Association of Oxidative Stress with Neurological Disorders

Fluoxetine attenuates chlorpyrifos-induced neuronal injury through the PPARγ, SIRT1, NF-κB, and JAK1/STAT3 signals

Chlorpyrifos (CPF) is a widely used organophosphate insecticide in agriculture and homes. Exposure to organophosphates is associated with neurotoxicity. Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRI) that is widely prescribed for depression and anxiety disorders. Studies have shown that FLX has neuroprotective, anti-inflammatory, antioxidant, and antiapoptotic effects. The molecular mechanisms underlying FLX are not fully understood. This work aimed to investigate the potential neuroprotective effect of FLX on CPF-induced neurotoxicity and the underlying molecular mechanisms involved. Thirty-two rats were randomly divided into four groups: (I) the vehicle control group; (II) the FLX-treated group (10 mg/kg/day for 28 days, p.o); (III) the CPF-treated group (10 mg/kg for 28 days); and (IV) the FLX+CPF group. FLX attenuated CPF-induced neuronal injury, as evidenced by a significant decrease in Aβ and p-Tau levels and attenuation of cerebral and hippocampal histological abrasion injury induced by CPF. FLX ameliorated neuronal oxidative stress, effectively reduced MDA production, and restored SOD and GSH levels through the coactivation of the PPARγ and SIRT1 proteins. FLX counteracted the neuronal inflammation induced by CPF by decreasing MPO, NO, TNF-α, IL-1β, and IL-6 levels by suppressing NF-κB and JAK1/STAT3 activation. The antioxidant and anti-inflammatory properties of FLX help to prevent CPF-induced neuronal intoxication.

The combined effects of preservative chemicals in consumer products: An analysis using embryonic and adult zebrafish

Benzisothiazolinone (BIT) and propyl paraben (PP) are preservatives in cleaning products; however, their toxicities are not well understood. In this study, zebrafish embryos were exposed to BIT, PP, and mixtures of both for 96 h to investigate the effects on growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the transcription of 19 genes related to the GH/IGFs axis. Concentrations of BIT and PP were measured in the whole body of larvae. Zebrafish pairs were also exposed to BIT, PP, and mixtures for 21 d to evaluate the effects on sex hormones, histology in gonad, and transcription of 22 genes related to the hypothalamus-pituitary-gonad axis and vitellogenin. The mixtures had potentiation effects on development, reproduction, hormones, and gene transcripts than individual exposure. Larvae exposed to 229 μg L-1 BIT, 64.5 μg L-1 PP, and mixtures showed reduced growth. Decreased GH and IGF-1 levels were supported by gene regulation associated with the GH/IGFs axis. In larvae, reactive oxygen species, superoxide dismutase, catalase, and glutathione peroxidase levels were increased under all exposures. The gonadosomatic index in males and number of eggs decreased after mixture exposure. In females exposed to mixtures, the percentage of atretic follicle in ovary was significantly increased. The significant decrease in testosterone in males and significant decrease in 17β-estradiol in females exposed to mixtures suggest anti-estrogenic and anti-androgenic potential. Thus, preservative mixtures in consumer products may be more toxic than the individual substances, which is important for managing the risks of mixing preservatives.

Exploring molecular mechanisms, therapeutic strategies, and clinical manifestations of Huntington's disease

Huntington's disease (HD) is a paradigm of a genetic neurodegenerative disorder characterized by the expansion of CAG repeats in the HTT gene. This extensive review investigates the molecular complexities of HD by highlighting the pathogenic mechanisms initiated by the mutant huntingtin protein. Adverse outcomes of HD include mitochondrial dysfunction, compromised protein clearance, and disruption of intracellular signaling, consequently contributing to the gradual deterioration of neurons. Numerous therapeutic strategies, particularly precision medicine, are currently used for HD management. Antisense oligonucleotides, such as Tominersen, play a leading role in targeting and modulating the expression of mutant huntingtin. Despite the promise of these therapies, challenges persist, particularly in improving delivery systems and the necessity for long-term safety assessments. Considering the future landscape, the review delineates promising directions for HD research and treatment. Innovations such as Clustered regularly interspaced short palindromic repeats associated system therapies (CRISPR)-based genome editing and emerging neuroprotective approaches present unprecedented opportunities for intervention. Collaborative interdisciplinary endeavors and a more insightful understanding of HD pathogenesis are on the verge of reshaping the therapeutic landscape. As we navigate the intricate landscape of HD, this review serves as a guide for unraveling the intricacies of this disease and progressing toward transformative treatments.

A translocation fluorescent probe for analyzing cellular physiological parameters in neurological disease models

Neurological disorders are closely linked to the alterations in cell membrane permeability (CMP) and mitochondrial membrane potential (MMP). Changes in CMP and MMP may lead to damage and death of nerve cells, thus triggering the onset and progression of neurological diseases. Therefore, monitoring the changes of these two physiological parameters not only benefits the accurate assessment of nerve cell health status, but also enables providing key information for the diagnosis and treatment of neurological diseases. However, the simultaneous monitoring of these two cellular physiological parameters is still challenging. Herein, we design and synthesize two quinolinium-carbazole-derivated fluorescent probes (OQ and PQ). As isomers, the only difference in their chemical structures is the linking position of the carbazole unit in quinoline rings. Strikingly, such a subtle difference endows OQ and PQ with significantly different organelle-staining behaviors. PQ mainly targets at the nucleus, OQ can simultaneously stain cell membranes and mitochondria in normal cells, and performs CMP and MMP-dependent translocation from the cell membrane to mitochondria then to the nucleus, thus holding great promise as an intracellular translocation probe to image the changes of CMP and MMP. After unraveling the intrinsic mechanism of their different translocation abilities by combining experiments with molecular dynamics simulations and density functional theory calculations, we successfully used OQ to monitor the continuous changes of CMP and MMP in three neurological disease-related cell models, including oxidative stress-damaged, Parkinson's disease, and virus-infected ones. Besides providing a validated imaging tool for monitoring cellular physiological parameters, this work paves a promising route for designing intracellular translocation probes to analyze cellular physiological parameters associated with various diseases.

The Chemical Reactivity of Membrane Lipids

It is well-known that aqueous dispersions of phospholipids spontaneously assemble into bilayer structures. These structures have numerous applications across chemistry and materials science and form the fundamental structural unit of the biological membrane. The particular environment of the lipid bilayer, with a water-poor low dielectric core surrounded by a more polar and better hydrated interfacial region, gives the membrane particular biophysical and physicochemical properties and presents a unique environment for chemical reactions to occur. Many different types of molecule spanning a range of sizes, from dissolved gases through small organics to proteins, are able to interact with membranes and promote chemical changes to lipids that subsequently affect the physicochemical properties of the bilayer. This Review describes the chemical reactivity exhibited by lipids in their membrane form, with an emphasis on conditions where the lipids are well hydrated in the form of bilayers. Key topics include the following: lytic reactions of glyceryl esters, including hydrolysis, aminolysis, and transesterification; oxidation reactions of alkenes in unsaturated fatty acids and sterols, including autoxidation and oxidation by singlet oxygen; reactivity of headgroups, particularly with reactive carbonyl species; and E/Z isomerization of alkenes. The consequences of reactivity for biological activity and biophysical properties are also discussed.

[Recent research on the role of oxidative stress in the pathogenesis of attention deficit hyperactivity disorder]

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children and adolescents, and its etiology and pathogenesis are still unclear. Brain is the organ with the largest oxygen consumption in human body and is easily affected by oxidative imbalance. Oxidative stress has become the key research direction for the pathogenesis of ADHD, but there is still a lack of relevant studies in China. Based on the latest research findings in China and overseas, this article reviews the clinical and experimental studies on oxidative stress in ADHD and explores the association of oxidative stress with neurotransmitter imbalance, neuroinflammation, and cell apoptosis in the pathogenesis of ADHD, so as to provide new research ideas for exploring the pathogenesis of ADHD.

Selenium- and/or Zinc-Enriched Egg Diet Improves Oxidative Damage and Regulates Gut Microbiota in D-Gal-Induced Aging Mice

Eggs, with their high nutritional value, are great carriers for enriching nutrients. In this study, selenium- and/or zinc-enriched eggs (SZE) were obtained and their effects on ameliorating oxidative stress injury, alleviating cognitive impairment, and maintaining intestinal flora balance in a D-gal-induced aging mice model were investigated. As determined by the Y-maze test, SZE restored the learning and memory abilities and increased the Ach level and AChE activity of aging mice (p < 0.05). Meanwhile, supplementation of low-dose SZE increased antioxidant levels and decreased inflammation levels (p < 0.05). High-dose SZE increased anti-inflammatory levels but were less effective than low dose. Additionally, SZE maintained the intestinal flora balance and significantly increased the ratio of Firmicutes and Bacteroidota. Blautia, as a probiotic, was negatively correlated with pro-inflammatory factors and positively correlated with antioxidant levels (p < 0.05). These results suggest that SZE might improve organ damage and cognitive function by attenuating oxidative stress and inflammatory response and maintaining healthy gut flora.

UBL3 Interaction with α-Synuclein Is Downregulated by Silencing MGST3

Ubiquitin-like 3 (UBL3) is a membrane-anchored protein that plays a crucial role in sorting proteins into small extracellular vesicles. Aggregations of alpha-synuclein (α-syn) are associated with the pathology of neurodegenerative diseases such as Parkinson's disease. Recently, the interaction between UBL3 and α-syn was discovered, with potential implications in clearing excess α-syn from neurons and its role in disease spread. However, the regulator that can mediate the interaction between UBL3 and α-syn remains unclear. In this study, using the split gaussian luciferase complementation assay and RNA interference technology, we identified that QSOX2, HTATIP2, UBE3C, MGST3, NSF, HECTD1, SAE1, and ATG3 were involved in downregulating the interaction between UBL3 and α-syn. Notably, silencing MGST3 had the most significant impact. Immunocytochemistry staining confirmed the impact of MGST3 silencing on the co-localization of UBL3 and α-syn in cells. MGST3 is a part of the antioxidant system, and silencing MGST3 is believed to contribute to oxidative stress. We induced oxidative stress with hydrogen peroxide, observing its effect on the UBL3-α-syn interaction, and showing that 800 µM of H2O2 downregulated this interaction. In conclusion, silencing MGST3 downregulates the interaction between UBL3 and α-syn.

Mitigation of behavioral deficits and cognitive impairment by antioxidant and neuromodulatory potential of Mukia madrespatana in D-galactose treated rats

Plants and their parts have been extensively used for the therapeutic purposes such as aging due to their powerful antioxidative belongings. Presently, we intended to examine the consequence of fruit peel of Mukia madrespatana (M.M) on D-galactose (D-Gal) persuaded anxiety and/or depression profile, cognition and serotonin metabolism in rats. Animals were divided in to 4 groups (n = 6). (i) Water treated (ii) D-Gal treated (iii) M.M. treated (iv) D-Gal + M.M. treated. All the animals received their respective treatment for 4 weeks. D-Gal and M.M. fruit peel were given to animals with oral gavage with doses 300 mg/ml/kg/day and 2 g/kg/day respectively. After 4 weeks' behavioral analysis performed to evaluate anxiety and depression profile, cognitive function of animals. After that animals were sacrificed and whole brain removed for biochemical (redox status, degradative enzyme of acetylcholine), and neurochemical (serotonin metabolism) analysis. Results showed that administration of M.M. inhibited D-Gal-instigated anxious and depressive behaviors and improved cognition. Treatment of M.M. decreased MDA levels, AChE activity and increased antioxidant enzyme activity in D-Gal administered and control rats. Enhanced serotonin metabolism also decreased by M.M. in control and D-Gal administered rats. In conclusion, M.M. fruit peel has powerful antioxidative and neuromodulatory properties and due to this effect, it may be a good source of mitigation/treatment for aging induced behavioral and cognitive impairment.

The regulatory role of PI3K in ageing-related diseases

Ageing is a physiological/pathological process accompanied by the progressive damage of cell function, triggering various ageing-related disorders. Phosphatidylinositol 3-kinase (PI3K), which serves as one of the central regulators of ageing, is closely associated with cellular characteristics or molecular features, such as genome instability, telomere erosion, epigenetic alterations, and mitochondrial dysfunction. In this review, the PI3K signalling pathway was firstly thoroughly explained. The link between ageing pathogenesis and the PI3K signalling pathway was then summarized. Finally, the key regulatory roles of PI3K in ageing-related illnesses were investigated and stressed. In summary, we revealed that drug development and clinical application targeting PI3K is one of the focal points for delaying ageing and treating ageing-related diseases in the future.

Myricetin attenuates hypoxic-ischemic brain damage in neonatal rats via NRF2 signaling pathway

Introduction: Hypoxic-ischemic encephalopathy (HIE) is a crucial cause of neonatal death and neurological sequelae, but currently there is no effective therapy drug for HIE. Both oxidative stress and apoptosis play critical roles in the pathological development of HIE. Myricetin, a naturally extracted flavonol compound, exerts remarkable effects against oxidative stress, apoptosis, and inflammation. However, the role and underlying molecular mechanism of myricetin on HIE remain unclear. Methods: In this study, we established the neonatal rats hypoxic-ischemic (HI) brain damage model in vivo and CoCl₂ induced PC1₂ cell model in vitro to explore the neuroprotective effects of myricetin on HI injury, and illuminate the potential mechanism. Results: Our results showed that myricetin intervention could significantly reduce brain infarction volume, glia activation, apoptosis, and oxidative stress marker levels through activating NRF2 (Nuclear factor-E2-related factor 2) and increase the expressions of NRF2 downstream proteins NQO-1 and HO-1. In addition, the NRF2 inhibitor ML385 could significantly reverse the effects of myricetin. Conclusion: This study found that myricetin might alleviate oxidative stress and apoptosis through NRF2 signaling pathway to exert the protective role for HI injury, which suggested that myricetin might be a promising therapeutic agent for HIE.

Th17 cells and inflammation in neurological disorders: Possible mechanisms of action

Neurological disorders (NDs) are one of the leading causes of global death. A sustained neuroinflammatory response has been reported to be associated with the pathogenesis of multiple NDs, including Parkinson’s disease (PD), multiple sclerosis (MS), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), and major depressive disorder (MDD). Accumulating evidence shows that the recruitment of abundant lymphocytes in the central nervous system may contribute to promoting the development and progress of inflammation in neurological disorders. As one subset of T lymphocytes, CD4⁺ T cells have a critical impact on the inflammation of neurological disorders. T helper (Th) 17 is one of the most studied CD4⁺ Th subpopulations that produces cytokines (e.g., IL-17A, IL-23, IL-21, IL-6, and IFN-γ), leading to the abnormal neuroinflammatory response including the excessive activation of microglia and the recruitment of other immune cell types. All these factors are involved in several neurological disorders. However, the possible mechanisms of Th17 cells and their associated cytokines in the immunopathology of the abovementioned neurological disorders have not been clarified completely. This review will summarize the mechanisms by which encephalitogenic inflammatory Th17 cells and their related cytokines strongly contribute to chronic neuroinflammation, thus perpetuating neurodegenerative processes in NDs. Finally, the potential therapeutic prospects of Th17 cells and their cytokines in NDs will also be discussed.

Hibiscus, Rooibos, and Yerba Mate for Healthy Aging: A Review on the Attenuation of In Vitro and In Vivo Markers Related to Oxidative Stress, Glycoxidation, and Neurodegeneration

The world is currently undergoing a demographic change towards an increasing number of elderly citizens. Aging is characterized by a temporal decline in physiological capacity, and oxidative stress is a hallmark of aging and age-related disorders. Such an oxidative state is linked to a decrease in the effective mechanisms of cellular repair, the incidence of post-translational protein glycation, mitochondrial dysfunction, and neurodegeneration, just to name some of the markers contributing to the establishment of age-related reduction-oxidation, or redox, imbalance. Currently, there are no prescribed therapies to control oxidative stress; however, there are strategies to elevate antioxidant defenses and overcome related health challenges based on the adoption of nutritional therapies. It is well known that herbal teas such, as hibiscus, rooibos, and yerba mate, are important sources of antioxidants, able to prevent some oxidation-related stresses. These plants produce several bioactive metabolites, have a pleasant taste, and a long-lasting history as safe foods. This paper reviews the literature on hibiscus, rooibos, and yerba mate teas in the context of nutritional strategies for the attenuation of oxidative stress-related glycoxidation and neurodegeneration, and, here, Alzheimer’s Disease is approached as an example. The focus is given to mechanisms of glycation inhibition, as well as neuroprotective in vitro effects, and, in animal studies, to frame interest in these plants as nutraceutical agents related to current health concerns.

Efficacy and Safety of Q10 Ubiquinol With Vitamins B and E in Neurodevelopmental Disorders: A Retrospective Chart Review

Increased oxidative stress and defective mitochondrial functioning are shared features among many brain disorders. The aim of this study was to verify retrospectively the clinical efficacy and safety of a metabolic support therapy with Q10 ubiquinol, vitamin E and complex-B vitamins in various neurodevelopmental disorders. This retrospective chart review study included 59 patients (mean age 10.1 ± 1.2 y.o., range 2.5-39 years; M:F = 2.47:1), diagnosed with Autism Spectrum Disorder (n = 17), Autism Spectrum Disorder with co-morbid Intellectual Disability (n = 19), Intellectual Disability or Global Developmental Delay (n = 15), Attention-Deficit/Hyperactivity Disorder (n = 3) and Intellectual Disability in Phelan-McDermid syndrome due to chr. 22q13.33 deletion (n = 5). After a minimum of 3 months of therapy, a positive outcome was recorded in 45/59 (76.27%) patients, with Clinical Global Impression-Improvement scores ranging between 1 ("very much improved") and 3 ("minimally improved"). The most widespread improvements were recorded in cognition (n = 26, 44.1%), adaptative functioning (n = 26, 44.1%) and social motivation (n = 19, 32.2%). Improvement rates differed by diagnosis, being observed most consistently in Phelan-McDermid Syndrome (5/5, 100%), followed by Intellectual Disability/Global Developmental Delay (13/15, 86.7%), Autism Spectrum Disorder with co-morbid Intellectual Disability (15/19, 78.9%), Autism Spectrum Disorder (11/17, 64.7%) and ADHD (1/3, 33.3%). No significant adverse event or side effect leading to treatment discontinuation were recorded. Mild side effects were reported in 18 (30.5%) patients, with the most frequent being increased hyperactivity (9/59, 15.3%). This retrospective chart review suggests that metabolic support therapy with Q10 ubiquinol, vitamin E and complex-B vitamins is well tolerated and produces some improvement in the majority of patients with neurodevelopmental disorders, especially in the presence of intellectual disability. Randomized controlled trials for each single neurodevelopmental disorder are now warranted to conclusively demonstrate the efficacy of these mitochondrial bioenergetic and antioxidant agents and to estimate their therapeutic effect size.