Oxidative stress and neurodegeneration: where are we now?

Transcriptomic responses in the nervous system and correlated behavioural changes of a cephalopod exposed to ocean acidification

BACKGROUND

The nervous system is central to coordinating behavioural responses to environmental change, likely including ocean acidification (OA). However, a clear understanding of neurobiological responses to OA is lacking, especially for marine invertebrates.

RESULTS

We evaluated the transcriptomic response of the central nervous system (CNS) and eyes of the two-toned pygmy squid (Idiosepius pygmaeus) to OA conditions, using a de novo transcriptome assembly created with long read PacBio ISO-sequencing data. We then correlated patterns of gene expression with CO2 treatment levels and OA-affected behaviours in the same individuals. OA induced transcriptomic responses within the nervous system related to various different types of neurotransmission, neuroplasticity, immune function and oxidative stress. These molecular changes may contribute to OA-induced behavioural changes, as suggested by correlations among gene expression profiles, CO2 treatment and OA-affected behaviours.

CONCLUSIONS

This study provides the first molecular insights into the neurobiological effects of OA on a cephalopod and correlates molecular changes with whole animal behavioural responses, helping to bridge the gaps in our knowledge between environmental change and animal responses.

H. pectinata (L.) Poit - traditional uses, phytochemistry and biological-pharmacological activities in preclinical studies: a systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

H. pectinata (L.) Poit, popularly known as "sambacaitá" or "canudinho", is a plant endemic to north-eastern Brazil. Its aerial parts, leaves and flowers have traditionally been used to treat gastrointestinal disorders, rhinopharyngitis, nasal congestion, bacterial and fungal infections, fever, colic, inflammation, and pain.

AIM OF THE STUDY

The aim of this review was to provide information on the botanical characteristics, ethnomedicinal uses, phytochemistry and biological-pharmacological activities of H. pectinata.

MATERIALS AND METHODS

This systematic review followed the Cochrane Handbook Collaboration and the PRISMA guidelines. The review question was what are the biological-pharmacological activities of H. pectinata presented in non-clinical studies. The search for articles was conducted in the Medline (via PubMed), Embase, Web of Science, Scopus, Virtual Health Library, SciELO, Google Scholar and the Brazilian Digital Library of Theses and Dissertations databases. Two reviewers independently selected the studies that met the inclusion criteria, extracted the data, and assessed the risk of bias of the included studies.

RESULTS

39 articles were included in this review, of which 19 reported in vitro experiments, 16 in vivo studies and 4 in vivo and in vitro experiments. H. pectinata is a plant widely used in folk medicine in north-eastern Brazil for the treatment of various ailments, such as respiratory diseases, gastrointestinal disorders, bacterial and fungal infections, and general inflammation. Supporting its popular use, several in vitro and in vivo pharmacological investigations of the essential oil and extract of H. pectinata have demonstrated their anti-inflammatory, antinociceptive, antioxidant, antidepressant, anticancer, hepatoregenerative, healing, and antimicrobial activities. H. pectinata has been reported to contain 75 bioactive constituents, comprising 9 flavonoids, 54 terpenes, and 12 other compounds.

CONCLUSION

H. pectinata is a plant commonly used in traditional medicine. Phytochemically, it contains several bioactive constituents, including terpenes and flavonoids, and has been shown to have antinociceptive, anti-inflammatory, antimicrobial and antitumour activity, as well as hepatorregenerative and healing effects, and low toxicity.

Comprehensive Exploration of the Neuroprotective Mechanisms of Ginkgo biloba Leaves in Treating Neurological Disorders

Neurological disorders (NDs) are diseases that seriously affect the health of individuals worldwide, potentially leading to a significant reduction in the quality of life for patients and their families. Herbal medicines have been widely used in the treatment of NDs due to their multi-target and multi-pathway features. Ginkgo biloba leaves (GBLs), one of the most popular herbal medicines in the world, have been demonstrated to present therapeutic effects on NDs. However, the pharmacological mechanisms of GBLs in the treatment of neurological disorders have not been systematically summarized. This study aimed to summarize the molecular mechanism of GBLs in treating NDs from the cell models, animal models, and clinical trials of studies. Four databases, i.e., PubMed, Google Scholar, CNKI, and Web of Science were searched using the following keywords: "Ginkgo biloba", "Ginkgo biloba extract", "Ginkgo biloba leaves", "Ginkgo biloba leaves extract", "Neurological disorders", "Neurological diseases", and "Neurodegenerative diseases". All items meeting the inclusion criteria on the treatment of NDs with GBLs were extracted and summarized. Additionally, PRISMA 2020 was performed to independently evaluate the screening methods. Out of 1385 records in the database, 52 were screened in relation to the function of GBLs in the treatment of NDs; of these 52 records, 39 were preclinical trials and 13 were clinical studies. Analysis of pharmacological studies revealed that GBLs can improve memory, cognition, behavior, and psychopathology of NDs and that the most frequently associated GBLs are depression, followed by Alzheimer's disease, stroke, Huntington's disease, and Parkinson's disease. Additionally, the clinical studies of depression, AD, and stroke are the most common, and most of the remaining ND data are available from in vitro or in vivo animal studies. Moreover, the possible mechanisms of GBLs in treating NDs are mainly through free radical scavenging, anti-oxidant activity, anti-inflammatory response, mitochondrial protection, neurotransmitter regulation, and antagonism of PAF. This is the first paper to systematically and comprehensively investigate the pharmacological effects and neuroprotective mechanisms of GBLs in the treatment of NDs thus far. All findings contribute to a better understanding of the efficacy and complexity of GBLs in treating NDs, which is of great significance for the further clinical application of this herbal medicine.

The Role of Water-Soluble Vitamins and Vitamin D in Prevention and Treatment of Depression and Seasonal Affective Disorder in Adults

Depression is a major global health concern expected to worsen by 2030. In 2019, 28 million individuals were affected by depressive disorders. Dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression. B vitamins are crucial for neurological function and mood regulation. Deficiencies in these vitamins are linked to depression. Studies on individual B vitamins show promise in improving depressive symptoms, particularly thiamin, riboflavin, niacin, and folate. Vitamin C deficiency may heighten depressive symptoms, but its exact role is not fully understood. Seasonal Affective Disorder (SAD) is associated with insufficient sunlight exposure and vitamin D deficiency. Vitamin D supplementation for SAD shows inconsistent results due to methodological variations. Further investigation is needed to understand the mechanisms of vitamins in depression treatment. Moreover, more research on SAD and light therapy's efficacy and underlying mechanisms involving photoreceptors, enzymes, and immune markers is needed. Although dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression, dietitians treating psychiatric disorders face challenges due to diverse study designs, making direct comparisons difficult. Therefore, this article reviews the current literature to assess the role of dietary and supplemental vitamins in the prevention and treatment of depression. This review found that, although evidence supports the role of B vitamins and vitamins C and D in preventing and treating depression, further research is needed to clarify their mechanisms of action and determine the most effective intervention strategies.

The protective role of sesame oil against Parkinson's-like disease induced by manganese in rats

Chronic exposure to manganese (Mn) results in motor dysfunction, biochemical and pathological alterations in the brain. Oxidative stress, inflammation, and dysfunction of dopaminergic and GABAergic systems stimulate activating transcription factor-6 (ATF-6) and protein kinase RNA-like ER kinase (PERK) leading to apoptosis. This study aimed to investigate the protective effect of sesame oil (SO) against Mn-induced neurotoxicity. Rats received 25 mg/kg MnCl2 and were concomitantly treated with 2.5, 5, or 8 ml/kg of SO for 5 weeks. Mn-induced motor dysfunction was indicated by significant decreases in the time taken by rats to fall during the rotarod test and in the number of movements observed during the open field test. Also, Mn resulted in neuronal degeneration as observed by histological staining. The striatal levels of lipid peroxides and reduced glutathione (oxidative stress markers), interleukin-6 and tumor necrosis factor-α (inflammatory markers) were significantly elevated. Mn significantly reduced the levels of dopamine and Bcl-2, while GABA, PERK, ATF-6, Bax, and caspase-3 were increased. Interestingly, all SO doses, especially at 8 ml/kg, significantly improved locomotor activity, biochemical deviations and reduced neuronal degeneration. In conclusion, SO may provide potential therapeutic benefits in enhancing motor performance and promoting neuronal survival in individuals highly exposed to Mn.

Evaluation of sub-chronic toxicity of melamine via systematic or oral delivery in adult zebrafish based on behavioral endpoints

Melamine-tainted products have been found in the market and raised issues about food safety. Recent studies done in rodents and humans demonstrated the toxicities of melamine, especially in causing kidney damage and bladder stone formation. However, very few studies assessed its behavior toxicity in organisms, including fish. Therefore, in this study, the researchers aim to determine whether sub-chronic exposure to melamine via oral and systematic administration could induce behavioral abnormality in zebrafish. After 14 days of systematic exposure to melamine at doses of 0.1 and 10 ppm levels, zebrafish were subjected to multiple behavioral assays. Results from both exposure routes showed that melamine indeed slightly increased fish locomotion and altered their exploratory behaviors in the novel tank assay. Furthermore, tightened shoaling formation was also displayed by the treated fish in the waterborne exposure group. However, melamine exposure did not cause any obvious alterations in fish behaviors during other behavioral tests. In addition, in comparison with previously published data on the behavior toxicities of several solvents in zebrafish, our phenomic analysis suggests the relatively low behavior toxicities of melamine via either systematic exposure or oral administration to zebrafish compared to those solvents. Nevertheless, our data indicate that the potential neurotoxicity of chronic low-dose melamine should not be ignored.

Inhibiting the Keap1/Nrf2 Protein-Protein Interaction with Protein-Like Polymers

Successful and selective inhibition of the cytosolic protein-protein interaction (PPI) between nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associating protein 1 (Keap1) can enhance the antioxidant response, with the potential for a therapeutic effect in a range of settings including in neurodegenerative disease (ND). Small molecule inhibitors have been developed, yet many have off-target effects, or are otherwise limited by poor cellular permeability. Peptide-based strategies have also been attempted to enhance specificity, yet face challenges due to susceptibility to degradation and lack of cellular penetration. Herein, these barriers are overcome utilizing a polymer-based proteomimetics. The protein-like polymer (PLP) consists of a synthetic, lipophilic polymer backbone displaying water soluble Keap1-binding peptides on each monomer unit forming a brush polymer architecture. The PLPs are capable of engaging Keap1 and displacing the cellular protective transcription factor Nrf2, which then translocates to the nucleus, activating the antioxidant response element (ARE). PLPs exhibit increased Keap1 binding affinity by several orders of magnitude compared to free peptides, maintain serum stability, are cell-penetrant, and selectively activate the ARE pathway in cells, including in primary cortical neuronal cultures. Keap1/Nrf2-inhibitory PLPs have the potential to impact the treatment of disease states associated with dysregulation of oxidative stress, such as NDs.

Quinic Acid Alleviates Behavior Impairment by Reducing Neuroinflammation and MAPK Activation in LPS-Treated Mice

Compared to other organs, the brain has limited antioxidant defenses. In particular, the hippocampus is the central region for learning and memory and is highly susceptible to oxidative stress. Glial cells are the most abundant cells in the brain, and sustained glial cell activation is critical to the neuroinflammation that aggravates neuropathology and neurotoxicity. Therefore, regulating glial cell activation is a promising neurotherapeutic treatment. Quinic acid and its derivatives possess anti-oxidant and anti-inflammatory properties. Although previous studies have evidenced quinic acid's benefit on the brain, in vivo and in vitro analyses of its anti-oxidant and anti-inflammatory properties in glial cells have yet to be established. This study investigated quinic acid's rescue effect in lipopolysaccharide (LPS)-induced behavior impairment. Orally administering quinic acid restored social impairment and LPS-induced spatial and fear memory. In addition, quinic acid inhibited proinflammatory mediator, oxidative stress marker, and mitogen-activated protein kinase (MAPK) activation in the LPS-injected hippocampus. Quinic acid inhibited nitrite release and extracellular signal-regulated kinase (ERK) phosphorylation in LPS-stimulated astrocytes. Collectively, quinic acid restored impaired neuroinflammation-induced behavior by regulating proinflammatory mediator and ERK activation in astrocytes, demonstrating its potential as a therapeutic agent for neuroinflammation-induced brain disease treatments.

An Update on the Potential of Tangeretin in the Management of Neuroinflammation-Mediated Neurodegenerative Disorders

Neuroinflammation is the major cause of neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Currently available drugs present relatively low efficacy and are not capable of modifying the course of the disease or delaying its progression. Identifying well-tolerated and brain-penetrant agents of plant origin could fulfil the pressing need for novel treatment techniques for neuroinflammation. Attention has been drawn to a large family of flavonoids in citrus fruits, which may function as strong nutraceuticals in slowing down the development and progression of neuroinflammation. This review is aimed at elucidating and summarizing the effects of the flavonoid tangeretin (TAN) in the management of neuroinflammation-mediated neurodegenerative disorders. A literature survey was performed using various resources, including ScienceDirect, PubMed, Google Scholar, Springer, and Web of Science. The data revealed that TAN exhibited immense neuroprotective effects in addition to its anti-oxidant, anti-diabetic, and peroxisome proliferator-activated receptor-γ agonistic effects. The effects of TAN are mainly mediated through the inhibition of oxidative and inflammatory pathways via regulating multiple signaling pathways, including c-Jun N-terminal kinase, phosphoinositide 3-kinase, mitogen-activated protein kinase, nuclear factor erythroid-2-related factor 2, extracellular-signal-regulated kinase, and CRE-dependent transcription. In conclusion, the citrus flavonoid TAN has the potential to prevent neuronal death mediated by neuroinflammatory pathways and can be developed as an auxiliary therapeutic agent in the management of neurodegenerative disorders.

The impact of enriched environments on cerebral oxidative balance in rodents: a systematic review of environmental variability effects

Introduction

The present review aimed to systematically summarize the impacts of environmental enrichment (EE) on cerebral oxidative balance in rodents exposed to normal and unfavorable environmental conditions.

Methods

In this systematic review, four databases were used: PubMed (830 articles), Scopus (126 articles), Embase (127 articles), and Science Direct (794 articles). Eligibility criteria were applied based on the Population, Intervention, Comparison, Outcomes, and Study (PICOS) strategy to reduce the risk of bias. The searches were carried out by two independent researchers; in case of disagreement, a third participant was requested. After the selection and inclusion of articles, data related to sample characteristics and the EE protocol (time of exposure to EE, number of animals, and size of the environment) were extracted, as well as data related to brain tissues and biomarkers of oxidative balance, including carbonyls, malondialdehyde, nitrotyrosine, oxygen-reactive species, and glutathione (reduced/oxidized).

Results

A total of 1,877 articles were found in the four databases, of which 16 studies were included in this systematic review. The results showed that different EE protocols were able to produce a global increase in antioxidant capacity, both enzymatic and non-enzymatic, which are the main factors for the neuroprotective effects in the central nervous system (CNS) subjected to unfavorable conditions. Furthermore, it was possible to notice a slowdown in neural dysfunction associated with oxidative damage, especially in the prefrontal structure in mice.

Discussion

In conclusion, EE protocols were determined to be valid tools for improving oxidative balance in the CNS. The global decrease in oxidative stress biomarkers indicates refinement in reactive oxygen species detoxification, triggering an improvement in the antioxidant network.

Cancer-induced morphological changes in enteric glial cells in the jejunum of Walker-256 tumor-bearing rats

Cancer-induced cachexia is associated with systemic inflammation and gastrointestinal dysfunction. How changes to cells of the enteric nervous system contribute to gut dysfunction in tumor development and cancer cachexia is unknown. Here, we tested the hypothesis that changes to enteric glia, a type of peripheral glia that surround enteric neurons and regulate gut homeostasis, are associated with tumor development and that supplementing with the antioxidant L-glutathione is protective against the changes induced. Immunohistochemistry for neurons, enteric glial cells and immune cells was performed in whole-mount preparations and frozen histological sections of the jejunum from 20 Wistar rats, distributed in 4 groups: control, tumor of Walker-256, control administered with 1 % L-glutathione, and tumor of Walker-256 administered with 1 % L-glutathione. Morphoquantitative analyses were made using Image-Pro® Plus 4.5 and ImageJ® 1.43° software. Tumor development significantly reduced neuronal and glial cell populations in the myenteric and submucosal plexuses and enlarged glial cell body area in the submucosal plexus. In contrast, tumors increased glia in the jejunal mucosa and this effect was accompanied by B-lymphocyte recruitment. GSH-supplemented diet was not sufficient to protect against changes to neurons and glia in the submucosal plexus but was partially protective in the myenteric plexus. L-glutathione had no effect on physiological parameters of cachexia but was sufficient to preserve enteric glial cell density in the myenteric plexus. These results suggest that changes to both enteric neurons and glia likely contribute to the gastrointestinal effects of tumor development and that oxidative stress contributes to these effects in the enteric nervous system.

The effect of topical magnesium on healing of pre-clinical burn wounds

BACKGROUND

Magnesium (Mg) is an essential factor in the healing process. This study aimed to evaluate the effect of Mg creams on healing burn wounds in the rat model.

METHODS

To induce burns under general anaesthesia, a 2 × 2 cm2, 100 °C plate was placed for 12 s between the scapulas in 100 male adult Sprague Dawley rats. Animals were divided into five groups (n = 20); positive control (induced burn without treatment); vehicle control (received daily Eucerin cream base topically); comparative control (induced burn and treated daily with Alpha burn cream topically); Treatment 1 and 2 (received daily Mg cream 2% and 4% topically, respectively). All animals were bled for hematological assessment of malondialdehyde (MDA) and TNF-α and sacrificed on days 0, 1, 7, 14, and 21 after interventions for biomechanical, histological, and stereological studies.

RESULTS

Stereologically speaking, in treatment groups an increase in dermal collagen volume and fibroblasts was noticed. In treatment groups, the length of vessels, angiogenesis, and skin stretch increased, but the wound area, MDA, and TNF-α level decreased.

CONCLUSION

Mg cream was effective in healing burns.

Cerium oxide nanoparticles as a new neuroprotective agent to promote functional recovery in a rat model of sciatic nerve crush injury

BACKGROUND

Peripheral nerve injury is a common clinical disorder. The aim of the present study was to investigate the role of cerium oxide nanoparticles on axonal regeneration and functional recovery of the sciatic nerve after a crush injury in the rat model.

METHOD

A total of 40 adult male Wistar rats were divided into four groups. The animals underwent deep anesthesia. Afterward, the right sciatic nerve of rats was exposed and crushed. In two experimental groups, rats were treated intraperitoneally with cerium oxide nanoparticles at the dosage of 20 or 80 mg/kg daily for 1 week. The control group was given a vehicle. Then, during the nerve regeneration motor and sensory function recovery tests, histomorphometric evaluations, histological assessment of gastrocnemius muscle, and gastrocnemius muscle wet weights tests were performed.

RESULTS

Results demonstrated that the rate of nerve regeneration increased with the administration of cerium oxide nanoparticle in high doses. Also, the morphometric analysis showed that the number of myelinated fibers and myelin sheath thicknesses was significantly greater in the cerium oxide nanoparticle group versus the control group. Other parameters also improved in the cerium oxide nanoparticle treatment groups compared with the control group.

CONCLUSION

These data indicate that this nanoparticle has therapeutic potential and can be considered as a new treatment for nervous system regeneration.

Theranostic Fluorescent Probes

The ability to gain spatiotemporal information, and in some cases achieve spatiotemporal control, in the context of drug delivery makes theranostic fluorescent probes an attractive and intensely investigated research topic. This interest is reflected in the steep rise in publications on the topic that have appeared over the past decade. Theranostic fluorescent probes, in their various incarnations, generally comprise a fluorophore linked to a masked drug, in which the drug is released as the result of certain stimuli, with both intrinsic and extrinsic stimuli being reported. This release is then signaled by the emergence of a fluorescent signal. Importantly, the use of appropriate fluorophores has enabled not only this emerging fluorescence as a spatiotemporal marker for drug delivery but also has provided modalities useful in photodynamic, photothermal, and sonodynamic therapeutic applications. In this review we highlight recent work on theranostic fluorescent probes with a particular focus on probes that are activated in tumor microenvironments. We also summarize efforts to develop probes for other applications, such as neurodegenerative diseases and antibacterials. This review celebrates the diversity of designs reported to date, from discrete small-molecule systems to nanomaterials. Our aim is to provide insights into the potential clinical impact of this still-emerging research direction.

Impact of glyphosate-based herbicide exposure through maternal milk on offspring's antioxidant status, neurodevelopment, and behavior

Glyphosate-based Herbicide (GBH) is a widely used pesticide that functions as a broad-spectrum, non-selective herbicide. Despite advanced research to describe the neurotoxic potential of GBH, the harmful effects on maternal behavior and neurodevelopment of offspring remain unclear. This study was conducted to highlight the effects of GBH on the antioxidant system, anxiety traits, social interaction, and cognitive and sensorimotor functions in pups exposed to 25 or 50 mg/l daily via their mother's milk. Concerning the biochemical biomarkers, GBH administered during the early stages of development negatively affected the status of antioxidant enzymes and lipid peroxidation in the brain structures of the pups. Furthermore, our results showed a significant decrease in acetylcholinesterase (AChE) specific activity within the brains of treated pups. The results of the behavioral tests indicated that the treated offspring developed anxiety, memory, and sociability disorders, as evidenced by the Open Field, Y-maze, object recognition task, and social interaction tests. Through neurodevelopmental testing, we also showed sensorimotor impairment (righting reflex and negative geotaxis) and abnormal maternal behavior. Altogether, our study clearly demonstrates that the developing brain is sensitive to GBH.

The effects of carvacrol and p-cymene on Aβ1-42 -induced long-term potentiation deficit in male rats

AIMS

Alzheimer's disease (AD) is the most common type of dementia in which oxidative stress plays an important role. In this disease, learning and memory and the cellular mechanism associated with it, long-term potentiation (LTP), are impaired. Considering the beneficial effects of carvacrol (CAR) and p-cymene against AD, their effect was assessed on in vivo hippocampal LTP in the perforant pathway (PP)-dentate gyrus (DG) pathway in an Aβ1-42 -induced rat model of AD.

METHODS

Male Wistar rats were randomly assigned to five groups: sham: intracerebroventricular (ICV) injection of phosphate-buffered saline, Aβ: ICV Aβ1-42 injections, Aβ + CAR (50 mg/kg), Aβ + p-cymene (50 mg/kg), and Aβ + CAR + p-cymene. Administration of CAR and p-cymene was done by gavage daily 4 weeks before and 4 weeks after the Aβ injection. The population spike (PS) amplitude and field excitatory postsynaptic potentials (fEPSP) slope were determined in DG against the applied stimulation to the PP.

RESULTS

Aβ-treated rats exhibited impaired LTP induction in the PP-DG synapses, resulting in significant reduction in both fEPSP slope and PS amplitude compared to the sham animals. Aβ-treated rats consumed either CAR or p-cymene separately (but not their combination), and showed an enhancement in fEPSP slope and PS amplitude of the DG granular cells.

CONCLUSIONS

These data indicate that CAR or p-cymene can ameliorate Aβ-associated changes in synaptic plasticity. Surprisingly, the combination of CAR and p-cymene did not yield the same effect, suggesting a potential interaction between the two substances.

Chronic exposure to tris (2-chloroethyl) phosphate (TCEP) induces brain structural and functional changes in zebrafish (Danio rerio): A comparative study on the environmental and LC50 concentrations of TCEP

Tris (2-chloroethyl) phosphate (TCEP) is a crucial organophosphorus flame retardant widely used in many industrial and commercial products. Available reports reported that TCEP could cause various toxicological effects on organisms, including humans. Unfortunately, toxicity data for TCEP (particularly on neurotoxicity) on aquatic organisms are lacking. In the present study, Danio rerio were exposed to different concentrations of TCEP for 42 days (chronic exposure), and oxidative stress, neurotoxicity, sodium, potassium-adenosine triphosphatase (Na+, K+-ATPase) activity, and histopathological changes were evaluated in the brain. The results showed that TCEP (100 and 1500 µg L-1) induced oxidative stress and significantly decreased the activities of antioxidant enzymes (SOD, CAT and GR) in the brain tissue of zebrafish. In contrast, the lipid peroxidation (LPO) level was increased compared to the control group. Exposure to TCEP inhibited the acetylcholinesterase (AChE) and Na+,K+-ATPase activities in the brain tissue. Brain histopathology after 42 days of exposure to TCEP showed cytoplasmic vacuolation, inflammatory cell infiltration, degenerated neurons, degenerated purkinje cells and binucleate. Furthermore, TCEP exposure leads to significant changes in dopamine and 5-HT levels in the brain of zebrafish. The data in the present study suggest that high concentrations of TCEP might affect the fish by altering oxidative balance and inducing marked pathological changes in the brain of zebrafish. These findings indicate that chronic exposure to TCEP may cause a neurotoxic effect in zebrafish.

Current potential pathogenic mechanisms of copper-zinc superoxide dismutase 1 (SOD1) in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease which damages upper and lower motor neurons (UMN and LMN) innervating the muscles of the trunk, extremities, head, neck and face in cerebrum, brain stem and spinal cord, which results in the progressive weakness, atrophy and fasciculation of muscle innervated by the related UMN and LMN, accompanying with the pathological signs leaded by the cortical spinal lateral tract lesion. The pathogenesis about ALS is not fully understood, and no specific drugs are available to cure and prevent the progression of this disease at present. In this review, we reviewed the structure and associated functions of copper-zinc superoxide dismutase 1 (SOD1), discuss why SOD1 is crucial to the pathogenesis of ALS, and outline the pathogenic mechanisms of SOD1 in ALS that have been identified at recent years, including glutamate-related excitotoxicity, mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, axonal transport disruption, prion-like propagation, and the non-cytologic toxicity of glial cells. This review will help us to deeply understand the current progression in this field of SOD1 pathogenic mechanisms in ALS.

Mitochondria Dysfunction and Neuroinflammation in Neurodegeneration: Who Comes First?

Neurodegenerative diseases (NDs) encompass an assorted array of disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, each characterised by distinct clinical manifestations and underlying pathological mechanisms. While some cases have a genetic basis, many NDs occur sporadically. Despite their differences, these diseases commonly feature chronic neuroinflammation as a hallmark. Consensus has recently been reached on the possibility that mitochondria dysfunction and protein aggregation can mutually contribute to the activation of neuroinflammatory response and thus to the onset and progression of these disorders. In the present review, we discuss the contribution of mitochondria dysfunction and neuroinflammation to the aetiology and progression of NDs, highlighting the possibility that new potential therapeutic targets can be identified to tackle neurodegenerative processes and alleviate the progression of these pathologies.

Research hotspots and frontiers of preconditioning in cerebral ischemia: A bibliometric analysis

Background

Preconditioning is a promising strategy against ischemic brain injury, and numerous studies in vitro and in vivo have demonstrated its neuroprotective effects. However, at present there is no bibliometric analysis of preconditioning in cerebral ischemia. Therefore, a comprehensive overview of the current status, hot spots, and emerging trends in this research field is necessary.

Materials and methods

Studies on preconditioning in cerebral ischemia from January 1999-December 2022 were retrieved from the Web of Science Core Collection (WOSCC) database. CiteSpace was used for data mining and visual analysis.

Results

A total of 1738 papers on preconditioning in cerebral ischemia were included in the study. The annual publications showed an upwards and then downwards trend but currently remain high in terms of annual publications. The US was the leading country, followed by China, the most active country in recent years. Capital Medical University published the largest number of articles. Perez-Pinzon, Miguel A contributed the most publications, while KITAGAWA K was the most cited author. The focus of the study covered three areas: (1) relevant diseases and experimental models, (2) types of preconditioning and stimuli, and (3) mechanisms of ischemic tolerance. Remote ischemic preconditioning, preconditioning of mesenchymal stem cells (MSCs), and inflammation are the frontiers of research in this field.

Conclusion

Our study provides a visual and scientific overview of research on preconditioning in cerebral ischemia, providing valuable information and new directions for researchers.

Cell non-autonomous signaling through the conserved C. elegans glycopeptide hormone receptor FSHR-1 regulates cholinergic neurotransmission

Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored. Glycoproteins and their G protein-coupled receptors (GPCRs) are well-established orchestrators of multi-tissue signaling events that govern diverse physiological processes through both cell-autonomous and cell non-autonomous regulation. Here, we show that follicle stimulating hormone receptor, FSHR-1, the sole Caenorhabditis elegans ortholog of mammalian glycoprotein hormone GPCRs, is important for cell non-autonomous modulation of synaptic transmission. Inhibition of fshr-1 expression reduces muscle contraction and leads to synaptic vesicle accumulation in cholinergic motor neurons. The neuromuscular and locomotor defects in fshr-1 loss-of-function mutants are associated with an underlying accumulation of synaptic vesicles, build-up of the synaptic vesicle priming factor UNC-10/RIM, and decreased synaptic vesicle release from cholinergic motor neurons. Restoration of FSHR-1 to the intestine is sufficient to restore neuromuscular activity and synaptic vesicle localization to fshr-1- deficient animals. Intestine-specific knockdown of FSHR-1 reduces neuromuscular function, indicating FSHR-1 is both necessary and sufficient in the intestine for its neuromuscular effects. Re-expression of FSHR-1 in other sites of endogenous expression, including glial cells and neurons, also restored some neuromuscular deficits, indicating potential cross-tissue regulation from these tissues as well. Genetic interaction studies provide evidence that downstream effectors gsa-1 / Gα S , acy-1 /adenylyl cyclase and sphk-1/ sphingosine kinase and glycoprotein hormone subunit orthologs, GPLA-1/GPA2 and GPLB-1/GPB5, are important for FSHR-1 modulation of the NMJ. Together, our results demonstrate that FSHR-1 modulation directs inter-tissue signaling systems, which promote synaptic vesicle release at neuromuscular synapses.

Activation of M1 muscarinic acetylcholine receptors by proline-rich oligopeptide 7a (<EDGPIPP) from Bothrops jararaca snake venom rescues oxidative stress-induced neurotoxicity in PC12 cells

Background

The bioactive peptides derived from snake venoms of the Viperidae family species have been promising as therapeutic candidates for neuroprotection due to their ability to prevent neuronal cell loss, injury, and death. Therefore, this study aimed to evaluate the cytoprotective effects of a synthetic proline-rich oligopeptide 7a (PRO-7a;

Methods

Both cells were pre-treated for four hours with different concentrations of PRO-7a, submitted to H2O2-induced damage for 20 h, and then the oxidative stress markers were analyzed. Also, two independent neuroprotective mechanisms were investigated: a) L-arginine metabolite generation via argininosuccinate synthetase (AsS) activity regulation to produce agmatine or polyamines with neuroprotective properties; b) M1 mAChR receptor subtype activation pathway to reduce oxidative stress and neuron injury.

Results

PRO-7a was not cytoprotective in C6 cells, but potentiated the H2O2-induced damage to cell integrity at a concentration lower than 0.38 μM. However, PRO-7a at 1.56 µM, on the other hand, modified H2O2-induced toxicity in PC12 cells by restoring cell integrity, mitochondrial metabolism, ROS generation, and arginase indirect activity. The α-Methyl-DL-aspartic acid (MDLA) and L-NΩ-Nitroarginine methyl ester (L-Name), specific inhibitors of AsS and nitric oxide synthase (NOS), which catalyzes the synthesis of polyamines and NO from L-arginine, did not suppress PRO-7a-mediated cytoprotection against oxidative stress. It suggested that its mechanism is independent of the production of L-arginine metabolites with neuroprotective properties by increased AsS activity. On the other hand, the neuroprotective effect of PRO-7a was blocked in the presence of dicyclomine hydrochloride (DCH), an M1 mAChR antagonist.

Conclusions

For the first time, this work provides evidence that PRO-7a-induced neuroprotection seems to be mediated through M1 mAChR activation in PC12 cells, which reduces oxidative stress independently of AsS activity and L-arginine bioavailability.

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Key Words

• Bioactive peptide
• Bothrops jararaca
• Neuroprotection
• Proline-rich oligopeptide

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Affiliation(s)

Carlos Alberto-Silva Natural and Humanities Sciences Center (CCNH), Experimental Morphophysiology Laboratory, Federal University of ABC (UFABC), São Bernardo do Campo, SP, Brazil
Halyne Queiroz Pantaleão Natural and Humanities Sciences Center (CCNH), Experimental Morphophysiology Laboratory, Federal University of ABC (UFABC), São Bernardo do Campo, SP, Brazil
Brenda Rufino da Silva Natural and Humanities Sciences Center (CCNH), Experimental Morphophysiology Laboratory, Federal University of ABC (UFABC), São Bernardo do Campo, SP, Brazil
Julio Cezar Araujo da Silva Natural and Humanities Sciences Center (CCNH), Experimental Morphophysiology Laboratory, Federal University of ABC (UFABC), São Bernardo do Campo, SP, Brazil
Marcela Bermudez Echeverry Center for Mathematics, Computation and Cognition (CMCC), Federal University of ABC, São Bernardo do Campo, SP, Brazil

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Long-term suboptimal dietary trace element supply does not affect trace element homeostasis in murine cerebellum

The ageing process is associated with alterations of systemic trace element (TE) homeostasis increasing the risk, e.g. neurodegenerative diseases. Here, the impact of long-term modulation of dietary intake of copper, iron, selenium, and zinc was investigated in murine cerebellum. Four- and 40-wk-old mice of both sexes were supplied with different amounts of those TEs for 26 wk. In an adequate supply group, TE concentrations were in accordance with recommendations for laboratory mice while suboptimally supplied animals received only limited amounts of copper, iron, selenium, and zinc. An additional age-adjusted group was fed selenium and zinc in amounts exceeding recommendations. Cerebellar TE concentrations were measured by inductively coupled plasma-tandem mass spectrometry. Furthermore, the expression of genes involved in TE transport, DNA damage response, and DNA repair as well as selected markers of genomic stability [8-oxoguanine, incision efficiency toward 8-oxoguanine, 5-hydroxyuracil, and apurinic/apyrimidinic sites and global DNA (hydroxy)methylation] were analysed. Ageing resulted in a mild increase of iron and copper concentrations in the cerebellum, which was most pronounced in the suboptimally supplied groups. Thus, TE changes in the cerebellum were predominantly driven by age and less by nutritional intervention. Interestingly, deviation from adequate TE supply resulted in higher manganese concentrations of female mice even though the manganese supply itself was not modulated. Parameters of genomic stability were neither affected by age, sex, nor diet. Overall, this study revealed that suboptimal dietary TE supply does not substantially affect TE homeostasis in the murine cerebellum.

The deleterious effects of maternal protein deprivation on the brainstem are minimized with moderate physical activity by offspring during early life

Maternal protein malnutrition during developmental periods might impair the redox state and the brain's excitatory/inhibitory neural network, increasing central sympathetic tone. Conversely, moderate physical exercise at an early age reduces the risk of chronic diseases. Thus, we hypothesized that a moderate training protocol could reduce the harmful effects of a low-protein maternal diet on the brainstem of young male offspring. We used a rat model of maternal protein restriction during the gestational and lactation period followed by an offspring's continuous treadmill exercise. Pregnant rats were divided into two groups according to the protein content in the diet: normoprotein (NP), receiving 17% of casein, and low protein (LP), receiving 8% of casein until the end of lactation. At 30 days of age, the male offspring were further subdivided into sedentary (NP-Sed and LP-Sed) or exercised (NP-Ex and LP-Ex) groups. Treadmill exercise was performed as follows: 4 weeks, 5 days/week, 60 min/day at 50% of maximal running capacity. The trained animals performed a treadmill exercise at 50% of the maximal running capacity, 60 min/day, 5 days/week, for 4 weeks. Our results indicate that a low-protein diet promotes deficits in the antioxidant system and a likely mitochondrial uncoupling. On the other hand, physical exercise restores the redox balance, which leads to decreased oxidative stress caused by the diet. In addition, it also promotes benefits to GABAergic inhibitory signaling. We conclude that regular moderate physical exercise performed in youthhood protects the brainstem against changes induced by maternal protein restriction.

Oxidative Imbalance in Pediatric Anxiety Disorders: A Preliminary Comparative Study

Background It is important to determine the possible related factors of anxiety disorder, one of the common psychiatric disorders of childhood. Our aims in this study were to compare oxidative stress markers between anxiety disorders in pediatric patients and healthy controls and to examine the relationship between anxiety symptom severity and oxidative stress indicators. Methods The study included 25 patients and 25 healthy controls. We measured the total oxidant capacity (TOS) and total antioxidant capacity (TAS) from the collected serum samples and calculated the oxidative stress index (OSI). We evaluated the clinical severity of the anxiety symptoms by the Revised Child Anxiety and Depression Scale-Child Version (RCADS-CV). Results The groups did not exhibit a noteworthy distinction in terms of TOS (p=0.128) and TAS (p=0.329). However, OSI was markedly elevated in the group with anxiety disorder (p=0.044). In the correlation analysis between anxiety symptom severity and oxidative stress indicators in the group with anxiety disorder, we found a positive correlation between TOS and RCADS total anxiety score (p=0.08). Conclusion These results may point to an oxidative dysfunction in anxiety disorders and the potential role of oxidative stress in their aetiology. Prospective, large-scale, randomized studies are needed to investigate if oxidative stress indicators can be used in the diagnosis of anxiety disorders and as new treatment targets.

Multifunctional role of dietary copper to regulate stress-responsive gene for mitigation of multiple stresses in Pangasianodon hypophthalmus

It is an urgent needs to address climate change and pollution in aquatic systems using suitable mitigation measures to avoid the aquatic animals' extinction. The vulnerability and extinction of the aquatic animals in the current scenario must be addressed to enhance safe fish food production. Taking into consideration of such issues in fisheries and aquaculture, an experiment was designed to mitigate high temperature (T) and low pH stress, as well as arsenic (As) pollution in fish using copper (Cu) containing diets. In the present investigation, the Cu-containing diets graded with 0, 4, 8, and 12 mg kg-1 were prepared and fed to Pangasianodon hypophthalmus reared under As, low pH, and high-temperature stress. The gene expression was highly affected in terms of the primary, secondary, and tertiary stress response, whereas supplementation of Cu-containing diet mitigates the stress response. Oxidative stress genes such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly upregulated by stressors (As, As + T, and As + pH + T). Whereas, heat shock protein (HSP 70), inducible nitric oxide synthase (iNOS), metallothionine (MT), caspase 3a (Cas 3a), and cytochrome P450 (CYP 450) were highly upregulated by stressors, while dietary Cu at 8 mg kg-1 diet significantly downregulated these gene expressions. Indeed, the immunity-related genes viz. TNFα, Ig, TLR, and immune-related attributes viz. albumin, globulin, total protein, A:G ratio, blood glucose, NBT, and myeloperoxidase (MPO) were also improved with Cu-containing diets. Cu containing diets substantially improved neurotransmitter enzyme (AChE) and vitamin C (Vit C). DNA damage was also reduced with supplementation of Cu at 8 mg kg-1 diet. The growth index viz. final body weight gain (%), specific growth rate, protein efficiency ratio, food conversion ratio, relative feed intake, and daily growth index were noticeably enhanced by Cu diets (4 and 8 mg kg-1 diet). The growth-related genes expressions viz. growth hormone (GH), growth hormone regulator 1 (Ghr1), growth hormone regulator β (Ghrβ,) myostatin (MYST), and somatostatin (SMT) supported the growth enhancement with Cu at 8 mg kg-1 diet. The bioaccumulation of As was reduced with Cu-containing diets. The fish were infected with Aeromonas hydrophila at the end of the 105 days experimental trial. Cu at 8 mg kg-1 diet improved immunity, reduced the cumulative mortality, and enhanced the relative percentage survival of the fish. The results revealed that the innovative Cu diets could reduce the extinction of the fish against climate change and pollution era and produce the safest production that is safe to humans for consumption.

Using Redox Proteomics to Gain New Insights into Neurodegenerative Disease and Protein Modification

Antioxidant defenses in biological systems ensure redox homeostasis, regulating baseline levels of reactive oxygen and nitrogen species (ROS and RNS). Oxidative stress (OS), characterized by a lack of antioxidant defenses or an elevation in ROS and RNS, may cause a modification of biomolecules, ROS being primarily absorbed by proteins. As a result of both genome and environment interactions, proteomics provides complete information about a cell's proteome, which changes continuously. Besides measuring protein expression levels, proteomics can also be used to identify protein modifications, localizations, the effects of added agents, and the interactions between proteins. Several oxidative processes are frequently used to modify proteins post-translationally, including carbonylation, oxidation of amino acid side chains, glycation, or lipid peroxidation, which produces highly reactive alkenals. Reactive alkenals, such as 4-hydroxy-2-nonenal, are added to cysteine (Cys), lysine (Lys), or histidine (His) residues by a Michael addition, and tyrosine (Tyr) residues are nitrated and Cys residues are nitrosylated by a Michael addition. Oxidative and nitrosative stress have been implicated in many neurodegenerative diseases as a result of oxidative damage to the brain, which may be especially vulnerable due to the large consumption of dioxygen. Therefore, the current methods applied for the detection, identification, and quantification in redox proteomics are of great interest. This review describes the main protein modifications classified as chemical reactions. Finally, we discuss the importance of redox proteomics to health and describe the analytical methods used in redox proteomics.

Influence of Long-Term Anti-Seizure Medications on Redox Parameters in Human Blood

BACKGROUND

Epilepsy is a chronic brain disease affecting millions of people worldwide, but little is known about the impact of anti-seizure medications on redox homeostasis.

METHODS

This study aimed to compare the effects of the long-term use of oral anti-seizure medications in monotherapy (lamotrigine, carbamazepine, and valproate) on antioxidant enzymes: superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, haemoglobin, and methaemoglobin content in erythrocytes, and concentrations of total proteins and thiols, nitrites, lipid peroxides and total glutathione in the plasma of epilepsy patients and drug-naïve patients.

RESULTS

The results showed that lamotrigine therapy led to lower superoxide dismutase activity (p < 0.005) and lower concentrations of total thiols (p < 0.01) and lipid peroxides (p < 0.01) compared to controls. On the other hand, therapy with carbamazepine increased nitrite levels (p < 0.01) but reduced superoxide dismutase activity (p < 0.005). In the valproate group, only a decrease in catalase activity was observed (p < 0.005). Canonical discriminant analysis showed that the composition of antioxidant enzymes in erythrocytes was different for both the lamotrigine and carbamazepine groups, while the controls were separated from all others.

CONCLUSIONS

Monotherapy with anti-seizure medications discretely alters redox homeostasis, followed by distinct relationships between antioxidant components.

Understanding mechanisms of antioxidant action in health and disease

Several different reactive oxygen species (ROS) are generated in vivo. They have roles in the development of certain human diseases whilst also performing physiological functions. ROS are counterbalanced by an antioxidant defence network, which functions to modulate ROS levels to allow their physiological roles whilst minimizing the oxidative damage they cause that can contribute to disease development. This Review describes the mechanisms of action of antioxidants synthesized in vivo, antioxidants derived from the human diet and synthetic antioxidants developed as therapeutic agents, with a focus on the gaps in our current knowledge and the approaches needed to close them. The Review also explores the reasons behind the successes and failures of antioxidants in treating or preventing human disease. Antioxidants may have special roles in the gastrointestinal tract, and many lifestyle features known to promote health (especially diet, exercise and the control of blood glucose and cholesterol levels) may be acting, at least in part, by antioxidant mechanisms. Certain reactive sulfur species may be important antioxidants but more accurate determinations of their concentrations in vivo are needed to help assess their contributions.

Exploring the Efficient Natural Products for the Therapy of Parkinson's Disease via Drosophila Melanogaster (Fruit Fly) Models

Parkinson's disease (PD) is a severe neurodegenerative disorder, partly attributed to mutations, environmental toxins, oxidative stress, abnormal protein aggregation, and mitochondrial dysfunction. However, the precise pathogenesis of PD and its treatment strategy still require investigation. Fortunately, natural products have demonstrated potential as therapeutic agents for alleviating PD symptoms due to their neuroprotective properties. To identify promising lead compounds from herbal medicines' natural products for PD management and understand their modes of action, suitable animal models are necessary. Drosophila melanogaster (fruit fly) serves as an essential model for studying genetic and cellular pathways in complex biological processes. Diverse Drosophila PD models have been extensively utilized in PD research, particularly for discovering neuroprotective natural products. This review emphasizes the research progress of natural products in PD using the fruit fly PD model, offering valuable insights into utilizing invertebrate models for developing novel anti-PD drugs.

Exposure to the environmentally relevant fungicide Maneb: Studying toxicity in the soil nematode Caenorhabditis elegans

Maneb is a manganese-containing ethylene bisdithiocarbamate fungicide and is still commonly used as no cases of resistance have been documented. However, studies have shown that Maneb exposure has neurodegenerative potential in mammals, resulting in symptoms affecting the motor system. Despite its extensive use, structural elucidation of Maneb has only recently been accomplished by our group. This study aimed to examine the bioavailability of Maneb, the quantification of oxidative stress-related endpoints and neurotransmitters employing pure Maneb, its metabolites and structural analogues, in the model organism Caenorhabditis elegans. Exposure to Maneb did not increase the bioavailability of Mn compared to manganese chloride, although Maneb was about 8 times more toxic with regard to lethality. Maneb generated not significantly reactive oxygen and nitrogen species (RONS) but decreased the ATP level while increasing the amount of glutathione and its oxidized form in a dose-dependent manner. Nevertheless, an alteration in the neurotransmitter homeostasis of dopamine, acetylcholine, and gamma-butyric acid (GABA) was observed as well as morphological changes in the dopaminergic neurons upon Maneb exposure, which underlines the assumption of the neurotoxic potential of Maneb. This study showed that Maneb exhibits effects based on a combined interaction of the ligand and manganese.

Lipid Carrier Nanostructured Astilbin Ameliorates Rotenone-Induced Neurodegeneration in Mice Brain via Modulation of GSK3β-Nrf2 Signaling Pathways

Astilbin is a flavanonol, found in St John's wort (Hypericum perforatum) and many other plants. It has been demonstrated that astilbin contains anti-inflammatory, antioxidant, and immune-suppressive properties. However, the bioavailability of astilbin remains a question for which drug delivery-based nanoparticles can be utilized. We formulated a nanostructured lipid carrier loaded with astilbin (NLC-AS) and tested its effects on the rotenone exposed PC12 cells and in a neurodegenerative mice model of Parkinson's disease (PD) induced by rotenone. Results show that rotenone caused dose-dependent inhibition of PC12 cell growth with about 50% cell death at 2 µM rotenone. Rotenone caused apoptosis in PC12 cells which was reduced to a notable level by NLC-AS through suppression of oxidative stress, especially via elevation of GSH and total antioxidant capacity, and inhibition of monoamine oxidase. Rotenone significantly augmented neurodegeneration in mouse brains by triggering apoptosis and oxidative damage, while NLC-AS treatment halted these processes. Rotenone-exposed mice showed neuronal deficits and impaired neurocognitive functions like loss of memory and learning restrictions which were restored to a remarkable level by NLC-AS administration. The protective effect of NLC-AS was mediated through the inhibition of GSK3β and induction of Nrf2 genes in the brain tissues. These findings suggest that NLC-AS administration may efficiently regulate the signs of PD in mice and prevent neurodegeneration and neurocognitive dysfunctions.

Neuroprotective responses of quercetin in regulation of biochemical, structural, and neurobehavioral effects in 28-day oral exposure of iron in rats

BACKGROUND

Iron is one of the essential metals that functions as a cofactor in various biological cascades in the brain. However, excessive iron accumulation in the brain may lead to neurodegeneration and may show toxic effects. Quercetin, a pigment flavonoid compound, has been proven to be a potent antioxidant and anti-inflammatory that can inhibit lipid peroxidation during metal-induced neurotoxicity. Although iron-induced neuroinflammation and neurodegeneration have been reported in many studies, but the proof for its exact mechanisms needs to be explored.

PURPOSE

The key target of the study was to explore the neuroprotective effect of quercetin after oral exposure of iron in rats and explore its underlying molecular mechanisms.

RESULTS

The outcomes of the study have shown that oral exposure to ferrous sulfate may modulate behavioral paradigms such as locomotor activity, neuromuscular coordination, and increased anxiety level. The pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), apoptotic protein (caspase 3), beta-amyloid and phosphorylated tau were found to be increased on iron exposure. Also, the expressions of ferritin heavy and light chain, BACE-1 and GFAP expressions were altered. These behavioral, structural, and biochemical alterations in the brain were significantly and dose-dependently reversed by treatment with quercetin.

CONCLUSION

The current study provides a fundamental understanding of molecular signaling pathways, and structural proteins implicated in iron-induced neurotoxicity along with the ameliorative effects of quercetin.

Ginsenoside RK1 improves cognitive impairments and pathological changes in Alzheimer's disease via stimulation of the AMPK/Nrf2 signaling pathway

BACKGROUND

The pathogenesis of Alzheimer's disease (AD) is complex, resulting in unsatisfactory effects of single-target therapeutic drugs. Accumulation evidence suggests that low toxicity multi-target drugs may play effective roles in AD. Ginseng is the root and rhizome of Panax ginseng Meyer, which can be used not only as herbal medicine but also as a functional food to support body functions. Ginsenoside RK1 (RK1), obtained from ginseng plants through high-temperature treatment, has antiapoptotic, antioxidant, anti-inflammatory effects and these events are involved in the development of AD. So, we believe that RK1 may be an effective drug for the treatment of AD.

HYPOTHESIS/PURPOSE

We aimed to investigate the potential protective effects and mechanisms of RK1 in AD.

METHODS

Neuronal damage was detected by MTT assay, LDH assay, immunofluorescence and western blotting. Oxidative stress was measured by JC-1 staining, reactive oxygen species (ROS) staining, superoxide dismutase (SOD) and malonaldehyde (MDA). The cognitive deficit was measured through morris water maze (MWM) and novel object recognition (NOR) tests.

RESULTS

RK1 attenuated Aβ-induced apoptosis, restored mitochondrial membrane potential (ΔΨm), and reduced intracellular levels of ROS in both PC12 cells and primary cultured neurons. In vivo, RK1 significantly improved cognitive deficits and mitigated AD-like pathological features. Notably, RK1 demonstrated superior efficacy compared to the positive control drug, donepezil. Mechanistically, our study elucidates that RK1 modulates the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target, NF-E2-related factor 2 (Nrf2), leading to the optimization of mitochondrial membrane potential, reduction of ROS levels, and mitigation of AD-like pathology. It's noteworthy that blocking the AMPK signaling pathway attenuated the protective effects of RK1.

CONCLUSION

RK1 demonstrates superior efficacy in alleviating cognitive deficits and mitigating pathological changes compared to donepezil. These findings suggest the potential utility of RK1-based therapies in the development of treatments for AD.

Copper Tolerance of Novel Rhodotorula sp. Yeast Isolated from Gold Mining Ore in Gia Lai, Vietnam

In this study, twenty-five yeast strains were isolated from soil samples collected in the gold mining ore in Gia Lai, Vietnam. Among them, one isolate named GL1T could highly tolerate Cu2+ up to 10 mM, and the isolates could also grow in a wide range of pH (3-7), and temperature (10-40 °C). Dried biomass of GL1 was able to remove Cu2+ effectively up to 90.49% with a maximal biosorption capacity of 18.1 mg/g at pH 6, temperature 30 °C, and incubation time 60 min. Sequence analysis of rDNA indicated this strain was closely related to Rhodotorula mucilaginosa but with 1.53 and 3.46% nucleotide differences in the D1/D2 domain of the 28S rRNA gene and the ITS1-5.8S rRNA gene-ITS2 region sequence, respectively. Based on phylogenetic tree analysis and the biochemical characteristics, the strain appears to be a novel Rhodotorula species, and the name Rhodotorula aurum sp. nov. is proposed. This study provides us with more information about heavy metal-tolerant yeasts and it may produce a new tool for environmental control and metal recovery operations.

Molecular and Medical Aspects of Psychedelics

Psychedelics belong to the oldest psychoactive drugs. They arouse recent interest due to their therapeutic applications in the treatment of major depressive disorder, substance use disorder, end-of-life anxiety,= and anxiety symptoms, and obsessive-compulsive disorder. In this review, the current state of preclinical research on the mechanism of action, neurotoxicity, and behavioral impact of psychedelics is summarized. The effect of selective 5-HT2A receptor agonists, 25I- and 25B-NBOMe, after acute and repeated administration is characterized and compared with the effects of a less selective drug, psilocybin. The data show a significant effect of NBOMes on glutamatergic, dopaminergic, serotonergic, and cholinergic neurotransmission in the frontal cortex, striatum, and nucleus accumbens. The increases in extracellular levels of neurotransmitters were not dose-dependent, which most likely resulted from the stimulation of the 5-HT2A receptor and subsequent activation of the 5-HT2C receptors. This effect was also observed in the wet dog shake test and locomotor activity. Chronic administration of NBOMes elicited rapid development of tolerance, genotoxicity, and activation of microglia. Acute treatment with psilocybin affected monoaminergic and aminoacidic neurotransmitters in the frontal cortex, nucleus accumbens, and hippocampus but not in the amygdala. Psilocybin exhibited anxiolytic properties resulting from intensification of GABAergic neurotransmission. The data indicate that NBOMes as selective 5-HT2A agonists exert a significant effect on neurotransmission and behavior of rats while also inducing oxidative DNA damage. In contrast to NBOMes, the effects induced by psilocybin suggest a broader therapeutic index of this drug.

The Role of Retinal Ganglion Cell Structure and Function in Glaucoma

Glaucoma, a leading cause of irreversible blindness globally, primarily affects retinal ganglion cells (RGCs). This review dives into the anatomy of RGC subtypes, covering the different underlying theoretical mechanisms that lead to RGC susceptibility in glaucoma, including mechanical, vascular, excitotoxicity, and neurotrophic factor deficiency, as well as oxidative stress and inflammation. Furthermore, we examined numerous imaging methods and functional assessments to gain insight into RGC health. Finally, we investigated the current possible neuroprotective targets for RGCs that could help with future glaucoma research and management.

Biomimetic nanoparticles in ischemic stroke therapy

Abstract

Ischemic stroke is one of the most severe neurological disorders with limited therapeutic strategies. The utilization of nanoparticle drug delivery systems is a burgeoning field and has been widely investigated. Among these, biomimetic drug delivery systems composed of biogenic membrane components and synthetic nanoparticles have been extensively highlighted in recent years. Biomimetic membrane camouflage presents an effective strategy to prolong circulation, reduce immunogenicity and enhance targeting. For one thing, biomimetic nanoparticles reserve the physical and chemical properties of intrinsic nanoparticle. For another, the biological functions of original source cells are completely inherited. Compared to conventional surface modification methods, this approach is more convenient and biocompatible. In this review, membrane-based nanoparticles derived from different donor cells were exemplified. The prospect of future biomimetic nanoparticles in ischemic stroke therapy was discussed.

Graphic abstract

Hallucinogenic activity, neurotransmitters release, anxiolytic and neurotoxic effects in Rat's brain following repeated administration of novel psychoactive compound 25B-NBOMe

2-(4-Bromo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)etanoamine (25B-NBOMe) is a highly selective 5-HT2A receptor agonist, exhibiting a potent hallucinogenic activity. In the present study, we investigated the effect of a 7-day treatment with 25B-NBOMe in a dose of 0.3 mg/kg on the following: the neurotransmitter release in vivo using microdialysis in freely moving animals, hallucinogenic activity measured in the Wet Dog Shake (WDS) test, anxiety level as measured in the light/dark box (LDB) and locomotor activity in the open field (OF) test, DNA damage with the comet assay, and on a number of neuronal and glial cells with immunohistochemistry. Repeated administration of 25B-NBOMe decreased the response to a challenge dose (0.3 mg/kg) on DA, 5-HT and glutamatergic neurons in the rats' frontal cortex, striatum, and nucleus accumbens. The WDS response dropped drastically after the second day of treatment, suggesting a rapid development of tolerance. LDB and OF tests showed that the effect of 25B-NBOMe on anxiety depends on the treatment and environmental settings. Results obtained with the comet assay indicate a genotoxic properties in the frontal cortex and hippocampus. An increase in immunopositive glial but not neuronal cells was observed in the cortical regions but not in the hippocampus. In conclusion, our study showed that a chronic administration of 25B-NBOMe produces the development of tolerance observed in the neurotransmitters release and hallucinogenic activity. The oxidative damage of cortical and hippocampal DNA implies the generation of free radicals by the drug, resulting in genotoxicity but rather not in neurotoxic tissue damage. Behavioral tests show that 25B-NBOMe exerts anxiogenic effect after single and repeated treatment.

Exercise to prevent the negative effects of sleep deprivation: A systematic review and meta-analysis

Ample sleep is an important basis for maintaining health, however with the pace of life accelerating in modern society, more people are using sacrificial sleep to cope with these social changes. Sleep deprivation can have negative effects on cognitive performance and psychosomatic health. It is well known that exercise, as a beneficial intervention strategy for human health, has been increasingly used in the clinic. But it's not clear if it can prevent the negative effects of sleep deprivation. In this meta-analysis, we reviewed 23 articles from PubMed and Web of Science to investigate whether moderate physical exercise can prevent the negative effects of sleep deprivation in rodents. Our findings suggest that exercise can prevent sleep deprivation-induced cognitive impairment and anxiety-like behaviors through multiple pathways. We also discuss possible molecular mechanisms involved in this protective effect, highlighting the potential of exercise as a preventive or therapeutic strategy for sleep deprivation-induced negative effects.

Healthy Human Fecal Microbiota Transplantation into Mice Attenuates MPTP-Induced Neurotoxicity via AMPK/SOD2 Pathway

Increasing evidence has shown that gut dysbacteriosis may play a crucial role in neuroinflammation in Parkinson's disease (PD). However, the specific mechanisms that link gut microbiota to PD remain unexplored. Given the critical roles of blood-brain barrier (BBB) dysfunction and mitochondrial dysfunction in the development of PD, we aimed to evaluate the interactions among the gut microbiota, BBB, and mitochondrial resistance to oxidation and inflammation in PD. We investigated the effects of fecal microbiota transplantation (FMT) on the physiopathology of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. The aim was to explore the role of fecal microbiota from PD patients and healthy human controls in neuroinflammation, BBB components, and mitochondrial antioxidative capacity via the AMPK/SOD2 pathway. Compared to control mice, MPTP-treated mice exhibited elevated levels of Desulfovibrio, whereas mice given FMT from PD patients exhibited enriched levels of Akkermansia and mice given FMT from healthy humans showed no significant alterations in gut microbiota. Strikingly, FMT from PD patients to MPTP-treated mice significantly aggravated motor impairments, dopaminergic neurodegeneration, nigrostriatal glial activation and colonic inflammation, and inhibited the AMPK/SOD2 signaling pathway. However, FMT from healthy human controls greatly improved the aforementioned MPTP-caused effects. Surprisingly, the MPTP-treated mice displayed a significant loss in nigrostriatal pericytes, which was restored by FMT from healthy human controls. Our findings demonstrate that FMT from healthy human controls can correct gut dysbacteriosis and ameliorate neurodegeneration in the MPTP-induced PD mouse model by suppressing microgliosis and astrogliosis, ameliorating mitochondrial impairments via the AMPK/SOD2 pathway, and restoring the loss of nigrostriatal pericytes and BBB integrity. These findings raise the possibility that the alteration in the human gut microbiota may be a risk factor for PD and provide evidence for potential application of FMT in PD preclinical treatment.

Mitochondrial Dysfunction in Skeletal Muscle of Rotenone-Induced Rat Model of Parkinson's Disease: SC-Nanophytosomes as Therapeutic Approach

The development of new therapeutic options for Parkinson's disease (PD) requires formulations able to mitigate both brain degeneration and motor dysfunctions. SC-Nanophytosomes, an oral mitochondria-targeted formulation developed with Codium tomentosum membrane polar lipids and elderberry anthocyanin-enriched extract, promote significant brain benefits on a rotenone-induced rat model of PD. In the present work, the effects of SC-Nanophytosome treatment on the skeletal muscle tissues are disclosed. It is unveiled that the rotenone-induced PD rat model exhibits motor disabilities and skeletal muscle tissues with deficient activity of mitochondrial complexes I and II along with small changes in antioxidant enzyme activity and skeletal muscle lipidome. SC-Nanophytosome treatment mitigates the impairment of complexes I and II activity, improving the mitochondrial respiratory chain performance at levels that surpass the control. Therefore, SC-Nanophytosome competence to overcome the PD-related motor disabilities should be also associated with its positive outcomes on skeletal muscle mitochondria. Providing a cellular environment with more reduced redox potential, SC-Nanophytosome treatment improves the skeletal muscle tissue's ability to deal with oxidative stress stimuli. The PD-related small changes on skeletal muscle lipidome were also counteracted by SC-Nanophytosome treatment. Thus, the present results reinforces the concept of SC-Nanophytosomes as a mitochondria-targeted therapy to address the neurodegeneration challenge.

Simultaneous, Real-Time Detection of Glutamate and Dopamine in Rat Striatum Using Fast-Scan Cyclic Voltammetry

Glutamate and dopamine (DA) represent two key contributors to striatal functioning, a region of the brain that is essential to motor coordination and motivated behavior. While electroanalytical techniques can be utilized for rapid, spatially resolved detection of DA in the interferent-rich brain environment, glutamate, a nonelectroactive analyte, cannot be directly detected using electroanalytical techniques. However, it can be probed using enzyme-based sensors, which generate an electroactive reporter in the presence of glutamate. The vast majority of glutamate biosensors have relied on amperometric sensing, which is an inherently nonselective detection technique. This approach necessitates the use of complex and performance-limiting modifications to ensure the desired single-analyte specificity. Here, we present a novel glutamate microbiosensor fabricated on a carbon-fiber microelectrode substrate and coupled with fast-scan cyclic voltammetry (FSCV) to enable the simultaneous quantification of glutamate and DA at single recording sites in the brain, which is impossible when using typical amperometric approaches. The glutamate microbiosensors were characterized for sensitivity, stability, and selectivity by using a voltammetric waveform optimized for the simultaneous detection of both species. The applicability of these sensors for the investigation of neural circuits was validated in the rat ventral striatum. Electrically evoked glutamate and DA release were recorded at single-micrometer-scale locations before and after pharmacological manipulation of glutamatergic signaling. Our novel glutamate microbiosensor advances the state of the art by providing a powerful tool for probing coordination between these two species in a way that has previously not been possible.

Iron and atherosclerosis: Lessons learned from rabbits relevant to human disease

The role of iron in promoting atherosclerosis, and hence the cardiovascular, neurodegenerative and other diseases that result from atherosclerosis, has been fiercely controversial. Many studies have been carried out on various rodent models of atherosclerosis, especially on apoE-knockout (apoE-/-) mice, which develop atherosclerosis more readily than normal mice. These apoE-/- mouse studies generally support a role for iron in atherosclerosis development, although there are conflicting results. The purpose of the current article is to describe studies on another animal model that is not genetically manipulated; New Zealand White (NZW) rabbits fed a high-cholesterol diet. This may be a better model than the apoE-/- mice for human atherosclerosis, although it has been given much less attention. Studies on NZW rabbits support the view that iron promotes atherosclerosis, although some uncertainties remain, which need to be resolved by further experimentation.

The Ethanolic Extract of Lycium ruthenicum Ameliorates Age-Related Physiological Damage in Mice

Aging and age-related diseases are important study topics due to their associations with progressive physiological damage to genes, cells, tissues, and the entire organism, which ultimately affects the functional efficiency of organs. Lycium ruthenicum Murr. is a functional food that is known for its high contents of anthocyanins and spermidines, both of which have been demonstrated to have positive effects on anti-aging activity and anti-oxidation. In this study, we used HPLC-MS to analyze the constituents of L. ruthenicum Murr. Extract (LRM) and investigated their potential mechanism for exerting antioxidative effects in D-galactose (D-Gal) aging model mice. LRM (25 mg/kg, 50 mg/kg, and 100 mg/kg) improved cognitive function in D-Gal-treated mice, as shown by reduced escape latencies and increased platform crossings in behavioral tests. We measured the contents of lipid peroxidation (LPO) and malondialdehyde (MDA) and the enzyme activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in mice serum and brain after 6 weeks of D-Gal treatment. LRM decreased the contents of LPO and MDA and increased the enzyme activities of SOD and GSH-Px, indicating the protection effect of LRM against D-Gal-induced oxidative stress. Additionally, LRM can inhibit oxidative stress in cells by reducing intracellular ROS levels and restoring mitochondrial membrane potential, thereby inhibiting paraquat (PQ)-induced cellular senescence and delaying cell aging. Therefore, LRM has the potential to be a healthcare product for the treatment of age-related diseases.

Dietary phytochemical index and psychological disorders in a large sample of Iranian adults: a population-based study

BACKGROUND

Intake of plant foods and phytochemicals can decrease the odds of mental health.

AIM

The aim of study is to investigate the association between Dietary Phytochemical Index (DPI) with symptoms of depression, anxiety and stress in a large sample of Iranian adults.

METHODS

In this cross-sectional study, a total of 7385 adults aged 20-50 years old were provided from the recruitment phase of Yazd Health Study, a population-based cohort research on Iranian adults. Food intakes were assessed via a validated and reliable food frequency questionnaire. Symptoms of depression, anxiety and stress were assessed using a validated Depression, Anxiety and Stress Scales questionnaire with 21-items. DPI was calculated by the percent of daily energy intake taken from phytochemical-rich foods.

RESULTS

After adjustment for potential confounders, normal weight subjects in the highest tertile of DPI had lower odds of depression (OR 0.65; 95% CI 0.44-0.97) and anxiety symptoms (OR 0.65; 95% CI 0.45-0.93) compared with those in the lowest tertile. However, the apparent association was not found between depression, anxiety and stress in overweight and obese subjects.

CONCLUSION

We found a significant association between DPI and mental health in normal weight adults. Prospective studies are required to approve these conclusions.

50 shades of oxidative stress: A state-specific cysteine redox pattern hypothesis

Oxidative stress is biochemically complex. Like primary colours, specific reactive oxygen species (ROS) and antioxidant inputs can be mixed to create unique "shades" of oxidative stress. Even a minimal redox module comprised of just 12 (ROS & antioxidant) inputs and 3 outputs (oxidative damage, cysteine-dependent redox-regulation, or both) yields over half a million "shades" of oxidative stress. The present paper proposes the novel hypothesis that: state-specific shades of oxidative stress, such as a discrete disease, are associated with distinct tell-tale cysteine oxidation patterns. The patterns are encoded by many parameters, from the identity of the oxidised proteins, the cysteine oxidation type, and magnitude. The hypothesis is conceptually grounded in distinct ROS and antioxidant inputs coalescing to produce unique cysteine oxidation outputs. And considers the potential biological significance of the holistic cysteine oxidation outputs. The literature supports the existence of state-specific cysteine oxidation patterns. Measuring and manipulating these patterns offer promising avenues for advancing oxidative stress research. The pattern inspired hypothesis provides a framework for understanding the complex biochemical nature of state-specific oxidative stress.

Plasma oxylipin profiling by high resolution mass spectrometry reveal signatures of inflammation and hypermetabolism in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of motor neurons, systemic hypermetabolism, and inflammation. In this context, oxylipins have been investigated as signaling molecules linked to neurodegeneration, although their specific role in ALS remains unclear. Importantly, most methods focused on oxylipin analysis are based on low-resolution mass spectrometry, which usually confers high sensitivity, but not great accuracy for molecular characterization, as provided by high-resolution MS (HRMS). Here, we established an ultra-high performance liquid chromatography HRMS (LC-HRMS) method for simultaneous analysis of 126 oxylipins in plasma. Intra- and inter-day method validation showed high sensitivity (0.3-25 pg), accuracy and precision for more than 90% of quality controls. This method was applied in plasma of ALS rats overexpressing the mutant human Cu/Zn-superoxide dismutase gene (SOD1-G93A) at asymptomatic (ALS 70 days old) and symptomatic stages (ALS 120 days old), and their respective age-matched wild type controls. From the 56 oxylipins identified in plasma, 17 species were significantly altered. Remarkably, most of oxylipins linked to inflammation and oxidative stress derived from arachidonic acid (AA), like prostaglandins and mono-hydroxides, were increased in ALS 120 d rats. In addition, ketones derived from AA and linoleic acid (LA) were increased in both WT 120 d and ALS 120 d groups, supporting that age also modulates oxylipin metabolism in plasma. Interestingly, the LA-derived diols involved in fatty acid uptake and β-oxidation, 9(10)-DiHOME and 12(13)-DiHOME, were decreased in ALS 120 d rats and showed significant synergic effects between age and disease factors. In summary, we validated a high-throughput LC-HRMS method for oxylipin analysis and provided a comprehensive overview of plasma oxylipins involved in ALS disease progression. Noteworthy, the oxylipins altered in plasma have potential to be investigated as biomarkers for inflammation and hypermetabolism in ALS.

Phycocyanin improved alcohol-induced hepatorenal toxicity and behavior impairment in Wistar rats

The aim of this study was to investigate a potential preventive effect of phycocyanin extract from Spirulina platensis against ethanol- induced hepatorenal toxicity and cognitive behavior impairment in male Wistar rats. The animals were randomly and equally divided into four groups (six animals each): control group received saline solution, ethanol (EtOH) group was injected intraperitoneally with 1 ml/kg of ethanol solution 38% (w/v), phycocyanin groups were treated with 25 (PC1) or 50 (PC2) mg/kg phycocyanin extract followed by ethanol administration. All treatments were conducted for 14 successive days. Results revealed that ethanol induced oxidative stress in brain, liver, and kidney by increasing lipid peroxidation level and SOD and CAT activities. Serum biochemical perturbations were also observed in EtOH group, which was indicated by a significant elevation in ALT, AST, cholesterol, triglycerides, creatinine, and urea levels. Combined exposure to EtOH with phytocyanin contracted these biochemical alterations. Phycocyanin decreased also EtOH-induced anxiety and ameliorated exploratory behavior assessed by the elevated-plus maze and open field tests respectively.

Relationship of depression with empathy, emotional intelligence, and symptoms of a weakened immune system

Introduction

Previous studies have used different individual scales to examine the relationship of depression with emotional intelligence, empathy, and immune-based diseases. In this study, we used a combination of psychometric scales to examine the relationships of depression with emotional intelligence (intrapersonal and interpersonal), empathy (affective and cognitive), and symptoms of weakened immune system.

Methods

This cross-sectional prospective study examined 158 volunteers (39 males and 119 females). A score of 10 or more on the Beck Depression Inventory-II (BDI-II) was used to define depression. The Cognitive and Affective Empathy Test (TECA) was used to assess empathy, and the Profile of Emotional Competence (PEC) was used to assess the self-perception of intrapersonal and interpersonal competence. The symptoms of a weakened immune system (WIS) were assessed by measurements of permanent tiredness, frequent infections and colds, slow wound healing, persistent and recurrent diarrhea, recurring herpes, insomnia and difficulty sleeping, and dry eyes.

Results

The total PEC score and intrapersonal PEC score had negative correlations with depression, and the WIS score had a positive correlation with depression. The TECA score had no significant correlation with depression or the WIS score, but had positive correlations with the total PEC score, intrapersonal PEC score, and interpersonal PEC score.

Conclusion

The total PEC score, intrapersonal PEC score, and WIS score were significantly associated with depression. The TECA score was not significantly associated with depression or the WIS score. Our findings suggest that improving intrapersonal emotional skills may improve function of the immune system and reduce the symptoms of depression. We suggest that further studies examine the effect of targeted improvement of interpersonal skills (empathy) on depression.