M1800-57). In conclusion, these results suggest that Nrf2 deficiency promotes ferroptosis of astrocytes involving oxidative stress in AD.

Diet and Nutrients in Rare Neurological Disorders: Biological, Biochemical, and Pathophysiological Evidence

Background/Objectives: Rare diseases are a wide and heterogeneous group of multisystem life-threatening or chronically debilitating clinical conditions with reduced life expectancy and a relevant mortality rate in childhood. Some of these disorders have typical neurological symptoms, presenting from birth to adulthood. Dietary patterns and nutritional compounds play key roles in the onset and progression of neurological disorders, and the impact of alimentary needs must be enlightened especially in rare neurological diseases. This work aims to collect the in vitro, in vivo, and clinical evidence on the effects of diet and of nutrient intake on some rare neurological disorders, including some genetic diseases, and rare brain tumors. Herein, those aspects are critically linked to the genetic, biological, biochemical, and pathophysiological hallmarks typical of each disorder. Methods: By searching the major web-based databases (PubMed, Web of Science Core Collection, DynaMed, and Clinicaltrials.gov), we try to sum up and improve our understanding of the emerging role of nutrition as both first-line therapy and risk factors in rare neurological diseases. Results: In line with the increasing number of consensus opinions suggesting that nutrients should receive the same attention as pharmacological treatments, the results of this work pointed out that a standard dietary recommendation in a specific rare disease is often limited by the heterogeneity of occurrent genetic mutations and by the variability of pathophysiological manifestation. Conclusions: In conclusion, we hope that the knowledge gaps identified here may inspire further research for a better evaluation of molecular mechanisms and long-term effects.

Treatment of Acute and Long-COVID, Diabetes, Myocardial Infarction, and Alzheimer's Disease: The Potential Role of a Novel Nano-Compound-The Transdermal Glutathione-Cyclodextrin Complex

Oxidative stress (OS) occurs from excessive reactive oxygen species or a deficiency of antioxidants-primarily endogenous glutathione (GSH). There are many illnesses, from acute and post-COVID-19, diabetes, myocardial infarction to Alzheimer's disease, that are associated with OS. These dissimilar illnesses are, in order, viral infections, metabolic disorders, ischemic events, and neurodegenerative disorders. Evidence is presented that in many illnesses, (1) OS is an early initiator and significant promotor of their progressive pathophysiologic processes, (2) early reduction of OS may prevent later serious and irreversible complications, (3) GSH deficiency is associated with OS, (4) GSH can likely reduce OS and restore adaptive physiology, (5) effective administration of GSH can be accomplished with a novel nano-product, the GSH/cyclodextrin (GC) complex. OS is an overlooked pathological process of many illnesses. Significantly, with the GSH/cyclodextrin (GC) complex, therapeutic administration of GSH is now available to reduce OS. Finally, rigorous prospective studies are needed to confirm the efficacy of this therapeutic approach.

Limitations and Challenges of Antioxidant Therapy

Our bodies are constantly exposed to or producing free radicals nearly on a daily basis. These highly reactive molecules are generated through a variety of internal and external processes and pathways within the body. If these free radicals are not neutralized by antioxidants, they can lead to a state of oxidative stress, which has been linked to a wide range of severe and debilitating disorders affecting various systems in the human body. This involves neurodegenerative diseases, diabetes, atherosclerosis, fatty liver, inflammation, and aging. Thankfully, the human body is armed with a repertoire of powerful antioxidants with different natures and modes of action. The recent decades witnessed the publication of enormous papers proving antioxidant activity of a novel synthesized compound, plant extract, or a purified drug in vitro, in vivo, and even on human beings. However, the efficacy of antioxidant therapies in clinical trials, including selenium, vitamin C, vitamin E, and vitamin A, has been notably inconsistent. This inconsistency can be primarily ascribed to different factors related to the nature of free radical generation, purpose and the specific type of therapy employed, and the intricate oxidative stress connected network, among others. Collectively, these factors will be explored in this review article to decipher the observed shortcomings in the application of antioxidant therapies within clinical settings.

Oxygen-induced stress reveals context-specific gene regulatory effects in human brain organoids

The interaction between genetic variants and environmental stressors is key to understanding the mechanisms underlying neurological diseases. In this study, we used human brain organoids to explore how varying oxygen levels expose context-dependent gene regulatory effects. By subjecting a genetically diverse panel of 21 brain organoids to hypoxic and hyperoxic conditions, we identified thousands of gene regulatory changes that are undetectable under baseline conditions, with 1,745 trait-associated genes showing regulatory effects only in response to oxygen stress. To capture more nuanced transcriptional patterns, we employed topic modeling, which revealed context-specific gene regulation linked to dynamic cellular processes and environmental responses, offering a deeper understanding of how gene regulation is modulated in the brain. These findings underscore the importance of genotype-environment interactions in genetic studies of neurological disorders and provide new insights into the hidden regulatory mechanisms influenced by environmental factors in the brain.

Quantitative proteome analysis of LAP1-deficient human fibroblasts: A pilot approach for predicting the signaling pathways deregulated in LAP1-associated diseases

Lamina-associated polypeptide 1 (LAP1), a ubiquitously expressed nuclear envelope protein, appears to be essential for the maintenance of cell homeostasis. Although rare, mutations in the human LAP1-encoding TOR1AIP1 gene cause severe diseases and can culminate in the premature death of affected individuals. Despite there is increasing evidence of the pathogenicity of TOR1AIP1 mutations, the current knowledge on LAP1's physiological roles in humans is limited; hence, investigation is required to elucidate the critical functions of this protein, which can be achieved by uncovering the molecular consequences of LAP1 depletion, a topic that remains largely unexplored. In this work, the proteome of patient-derived LAP1-deficient fibroblasts carrying a pathological TOR1AIP1 mutation (LAP1 E482A) was quantitatively analyzed to identify global changes in protein abundance levels relatively to control fibroblasts. An in silico functional enrichment analysis of the mass spectrometry-identified differentially expressed proteins was also performed, along with additional in vitro functional assays, to unveil the biological processes that are potentially dysfunctional in LAP1 E482A fibroblasts. Collectively, our findings suggest that LAP1 deficiency may induce significant alterations in various cellular activities, including DNA repair, messenger RNA degradation/translation, proteostasis and glutathione metabolism/antioxidant response. This study sheds light on possible new functions of human LAP1 and could set the basis for subsequent in-depth mechanistic investigations. Moreover, by identifying deregulated signaling pathways in LAP1-deficient cells, our work may offer valuable molecular targets for future disease-modifying therapies for TOR1AIP1-associated nuclear envelopathies.

Hematological and neurological impact studies on the exposure to naturally occurring radioactive materials

Naturally Occurring Radioactive Materials (NORM) contribute to everyone's natural background radiation dose. The technologically advanced activities of the gas and oil sectors produce considerable amounts of radioactive materials as industrial by-products or waste products. The goal of the current study is to estimate the danger of long-term liability to Technologically Enhanced Naturally Occurring Radioactive Materials (TE-NORM) on blood indices, neurotransmitters, oxidative stress markers, and β-amyloid in the cerebral cortex of rats' brains. Twenty adult male albino rats were divided into two equal groups (n = 10): control and irradiated. Irradiated rats were exposed to a total dose of 0.016 Gy of TE-NORM as a whole-body chronic exposure over a period of two months. It should be ''The results showed no significant changes in RBC count, Hb concentration, hematocrit percentage (HCT%), and Mean Corpuscular Hemoglobin Concentration (MCHC). However, there was a significant increase in the Mean Corpuscular Volume of RBCs (MCV) and a significant decrease in cell distribution width (RDW%) compared to the control. Alteration in neurotransmitters is noticeable by a significant increase in glutamic acid and significant decreases in serotonin and dopamine. Increased lipid peroxidation, decreased glutathione content, superoxide dismutase, catalase, and glutathione peroxidase activities indicating oxidative stress were accompanied by increased β-amyloid in the cerebral cortex of rats' brains. The findings of the present study showed that chronic radiation liability has some harmful effects, that may predict the risks of future health problems in occupational radiation exposure in the oil industries. Therefore, the control of exposure and application of sample dosimetry is recommended for health and safety.

Computational modeling of neuronal nitric oxide synthase biochemical pathway: A mechanistic analysis of tetrahydrobiopterin and oxidative stress

Neuronal cell dysfunction plays an important role in neurodegenerative diseases. Oxidative stress can disrupt the redox balance within neuronal cells and may cause neuronal nitric oxide synthase (nNOS) to uncouple, contributing to the neurodegenerative processes. Experimental studies and clinical trials using nNOS cofactor tetrahydrobiopterin (BH4) and antioxidants in neuronal cell dysfunction have shown inconsistent results. A better mechanistic understanding of complex interactions of nNOS activity and oxidative stress in neuronal cell dysfunction is needed. In this study, we developed a computational model of neuronal cell using nNOS biochemical pathways to explore several key mechanisms that are known to influence neuronal cell redox homeostasis. We studied the effects of oxidative stress and BH4 synthesis on nNOS nitric oxide production and biopterin ratio (BH4/total biopterin). Results showed that nNOS remained coupled and maintained nitric oxide production for oxidative stress levels less than 230 nM/s. The results showed that neuronal oxidative stress above 230 nM/s increased the degree of nNOS uncoupling and introduced instability in the nitric oxide production. The nitric oxide production did not change irrespective of initial biopterin ratio of 0.05-0.99 for a given oxidative stress. Oxidative stress resulted in significant reduction in BH4 levels even when nitric oxide production was not affected. Enhancing BH4 synthesis or supplementation improved nNOS coupling, however the degree of improvement was determined by the levels of oxidative stress and BH4 synthesis. The results of our mechanistic analysis indicate that there is a potential for significant improvement in neuronal dysfunction by simultaneously increasing BH4 levels and reducing cellular oxidative stress.

Redox imbalance and metabolic defects in the context of Alzheimer disease

Redox reactions play a critical role for intracellular processes, including pathways involved in metabolism and signaling. Reactive oxygen species (ROS) act either as second messengers or generators of protein modifications, fundamental mechanisms for signal transduction. Disturbance of redox homeostasis is associated with many disorders. Among these, Alzheimer's disease is a neurodegenerative pathology that presents hallmarks of oxidative damage such as increased ROS production, decreased activity of antioxidant enzymes, oxidative modifications of macromolecules, and changes in mitochondrial homeostasis. Interestingly, alteration of redox homeostasis is closely associated with defects of energy metabolism, involving both carbohydrates and lipids, the major energy fuels for the cell. As the brain relies exclusively on glucose metabolism, defects of glucose utilization represent a harmful event for the brain. During aging, a progressive perturbation of energy metabolism occurs resulting in brain hypometabolism. This condition contributes to increase neuronal cell vulnerability ultimately resulting in cognitive impairment. The current review discusses the crosstalk between alteration of redox homeostasis and brain energy defects that seems to act in concert in promoting Alzheimer's neurodegeneration.

Embracing complexity of (brain) aging

Aging is a multifactorial process occurring in a pathophysiological continuum which leads to organ and system functional loss. While aging is not a disease, its pathophysiological continuum predisposes to illness and multimorbidity clusters which share common biomolecular mechanisms-the pillars of aging. Brain aging and neurodegeneration share many hallmarks with other age-related diseases. The central nervous system is often the weakest link susceptible to the aging process and its deterioration, resulting in cognitive impairment and other symptoms; the aging process is associated with proteostasis collapse, stem cell exhaustion, repair mechanisms, altered brain nutrient sensing, endothelial changes, inflammation, oxidative distress, and energy unbalance, as well as other disturbances. These mechanisms are highly interwoven, and considerable research is aimed at their disentanglement and detection of their clinically relevant impact, particularly in order to identify pharmacological and non-pharmacological preventive and therapeutic strategies.

Neurotoxicity of tetramethylammonium ion on larval and juvenile zebrafish: Effects on neurobehaviors and multiple biomarkers

Tetramethylammonium hydroxide (TMAH) is an important compound that utilized and released by the rapidly expanding semiconductor industry, which could hardly be removed by the conventional wastewater treatment techniques. As a cholinergic agonist, the tetramethylammonium ion (TMA+) has been reported to induce toxicity to muscular and respiratory systems of mammals and human, however the toxicity on aquatic biota remains poorly known. We investigated the neurotoxic effects of TMA+ exposure on zebrafish, based on neurobehavior tests and a series of biomarkers. Significant inhibitions on the swimming distance of zebrafish larvae were observed when the exposure level exceeded 50 mg/L, and significant alterations on swimming path angles (straight and deflective movements) occurred even at 10 mg/L. The tested neurobehavioral endpoints of zebrafish larvae were significantly positively correlated with reactive oxygen species (ROS) and malondialdehyde (MDA), significantly negatively related with the activities of antioxidant enzymes, but not significantly correlated with the level of acetylcholinesterase (AChE). Such relationship indicates that the observed neurotoxic effects on swimming behavior of zebrafish larvae is mainly driven by oxidative stress, rather than the alterations of neurotransmitter. At the highest exposure concentration (200 mg/L), TMA+ evoked more severe toxicity on zebrafish juveniles, showing significantly stronger elevation on the MDA activity, and greater inhibitions on the activities of antioxidant enzymes and AChE, suggesting juveniles were more susceptible to TMA+ exposure than larval zebrafish.

Exploring the unmapped cysteine redox proteoform landscape

Cysteine redox proteoforms define the diverse molecular states that proteins with cysteine residues can adopt. A protein with one cysteine residue must adopt one of two binary proteoforms: reduced or oxidized. Their numbers scale: a protein with 10 cysteine residues must assume one of 1,024 proteoforms. Although they play pivotal biological roles, the vast cysteine redox proteoform landscape comprising vast numbers of theoretical proteoforms remains largely uncharted. Progress is hampered by a general underappreciation of cysteine redox proteoforms, their intricate complexity, and the formidable challenges that they pose to existing methods. The present review advances cysteine redox proteoform theory, scrutinizes methodological barriers, and elaborates innovative technologies for detecting unique residue-defined cysteine redox proteoforms. For example, chemistry-enabled hybrid approaches combining the strengths of top-down mass spectrometry (TD-MS) and bottom-up mass spectrometry (BU-MS) for systematically cataloguing cysteine redox proteoforms are delineated. These methods provide the technological means to map uncharted redox terrain. To unravel hidden redox regulatory mechanisms, discover new biomarkers, and pinpoint therapeutic targets by mining the theoretical cysteine redox proteoform space, a community-wide initiative termed the "Human Cysteine Redox Proteoform Project" is proposed. Exploring the cysteine redox proteoform landscape could transform current understanding of redox biology.

Obesity aggravates neuroinflammatory and neurodegenerative effects of bisphenol A in female rats

Bisphenol A (BPA), a common plasticizer, is categorized as a neurotoxic compound. Its impact on individuals exhibits sex-linked variations. Several biological and environmental factors impact the degree of toxicity. Moreover, nutritional factors have profound influence on toxicity outcome. BPA has been demonstrated to be an obesogen. However, research on the potential role of obesity as a confounding factor in BPA toxicity is lacking. We studied the neurodegenerative effects in high-fat diet (HFD)-induced obese female rats after exposure to BPA (10 mg/L via drinking water for 90 days). Four groups were taken in this study - Control, HFD, HFD + BPA and BPA. Cognitive function was evaluated through novel object recognition (NOR) test. Inflammatory changes in brain, and changes in hormonal level, lipid profile, glucose tolerance, oxidative stress, and antioxidants were also determined. HFD + BPA group rats showed a significant decline in memory function in NOR test. The cerebral cortex (CC) of the brain showed increased neurodegenerative changes as measured by microtubule-associated protein-2 (MAP-2) accompanied by histopathological confirmation. The increased level of neuroinflammation was demonstrated by microglial activation (Iba-1) and protein expression of nuclear factor- kappa B (NF-КB) in the brain. Obesity also caused significant (p < 0.05) increase in lipid peroxidation accompanied by reduced activities of antioxidant enzymes (glutathione S-transferase, catalase and glutathione peroxidase) and decrease in reduced-glutathione (p < 0.05) when compared to non-obese rats with BPA treatment. Overall, study revealed that obesity serves as a risk factor in the toxicity of BPA which may exacerbate the progression of neurological diseases.

Discovery of 23,24-diols containing ergosterols with anti-neuroinflammatory activity from Penicillium citrinum TJ507

Citristerones A-E (1-5), five new 23,24-diols containing ergosterols, along with three known analogues, were isolated from the endophytic fungus Penicillium citrinum TJ507 obtained from Hypericum wilsonii N. Robson. Their structures and absolute configurations were determined by NMR, HRESIMS, Snatzke's method, X-ray diffraction analyses and ECD calculation. Subsequently, the anti-neuroinflammatory effects of these isolates were screened using lipopolysaccharide (LPS)-induced BV-2 microglial cells, and citristerone B (2) showed outstanding anti-neuroinflammatory activity, with IC50 value of 0.60 ± 0.04 μM. Moreover, immunofluorescence and western blot analysis suggested that citristerone B not only reduced the release of nitric oxide (NO) and proinflammatory cytokines in LPS-induced BV-2 microglial cells, but also significantly inhibited the expression of TNF-α, iNOS and NF-κB, along with the production of cellular ROS.

Ethanolic extract of Ficus religiosa leaves alleviates aluminum-induced oxidative stress, lipid peroxidation, and neuroinflammation in rat brain

Background and Aim

Aluminum (Al)-induced neurotoxicity is known to play a pivotal role in the development of various neurodegenerative diseases, and this is alleged to occur through neuroinflammation and oxidative stress in the brain. This study aimed to determine the effect of Ficus religiosa (FR) leaf extract on oxidative stress and neuroinflammation induced by Al exposure in the rat brain by estimating malondialdehyde (MDA), interleukin-6 (IL6), and total antioxidant (TAO) levels along with the degree of neurodegeneration in the brain of AlCl3-administered and FR leaf extract-treated rats.

Materials and Methods

Two- to three-month-old male albino Wistar rats weighing 250-280 g were used in the present study. The animals were randomly divided into seven groups, with 12 rats in each group. The groups were categorized as control, Al-intoxicated, FR treatment groups of two dosages, FR control rats of two dosages, and FR pre-treatment group.

Results

We observed a substantial increase in the levels of MDA and IL6 along with a decline in the TAO level in Al-intoxicated rats, suggesting increased lipid peroxidation (LPO), neuroinflammation, and oxidative stress, respectively. In the FR-treated animals, MDA as well as IL6 levels was decreased, and TAO was enhanced in addition to improved neuronal architecture, demonstrating the ameliorative effect of FR.

Conclusion

The present study observed a decline in LPO and neuroinflammation in FR-treated rats, demonstrating the protective effect of FR leaves against Al-induced neurotoxicity. The level of TAO also improved along with improvement in neuronal mass in FR-treated rats, adding to its ameliorative effect. However, further elaborate research is needed to confirm its therapeutic potential against inflammation-driven neurodegenerative diseases.

Coenzyme Q10 ameliorates cyclophosphamide-induced chemobrain by repressing neuronal apoptosis and preserving hippocampal neurogenesis: Mechanistic roles of Wnt/ β-catenin signaling pathway

Deterioration in the neurocognitive function of cancer patients referred to as "Chemobrain" is a devastating obstacle associated with cyclophosphamide (CYP). CYP is an alkylating agent, clinically utilized as an efficient anticancer and immunosuppressant. Coenzyme Q10 (CoQ10) is a worthwhile micronutrient with diverse biological activities embracing antioxidant, anti-apoptotic, and neuroprotective effects. The current experiment was designed for investigating the neuroprotective capability of CoQ10 versus CYP-elicited chemobrain in rats besides elucidating the causal molecular mechanisms. Male Sprague Dawley rats received CoQ10 (10 mg/kg, orally, once daily, for 10 days) and/or a single dose of CYP (200 mg/kg i.p. on day 7). CoQ10 counteracted CYP-induced cognitive and motor dysfunction as demonstrated by the findings of neurobehavioral tests (passive avoidance, Y maze, locomotion, and rotarod tests). Histopathological analysis further affirmed the neuroprotective abilities of CoQ10. CoQ10 effectually diminished CYP-provoked oxidative injury by restoring the antioxidant activity of catalase (CAT) enzyme while reducing malondialdehyde (MDA) levels. Besides, CoQ10 efficiently repressed CYP-induced neuronal apoptosis by downregulating the expression of Bax and caspase-3 while upregulating the Bcl-2 expression. Moreover, CoQ10 hampered CYP-provoked upregulation in acetylcholinesterase (AChE) activity. Furthermore, CoQ10 considerably augmented hippocampal neurogenesis by elevating the expressions of brain-derived neurotrophic factor (BDNF) and Ki-67. These promising neuroprotective effects can be credited to upregulating Wnt/β-catenin pathway as evidenced by the elevated expressions of Wnt-3a, β-catenin, and Phoshpo-glycogen synthase kinase-3 β (p-GSK-3β). Collectively, these findings proved the neuroprotective capabilities of CoQ10 against CYP-induced chemobrain through combating oxidative injury, repressing intrinsic apoptosis, boosting neurogenesis, and eventually upregulating the Wnt/β-catenin pathway.

Lower distress intolerance is associated with higher glutathione levels in adolescent cannabis users

Cannabis (CB) use and psychological stressors increase oxidative stress in the brain. Glutathione (GSH), the most abundant antioxidant in the brain, protects against oxidative stress. Furthermore, distress intolerance, the inability to tolerate psychological or physiological stress is a risk factor for CB use. The relationship between CB use, brain GSH levels and distress intolerance remains unknown. Therefore, we examined GSH levels in the anterior cingulate cortex (ACC), as a measure of oxidative stress, and its relationship with distress intolerance in adolescent CB users and healthy controls (HC). Sixteen HC and 17 CB-using adolescents were included in the analysis. GSH levels were measured in the ACC using a metabolite-edited proton magnetic resonance spectroscopy sequence on a 3T scanner. Distress intolerance was assessed using the Distress Intolerance Index (DII) and CB use was evaluated using a structured clinical interview. In the CB group, lower CSF-corrected GSH levels in the ACC were correlated with higher DII scores. However, no significant between group differences were observed for ACC CSF-corrected GSH levels or on DII scores. No significant correlations were observed in the HC group between GSH levels and DII. Our findings suggests that the association between lower GSH levels and greater distress intolerance in CB users might reflect alterations in the balance between protective and oxidative stress conditions linked to the ability to tolerate distress. Further examination into this relationship can provide important insights into neurobiological correlates and risk factors associated with CB use to help inform preventive and treatment targets in the future.

Zinc ions regulate mitochondrial quality control in neurons under oxidative stress and reduce PANoptosis in spinal cord injury models via the Lgals3-Bax pathway

Spinal cord injury is a serious traumatic nervous system disorder characterized by extensive neuronal apoptosis. Oxidative stress, a key factor in neuronal apoptosis, leads to the accumulation of reactive oxygen species, making mitochondrial quality control within cells crucial. Previous studies have demonstrated zinc's anti-inflammatory and anti-apoptotic properties in protecting mitochondria during spinal cord injury treatment, yet the precise mechanisms remain elusive. Single-cell sequencing analysis has identified Lgals3 and Bax as core genes in apoptosis. This study aimed to investigate whether zinc ions protect intracellular mitochondria by inhibiting the apoptotic proteins Lgals3 and Bax. We elucidated zinc ions' key role in mitigating mitochondrial quality control dysfunction triggered by oxidative stress and confirmed this was achieved by targeting the Lgals3-Bax pathway. Zinc's inhibitory effect on this pathway not only preserved mitochondrial integrity but also significantly reduced PANoptosis after spinal cord injury. Under oxidative stress, zinc ion regulation of mitochondrial quality control reveals an organelle-targeted therapeutic strategy, offering a novel approach for more precise treatment of spinal cord injury.

The Role of S-Glutathionylation in Health and Disease: A Bird's Eye View

Protein glutathionylation is a reversible post-translational modification that involves the attachment of glutathione to cysteine residues. It plays a role in the regulation of several cellular processes and protection against oxidative damage. Glutathionylation (GS-ylation) modulates protein function, inhibits or enhances enzymatic activity, maintains redox homeostasis, and shields several proteins from irreversible oxidative stress. Aberrant GS-ylation patterns are thus implicated in various diseases, particularly those associated with oxidative stress and inflammation, such as cardiovascular diseases, neurodegenerative disorders, cancer, and many others. Research in the recent years has highlighted the potential to manipulate protein GS-ylation for therapeutic purposes with strategies that imply both its enhancement and inhibition according to different cases. Moreover, it has become increasingly evident that monitoring the GS-ylation status of selected proteins offers diagnostic potential in different diseases. In this review, we try to summarize recent research in the field with a focus on our current understanding of the molecular mechanisms related to aberrant protein GS-ylation.

Lipid-lowering and antioxidant effects of Polygonatum fermented liquor: a study on intestinal microbiota and brain-gut axis in mice

Introduction

This study aims to investigate the effects of Polygonatum fermented liquor (PFL) on improving lipid metabolism and oxidative stress in mice by regulating the gut microbiota.

Methods

Forty SPF-grade male Kunming mice were randomly divided into four groups: normal control group (NC), general liquor group (GC), fresh Polygonatum fermented liquor group (FPC), and nine-steam-nine-bask Polygonatum fermented liquor group (NPC). Each group was administered with sterile water, general liquor, fresh Polygonatum fermented liquor, and nine-steam-nine-bask Polygonatum fermented liquor, respectively, by gavage. The mice's liver, brain tissue, serum, and intestinal contents were collected. The indicators of oxidative stress in the liver, four blood lipid indicators, gamma-aminobutyric acid (GABA), and brain-derived neurotrophic factor (BDNF) levels in the brain tissue were measured, liver hematoxylin and eosin (HE) staining was performed, and the gut microbiota in the small intestine were analyzed using 16S rRNA second-generation sequencing technology.

Results

Compared with the NC group, the NPC group showed significantly increased liver glutathione peroxidase (GSH-Px) content in mice (p < 0.05), reduced number of lipid droplets in the liver cells, and increased GABA and BDNF content in the brain tissues. The NPC group regulated lipid metabolism by lowering low-density lipoprotein cholesterol (LDL-C) and increasing high-density lipoprotein cholesterol (HDL-C) content in the mouse serum. Gut microbiota analysis showed significant changes in the gut microbiota of mice in the FPC and NPC groups, with increased richness and species diversity. These two groups increased the abundance of beneficial bacteria such as Lactobacillus, unclassified Muribaculaceae, unclassified Bacilli, and uncultured Bacteroidales bacterium while reducing the abundance of harmful bacteria such as Candidatus Arthromitus, and Staphylococcus, with a particularly significant reduction in Staphylococcus (p < 0.05). It is speculated that the two types of PFL may exert lipid-lowering and antioxidant effects by modulating the abundance of these dominant bacteria. Further studies showed that various environmental factors are closely related to the dominant gut bacteria. Malondialdehyde (MDA) was significantly negatively correlated with Lactobacillus and unclassified Bacilli, superoxide dismutase (SOD) was significantly negatively correlated with Staphylococcus (p < 0.01) and significantly negatively correlated with Candidatus Arthromitus (p < 0.05), and HDL-C was significantly negatively correlated with Staphylococcus and Facklamia (p < 0.05).

Discussion

The two types of PFL chosen in this study may exert lipid-lowering and antioxidant effects by modulating the composition and function of the gut microbiota, providing guidance for the industrial application of Polygonatum.

Cytarabine prevents neuronal damage by enhancing AMPK to stimulate PINK1 / Parkin-involved mitophagy in Parkinson's disease model

Parkinson's disease (PD) is a common age-related neurodegenerative disorder, which may be largely due to the mitochondrial dysfunction and impaired mitophagy. Thus, it is of great importance to seek novel therapeutic strategies for PD targeting mitochondrial function and mitophagy. Cytarabine is a marine-derived antimetabolite used in the treatment of acute leukemia, which is also used in the study of the nervous system. In this study, we found that cytarabine pretreatment significantly inhibited the apoptosis and necrosis in the ROT-induced SH-SY5Y cell PD model and reduced the oxidative stress, as evidenced by the reduced MDA levels and the increased levels of SOD, GSH, and total antioxidant capacity. Cytarabine can also enhance mitochondrial vitality, improve mitochondrial respiratory function, and preserve mitochondrial morphology. Cytarabine also enhanced the expression of the mitophagy-related proteins PINK1, Parkin, VDAC1, and DJ-1, and its actions can be reversed by treatment with AMPK inhibitor - Compound C (CC), suggesting that AMPK activation may be involved in cytarabine-enhanced mitophagy. Furthermore, cytarabine can also ameliorate the motor symptoms in the MPTP-induced PD-like mice model, and attenuate the neuropathy in the substantia nigra (SN) of PD mice, while Compound C antagonized cytarabine's beneficial effects. In summary, marine-derived compound cytarabine could resist neurological damage both in vitro and in vivo by activating AMPK to increase PINK1/Parkin-induced mitophagy, serving as a promising disease modulator for treating neurodegenerative disease.

The benefits of ashwagandha (Withania somnifera) supplements on brain function and sports performance

Ashwagandha or Withania somnifera is an herbal plant belonging to the Solanaceae family. Because of its wide range of phytochemicals, ashwagandha root extract has been used in numerous research studies, either alone or in conjunction with other natural plants, for various biomedical applications, which include its anti-microbial, anti-inflammatory, anti-stress, anti-tumor, cardioprotective, and neuroprotective properties. Additionally, it improves endothelial function, lowers reactive oxygen species, controls apoptosis, and improves mitochondrial function. These properties make it a useful treatment for a variety of conditions, including age-related symptoms, anxiety, neurodegenerative diseases, diabetes, stress, arthritis, fatigue, and cognitive/memory impairment. Despite the numerous benefits of ashwagandha supplementation, there have been just four meta-analyses on the herb's effectiveness in treating anxiety, neurobehavioral disorders, impotence, and infertility. Moreover, no reviews exist that examine how ashwagandha affects antioxidant response and physical sports performance. Consequently, the goal of this study was to analyze the scientific literature regarding the effects of ashwagandha consumption on antioxidant response and athletic performance.

Calycosin activates Nrf2/Keap1 signaling to ameliorate hydrogen peroxide-induced spinal cord neuron death and mitochondrial dysfunction

Oxidative stress is a hallmark of secondary injury of spinal cord injuries. Controlling oxidative stress is crucial for mitigating secondary injury and promoting functional recovery after spinal cord injuries. Calycosin is an O-methylated isoflavone with antioxidant activity. To evaluate the effect of calycosin on spinal cord neurons under oxidative stress and clarify the molecular mechanism underlying the effect, we tested the neuroprotective activity of calycosin in a primary spinal cord neuron culture model. We found that calycosin protected neurons from H2O2-induced neuronal death in a dose-dependent manner. Further experiments revealed that calycosin decreased H2O2-induced mitochondrial fragmentation and mitochondrial membrane potential loss, and subsequently reduced H2O2-triggered release of mitochondrial cytochrome c into the cytoplasm. In addition, calycosin inhibited H2O2-induced reactive oxygen species generation and activation of NF-κB signaling in spinal cord neurons. Furthermore, the expression of several antioxidant enzymes such as HO-1, NQO1, GCLC, GCLM, TrxR1, and Trx1 was significantly promoted by calycosin. More importantly, we revealed that the Nrf2/Keap1 signal is crucial for the effect of calycosin, because calycosin increased the amount of nuclear Nrf2 while decreasing the amount of cytoplasmic Nrf2. Nrf2 knockdown with siRNA transfection abolished the neuroprotective effect of calycosin. Taken together, this study disclosed a novel mechanism by which calycosin combats oxidative stress. Our study thus sheds light on the potential clinical application of calycosin in SCI treatment.

Glycitein prevents reserpine-induced depression and associated comorbidities in mice: modulation of lipid peroxidation and TNF-α levels

Depression is a debilitating mood disorder affecting millions worldwide and continues to pose a significant global health burden. Due to the multifaceted nature of depression, the current treatment regimens are not up to mark in terms of their multitargeting potential and least side effect profile. Molecules within the isoflavone class demonstrate promising potential in alleviating depression and associated conditions, offering a multifaceted approach to manage mental health concerns. Therefore, the current study was designed to explore the potential of glycitein, an isoflavone in managing reserpine-induced depression and associated comorbidities in mice. Reserpine (0.5 mg/kg; i.p.) administration for the first 3 days induced depression and associated comorbidities as evidenced by increased immobility time in forced swim test (FST) and tail suspension test (TST), along with reduced locomotor activity in the open field test (OFT) and increased latency to reach the platform in the Morris water maze (MWM) test. Reserpine treatment also upregulated and downregulated the brain thiobarbituric acid reactive substance (TBARS) and glutathione (GSH) levels, respectively. Furthermore, reserpine administration also uplifted the level of TNF-α in the serum samples. Glycitein (3 mg/kg and 6 mg/kg; p.o.) treatment for 5 days prevented the depressive effect of reserpine. It also improved the spatial memory at both dose levels. Moreover, in biochemical analysis, glycitein also reduced the brain TBARS and serum tumor necrosis factor-alpha (TNF-α) levels. Whereas, no significant effect was seen on the brain GSH level. Glycitein (6 mg/kg) was found to be more effective than the 3 mg/kg dose of glycitein. Overall results delineate that glycitein has the potential to manage depression and impaired memory by inhibiting lipid peroxidation and inflammatory stress.

Neuroprotective effects of saxagliptin against radiation-induced cognitive impairment: Insights on Akt/CREB/SIRT1/BDNF signaling pathway

Radiation-induced cognitive impairment has recently fueled scientific interest with an increasing prevalence of cancer patients requiring whole brain irradiation (WBI) in their treatment algorithm. Saxagliptin (SAXA), a dipeptidyl peptidase-IV (DPP-IV) inhibitor, has exhibited competent neuroprotective effects against varied neurodegenerative disorders. Hence, this study aimed at examining the efficacy of SAXA in alleviating WBI-induced cognitive deficits. Male Sprague Dawley rats were distributed into control group, WBI group exposed to 20 Gy ϒ-radiation, SAXA group treated for three weeks with SAXA (10 mg/kg. orally, once daily), and WBI/SAXA group exposed to 20 Gy ϒ-radiation then treated with SAXA (10 mg/kg. orally, once daily). SAXA effectively reversed memory deterioration and motor dysfunction induced by 20 Gy WBI during behavioural tests and preserved normal histological architecture of the hippocampal tissues of irradiated rats. Mechanistically, SAXA inhibited WBI-induced hippocampal oxidative stress via decreasing lipid peroxidation while restoring catalase antioxidant activity. Moreover, SAXA abrogated radiation-induced hippocampal neuronal apoptosis through downregulating proapoptotic Bcl-2 Associated X-protein (Bax) and upregulating antiapoptotic B-cell lymphoma 2 (Bcl-2) expressions and eventually diminishing expression of cleaved caspase 3. Furthermore, SAXA boosted hippocampal neurogenesis by upregulating brain-derived neurotrophic factor (BDNF) expression. These valuable neuroprotective capabilities of SAXA were linked to activating protein kinase B (Akt), and cAMP-response element-binding protein (CREB) along with elevating the expression of sirtuin 1 (SIRT-1). SAXA successfully mitigated cognitive dysfunction triggered by WBI, attenuated oxidative injury, and neuronal apoptosis, and enhanced neurogenesis through switching on Akt/CREB/BDNF/SIRT-1 signaling axes. Such fruitful neurorestorative effects of SAXA provide an innovative therapeutic strategy for improving the cognitive capacity of cancer patients exposed to radiotherapy.

The familial amyotrophic lateral sclerosis-associated A4V SOD1 mutant is not able to regulate aerobic glycolysis

Under certain stress conditions, astrocytes operate in aerobic glycolysis, a process controlled by pyruvate dehydrogenase (PDH) inhibition through its E1 α subunit (Pda1) phosphorylation. This supplies lactate to neurons, which save glucose to obtain NADPH to, among other roles, counteract reactive oxygen species. A failure in this metabolic cooperation causes severe damage to neurons. In this work, using humanized Saccharomyces cerevisiae cells in which its endogenous Cu/Zn Superoxide Dismutase (SOD1) was replaced by human ortholog, we investigated the role of human SOD1 (hSOD1) in aerobic glycolysis regulation and its implications to amyotrophic lateral sclerosis (ALS), a neurodegenerative disease. Yeast cells ferment glucose even in the presence of oxygen and switch to respiratory metabolism after glucose exhaustion. However, like cells of SOD1-knockout strain, cells expressing A4V mutant of hSOD1 growing on glucose showed a respiratory phenotype, i.e., low glucose and high oxygen consumptions and low intracellular oxidation levels in response to peroxide stress, contrary to cells expressing wild-type (WT) SOD1 (yeast or human). The A4V mutation in hSOD1 is linked to ALS. In contrast to WT SOD1 strains, PDH activity of both sod1Δ and A4V hSOD1 cells did not change in response to a metabolic shift toward oxidative metabolism, which was associated to lower Pda1 phosphorylation levels under growth on glucose. Taken together, our results suggest that A4V mutant cannot regulate aerobic glycolysis via Pda1 phosphorylation the same way WT hSOD1, which might be linked to problems observed in the motor neurons of ALS patients with the SOD1 A4V mutation.

Ten "Cheat Codes" for Measuring Oxidative Stress in Humans

Formidable and often seemingly insurmountable conceptual, technical, and methodological challenges hamper the measurement of oxidative stress in humans. For instance, fraught and flawed methods, such as the thiobarbituric acid reactive substances assay kits for lipid peroxidation, rate-limit progress. To advance translational redox research, we present ten comprehensive "cheat codes" for measuring oxidative stress in humans. The cheat codes include analytical approaches to assess reactive oxygen species, antioxidants, oxidative damage, and redox regulation. They provide essential conceptual, technical, and methodological information inclusive of curated "do" and "don't" guidelines. Given the biochemical complexity of oxidative stress, we present a research question-grounded decision tree guide for selecting the most appropriate cheat code(s) to implement in a prospective human experiment. Worked examples demonstrate the benefits of the decision tree-based cheat code selection tool. The ten cheat codes define an invaluable resource for measuring oxidative stress in humans.

The potential roles of PKM2 in cerebrovascular diseases

Pyruvate kinase M2 (PKM2), a key enzyme involved in glycolysis,plays an important role in regulating cell metabolism and growth under different physiological conditions. PKM2 has been intensively investigated in multiple cancer diseases. Recent years, many studies have found its pivotal role in cerebrovascular diseases (CeVDs), the disturbances in intracranial blood circulation. CeVDs has been confirmed to be closely associated with oxidative stress (OS), mitochondrial dynamics, systemic inflammation, and local neuroinflammation in the brain. It has further been revealed that PKM2 exerts various biological functions in the regulation of energy supply, OS, inflammatory responses, and mitochondrial dysfunction. The roles of PKM2 are closely related to its different isoforms, expression levels in subcellular localization, and post-translational modifications. Therefore, summarizing the roles of PKM2 in CeVDs will help further understanding the molecular mechanisms of CeVDs. In this review, we illustrate the characteristics of PKM2, the regulated PKM2 expression, and the biological roles of PKM2 in CeVDs.

SUMOylation of nuclear receptor Nor1/NR4A3 coordinates microtubule cytoskeletal dynamics and stability in neuronal cells

BACKGROUND

Nor1/NR4A3 is a member of the NR4A subfamily of nuclear receptors that play essential roles in regulating gene expression related to development, cell homeostasis and neurological functions. However, Nor1 is still considered an orphan receptor, as its natural ligand remains unclear for mediating transcriptional activation. Yet other activation signals may modulate Nor1 activity, although their precise role in the development and maintenance of the nervous system remains elusive.

METHODS

We used transcriptional reporter assays, gene expression profiling, protein turnover measurement, and cell growth assays to assess the functional relevance of Nor1 and SUMO-defective variants in neuronal cells. SUMO1 and SUMO2 conjugation to Nor1 were assessed by immunoprecipitation. Tubulin stability was determined by acetylation and polymerization assays, and live-cell fluorescent microscopy.

RESULTS

Here, we demonstrate that Nor1 undergoes SUMO1 conjugation at Lys-89 within a canonical ψKxE SUMOylation motif, contributing to the complex pattern of Nor1 SUMOylation, which also includes Lys-137. Disruption of Lys-89, thereby preventing SUMO1 conjugation, led to reduced Nor1 transcriptional competence and protein stability, as well as the downregulation of genes involved in cell growth and metabolism, such as ENO3, EN1, and CFLAR, and in microtubule cytoskeleton dynamics, including MAP2 and MAPT, which resulted in reduced survival of neuronal cells. Interestingly, Lys-89 SUMOylation was potentiated in response to nocodazole, a microtubule depolymerizing drug, although this was insufficient to rescue cells from microtubule disruption despite enhanced Nor1 gene expression. Instead, Lys-89 deSUMOylation reduced the expression of microtubule-severing genes like KATNA1, SPAST, and FIGN, and enhanced α-tubulin cellular levels, acetylation, and microfilament organization, promoting microtubule stability and resistance to nocodazole. These effects contrasted with Lys-137 SUMOylation, suggesting distinct regulatory mechanisms based on specific Nor1 input SUMOylation signals.

CONCLUSIONS

Our study provides novel insights into Nor1 transcriptional signaling competence and identifies a hierarchical mechanism whereby selective Nor1 SUMOylation may govern neuronal cytoskeleton network dynamics and resistance against microtubule disturbances, a condition strongly associated with neurodegenerative diseases.

Embryonic Zebrafish as a Model for Investigating the Interaction between Environmental Pollutants and Neurodegenerative Disorders

Environmental pollutants have been linked to neurotoxicity and are proposed to contribute to neurodegenerative disorders. The zebrafish model provides a high-throughput platform for large-scale chemical screening and toxicity assessment and is widely accepted as an important animal model for the investigation of neurodegenerative disorders. Although recent studies explore the roles of environmental pollutants in neurodegenerative disorders in zebrafish models, current knowledge of the mechanisms of environmentally induced neurodegenerative disorders is relatively complex and overlapping. This review primarily discusses utilizing embryonic zebrafish as the model to investigate environmental pollutants-related neurodegenerative disease. We also review current applicable approaches and important biomarkers to unravel the underlying mechanism of environmentally related neurodegenerative disorders. We found embryonic zebrafish to be a powerful tool that provides a platform for evaluating neurotoxicity triggered by environmentally relevant concentrations of neurotoxic compounds. Additionally, using variable approaches to assess neurotoxicity in the embryonic zebrafish allows researchers to have insights into the complex interaction between environmental pollutants and neurodegenerative disorders and, ultimately, an understanding of the underlying mechanisms related to environmental toxicants.

Postbiotics as Molecules Targeting Cellular Events of Aging Brain-The Role in Pathogenesis, Prophylaxis and Treatment of Neurodegenerative Diseases

Aging is the most prominent risk factor for neurodegeneration occurrence. The most common neurodegenerative diseases (NDs), Alzheimer's (AD) and Parkinson's (PD) diseases, are characterized by the incidence of proteinopathy, abnormal activation of glial cells, oxidative stress, neuroinflammation, impaired autophagy and cellular senescence excessive for the patient's age. Moreover, mitochondrial disfunction, epigenetic alterations and neurogenesis inhibition, together with increased blood-brain barrier permeability and gut dysbiosis, have been linked to ND pathogenesis. Since NDs still lack curative treatment, recent research has sought therapeutic options in restoring gut microbiota and supplementing probiotic bacteria-derived metabolites with beneficial action to the host-so called postbiotics. The current review focuses on literature explaining cellular mechanisms involved in ND pathogenesis and research addressing the impact that postbiotics as a whole mixture and particular metabolites, such as short-chain fatty acids (SCFAs), lactate, polyamines, polyphenols, tryptophan metabolites, exopolysaccharides and bacterial extracellular vesicles, have on the ageing-associated processes underlying ND occurrence. The review also discusses the issue of implementing postbiotics into ND prophylaxis and therapy, depicting them as compounds addressing senescence-triggered dysfunctions that are worth translating from bench to pharmaceutical market in response to "silver consumers" demands.