Thiol redox homeostasis in neurodegenerative disease

The Role of One-Carbon Metabolism and Methyl Donors in Medically Assisted Reproduction: A Narrative Review of the Literature

One-carbon (1-C) metabolic deficiency impairs homeostasis, driving disease development, including infertility. It is of importance to summarize the current evidence regarding the clinical utility of 1-C metabolism-related biomolecules and methyl donors, namely, folate, betaine, choline, vitamin B12, homocysteine (Hcy), and zinc, as potential biomarkers, dietary supplements, and culture media supplements in the context of medically assisted reproduction (MAR). A narrative review of the literature was conducted in the PubMed/Medline database. Diet, ageing, and the endocrine milieu of individuals affect both 1-C metabolism and fertility status. In vitro fertilization (IVF) techniques, and culture conditions in particular, have a direct impact on 1-C metabolic activity in gametes and embryos. Critical analysis indicated that zinc supplementation in cryopreservation media may be a promising approach to reducing oxidative damage, while female serum homocysteine levels may be employed as a possible biomarker for predicting IVF outcomes. Nonetheless, the level of evidence is low, and future studies are needed to verify these data. One-carbon metabolism-related processes, including redox defense and epigenetic regulation, may be compromised in IVF-derived embryos. The study of 1-C metabolism may lead the way towards improving MAR efficiency and safety and ensuring the lifelong health of MAR infants.

The Role of Glutathione in Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is a chronic disease that usually develops in older people. Pathogenetic changes in this disease include anatomical and functional complexes. Harmful factors damage the retina and macula. These changes may lead to partial or total loss of vision. The disease can occur in two clinical forms: dry (the progression is slow and gentle) and exudative (wet-progression is acute and severe), which usually starts in the dry form; however, the coexistence of both forms is possible. The etiology of AMD is not fully understood, and the precise mechanisms of the development of this illness are still unknown. Extensive genetic studies have shown that AMD is a multi-factorial disease and that genetic determinants, along with external and internal environmental and metabolic-functional factors, are important risk factors. This article reviews the role of glutathione (GSH) enzymes engaged in maintaining the reduced form and polymorphism in glutathione S-transferase theta-1 (GSTT1) and glutathione S-transferase mu-1 (GSTM1) in the development of AMD. We only chose papers that confirmed the influence of the parameters on the development of AMD. Because GSH is the most important antioxidant in the eye, it is important to know the influence of the enzymes and genetic background to ensure an optimal level of glutathione concentration. Numerous studies have been conducted on how the glutathione system works till today. This paper presents the current state of knowledge about the changes in GSH, GST, GR, and GPx in AMD. GST studies clearly show increased activity in ill people, but for GPx, the results relating to activity are not so clear. Depending on the research, the results also suggest higher and lower GPx activity in patients with AMD. The analysis of polymorphisms in GST genes confirmed that mutations lead to weaker antioxidant barriers and may contribute to the development of AMD; unfortunately, a meta-analysis and some research did not confirm that connection. Unspecific results of many of the parameters that make up the glutathione system show many unknowns. It is so important to conduct further research to understand the exact mechanism of defense functions of glutathione against oxidative stress in the human eye.

Finding biomarkers of experience in animals

At a time when there is a growing public interest in animal welfare, it is critical to have objective means to assess the way that an animal experiences a situation. Objectivity is critical to ensure appropriate animal welfare outcomes. Existing behavioural, physiological, and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes. But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal, from negative to positive. In this review, we draw from the knowledge of human biomedical science to propose a list of candidate biological markers (biomarkers) that should reflect the experiential state of non-human animals. The proposed biomarkers can be classified on their main function as endocrine, oxidative stress, non-coding molecular, and thermobiological markers. We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.

The Immunomodulatory Effects of A2 β-Casein on Immunosuppressed Mice by Regulating Immune Responses and the Gut Microbiota

The aim of this study was to investigate the immunomodulatory effects of A2 β-casein (β-CN) in cyclophosphamide-induced immunosuppressed BALB/c mice. Experiments conducted in vitro revealed that A2 β-CN digestive products have potent immunostimulatory activities. Animal studies demonstrated that A2 β-CN improved the immunological organ index reduction trend caused by cyclophosphamide, reduced the pathological damage to the spleen tissue in immunosuppressed mice, increased the release of IL-17A, IgG, and IgA, and reduced the production of IL-4. By regulating the relative abundance of advantageous bacteria like Oscillospira, Lactobacillus, and Bifidobacteria and harmful bacteria like Coprococcus and Desulfovibrionaceae, A2 β-CN improved gut microbiota disorders in immunosuppressed mice. Moreover, A2 β-CN promoted the production of short-chain fatty acids and increased the diversity of the gut microbiota. Therefore, ingestion of A2 β-CN is beneficial to the host's immune system and gut health. These findings provide insights for the future application of A2 β-CN-related dairy products.

Next-Generation Femtech: Urine-Based Cervical Cancer Diagnosis Using a Fluorescent Biothiol Probe with Controlled Smiles Rearrangement

Cervical cancer screening is a crucial field of femtech (female technology). In this work, we disclosed a new femtech solution─a simple, straightforward, and on-site applicable urine-based cervical cancer diagnostic method using a fluorescent biothiol probe. Our newly developed nitrobenzene-based fluorescent probe, named NPS-B, effectively differentiates between cysteine and homocysteine within urine samples via controlled Smiles rearrangement. The analysis of emission-based signals offers the potential utility of this method in cervical cancer. NPS-B was designed by considering the substitution effect and structural polarity of the nitrobenzene-based fluorophore. This controlled modification of nitrobenzene-induced substantial intramolecular charge transfer changes in the fluorophore when exposed to biothiols, resulting in significant changes in photophysical properties. NPS-B displayed different emissions of cysteine and homocysteine in clinical human urine (without prior urine treatment). Overall, our findings provide insights not only into fundamental chemical science but also into the broader domain of applied sciences.

Oxidant and antioxidant balance in children with bacteremia

BACKGROUND

There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream infection.

METHODS

We analyzed prospectively oxidant and antioxidant stress parameters from serum samples of children with BSI besides demographic and clinical data of children. Serum levels of the total antioxidant status (TAS), total oxidant status (TOS), albumin, plasma thiol, disulphide, catalase (CAT), myeloperoxidase (MPO), ischemia-modified albumin (IMA) levels, ferroxidase and arylesterase (ARES) activity were evaluated in both patients and healthy controls.

RESULTS

A total of 113 children were evaluated, 50 of them had bacteremia and the remaining 63 were healthy subjects. The median TOS values were 18.5 µmol H2O2/L and 13.1 µmol H2O2/L in patient and control groups, respectively with a statistically significant difference between groups. The mean serum IMA levels were 0.8±0.1 absorbance unit (ABSU) in patients and 0.5±0.09 ABSU in control, the difference between groups was statistically significant. The native thiol, total thiol levels and the disulphide levels were significantly lower in the patient group as compared with the control group. The myeloperoxidase level was 136 U/L in patients and 107 in controls with a statistically significant difference between groups.

CONCLUSIONS

TOS, IMA, MPO, and particularly plasma thiols seem good candidates for accurate diagnosis of bacteremia in children.

Thiol-disulphide homeostasis, ischemia-modified albumin, complete blood count-derived inflammatory markers and C-reactive protein from acute mania to early remission in bipolar disorder

OBJECTIVES

There is much recent evidence that inflammation contributes to the pathophysiology of acute mania in bipolar disorder (BD). However, no study was evaluated in which the change in thiol-disulphide homeostasis, ischemia-modified albumin (IMA), complete blood count-derived inflammatory markers (CBC-IMs) and C-reactive protein (CRP) levels in bipolar patients was followed-up from acute mania to early remission.

METHODS

Seventy-seven bipolar patients in acute mania and ninety-one HC were enrolled. We measured levels of thiol-disulphide parameters, IMA, and CBC-IMs such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), red-cell-distribution-width (RDW)-to-platelet ratio (RPR), systemic immune-inflammatory index (SII), and systemic inflammatory response index (SIRI), CRP and platelet-to-albumin ratio (PAR), after adjusting for age, gender, body-mass index (BMI) and smoking status, during acute mania to subsequent early remission. The results were compared with HC.

RESULTS

The levels or ratios of all thiol-disulphide parameters except for disulphide, IMA and CRP of bipolar patients in both acute mania and early remission were significantly different from HC, after adjusting for confounders. The NLR, SII, CRP and PAR values of bipolar patients were significantly higher in only acute mania compared to HC. Significant changes in thiol-disulphide parameters and IMA levels were not found in early remission after acute mania.

LIMITATIONS

Short follow-up period and lack of drug-naive patients.

CONCLUSIONS

Our results suggest that thiol-disulphide parameters, IMA level and SIRI value might be a trait biomarkers of inflammation in BD. In addition, NLR, SII and PAR values and CRP level might be a state biomarker of inflammation in bipolar patients in a manic phase.

Oxytocin as neuro-hormone and neuro-regulator exert neuroprotective properties: A mechanistic graphical review

BACKGROUND

Neurodegeneration is progressive cell loss in specific neuronal populations, often resulting in clinical consequences with significant medical, societal, and economic implications. Because of its antioxidant, anti-inflammatory, and anti-apoptotic properties, oxytocin has been proposed as a potential neuroprotective and neurobehavioral therapeutic agent, including modulating mood disturbances and cognitive enchantment.

METHODS

Literature searches were conducted using the following databases Web of Science, PubMed, Elsevier Science Direct, Google Scholar, the Core Collection, and Cochrane from January 2000 to February 2023 for articles dealing with oxytocin neuroprotective properties in preventing or treating neurodegenerative disorders and diseases with a focus on oxidative stress, inflammation, and apoptosis/cell death.

RESULTS

The neuroprotective effects of oxytocin appears to be mediated by its anti-inflammatory properties, inhibition of neuro inflammation, activation of several antioxidant enzymes, inhibition of oxidative stress and free radical formation, activation of free radical scavengers, prevent of mitochondrial dysfunction, and inhibition of apoptosis.

CONCLUSION

Oxytocin acts as a neuroprotective agent by preventing neuro-apoptosis, neuro-inflammation, and neuronal oxidative stress, and by restoring mitochondrial function.

Research Progress of SERS Sensors Based on Hydrogen Peroxide and Related Substances

Hydrogen peroxide (H2O2) has an important role in living organisms, and its detection is of great importance in medical, chemical, and food safety applications. This review provides a comparison of different types of Surface-enhanced Raman scattering (SERS) sensors for H2O2 and related substances with respect to their detection limits, which are of interest due to high sensitivity compared to conventional sensors. According to the latest research report, this review focuses on the sensing mechanism of different sensors and summarizes the linear range, detection limits, and cellular applications of new SERS sensors, and discusses the limitations in vivo and future prospects of SERS technology for the detection of H2O2.

The role of hydrogen sulfide in the retina

The discovery of the hydrogen sulfide (H2S) and the transsulfuration pathway (TSP) responsible for its synthesis in the mammalian retina has highlighted this molecule's wide range of physiological processes that influence cellular signaling, redox homeostasis, and cellular metabolism. The multi-level regulatory program that influences H2S levels in the retina depends on the relative expression and activity of TSP enzymes, which regulate the abundance of competitive substrates that support or abrogate H2S synthesis. In addition, and apart from TSP, intracellular H2S levels are regulated by mitochondrial sulfide oxidizing pathways. Retinal layers natively express differing levels of TSP enzymes, which highlight the differences in the metabolite and substrate requirement. Recent studies indicate that these systems are susceptible to pathophysiologies affecting the retina. Dysregulation at any level can upset the balance of redox and signaling processes and possibly upset oxidative stress, apoptotic signaling, ion channels, and immune response within this sensitive tissue. H2S donors are a potential therapeutic in such cases and have been demonstrated to bridge the gap, positively impacting the damaged retina. Here, we review the recent findings of H2S, how its multi-level regulation impacts the retina, and how its dysregulation is implicated in retinal pathologies.

Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability, thus adversely affecting locomotion ability and life quality. Consequently, good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA. Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging. Herein, we review the fluorescent probes developed for the detection and imaging of RA biomarkers, namely reactive oxygen/nitrogen species (hypochlorous acid, peroxynitrite, hydroxyl radical, nitroxyl), pH, and cysteine, and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

The mitochondrial calcium uniporter (MCU) activates mitochondrial respiration and enhances mobility by regulating mitochondrial redox state

Regulation of mitochondrial redox balance is emerging as a key event for cell signaling in both physiological and pathological conditions. However, the link between the mitochondrial redox state and the modulation of these conditions remains poorly defined. Here, we discovered that activation of the evolutionary conserved mitochondrial calcium uniporter (MCU) modulates mitochondrial redox state. By using mitochondria-targeted redox and calcium sensors and genetic MCU-ablated models, we provide evidence of the causality between MCU activation and net reduction of mitochondrial (but not cytosolic) redox state. Redox modulation of redox-sensitive groups via MCU stimulation is required for maintaining respiratory capacity in primary human myotubes and C. elegans, and boosts mobility in worms. The same benefits are obtained bypassing MCU via direct pharmacological reduction of mitochondrial proteins. Collectively, our results demonstrate that MCU regulates mitochondria redox balance and that this process is required to promote the MCU-dependent effects on mitochondrial respiration and mobility.

Increased Cerebral Serum Amyloid A2 and Parameters of Oxidation in Arylsulfatase B (N-Acetylgalactosamine-4-Sulfatase)-Null Mice

Background

Chondroitin sulfate and chondroitin sulfate proteoglycans have been associated with Alzheimer's disease (AD), and the impact of modified chondroitin sulfates is being investigated in several animal and cell-based models of AD. Published reports have shown the role of accumulation of chondroitin 4-sulfate and decline in Arylsulfatase B (ARSB; B-acetylgalactosamine-4-sulfatase) in other pathology, including nerve injury, traumatic brain injury, and spinal cord injury. However, the impact of ARSB deficiency on AD pathobiology has not been reported, although changes in ARSB were associated with AD in two prior reports. The enzyme ARSB removes 4-sulfate groups from the non-reducing end of chondroitin 4-sulfate and dermatan sulfate and is required for their degradation. When ARSB activity declines, these sulfated glycosaminoglycans accumulate, as in the inherited disorder Mucopolysaccharidosis VI.

Objective

Reports about chondroitin sulfate, chondroitin sulfate proteoglycans, and chondroitin sulfatases in AD were reviewed.

Methods

Measurements of SAA2, iNOS, lipid peroxidation, chondroitin sulfate proteoglycan 4 (CSPG4), and other parameters were performed in cortex and hippocampus from ARSB-null mice and controls by QRT-PCR, ELISA, and other standard assays.

Results

SAA2 mRNA expression and protein, CSPG4 mRNA, chondroitin 4-sulfate, and iNOS were increased significantly in ARSB-null mice. Measures of lipid peroxidation and redox state were significantly modified.

Conclusion

Findings indicate that decline in ARSB leads to changes in expression of parameters associated with AD in the hippocampus and cortex of the ARSB-deficient mouse. Further investigation of the impact of decline in ARSB on the development of AD may provide a new approach to prevent and treat AD.

Glucose Transporter Glut1-Dependent Metabolic Reprogramming Regulates Lipopolysaccharide-Induced Inflammation in RAW264.7 Macrophages

This study investigated the critical role of Glut1-mediated glucose metabolism in the inflammatory response of macrophages, which are energy-intensive cells within the innate immune system. Inflammation leads to increased Glut1 expression, ensuring sufficient glucose uptake to support macrophage functions. We demonstrated that using siRNA to knock down Glut1 reduces the expression of various pro-inflammatory cytokines and markers, such as IL-6, iNOS, MHC II/CD40, reactive oxygen species, and the hydrogen sulfide (H₂S)-producing enzyme cystathionine γ-lyase (CSE). Glut1 activates a pro-inflammatory profile through a nuclear factor (NF)-κB, while silencing Glut1 can prevent lipopolysaccharide (LPS)-induced IκB degradation, blocking NF-κB activation. Glut1's role in autophagy, an essential process for macrophage functions such as antigen presentation, phagocytosis, and cytokine secretion, was also measured. The findings show that LPS stimulation decreases autophagosome formation, but Glut1 knockdown reverses this effect, increasing autophagy beyond control levels. The study highlights Glut1's importance in macrophage immune responses and its regulation of apoptosis during LPS stimulation. Knocking down Glut1 negatively impacts cell viability and mitochondrial intrinsic pathway signaling. These findings collectively suggest that targeting macrophage glucose metabolism through Glut1 could potentially serve as a target for controlling inflammation.

Critical Roles of the Cysteine-Glutathione Axis in the Production of γ-Glutamyl Peptides in the Nervous System

γ-Glutamyl moiety that is attached to the cysteine (Cys) residue in glutathione (GSH) protects it from peptidase-mediated degradation. The sulfhydryl group of the Cys residue represents most of the functions of GSH, which include electron donation to peroxidases, protection of reactive sulfhydryl in proteins via glutaredoxin, and glutathione conjugation of xenobiotics, whereas Cys-derived sulfur is also a pivotal component of some redox-responsive molecules. The amount of Cys that is available tends to restrict the capacity of GSH synthesis. In in vitro systems, cystine is the major form in the extracellular milieu, and a specific cystine transporter, xCT, is essential for survival in most lines of cells and in many primary cultivated cells as well. A reduction in the supply of Cys causes GPX4 to be inhibited due to insufficient GSH synthesis, which leads to iron-dependent necrotic cell death, ferroptosis. Cells generally cannot take up GSH without the removal of γ-glutamyl moiety by γ-glutamyl transferase (GGT) on the cell surface. Meanwhile, the Cys-GSH axis is essentially common to certain types of cells; primarily, neuronal cells that contain a unique metabolic system for intercellular communication concerning γ-glutamyl peptides. After a general description of metabolic processes concerning the Cys-GSH axis, we provide an overview and discuss the significance of GSH-related compounds in the nervous system.

From Gasotransmitter to Immunomodulator: The Emerging Role of Hydrogen Sulfide in Macrophage Biology

Hydrogen sulfide (H₂S) has been increasingly recognized as a crucial inflammatory mediator in immune cells, particularly macrophages, due to its direct and indirect effects on cellular signaling, redox homeostasis, and energy metabolism. The intricate regulation of endogenous H₂S production and metabolism involves the coordination of transsulfuration pathway (TSP) enzymes and sulfide oxidizing enzymes, with TSP's role at the intersection of the methionine pathway and glutathione synthesis reactions. Additionally, H₂S oxidation mediated by sulfide quinone oxidoreductase (SQR) in mammalian cells may partially control cellular concentrations of this gasotransmitter to induce signaling. H₂S is hypothesized to signal through the posttranslational modification known as persulfidation, with recent research highlighting the significance of reactive polysulfides, a derivative of sulfide metabolism. Overall, sulfides have been identified as having promising therapeutic potential to alleviate proinflammatory macrophage phenotypes, which are linked to the exacerbation of disease outcomes in various inflammatory conditions. H₂S is now acknowledged to have a significant influence on cellular energy metabolism by affecting the redox environment, gene expression, and transcription factor activity, resulting in changes to both mitochondrial and cytosolic energy metabolism processes. This review covers recent discoveries pertaining to the involvement of H₂S in macrophage cellular energy metabolism and redox regulation, and the potential implications for the inflammatory response of these cells in the broader framework of inflammatory diseases.

Increased Cerebral Serum Amyloid A2 and Parameters of Oxidation in Arylsulfatase B (N-Acetylgalactosamine-4-Sulfatase)-Null Mice

Introduction

Chondroitin sulfate and chondroitin sulfate proteoglycans have been associated with Alzheimer's Disease (AD), and the impact of modified chondroitin sulfates is being investigated in several animal and cell-based models of AD. Published reports have shown the role of accumulation of chondroitin 4-sulfate and decline in Arylsulfatase B (ARSB; B-acetylgalactosamine-4-sulfatase) in other pathology, including nerve injury, traumatic brain injury, and spinal cord injury. However, the impact of ARSB deficiency on AD pathobiology has not been reported, although changes in ARSB were associated with AD in two prior reports. The enzyme ARSB removes 4-sulfate groups from the non-reducing end of chondroitin 4-sulfate and dermatan sulfate and is required for their degradation. When ARSB activity declines, these sulfated glycosaminoglycans accumulate, as in the inherited disorder Mucopolysaccharidosis VI.

Methods

Reports about chondroitin sulfate, chondroitin sulfate proteoglycans and chondroitin sulfatases in Alzheimer's Disease were reviewed. Measurements of SAA2, iNOS, lipid peroxidation, chondroitin sulfate proteoglycan 4, and other parameters were performed in cortex and hippocampus from ARSB-null mice and controls by QRT-PCR, ELISA, and other standard assays.

Results

SAA2 mRNA expression and protein, CSPG4 mRNA, chondroitin 4-sulfate and i-NOS were increased significantly in ARSB-null mice. Measures of lipid peroxidation and redox state were significantly modified.

Discussion

Findings indicate that decline in ARSB leads to changes in expression of parameters associated with AD in the hippocampus and cortex of the ARSB-deficient mouse.

Conclusions

Further investigation of the impact of decline in ARSB on the development of AD may provide a new approach to prevent and treat AD.

Redox Modulation of Mitochondrial Proteins in the Neurotoxicant Models of Parkinson's Disease

Significance: Mitochondrial proteins regulate the oxidative phosphorylation, cellular metabolism, and free radical generation. Redox modulation alters the mitochondrial proteins and instigates the damage to dopaminergic neurons. Toxicants contribute to Parkinson's disease (PD) pathogenesis in conjunction with aging and genetic factors. While oxidative modulation of a number of mitochondrial proteins is linked to xenobiotic exposure, little is known about its role in the toxicant-induced PD. Understanding the role of redox modulation of mitochondrial proteins in complex cellular events leading to neurodegeneration is highly relevant. Recent Advances: Many toxicants are shown to inhibit complex I or III and elicit free radical production that alters the redox status of mitochondrial proteins. Implication of redox modulation of the mitochondrial proteins makes them a target to comprehend the underlying mechanism of toxicant-induced PD. Critical Issues: Owing to multifactorial etiology, exploration of onset and progression and treatment outcomes needs a comprehensive approach. The article explains about a few mitochondrial proteins that undergo redox changes along with the promising strategies, which help to alleviate the toxicant-induced redox imbalance leading to neurodegeneration. Future Directions: Although mitochondrial proteins are linked to PD, their role in toxicant-induced parkinsonism is not yet completely known. Preservation of antioxidant defense machinery could alleviate the redox modulation of mitochondrial proteins. Targeted antioxidant delivery, use of metal chelators, and activation of nuclear factor erythroid 2-related factor 2, and combinational therapy that encounters multiple free radicals, could ameliorate the redox modulation of mitochondrial proteins and thereby PD progression.

Serum free thiols in recently diagnosed patients with schizophrenia spectrum disorder: A potentially useful biomarker of oxidative stress

Schizophrenia spectrum disorders (SSD) have been linked to oxidative stress (OS). Recent findings from our group show that serum free thiols (R-SH, sulfhydryl groups) can function as an accurate biomarker of systemic OS, since they are readily oxidized by reactive species (ROS), thereby serving as potent antioxidants. The aim of this study is to investigate if reduced R-SH levels can be demonstrated in recently diagnosed patients with SSD compared to healthy controls (HC). In this study, 102 patients with recently diagnosed SSD (< three years), and 42 HC were included. Levels of R-SH were quantified and studied for correlations with age, C-reactive protein (CRP) as proxy of inflammation as well as body mass index (BMI) and total cholesterol as indices of metabolic health. R-SH levels were significantly lower in patients when compared to HC. When correcting for age the difference was borderline significant (p=0.05). Moreover, R-SH correlated significantly with age (r = -0.29) and CRP (r = -0.29) in patients with SSD, but not in the HC. R-SH levels are reduced in SSD as compared to HC and correlate negatively with CRP and age in SSD. Future studies are required to further investigate R-SH and its role in SSD.

Molecular Genetics of Abnormal Redox Homeostasis in Type 2 Diabetes Mellitus

Numerous studies have shown that oxidative stress resulting from an imbalance between the production of free radicals and their neutralization by antioxidant enzymes is one of the major pathological disorders underlying the development and progression of type 2 diabetes (T2D). The present review summarizes the current state of the art advances in understanding the role of abnormal redox homeostasis in the molecular mechanisms of T2D and provides comprehensive information on the characteristics and biological functions of antioxidant and oxidative enzymes, as well as discusses genetic studies conducted so far in order to investigate the contribution of polymorphisms in genes encoding redox state-regulating enzymes to the disease pathogenesis.

A 'double locked' ratiometric fluorescent probe for detection of cysteine in a viscous system and its application in cancer cells

Intracellular viscosity is a physicochemical property that regulates the consequences of several biological progressions. Cysteine (Cys) is an important signaling molecule that commands many cellular activities, such as antioxidant generation. Predicting that both may be interconnected with a diversity of pathological processes, their contemporaneous measurement would be valuable for studying the pathological ailment of cells. Herein, we have synthesized a 'double locked' probe, acrylic acid 6-[4-(2-benzothiazol-2-yl-2-cyano-vinyl)-phenyl]-naphthalen-2-yl ester (ABN) for the detection of Cys in a viscous medium and explored its application to living cells that were exposed to dexamethasone to regulate the intracellular viscosity level. ABN displayed a satisfactory ratiometric (blue to orange) fluorescence response in solution and in living cells when Cys and viscosity coexisted. A turn-on fluorescence signal was visualized when the probe was individually treated with Cys and glycerol (a standard viscosity source). Therefore, we propose that ABN is a fluorescent probe that permits the monitoring of variations in intracellular viscosity and Cys levels in a biological environment, and it can be utilized in innumerable cellular damage models.

Behavioral and neurochemical impairments after intranasal administration of chlorpyrifos formulation in mice

Among the most relevant environmental factors associated with the etiology of neurodegenerative disorders are pesticides. Spray drift or volatilization generates pesticide dispersion after its application. In addition, inhalation or intranasal (IN) administration of xenobiotics constitutes a feasible route for substance delivery to the brain. This study investigates the behavioral and neurochemical effects of IN exposure to a commercial formulation of chlorpyrifos (fCPF). Adult male CF-1 mice were intranasally administered with fCPF (3-10 mg/kg/day) three days a week, for 2 weeks. Behavioral and biochemical analyses were conducted 20 and 30 days after the last IN fCPF administration, respectively. No significant behavioral or biochemical effects were observed in the 3 mg/kg fCPF IN exposure group. However, animals exposed to 10 mg/kg fCPF showed anxiogenic behavior and recognition memory impairment, with no effects on locomotor activity. In addition, the IN administration of 10 mg/kg fCPF altered the redox balance, modified the activity of enzymes belonging to the cholinergic and glutamatergic pathways, and affected glucose metabolism, and cholesterol levels in different brain areas. Taken together, these observations suggest that these biochemical imbalances could be responsible for the neurobehavioral disturbances observed after IN administration of fCPF in mice.

Metabolic Basis and Clinical Evidence for Skin Lightening Effects of Thiol Compounds

Melanin pigment is a major factor in determining the color of the skin, and its abnormal increase or decrease can cause serious pigmentation disorders. The melanin pigment of the skin is divided into light pheomelanin and dark eumelanin, and a big difference between them is whether they contain sulfur. Melanin synthesis starts from a common reaction in which tyrosine or dihydroxyphenylalanine (DOPA) is oxidized by tyrosinase (TYR) to produce dopaquinone (DQ). DQ is spontaneously converted to leukodopachrome and then oxidized to dopachrome, which enters the eumelanin synthesis pathway. When DQ reacts with cysteine, cysteinyl dopa is generated, which is oxidized to cysteinyl DQ and enters the pheomelanin synthesis pathway. Therefore, thiol compounds can influence the relative synthesis of eumelanin and pheomelanin. In addition, thiol compounds can inhibit enzymatic activity by binding to copper ions at the active site of TYR, and act as an antioxidant scavenging reactive oxygen species and free radicals or as a modulator of redox balance, thereby inhibiting overall melanin synthesis. This review will cover the metabolic aspects of thiol compounds, the role of thiol compounds in melanin synthesis, comparison of the antimelanogenic effects of various thiol compounds, and clinical trials on the skin lightening efficacy of thiol compounds. We hope that this review will help identify the advantages and disadvantages of various thiol compounds as modulators of skin pigmentation and contribute to the development of safer and more effective strategies for the treatment of pigmentation disorders.

A dual responsive fluorescent probe for selective detection of cysteine and bisulfite and its application in bioimaging

A coumarin-based dual responsive fluorescent probe with a simple structure was developed for the detection of Cys and HSO₃ ^-. Under simulated physiological conditions, Cou-F displayed an on-off fluorescence response to Cys at 521 nm and an off-on fluorescence response to HSO₃ ^- at 500 nm. Furthermore, Cou-F had the advantages of high sensitivity, strong specificity and rapid response. The detection limits of Cou-F toward Cys and HSO₃ ^- were 0.54 μM and 0.65 μM, respectively. Cou-F enabled high selective responses to Cys and HSO₃ ^- over other biologically related species. The response times of Cou-F toward Cys and HSO₃ ^- were 80 s and 100 s. The fluorescence imaging of Cys and HSO₃ ^- was achieved in living RAW246.7 cells.

Effects of Panthenol and N-Acetylcysteine on Changes in the Redox State of Brain Mitochondria under Oxidative Stress In Vitro

The glutathione system in the mitochondria of the brain plays an important role in maintaining the redox balance and thiol–disulfide homeostasis, whose violations are the important component of the biochemical shifts in neurodegenerative diseases. Mitochondrial dysfunction is known to be accompanied by the activation of free radical processes, changes in energy metabolism, and is involved in the induction of apoptotic signals. The formation of disulfide bonds is a leading factor in the folding and maintenance of the three-dimensional conformation of many specific proteins that selectively accumulate in brain structures during neurodegenerative pathology. In this study, we estimated brain mitochondria redox status and functioning during induction of oxidative damage in vitro. We have shown that the development of oxidative stress in vitro is accompanied by inhibition of energy metabolism in the brain mitochondria, a shift in the redox potential of the glutathione system to the oxidized side, and activation of S-glutathionylation of proteins. Moreover, we studied the effects of pantothenic acid derivatives—precursors of coenzyme A (CoA), primarily D-panthenol, that exhibit high neuroprotective activity in experimental models of neurodegeneration. Panthenol contributes to the significant restoration of the activity of enzymes of mitochondrial energy metabolism, normalization of the redox potential of the glutathione system, and a decrease in the level of S-glutathionylated proteins in brain mitochondria. The addition of succinate and glutathione precursor N-acetylcysteine enhances the protective effects of the drug.

Nanoparticle-based colorimetric sensors to detect neurodegenerative disease biomarkers

Neurodegenerative disorders (NDDs) are progressive, incurable health conditions that primarily affect brain cells, and result in loss of brain mass and impaired function. Current sensing technologies for NDD detection are limited by high cost, long sample preparation, and/or require skilled personnel. To overcome these limitations, optical sensors, specifically colorimetric sensors, have garnered increasing attention towards the development of a cost-effective, simple, and rapid alternative approach. In this review, we evaluate colorimetric sensing strategies of NDD biomarkers (e.g. proteins, neurotransmitters, bio-thiols, and sulfide), address the limitations and challenges of optical sensor technologies, and provide our outlook on the future of this field.

Can thiol-disulfide balance be an indicator of oxidative stress for hyperhidrosis?

BACKGROUND

Hyperhidrosis is responsible for various causes. The increased reactive oxygen radical production with insufficient antioxidant mechanism capacity may play a role in the etiopathogenesis of hyperhidrosis. It is probable to gather data about oxidative stress by detecting plasma thiol/disulfide ratio. The aim of this study was to determine whether thiol-disulfide balance changes in patients with hyperhidrosis.

METHODS

The files of patients who were diagnosed with hyperhidrosis in the dermatology outpatient clinic between 2015 and 2018 and whose native thiol, total thiol, and disulfide values were examined for any reason were examined.

RESULTS

Seventy-three patients were included in the study. 33 of the patients with hyperhidrosis were primary. Mean age; for primary hyperhidrosis patients (PHH) = 26.36 ± 7.61, primary hyperhidrosis (PHH) control group = 27.16 ± 7.94; secondary hyperhidrosis (SHH) patients = 47.88 ± 12.29, SHH control (45.40 ± 12.02). The native thiol values of PHH (469.93 ± 56.82 μmol/L) were higher than SHH (440.64 ± 62.72) (p = 0.024). However, as a result of thiol-disulfide comparison between hyperhidrosis patients (PHH and SHH) and control groups, disulfide levels increased (p = 0.04). In the PHH group, total thiol was measured as 512 ± 54.84 μmol/L, and SHH was measured as 484.11 ± 58.9 μmol/L, (p = 0.074).

CONCLUSION

Serum thiol levels in SHH increased more than PHH. As a result of thiol-disulfide comparison between hyperhidrosis patients and control groups, the balance shifted in favor of disulfide and oxidative side.

Duchenne's muscular dystrophy involves a defective transsulfuration pathway activity

Duchenne muscular dystrophy (DMD) is the most frequent X chromosome-linked disease caused by mutations in the gene encoding for dystrophin, leading to progressive and unstoppable degeneration of skeletal muscle tissues. Despite recent advances in the understanding of the molecular processes involved in the pathogenesis of DMD, there is still no cure. In this study, we aim at investigating the potential involvement of the transsulfuration pathway (TSP), and its by-end product namely hydrogen sulfide (H2S), in primary human myoblasts isolated from DMD donors and skeletal muscles of dystrophic (mdx) mice. In myoblasts of DMD donors, we demonstrate that the expression of key genes regulating the H2S production and TSP activity, including cystathionine γ lyase (CSE), cystathionine beta-synthase (CBS), 3 mercaptopyruvate sulfurtransferase (3-MST), cysteine dioxygenase (CDO), cysteine sulfonic acid decarboxylase (CSAD), glutathione synthase (GS) and γ -glutamylcysteine synthetase (γ-GCS) is reduced. Starting from these findings, using Nuclear Magnetic Resonance (NMR) and quantitative Polymerase Chain Reaction (qPCR) we show that the levels of TSP-related metabolites such as methionine, glycine, glutathione, glutamate and taurine, as well as the expression levels of the aforementioned TSP related genes, are significantly reduced in skeletal muscles of mdx mice compared to healthy controls, at both an early (7 weeks) and overt (17 weeks) stage of the disease. Importantly, the treatment with sodium hydrosulfide (NaHS), a commonly used H2S donor, fully recovers the impaired locomotor activity in both 7 and 17 old mdx mice. This is an effect attributable to the reduced expression of pro-inflammatory markers and restoration of autophagy in skeletal muscle tissues. In conclusion, our study uncovers a defective TSP pathway activity in DMD and highlights the role of H2S-donors for novel and safe adjuvant therapy to treat symptoms of DMD.

Glutathione: An Old and Small Molecule with Great Functions and New Applications in the Brain and in Alzheimer's Disease

Significance: Glutathione (GSH) represents the most abundant and the main antioxidant in the body with important functions in the brain related to Alzheimer's disease (AD). Recent Advances: Oxidative stress is one of the central mechanisms in AD. We and others have demonstrated the alteration of GSH levels in the AD brain, its important role in the detoxification of advanced glycation end-products and of acrolein, a by-product of lipid peroxidation. Recent in vivo studies found a decrease of GSH in several areas of the brain from control, mild cognitive impairment, and AD subjects, which are correlated with cognitive decline. Critical Issues: Several strategies were developed to restore its intracellular level with the l-cysteine prodrugs or the oral administration of γ-glutamylcysteine to prevent alterations observed in AD. To date, no benefit on GSH level or on oxidative biomarkers has been reported in clinical trials. Thus, it remains uncertain if GSH could be considered a potential preventive or therapeutic approach or a biomarker for AD. Future Directions: We address how GSH-coupled nanocarriers represent a promising approach for the functionalization of nanocarriers to overcome the blood/brain barrier (BBB) for the brain delivery of GSH while avoiding cellular toxicity. It is also important to address the presence of GSH in exosomes for its potential intercellular transfer or its shuttle across the BBB under certain conditions. Antioxid. Redox Signal. 35, 270-292.

Redox index of Cys-thiol residues of serum apolipoprotein E and its diagnostic potential

Background: The redox modulation of Cys-thiol participates in various pathophysiological processes. We explored the proper index for estimating the redox status of Cys-thiol of serum apolipoprotein E (apoE), named “redox-IDX-apoE,” which is necessary to understand the redox biology of age-related diseases.

Methods: The fractions of the reduced form (red-), reversible oxidized form (roxi-), and irreversibly oxidized form (oxi-) apoE in serum, obtained from the patients with no apparent disease (controls, n=192) and with atherosclerosis and type 2 diabetes (patients, n=16), were measured by a band-shift assay using a maleimide compound. Redox-IDX-apoE candidates were determined by calculating the values of these fractions and the total apoE concentration.

Results: Cys number of apoE significantly increased for the ratio of roxi-apoE to total-apoE (roxi/total) (E2/E3>E3/E3>E3/E4) but decreased for the ratios of red-apoE to roxi-apoE (red/roxi) and [red-apoE + oxi-apoE] to roxi-apoE ([red + oxi]/roxi) (E2/E3<E3/E3<E3/E4). Considering the subjects with apoE3/E3, these ratios were independent of age and sex. Roxi/total showed negative correlations with serum triglyceride (TG) and HbA1c levels, while both red/roxi and [red + oxi]/roxi showed significant positive correlations with them. However, red/roxi and [red + oxi]/roxi in patients were significantly lower than those in controls, although serum TG and HbA1c levels in the patients were significantly higher than those in controls.

Conclusion: The redox status of serum apoE-Cys-thiol is closely involved in the metabolism of TG-rich lipoproteins and glucose. The appropriate use of redox-IDX-apoE could be helpful in the diagnosis and prognosis of age-related diseases and in understanding the underlying mechanisms.

Thiol-based redox-active proteins as cardioprotective therapeutic agents in cardiovascular diseases

Thiol-based redox compounds, namely thioredoxins (Trxs), glutaredoxins (Grxs) and peroxiredoxins (Prxs), stand as a pivotal group of proteins involved in antioxidant processes and redox signaling. Glutaredoxins (Grxs) are considered as one of the major families of proteins involved in redox regulation by removal of S-glutathionylation and thereby reactivation of other enzymes with thiol-dependent activity. Grxs are also coupled to Trxs and Prxs recycling and thereby indirectly contribute to reactive oxygen species (ROS) detoxification. Peroxiredoxins (Prxs) are a ubiquitous family of peroxidases, which play an essential role in the detoxification of hydrogen peroxide, aliphatic and aromatic hydroperoxides, and peroxynitrite. The Trxs, Grxs and Prxs systems, which reversibly induce thiol modifications, regulate redox signaling involved in various biological events in the cardiovascular system. This review focuses on the current knowledge of the role of Trxs, Grxs and Prxs on cardiovascular pathologies and especially in cardiac hypertrophy, ischemia/reperfusion (I/R) injury and heart failure as well as in the presence of cardiovascular risk factors, such as hypertension, hyperlipidemia, hyperglycemia and metabolic syndrome. Further studies on the roles of thiol-dependent redox systems in the cardiovascular system will support the development of novel protective and therapeutic strategies against cardiovascular diseases.

A cysteine-selective fluorescent probe for monitoring stress response cysteine fluctuations

Rare studies provided evidence for the real-time monitoring of stress response cysteine fluctuations. Here, we have successfully designed and synthesized a cysteine-selective fluorescent probe 1 to monitor stress response Cys fluctuations, providing visual evidence of Hg2+ regulated cysteine fluctuations for the first time, which may open a new way to help researchers to reveal the mechanism of heavy metal ion poisoning.

Natural Molecules Targeting Thioredoxin System and Their Therapeutic Potential

Significance: Thioredoxin (Trx) and thioredoxin reductase are two core members of the Trx system. The system bridges the gap between the universal reducing equivalent NADPH and various biological molecules and plays an essential role in maintaining cellular redox homeostasis and regulating multiple cellular redox signaling pathways. Recent Advance: In recent years, the Trx system has been well documented as an important regulator of many diseases, especially tumorigenesis. Thus, the development of potential therapeutic molecules targeting the system is of great significance for disease treatment. Critical Issues: We herein first discuss the physiological functions of the Trx system and the role that the Trx system plays in various diseases. Then, we focus on the introduction of natural small molecules with potential therapeutic applications, especially the anticancer activity, and review their mechanisms of pharmacological actions via interfering with the Trx system. Finally, we further discuss several natural molecules that harbor therapeutic potential and have entered different clinical trials. Future Directions: Further studies on the functions of the Trx system in multiple diseases will not only improve our understanding of the pathogenesis of many human disorders but also help develop novel therapeutic strategies against these diseases. Antioxid. Redox Signal. 34, 1083-1107.

Glutathione in the Brain

Glutathione (GSH) is the most abundant non-protein thiol, and plays crucial roles in the antioxidant defense system and the maintenance of redox homeostasis in neurons. GSH depletion in the brain is a common finding in patients with neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, and can cause neurodegeneration prior to disease onset. Excitatory amino acid carrier 1 (EAAC1), a sodium-dependent glutamate/cysteine transporter that is selectively present in neurons, plays a central role in the regulation of neuronal GSH production. The expression of EAAC1 is posttranslationally controlled by the glutamate transporter-associated protein 3–18 (GTRAP3-18) or miR-96-5p in neurons. The regulatory mechanism of neuronal GSH production mediated by EAAC1 may be a new target in therapeutic strategies for these neurodegenerative diseases. This review describes the regulatory mechanism of neuronal GSH production and its potential therapeutic application in the treatment of neurodegenerative diseases.

Syntheses of Water-Soluble Silver(II)-Phthalocyanines toward Optical Sensing for Thiol Detection

Water-soluble silver(II)-phthalocyanine complexes (AgPcs), tetrakis{4-(N-alkylpyridinium)thio}phthalocyaninato silver(II) tetrafluoroborate, [Ag(tRpySpc)](BF₄)₄, (R = Me and Et), have been synthesized for the first time by quaternization of pyridyl groups of tetrakis(4-pyridylthio)phthalocyaninato silver(II) by using Meerwein reagents and characterized by ESI-MS, elemental analyses, and optical absorption spectroscopy. Although they strongly aggregate in water, the presence of appropriate surfactants, such as polyethyleneglycol-monooleyl ether (n = approximately 50; PEG50) and sodium dodecyl sulfate, effectively disaggregates them to monomeric species. The spectral properties of the AgPcs and their aggregates in aqueous and nonaqueous solutions have been investigated by optical absorption, emission, and magnetic circular dichroism spectroscopy. These AgPcs rapidly react with thiols such as cysteine, glutathione, homocysteine, and sodium 2-sulfanylethanesulfonate (even on the order of 0.01 mM) in aqueous PEG50 solutions at room temperature to liberate the corresponding macrocyclic ligand, H₂Pc, but not with the other amino-acid analogs without sulfhydryl groups. The molar ratio of thiol to AgPc has been determined to be 1:1. Since AgPcs are essentially nonfluorescent at room temperature, while H₂Pcs emit intense red fluorescence, AgPcs can be a potent thiol-sensor toward bioimaging.

Intersection between Redox Homeostasis and Autophagy: Valuable Insights into Neurodegeneration

Autophagy, a main degradation pathway for maintaining cellular homeostasis, and redox homeostasis have recently been considered to play protective roles in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Increased levels of reactive oxygen species (ROS) in neurons can induce mitochondrial damage and protein aggregation, thereby resulting in neurodegeneration. Oxidative stress is one of the major activation signals for the induction of autophagy. Upon activation, autophagy can remove ROS, damaged mitochondria, and aggregated proteins from the cells. Thus, autophagy can be an effective strategy to maintain redox homeostasis in the brain. However, the interaction between redox homeostasis and autophagy is not clearly elucidated. In this review, we discuss recent studies on the relationship between redox homeostasis and autophagy associated with neurodegenerative diseases and propose that autophagy induction through pharmacological intervention or genetic activation might be a promising strategy to treat these disorders.

The Impact of H2S on Obesity-Associated Metabolic Disturbances

Over the last several decades, hydrogen sulfide (H₂S) has gained attention as a new signaling molecule, with extensive physiological and pathophysiological roles in human disorders affecting vascular biology, immune functions, cellular survival, metabolism, longevity, development, and stress resistance. Apart from its known functions in oxidative stress and inflammation, new evidence has emerged revealing that H₂S carries out physiological functions by targeting proteins, enzymes, and transcription factors through a post-translational modification known as persulfidation. This review article provides a critical overview of the current state of the literature addressing the role of H₂S in obesity-associated metabolic disturbances, with particular emphasis on its mechanisms of action in obesity, diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases.

Spectral investigation of phthalocyanine complexes of high-valence silver and their aggregates

Several novel silver(II) complexes ligating a tetra-substituted phthalocyaninate, [Ag(tbpc)] (where tbpc denotes tetra-tert-butylphthalocyaninate), [Ag(tppc)] (tppc = tetrakis(2,6-dimethylphenoxy)phthalocyaninate), [Ag(tObpc)] (tObpc = tetra-n-butoxyphthalocyaninate), and [Ag(tpySpc)] (tpySpc = tetrakis(4-pyridylthio)phthalocyaninate) have been synthesized and characterized by elemental analyses, MALDI-TOF MS, optical absorption, and magnetic circular dichroism (MCD) spectroscopy. Although all the compounds are well soluble in common organic solvents, concentration studies on their optical spectra in solutions have found that they are prone to strongly aggregate in a cofacial manner (i.e., H-aggregate). Silver(II) complexes, which are essentially non-fluorescent, are readily demetallated in the presence of appropriate reductant (e.g., I^- or BH₄^-) to liberate the corresponding macrocyclic ligand, which emits intense red fluorescence. Chemical oxidation by using NOBF₄ generates the corresponding silver(III) species.

Mitochondrial function and oxidative stress markers in higher-frequency episodic migraine

Increasing evidence points towards the role of mitochondrial functioning, energy metabolism, and oxidative stress in migraine. However not all previous research has been conclusive and some mitochondrial function/oxidative stress markers have not yet been examined. To this end, alpha-lipoic acid (ALA), total thiols, total plasma antioxidant capacity (TAC), lipid peroxide (PerOx), oxidised LDL (oxLDL), HbA1c and lactate were determined in the serum of 32 higher frequency episodic migraineurs (5-14 migraine days/ months, 19 with aura, 28 females) in this cross-sectional study. The majority of patients had abnormally low ALA and lactate levels (87.5% and 78.1%, respectively). 46.9% of the patients had abnormally high PerOx values, while for thiols and TAC over one third of patients had abnormally low values (31.2% and 37.5%, respectively). 21.9% of patients had abnormally low HbA1c and none had an HbA1c level above 5.6%. oxLDL was normal in all but one patient. This study provides further evidence for a role of oxidative stress and altered metabolism in migraine pathophysiology, which might represent a suitable therapeutic target. ALA, being too low in almost 90% of patients, might represent a potential biomarker for migraine. Further research is needed to replicate these results, in particular a comparison with a control group.This study is part of the trial registration: ClinicalTrials.gov: NCT03132233, registered on 27.04.2017, https://clinicaltrials.gov/ct2/show/NCT03132233 .

Emerging Evidence Highlighting the Importance of Redox Dysregulation in the Pathogenesis of Amyotrophic Lateral Sclerosis (ALS)

The cellular redox state, or balance between cellular oxidation and reduction reactions, serves as a vital antioxidant defence system that is linked to all important cellular activities. Redox regulation is therefore a fundamental cellular process for aerobic organisms. Whilst oxidative stress is well described in neurodegenerative disorders including amyotrophic lateral sclerosis (ALS), other aspects of redox dysfunction and their contributions to pathophysiology are only just emerging. ALS is a fatal neurodegenerative disease affecting motor neurons, with few useful treatments. Hence there is an urgent need to develop more effective therapeutics in the future. Here, we discuss the increasing evidence for redox dysregulation as an important and primary contributor to ALS pathogenesis, which is associated with multiple disease mechanisms. Understanding the connection between redox homeostasis, proteins that mediate redox regulation, and disease pathophysiology in ALS, may facilitate a better understanding of disease mechanisms, and lead to the design of better therapeutic strategies.

Effect of citrus peels-supplemented diet on longevity, memory index, redox status, cholinergic and monoaminergic enzymes in Drosophila melanogaster model

This study sought to determine the life span promoting effecof orange (Citrus sinensis), tangerine (Citrus maxima) and grapefruit (Citrus paradisi) peels in Drosophila melanogaster model. Flies (both gender, 3 to 5 days old) were divided into seven (7) groups (n = 5) containing 40 flies each; group I (control) flies were fed with basal diet, II-VII were flies were fed with basal diet containing 0.1 and 1.0% of tangerine peel (TP), orange peel (CP), and grapefruit peel (GP) respectively, for 14 days. Locomotor performance and memory index were assessed via negative geotaxis and aversive phototaxis suppression assays, respectively. Thereafter, the fly homogenates were assayed for activities of acetylcholinesterase (AChE), monoamine oxidase (MAO) and antioxidant enzymes as well as other indices of their redox. The results revealed that the citrus peels significantly improved longevity, locomotor performance, memory index, antioxidant status, and modulate cholinesterase and monoamine oxidase enzyme activities in treated flies when compared to the control. The results obtained suggest that the citrus peels offer potentials as dietary supplement with life span promoting properties in D. melanogaster model which could as well serve as a functional food additives. PRACTICAL APPLICATIONS: Citrus peels, although often considered agro-wastes, are used as food supplements and food ingredents especially in production of candies, jams and custards. This study suggests the use of orange (Citrus sinensis), tangerine (Citrus maxima), and grapefruit (Citrus paradisi) peels as dietary supplements which offers potential life span promoting properties.

Noise-induced hippocampal oxidative imbalance and aminoacidergic neurotransmitters alterations in developing male rats: Influence of enriched environment during adolescence

Living in big cities might involuntarily expose people to high levels of noise causing auditory and/or extra-auditory impairments, including adverse effects on central nervous system (CNS) areas such as the hippocampus. In particular, CNS development is a very complex process that can be altered by environmental stimuli. We have previously shown that noise exposure of developing rats can induce hippocampal-related behavioral alterations. However, noise-induced biochemical alterations had not been studied yet. Thus, the aim of this work was to assess whether early noise exposure can affect rat hippocampal oxidative state and aminoacidergic neurotransmission tone. Additionally, the effectiveness of an enriched environment (EE) as a neuroprotective strategy was evaluated. Male Wistar rats were exposed to different noise schemes at 7 or 15 days after birth. Upon weaning, some animals were transferred to an EE whereas others were kept in standard cages. Short- and long-term measurements were performed to evaluate reactive oxygen species, thioredoxins levels and catalase activity as indicators of hippocampal oxidative status as well as glutamic acid decarboxylase and a subtype of glutamate transporter to evaluate aminoacidergic neurotransmission tone. Results showed noise-induced changes in hippocampal oxidative state and aminoacidergic neurotransmission markers that lasted until adolescence and differed according to the scheme and the age of exposure. Finally, EE housing was effective in preventing some of these changes. These findings suggest that CNS development seems to be sensitive to the effects of stressors such as noise, as well as those of an environmental stimulation, favoring prompt and lasting molecular changes.

Neuroprotective potential of hydroethanolic hull extract of Juglans regia L. on isoprenaline induced oxidative damage in brain of Wistar rats

The study was aimed at assessing isoprenaline (ISO) induced oxidative damage in brain of Wistar rats and its protection by hydroethanolic hull extract of Juglans regia. Administration of ISO significantly increases catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), malondialdehyde (MDA) and advanced oxidation protein product (AOPP) levels and significantly reduced activities of antioxidant status (TAS), total thiols (TTH), acetylcholinesterase (AChE), arylesterase (AE), and glutathione peroxidase (GPx) in rat brain. Histopathologically, neuronal degeneration, spongiosis and gliosis were seen in cerebral cortex after ISO administration. Pretreatment with hull extract restored TAS, TTH, AChE, CAT and SOD values. Additionally, significant reductions were noted in levels of MDA, AOPP, and severity of histomorphological changes in cerebral cortex following hull extract treatment. Altered antioxidant biomarkers along with histopathological changes indicate oxidative injury in rat brain following ISO administration. Repeated administration of J. regia hull extract demonstrating presence of neuroprotective properties against ISO induced oxidative damage in rat brain.

Assessment of Plasma Thiol-disulfide Balance in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

OBJECTIVES

The thiol-disulfide balance is very important in cellular events such as apoptosis and oxidative stress. This study is a comparison of plasma thiol-disulfide homeostasis in patients with pseudoexfoliation syndrome (PEXS) and pseudoexfoliation glaucoma (PEXG).

METHODS

Thirty-one patients with PEXS, 43 patients with PEXG, and 38 healthy controls were included in this prospective study. The plasma level of native thiol and disulfide were measured using a spectrophotometric assay and the native thiol/disulfide ratio was analyzed.

RESULTS

The demographic characteristics of the 3 groups were similar (p>0.05). Statistically significant differences were observed in the plasma disulfide levels (21.6±7.3 µmol/L vs. 17.4±6.8 µmol/L) and the native thiol/disulfide ratio (22.9±9.1 vs. 29.9±14.7) between the PEXG group and the controls (p=0.03, p=0.02, respectively).

CONCLUSION

Significant differences in the plasma levels of disulfide and the native thiol/disulfide ratio in PEXG patients indicated a breakdown of the thiol-disulfide circuits.