Analysis of glutathione: implication in redox and detoxification

Glutathione: A Samsonian life-sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation

Many local and systemic diseases especially diseases that are leading causes of death globally like chronic obstructive pulmonary disease, atherosclerosis with ischemic heart disease and stroke, cancer and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 19 (COVID-19), involve both, (1) oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels, and (2) inflammation. The GSH tripeptide (γ- L-glutamyl-L-cysteinyl-glycine), the most abundant water-soluble non-protein thiol in the cell (1-10 mM) is fundamental for life by (a) sustaining the adequate redox cell signaling needed to maintain physiologic levels of oxidative stress fundamental to control life processes, and (b) limiting excessive oxidative stress that causes cell and tissue damage. GSH activity is facilitated by activation of the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 that regulates expression of genes controlling antioxidant, inflammatory and immune system responses. GSH exists in the thiol-reduced (>98% of total GSH) and disulfide-oxidized (GSSG) forms, and the concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell. GSH depletion may play a central role in inflammatory diseases and COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of inflammatory diseases and COVID-19 and increasing GSH levels may prevent and subdue these diseases. The life value of GSH makes for a paramount research field in biology and medicine and may be key against systemic inflammation and SARS-CoV-2 infection and COVID-19 disease. In this review, we emphasize on (1) GSH depletion as a fundamental risk factor for diseases like chronic obstructive pulmonary disease and atherosclerosis (ischemic heart disease and stroke), (2) importance of oxidative stress and antioxidants in SARS-CoV-2 infection and COVID-19 disease, (3) significance of GSH to counteract persistent damaging inflammation, inflammaging and early (premature) inflammaging associated with cell and tissue damage caused by excessive oxidative stress and lack of adequate antioxidant defenses in younger individuals, and (4) new therapies that include antioxidant defenses restoration.

S-Glutathionylation-Controlled Apoptosis of Lung Epithelial Cells; Potential Implications for Lung Fibrosis

Glutathione (GSH), a major antioxidant in mammalian cells, regulates several vital cellular processes, such as nutrient metabolism, protein synthesis, and immune responses. In addition to its role in antioxidant defense, GSH controls biological processes through its conjugation to reactive protein cysteines in a post-translational modification known as protein S-glutathionylation (PSSG). PSSG has recently been implicated in the pathogenesis of multiple diseases including idiopathic pulmonary fibrosis (IPF). Hallmarks of IPF include repeated injury to the alveolar epithelium with aberrant tissue repair, epithelial cell apoptosis and fibroblast resistance to apoptosis, and the accumulation of extracellular matrix and distortion of normal lung architecture. Several studies have linked oxidative stress and PSSG to the development and progression of IPF. Additionally, it has been suggested that the loss of epithelial cell homeostasis and increased apoptosis, accompanied by the release of various metabolites, creates a vicious cycle that aggravates disease progression. In this short review, we highlight some recent studies that link PSSG to epithelial cell apoptosis and highlight the potential implication of metabolites secreted by apoptotic cells.

Study of the Association between Thiols and Oxidative Stress Markers in Children with Obesity

Obesity has reached epidemic proportions, and the World Health Organization defined childhood overweight and obesity as a noncommunicable disease that represents the most serious public health challenges of the twenty-first century. Oxidative stress, defined as an imbalance between oxidants and antioxidants causing an impairment of the redox signals, is linked to the development of metabolic diseases. In addition, reactive oxygen species generated during metabolic disorder could increase inflammation, causing the development of insulin resistance, diabetes, and cardiovascular disease. We analyze serum levels of cysteine (Cys), cysteinyl-glycine (Cys-Gly), homocysteine (Hcy), and glutathione (GSH), and other markers of oxidative stress, such as thiobarbituric acid reactive substances (T-BARS), 8-isoprostane, and protein carbonyl in our children with obesity. Total antioxidant status was also determined. We found lower GSH and Cys-Gly levels, and higher Hcy and oxidative stress markers levels. We also found a positive correlation between Body Mass Index (BMI), Cys, GSH, and Hcy levels, between insulin and Cys levels, and between BMI and the homeostasis model assessment-estimated insulin resistance (HOMA-IR) with 8-isoprostane levels. Finally, we found a correlation between age and GSH and Cys levels. The deficiency of GSH could be restored by dietary supplementation with GSH precursors, supplying an inexpensive approach to oppose oxidative stress, thus avoiding obesity complications.

Arthrospira platensis nanoparticles defeat against diabetes-induced testicular injury in rat targeting, oxidative, apoptotic, and steroidogenesis pathways

Varieties of studies have been used to investigate the health benefits of Spirulina (Arthrospira platensis); however, more research is needed to examine if its nano form may be utilized to treat or prevent several chronic diseases. So, we designed this study to explore the effect and the cellular intracellular mechanisms by which Arthrospira platensis Nanoparticles (NSP) alleviates the testicular injury induced by diabetes in male Wistar rats. Eighty Wistar male rats (n = 80) were randomly allocated into eight groups. Group 1 is untreated rats (control), Group 2 including STZ-induced diabetic rats with 65 mg/kg body weight STZ (STZ-diabetic), Group 3-5: including diabetic rats treated with NSP1, NSP2, and NSP3 at 0.25, 0.5, and 1 mg/kg body weight, respectively, once daily orally by the aid of gastric gavage for 12 consecutive weeks and groups 6-8 include normal rats received NSP (0.25, 0.5, and 1 mg/kg body weight once daily orally. The identical volume of normal saline was injected into both control and diabetic rats. After 12 weeks of diabetes induction, the rats were killed. According to our findings, NSP administration to diabetic rats enhances the total body weight and the weight of testes and accessory glands; in addition, NSP significantly reduced nitric oxide and malondialdehyde in testicular tissue improved sperm parameters. Intriguingly, it raises testicular GSH and SOD activity by a significant amount (p < 0.05). As well, Oral administration of NSP to diabetic rats resulted in a decrease in the blood glucose levels, HA1C, induced in the diabetic group, which overcame the diabetic complications NSP caused down-regulation of apoptotic genes with upregulation of BCL-2 mRNA expression (p < 0.05) and prominent up-regulation of steroidogenesis genes expression level in testes in comparison to the diabetic rats which resulted in improving the decreased levels of testosterone hormone, FSH, and LH induced by diabetes. In the same way, our histopathological findings support our biochemical and molecular findings; in conclusion, NSP exerted a protective effect against reproductive dysfunction induced by diabetes not only through its high antioxidant and hypoglycemic action but also through its down-regulation of Apoptotic genes and up-regulation of steroidogenesis regulatory genes expression level in diabetic testes.

Small-Molecule Fluorescent Probes for Detecting Several Abnormally Expressed Substances in Tumors

Malignant tumors have always been the biggest problem facing human survival, and a huge number of people die from cancer every year. Therefore, the identification and detection of malignant tumors have far-reaching significance for human survival and development. Some substances are abnormally expressed in tumors, such as cyclooxygenase-2 (COX-2), nitroreductase (NTR), pH, biothiols (GSH, Cys, Hcy), hydrogen sulfide (H2S), hydrogen sulfide (H2O2), hypochlorous acid (HOCl) and NADH. Consequently, it is of great value to diagnose and treat malignant tumors due to the identification and detection of these substances. Compared with traditional tumor detection methods, fluorescence imaging technology has the advantages of an inexpensive cost, fast detection and high sensitivity. Herein, we mainly introduce the research progress of fluorescent probes for identifying and detecting abnormally expressed substances in several tumors.

Transcriptional Profiling of the Candida albicans Response to the DNA Damage Agent Methyl Methanesulfonate

The infection of a mammalian host by the pathogenic fungus Candida albicans involves fungal resistance to reactive oxygen species (ROS)—induced DNA damage stress generated by the defending macrophages or neutrophils. Thus, the DNA damage response in C. albicans may contribute to its pathogenicity. Uncovering the transcriptional changes triggered by the DNA damage—inducing agent MMS in many model organisms has enhanced the understanding of their DNA damage response processes. However, the transcriptional regulation triggered by MMS remains unclear in C. albicans. Here, we explored the global transcription profile in response to MMS in C. albicans and identified 306 defined genes whose transcription was significantly affected by MMS. Only a few MMS-responsive genes, such as MGT1, DDR48, MAG1, and RAD7, showed potential roles in DNA repair. GO term analysis revealed that a large number of induced genes were involved in antioxidation responses, and some downregulated genes were involved in nucleosome packing and IMP biosynthesis. Nevertheless, phenotypic assays revealed that MMS-induced antioxidation gene CAP1 and glutathione metabolism genes GST2 and GST3 showed no direct roles in MMS resistance. Furthermore, the altered transcription of several MMS—responsive genes exhibited RAD53—related regulation. Intriguingly, the transcription profile in response to MMS in C. albicans shared a limited similarity with the pattern in S. cerevisiae, including COX17, PRI2, and MGT1. Overall, C. albicans cells exhibit global transcriptional changes to the DNA damage agent MMS; these findings improve our understanding of this pathogen’s DNA damage response pathways.

Anti-Inflammatory Food in Asthma Prepared from Combination of Raphanus sativus L., Allium hookeri, Acanthopanax sessiliflorum, and Dendropanax morbiferus Extracts via Bioassay-Guided Selection

Asthma is a highly prevalent inflammatory disease of the respiratory airways and an increasing health risk worldwide. Hence, finding new strategies to control or attenuate this condition is necessary. This study suggests nutraceuticals that are a combination of herbal plant extracts prepared from Acanthopanax sessiliflorum (AS), Codonopsis lanceolate (CL), Dendropanax morbiferus (DM), Allium hookeri (AH), and Raphanus sativus L. (RS) that can improve immunomodulatory ability through the detoxification and diuresis of air pollutants. Herbal parts (AH whole plant, RS and CL roots, AS and DM stems, and DM leaves) were selected, and four types of mixtures using plant extracts were prepared. Among these mixtures, M2 and M4 exhibited antioxidant activities in potent 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-β-picrylhydrazine (DPPH) radical assays. Moreover, M4 exhibited a marked increase in glutathione S-transferase (GST) activity and significantly inhibited the inflammatory mediator, nitric oxide (NO) and proinflammatory cytokines, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α generation. Furthermore, M4 exhibited the strongest antioxidant, hepatoprotective, and anti-inflammatory effects and was selected to prepare the product. Before manufacturing the product, we determined that the active mixture, M4, inhibited gene expression and generation of proinflammatory cytokines IL-1β, IL-6 and TNF-α in ovalbumin (OVA)-, lipopolysaccharide (LPS)-, and particulate matter (PM)-induced asthmatic rat models. The granular product (GP) was manufactured using M4 along with additives, i.e., lactose, oligosaccharide, stevioside extract, and nutmeg seed essential oils (flavor masking), in a ratio of 1:4 using a granulation machine, dried and ultimately packaged. The GP inhibited the generation of proinflammatory cytokines IL-1β, IL-6 and TNF-α in OVA-, LPS- and PM-induced asthmatic rat models. These results suggest that GP prepared from a combination of herbal plants (AS, CL, DM, AH and RS) is a potent functional food with anti-inflammatory activity that can be used to treat asthma caused by ambient air pollutants.

Metabolomics and proteomics study reveals the effects of benzo[a]pyrene on the viability and migration of KYSE-150 esophageal cells

A representative polycyclic aromatic hydrocarbon, benzo[a]pyrene (B[a]P), has been widely detected in environmental compartments and is highly carcinogenic to humans. Oral ingestion of B[a]P is the dominant exposure pathway. The esophagus acts as the first contact point when B[a]P enters the human body. However, its role in the development of human esophageal cancer is rarely discussed. Herein, we employed untargeted metabolomics in combination with proteomics to explore B[a]P-related intracellular responses in human esophageal cell lines. Our results demonstrated that B[a]P exposure induced significant metabolic disorders, further leading to overproduction of reactive oxygen species (ROS) and disturbance of the cellular viability process and migration ability of esophageal cells. In response, glutathione (GSH) was consumed to meet the demand for cellular detoxification, and thioredoxin (TXN) was upregulated to balance the cellular redox. These alterations caused the reregulation of some specific protein families, including S100A proteins, ribosomal proteins, and histone H1 proteins. Such changes impeded the viability and migration of esophageal cells, which could adversely affect wound healing of the epithelium. These cellular responses indicate that B[a]P will cause serious cellular damage to esophageal cells and increase the carcinogenic risk even as a result of short-term exposure. SYNOPSIS: Our omics study demonstrated how benzo[a]pyrene hampered the migration of esophageal cells and proposed a plausible mechanism underlying its carcinogenicity, which may contribute to our understanding of environmental pollutants.

Improved Cytocompatibility and Reduced Calcification of Glutaraldehyde-Crosslinked Bovine Pericardium by Modification With Glutathione

Bioprosthetic heart valves (BHVs) used in clinics are fabricated via glutaraldehyde (GLUT) crosslinking, which results in cytotoxicity and causes eventual valve calcification after implantation into the human body; therefore, the average lifetime and application of BHVs are limited. To address these issues, the most commonly used method is modification with amino acids, such as glycine (GLY), which is proven to effectively reduce toxicity and calcification. In this study, we used the l-glutathione (GSH) in a new modification treatment based on GLUT-crosslinked bovine pericardium (BP) as the GLUT + GSH group, BPs crosslinked with GLUT as GLUT-BP (control group), and GLY modification based on GLUT-BP as the GLUT + GLY group. We evaluated the characteristics of BPs in different treatment groups in terms of biomechanical properties, cell compatibility, aldehyde group content detection, and the calcification content. Aldehyde group detection tests showed that the GSH can completely neutralize the residual aldehyde group of GLUT-BP. Compared with that of GLUT-BP, the endothelial cell proliferation rate of the GLUT + GSH group increased, while its hemolysis rate and the inflammatory response after implantation into the SD rat were reduced. The results show that GSH can effectively improve the cytocompatibility of the GLUT-BP tissue. In addition, the results of the uniaxial tensile test, thermal shrinkage temperature, histological and SEM evaluation, and enzyme digestion experiments proved that GSH did not affect the ECM stability and biomechanics of the GLUT-BP. The calcification level of GLUT-BP modified using GSH technology decreased by 80%, indicating that GSH can improve the anti-calcification performance of GLUT-BP. Compared with GLUT-GLY, GLUT + GSH yielded a higher cell proliferation rate and lower inflammatory response and calcification level. GSH can be used as a new type of anti-calcification agent in GLUT crosslinking biomaterials and is expected to expand the application domain for BHVs in the future.

Synthesis of a Novel Electrochemical Probe for the Sensitive and Selective Detection of Biothiols and Its Clinical Applications

The ability to estimate and quantify biothiols in biological fluids is very significant for attaining a detailed understanding of biothiols-related pathological diseases. Most of the developed methods for biothiols detection are not suitable for this purpose owing to their low sensitivity, poor selectivity, and long experimental procedures. In this study, a novel and simple structure electrochemical probe has been synthesized for the first time for the selective determination of biothiols. The developed probe is based on using 2,4-dinitrobenzenesulfonyl moiety (DNBS) as a selective recognition moiety for biothiols. The electrochemical probe was successfully fabricated through a facile one-step reaction between 2,4-dinitrobenzenesulfonyl chloride (DNBS-Cl) and p-aminophenol. The successful synthesis of the probe was confirmed by using different characterization techniques such as an NMR spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, and mass spectrometry. Biothiols can selectively cleave the DNBS moiety through an aromatic nucleophilic substitution (ANS) reaction within 10 min to release p-aminophenol, which is a highly electrochemical active molecule that can be selectively detected easily by cyclic voltammetry at low potential. The probe has been employed for the quantification of cysteine, glutathione, and homocysteine with a LOD of 1.50, 3.48, and 4.67 μM, respectively. Excellent recoveries have been achieved in the range of 95.44-98.71% for the determination of the total biothiols in the human plasma sample.

Effects of subchronic dietary exposure to the engineered nanomaterials SiO2 and CeO2 in C57BL/6J and 5xFAD Alzheimer model mice

BACKGROUND

There is an increasing concern about the neurotoxicity of engineered nanomaterials (NMs). To investigate the effects of subchronic oral exposures to SiO2 and CeO2 NMs on Alzheimer's disease (AD)-like pathology, 5xFAD transgenic mice and their C57BL/6J littermates were fed ad libitum for 3 or 14 weeks with control food pellets, or pellets dosed with these respective NMs at 0.1% or 1% (w/w). Behaviour effects were evaluated by X-maze, string suspension, balance beam and open field tests. Brains were analysed for plaque load, beta-amyloid peptide levels, markers of oxidative stress and neuroinflammation.

RESULTS

No marked behavioural impairments were observed in the mice exposed to SiO2 or CeO2 and neither treatment resulted in accelerated plaque formation, increased oxidative stress or inflammation. In contrast, the 5xFAD mice exposed to 1% CeO2 for 14 weeks showed significantly lower hippocampal Aβ plaque load and improved locomotor activity compared to the corresponding controls.

CONCLUSIONS

The findings from the present study suggest that long-term oral exposure to SiO2 or CeO2 NMs has no neurotoxic and AD-promoting effects. The reduced plaque burden observed in the mice following dietary CeO2 exposure warrants further investigation to establish the underlying mechanism, given the easy applicability of this administration method.

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.

A coumarin-based reversible two-photon fluorescence probe for imaging glutathione near N-methyl-D-aspartate (NMDA) receptors

Glutathione (GSH) is known to play a key role in the modulation of the redox environment in N-methyl-d-aspartate (NMDA) receptors. Coumarin derivative 1 bearing cyanoacrylamide and ifenprodil moieties was synthesized and reported to monitor GSH near NMDA receptors. The cyanoacrylamide moiety allows probe 1 to monitor GSH reversibly at pH 7.4 and the ifenprodil group acts as a directing group for NMDA receptors. Two-photon fluorescence microscopy allows probe 1 to successfully sense endogenous GSH in neuronal cells and hippocampal tissues with excitation at 750 nm. Furthermore, the addition of H₂O₂ and GSH induced a decrease and an increase in fluorescence emission. Probe 1 can serve as a potential practical imaging tool to get important information on GSH in the brain.

Activity-based NIR fluorescent probes based on the versatile hemicyanine scaffold: design strategy, biomedical applications, and outlook

The discovery of a near-infrared (NIR, 650-900 nm) fluorescent chromophore hemicyanine dye with high structural tailorability is of great significance in the field of detection, bioimaging, and medical therapeutic applications. It exhibits many outstanding advantages including absorption and emission in the NIR region, tunable spectral properties, high photostability as well as a large Stokes shift. These properties are superior to those of conventional fluorogens, such as coumarin, fluorescein, naphthalimides, rhodamine, and cyanine. Researchers have made remarkable progress in developing activity-based multifunctional fluorescent probes based on hemicyanine skeletons for monitoring vital biomolecules in living systems through the output of fluorescence/photoacoustic signals, and integration of diagnosis and treatment of diseases using chemotherapy or photothermal/photodynamic therapy or combination therapy. These achievements prompted researchers to develop more smart fluorescent probes using a hemicyanine fluorogen as a template. In this review, we begin by describing the brief history of the discovery of hemicyanine dyes, synthetic approaches, and design strategies for activity-based functional fluorescent probes. Then, many selected hemicyanine-based probes that can detect ions, small biomolecules, overexpressed enzymes and diagnostic reagents for diseases are systematically highlighted. Finally, potential drawbacks and the outlook for future investigation and clinical medicine transformation of hemicyanine-based activatable functional probes are also discussed.

Determination of low molecular thiols and protein sulfhydryl groups using heterocyclic disulfides

A promising area in the analytical chemistry of thiol-containing compounds is the use of heterocyclic disulfides as analytical agents, but now only a few of them are widely used. In this paper, we evaluate the possibility of using three different heterocyclic disulfides 2,2'-dithiobis[5-phenyl-1,3,4-oxadiazole] (I), 2,2'-dithiobis[benzoxazole] (II) and 8,8'-dithiobis-quinoline (III) as analytical reagents for the low-mass aminothiols cysteine and glutathione determination. The optimal analysis conditions were found. Spectrophotometric, kinetic, CE, and HPLC methods using I, II, III for the determination of cysteine and glutathione were developed. The obtained methods are characterized by accuracy and sensitivity (detection limits in the range of 10^-5-10^-6 M) sufficient to quantify cysteine and glutathione in their physiological concentrations. Finally, the proposed disulfides were used to determine the SH-content in the bovine serum albumin (BSA). Considering a number of criteria (applicable pH range, absorption properties, susceptibility to hydrolysis) it was concluded that the proposed reagents have advantages over the commonly used ones (such as the Ellman reagent).

Serum Indicators of Oxidative Damage from Embedded Metal Fragments in a Rat Model

Injuries suffered in armed conflicts often result in embedded metal fragments. Standard surgical guidance recommends leaving embedded fragments in place except under certain circumstances in an attempt to avoid the potential morbidity that extensive surgery often brings. However, technological advances in weapon systems and insurgent use of improvised explosive devices now mean that practically any metal can be found in these types of wounds. Unfortunately, in many cases, the long-term toxicological properties of embedded metals are not known, further complicating treatment decisions. Because of concerns over embedded metal fragment injuries, the U.S. Departments of Defense and Veterans' Affairs developed a list of “metals of concern” for these types of injuries. In this study, we selected eight of these metals including tungsten, nickel, cobalt, iron, copper, aluminum, lead, and depleted uranium to investigate the long-term health effects using a rodent model developed in our Institute to study embedded fragment injuries. In this report, we show that metals surgically implanted into the gastrocnemius muscle of laboratory rats to simulate a shrapnel wound induce a variety of cytokines including IFN-γ, IL-4, IL-5, IL-6, IL-10, and IL-13. TNF-α and KC/GRO were not affected, and IL-1β was below the limit of detection. Serum levels of C-reactive protein were also affected, increasing with some metals and decreasing with others. The TBARS assay, an assessment of lipid peroxidation, demonstrated that implanted aluminum and lead increased markers of lipid peroxidation in serum. Taken together, the results suggest that serum cytokine levels, as well as other indicators of oxidative damage, may prove useful in identifying potential adverse health effects of embedded metals.

Ginsenoside Rg1 inhibits oxidative stress and inflammation in rats with spinal cord injury via Nrf2/HO-1 signaling pathway

OBJECTIVES

In this study, our objective was to investigate the underlying mechanism of the neuroprotective role of ginsenoside Rg1 in attenuating spinal cord injury (SCI).

METHODS

A rat SCI model was established and treated with ginsenoside Rg1 and nuclear factor erythroid 2-related factor2(Nrf2) inhibitor all-trans retinoic acid (ATRA). The protective effects of ginsenoside Rg1 were evaluated by Basso, Beattie and Bresnahan (BBB) scale, hematoxylin/eosin staining, ELISA assay, western blotting and quantitative reverse transcription PCR (RT-qPCR).

RESULTS

Ginsenoside Rg1 alleviated neuronal edema and bleeding in the injured spinal cord, reduced inflammatory cell infiltration and cell necrosis, further repaired the injured spinal cord structure, improved BBB motor score in the SCI rat model and improved hind limb motor function. Meanwhile, ginsenoside Rg1 significantly increased the content of antioxidant enzymes superoxide dismutase and glutathione, and inhibited the production of oxidative marker malondialdehyde. In addition, ginsenoside Rg1also significantly inhibits the activities of the inflammatory factors tumor necrosis factor-α, interleukin-1β (IL-1β) and interleukin-6 (IL-6) to reduce the inflammatory response after trauma. Furthermore, western blot and RT-qPCR also suggested that ginsenoside Rg1 could activate the protein expression of Nrf2 and heme oxygenase-1 (HO-1) after SCI, and the inhibition of ATRA on these improvements further verified the neuroprotective effect of Nrf2 and HO-1 in ginsenoside Rg1 on SCI.

CONCLUSION

Ginsenoside Rg1 has a neuroprotective effect on SCI and can improve motor dysfunction caused by injury. The underlying mechanism may play antioxidative stress and anti-inflammatory effect by regulating the Nrf2/HO-1 signaling pathway.

Potential Anticancer Agents against Melanoma Cells Based on an As-Synthesized Thiosemicarbazide Derivative

In this paper, thiosemicarbazide derivatives were synthesized as potential anticancer agents. X-ray investigations for 1-(2,4-dichlorophenoxy)acetyl-4-(2-fluorophenyl) thiosemicarbazide, 1-(2,4-dichlorophenoxy)acetyl-4-(4-metylothiophenyl)thiosemicarbazide and 1-(2,4-di chlorophenoxy)acetyl-4-(4-iodophenyl)thiosemicarbazide were carried out in order to confirm the synthesis pathways, identify their tautomeric forms, analyze the conformational preferences of molecules, and identify intra- and intermolecular interactions in the crystalline state. TLC and RP-HPLC analyses were used to determine lipophilicity. The lipophilicity analysis revealed that the 4-substituted halogen derivatives of thiosemicarbazides showed greater lipophilicity compared with 2-substituted derivatives. The optimal range of lipophilicity for biologically active compounds logkw is between 4.14 and 4.78. However, as the analysis showed, it is not a decisive parameter. The cytotoxicity of the new compounds was evaluated against both the G-361 and BJ cell lines. Cytotoxicity analyses and cell-cycle and cell apoptosis assays were performed. The MTT test demonstrated that three compounds were cytotoxic to melanoma cells and not toxic to normal fibroblasts in the concentration range used. The cell cycle analysis showed that the compounds had no significant effect on the cell cycle inhibition. An extensive gene expression analysis additionally revealed that all compounds tested downregulated the expression of dihydroorotate dehydrogenase (DHODH). DHODH is a mitochondrial enzyme involved in the de novo synthesis of pyrimidines. Due to the rapid rate of cancer cell proliferation and the increased demand for nucleotide synthesis, it has become a potential therapeutic target.

Reactivity of γ-glutamyl-cysteine with intracellular and extracellular glutathione metabolic enzymes

Gamma-glutamyl-cysteine (γ-EC) is a precursor of glutathione (GSH) biosynthesis. We investigated whether it functions as a substrate for three intracellular and one extracellular GSH metabolic enzymes, which mediate the antioxidant defence function of GSH. Among them, glutathione peroxidase, glutathione S-transferase and γ-glutamyl transferase (GGT) exhibited substrate specificity for γ-EC, whereas glutathione reductase did not. The specificities of γ-EC and its disulphide form to GGT were comparable to GSH and its oxidized form, GSSG respectively. These results indicate that they can supply GSH constituent amino acids, glutamate, cysteine and cystine through degradation by GGT. γ-EC may contribute valuable antioxidant defence properties as a food and cosmetic additive.

Untargeted metabolomic study of HepG2 cells under the effect of Fucus vesiculosus aqueous extract

RATIONALE

Fucus vesiculosus has been described with potential to develop functional foods containing bioactive compounds against various diseases. However, more studies are needed to better understand its functioning and its previously reported bioactivities, mainly at the molecular level.

METHODS

An untargeted metabolomic study was performed to analyse HepG2 cells exposed to F. vesiculosus aqueous extract, rich in phlorotannins and peptides, during 24 h. This study was carried out using liquid chromatography combined with high-resolution tandem mass spectrometry.

RESULTS

This metabolomic study showed significant changes in HepG2 metabolites in the presence of the extract, standing out being the increased intensity of various fatty acid amides (oleamide, (Z)-eicos-11-enamide, linoleamide, palmitamide, dodecanamide and stearamide). This group of metabolites is reported in the literature with anticancer and hypocholesterolemic activity, bioactivities also described for F. vesiculosus. The extract induced, likewise, the expression of glutathione indicating its antioxidant effect.

CONCLUSIONS

This study demonstrated the potential of the compounds present in the F. vesiculosus aqueous extract for the development of natural drugs, nutraceuticals or dietary supplements, justified at the molecular level by changes in cell metabolites related to anticancer and hypocholesterolemic activity. The results here described, using an untargeted metabolomic approach, may contribute to a better understanding of algal behaviour, when used as food, in health-promoting effects.

Characterization of oxidation of glutathione by cytochrome c

Cytochrome c is a member of the respiratory chain of the mitochondria. Non-membrane-bound (free) cytochrome c can be reduced by gluthatione as well as ascorbic acid. We investigated the effect of pH, Ca²⁺, Mg²⁺ and anionic phospholipids on the reduction of cytochrome c by glutathione.The reduction of cytochrome c by thiols was measured using photometry. Mitochondrial oxygen consumption was detected by use of oxygen electrode. Glutathione does not reduce cytochrome c at pH = 7.0 in the absence of Ca²⁺ and Mg²⁺. The reduction of cytochrome c by glutathione is inhibited by anionic lipids, especially cardiolipin. The typical conditions of apoptosis-elevated pH, Ca²⁺ level and Mg²⁺-increases the reduction of cytochrome c. Glutathione (5 mM) causes increased mitochondrial O₂ consumption at pH = 8.0, in the presence of ADP either 1 mM Mg²⁺ or 1 mM Ca²⁺. Our results suggest that membrane bound cyt c does not oxidize glutathione. Free (not membrane bound) cytochrome c can oxidize glutathione. In mitochondria, O₂ is depleted only in the presence of ADP, so the O₂ depletion observed in the presence of glutathione can be related to the respiratory chain. Decreased glutathione levels play a role in apoptosis. Therefore, membrane unbound cyt c can contribute to apoptosis by oxidation of glutathione.

Optimization of Reaction Conditions for γ-Glutamylcysteine Production from Glutathione Using a Phytochelatin Synthase-Like Enzyme from Nostoc sp. Pasteur Culture Collection 7120

γ-Glutamylcysteine (γ-EC) has antioxidant properties similar to those of glutathione (GSH) and acts as its precursor in mammals. There are a few procedures for the production of γ-EC, such as chemical synthesis or enzymatic synthesis from glutamate and cysteine; however, they are very costly and not suitable for industrial production. A phytochelatin synthase-like enzyme derived from Nostoc sp. Pasteur Culture Collection 7120 (NsPCS) catalyzes the hydrolysis of GSH to γ-EC and glycine in the absence of ATP or other additives. Our research aims to establish an alternative γ-EC production procedure with low cost and high productivity. To this end, we optimized the reaction conditions of NsPCS and characterized its properties in this study. We found that 200 mM potassium phosphate buffer, pH 8.0, at 37 °C, had the highest NsPCS activity among the conditions we tested. Under these conditions, NsPCS had a K_m of 385 µM and a V_max of 26 mol/min/mg-protein. In addition, NsPCS converted 100 mM GSH into γ-EC with high yields. These results suggest that the NsPCS reaction has great potential for the low-cost, industrial-scale production of γ-EC.

Impact of cypermethrin in nephrocytes of freshwater fish Catla catla

The kidney of Catla catla, chronically exposed to sub-lethal concentrations (0.24 μg/L and 0.41 μg/L) of cypermethrin revealed a significant elevation in the activity of antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and reduced glutathione (GSH) after 15 days, followed by a decline of up to 45 days. Lipid peroxidation (LPO) remained elevated throughout the exposure duration. Histology presented proliferated haematopoietic tissue, tubular and glomerular degeneration. The maximum increase in the mean degree of tissue change (DTC) was observed on the 45th day of treatment. Ultra-structure study depicted cytoplasmic vacuolation, fragmented RER, the proliferation of lysosomes, mitochondrial degeneration, and degenerative changes in the epithelial lining of renal tubules. Principal component analysis (PCA) of various biomarkers generated two components PCI (SOD, GST, GSH, LPO and DTC) and PCII (CAT). These findings suggest that long term exposure to cypermethrin can lead to various pathological alterations in the fish kidney which in turn might interfere with normal renal excretory mechanism.

Chronic bisphenol A exposure induces temporal neurobehavioral transformation and augmented chromatin condensation in the periventricular gray zone of zebrafish brain

Bisphenol A (BPA) is an industrial synthetic chemical that is extensively used for manufacturing polycarbonate plastics and epoxy resins. However, there is limited literature on BPA-induced temporal neurobehavioral transformation and oxidative stress-mediated neurodegeneration in the subtle region of the zebrafish brain. Consequently, an investigational setup was prepared to study the temporal response to duration-dependent BPA exposure on neurobehavioral, oxidative stress, and neurodegeneration in zebrafish. Zebrafish were divided into five groups: naïve, control, 7 days (BPA7D), 14 days (BPA14D), and 21 days (BPA21D). Our findings indicated that chronic waterborne exposure to BPA substantially altered the light/dark preference and bottom-dwelling behavior of zebrafish in the BPA14D, and BPA21D groups compared with naïve and control groups. Biochemical studies revealed that there was a significant downregulation in the cellular level of small-molecule antioxidants evidenced by reduced glutathione (GSH) and activity of antioxidant enzymes of glutathione biosynthesis in a duration-dependent manner after exposure to BPA. However, exposure to BPA for 7 days did not induce substantial alteration in biochemical parameters, such as GSH level, protein carbonylation, and superoxide dismutase activity, although the neurobehavioral responses expressively differed from those of the naïve and control groups. Moreover, our histopathological observation also indicated a temporal augmentation in chromatin condensation in the periventricular gray zone (PGZ) of the zebrafish brain after chronic exposure to BPA. The overall outcomes of the present study indicated that the transformed neurobehavioral phenotypes in zebrafish are a consequence of BPA-induced oxidative stress and PGZ neurodegeneration and clearly show a temporal transformation under BPA exposure.

Folinic Acid as Adjunctive Therapy in Treatment of Inappropriate Speech in Children with Autism: A Double-Blind and Placebo-Controlled Randomized Trial

This is a double-blind, placebo-controlled randomized trial to investigate the potential therapeutic effects of folinic acid/placebo as an adjuvant to risperidone on inappropriate speech and other behavioral symptoms of autism spectrum disorder (ASD). Fifty-five ASD children (age (mean ± standard deviation) = 13.40 ± 2.00; male/female: 35/20) were evaluated for behavioral symptoms at baseline, week 5, and week 10 using the aberrant behavior checklist-community (ABC-C). Folinic acid dosage was 2 mg/kg up to 50 mg per day for the entire course of the study. The repeated measures analysis showed significant effect for time × treatment interaction on inappropriate speech (F = 3.51; df = 1.61; P = 0.044), stereotypic behavior (F = 4.02; df = 1.37; P = 0.036), and hyperactivity/noncompliance (F = 6.79; df = 1.66; P = 0.003) subscale scores. In contrast, no significant effect for time × treatment interaction was found on lethargy/social withdrawal (F = 1.06; df = 1.57; P = 0.336) and irritability (F = 2.86; df = 1.91; P = 0.064) subscale scores. Our study provided preliminary evidence suggesting that folinic acid could be recommended as a beneficial complementary supplement for alleviating speech and behavioral symptoms in children with ASD.Clinical trial registeration: This trial was registered in the Iranian Registry of Clinical Trials ( www.irct.ir ; No. IRCT20090117001556N114).

Anti-melanoma effect of ruthenium(II)-diphosphine complexes containing naphthoquinone ligand

The use of natural products as potential ligands has been explored as a strategy in the development of metal-based chemotherapy. Since ruthenium complexes are promising alternatives to traditional antitumor agents, this study evaluated the anti-melanoma potential of two ruthenium(II) complexes containing the naphthoquinone ligands lapachol (lap), [Ru(lap)(dppm)2]PF6, and lawsone (law), [Ru(law)(dppm)2]PF6, in addition to the bis(diphenylphosphino)methane (dppm) ligand, referred to as complexes (1) and (2), respectively, using a syngeneic murine melanoma model. Activation of the apoptotic pathway by the treatments was assessed by immunohistochemistry in tumor tissue. Additionally, toxicity of the treatments was evaluated by variation in body and organ weight, quantification of biochemical indicators of renal damage, and genotoxicity in bone marrow and hepatocytes. First, the antiproliferative activity of (1) and (2) was observed in B16F10 cells, with IC50 values of 2.78 and 1.68 μM, respectively. The results obtained in mice showed that, unlike complex (1), (2) possesses significant anti-melanoma activity demonstrated by a reduction in tumor volume and mass (88.42%), as well as in mitosis frequency (83.86%). Additionally, complex (2) increased the levels of cleaved caspase-3, inducing tumor cell apoptosis. When compared to the metallodrug cisplatin, complex (2) exhibited similar anti-melanoma activity and lower toxicity considering all parameters evaluated. In silico studies demonstrated no difference in the binding energy of the naphthoquinone complex between complexes (1) and (2). However, the complex containing the lawsone ligand has a lower molar volume, which may be important for interactions with minor DNA grooves. The present results demonstrate the antitumor efficiency of complex (2) and a significantly lower systemic toxicity compared to cisplatin.

MiADMSA abrogates sodium tungstate-induced oxidative stress in rats

Tungsten (W) and its compounds have emerged as a relatively new area of environmental health concern in the last decade. Tungsten is environmentally benign due to its increasing use in armour-piercing munitions and as a replacement for lead in other ammunition. It has also been identified in various hazardous waste sites and therefore been proposed for inclusion in the Environmental Protection Agency National Priorities List. The major objective of this study was to evaluate the therapeutic efficacy of orally administered monoisoamyl 2, 3-dimercaptosuccinic acid (MiADMSA) against tungstate induced oxidative injury in blood, liver and kidneys of male Wistar rats. MiADMSA, a thiol chelator has gained wide recognition recently as a future chelating drug of choice specifically for arsenic and was chosen for this study as tungstate ions too have an affinity toward the -SH group thus, being less bioavailable in the body. We determined the effects of MiADMSA (50 mg/kg, p.o.) against sodium tungstate (500 ppm in drinking water, daily for 28 days) induced biochemical changes indicative of oxidative stress in blood, and other soft tissues of of male Wistar rats. Tungsten exposure led to an increased levels of Reactive Oxygen Species (ROS) in liver, kidney, spleen and blood accompanied also by an increase in TBARS levels. The GSH: GSSG ratio also showed a decrease on sodium tungstate intoxication. Treatment with MiADMSA restored most of the sodium tungstate-induced alterations in the biomarkers suggestive of oxidative stress. These preliminary results led us to conclude that sub-acute exposure to tungstate-induced oxidative stress could be effectively reduced by the administration of MiADMSA and thus might be a promising antidote for studying in detail its efficacy in reducing body tungstate burden and its excretion post tungstate exposure.

Heterojunction of Vertically Arrayed MoS2 Nanosheet/N-Doped Reduced Graphene Oxide Enabling a Nanozyme for Sensitive Biomolecule Monitoring

Enzymes are still indispensable for bio-assaying methods in biomolecule detection by far. The unsatisfied long-term instability, high cost, and susceptibility to the physical environment of natural enzymes are obvious weak points. Here, we developed peroxidase-like heterostructured nanozyme, vertically arraying molybdenum disulfide nanosheets on a substrate layer of nitrogen-doped reduced graphene oxide (MoS₂/N-rGO), with a well-pleasing stability that is characterized by the retained enzymatic activity and maintained structure after 2 years of casual storage at ambient temperatures or 80 cycles of catalytic reaction. The catalytic kinetics of the as-prepared heterostructured nanozyme was superior to some reported nanozymes and even horse radish peroxidase, which was demonstrated due to the defect-rich MoS₂ with Mo and S vacancies and nitrogen-doped rGO experimentally and theoretically. The vertically heterostructured nanozyme exhibited adequate analytical performance in sensitive and quantitative detection of glucose and glutathione (GSH), with a large dynamic sensing range and extremely low limit of detection (0.02 and 0.12 μM (3σ/slope) for glucose and GSH, respectively). We hope this inspired artificial nanozyme will contribute to the future development in sensitive detection of other biomolecules in physiological conditions.

Ecotoxicological effect of ketoconazole on the antioxidant system of Daphnia similis

The occurrence of emerging pharmaceutical pollutants (i.e. small drugs, antibiotics) present in aquatic environments shown to be a current environmental problem still without apparent solution. In this regard, the use of ecotoxicological techniques has been shown fundamental for the appraisal of damage to affected living organisms. Herein, ecotoxicological tests were conducted, focusing on the evaluation of the effects of ketoconazole (KTZ) on the antioxidant system of the model body Daphnia similis. In order to study the biochemical changes caused by KTZ in the antioxidant system, the enzymatic biomarkers glutathione S-transferase (GST), catalase (CAT), and ascorbate peroxidase (APX) were monitored. Toxicological tests were conducted using KTZ concentrations (0-10 μg·L^-1). Prolonged exposure to KTZ (336 h) caused changes upon the expression of antioxidant enzymes and simultaneously affected the reproductive system in those organisms. Moreover, a decrease in GST and APX activity was observed caused by KTZ exposure, respectively 79.2% (3.53 μmol min^-1 mg^-1 protein) and 24.4% (0.88 μmol min^-1 mg^-1 protein). On the other hand, it was observed an increase of 27% (0.17 μmol min^-1 mg^-1 protein) in CAT activity. Through this study, it was possible to observe the toxicological effects of KTZ, which proves its action as an oxidative stress-inducing agent and endocrine modifier in daphnids organisms.

Glutathione Participation in the Prevention of Cardiovascular Diseases

Cardiovascular diseases (CVD) (such as occlusion of the coronary arteries, hypertensive heart diseases and strokes) are diseases that generate thousands of patients with a high mortality rate worldwide. Many of these cardiovascular pathologies, during their development, generate a state of oxidative stress that leads to a deterioration in the patient's conditions associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Within these reactive species we find superoxide anion (O2•-), hydroxyl radical (•OH), nitric oxide (NO•), as well as other species of non-free radicals such as hydrogen peroxide (H2O2), hypochlorous acid (HClO) and peroxynitrite (ONOO-). A molecule that actively participates in counteracting the oxidizing effect of reactive species is reduced glutathione (GSH), a tripeptide that is present in all tissues and that its synthesis and/or regeneration is very important to be able to respond to the increase in oxidizing agents. In this review, we will address the role of glutathione, its synthesis in both the heart and the liver, and its importance in preventing or reducing deleterious ROS effects in cardiovascular diseases.

Antioxidant-rich fraction of Amomum subulatum fruits mitigates experimental methotrexate-induced oxidative stress by regulating TNF-α, IL-1β, and IL-6 proinflammatory cytokines

The culinary spice Amomum subulatum was assessed for its phytochemical composition, in vitro antioxidant potential, and in vivo ameliorating effect against methotrexate (MTX)-induced toxicities. Phytochemical analysis of methanolic extract of A. subulatum dry fruits (MEAS) confirmed the presence of different bioactive secondary metabolites. MEAS scavenged reactive free radicals and inhibited lipid peroxidation in vitro. To confirm the antioxidant efficiency of MEAS, in vivo experiment was carried out in which MTX was administered to induce oxidative stress. Co-administration of MEAS reduced MTX-induced hepatic, renal, and pulmonary toxicities via significantly (p < .01) enhancing antioxidant status and reducing oxidative stress. MTX treatment significantly (p < .01) increased liver and kidney toxicity markers and increased proinflammatory cytokine (TNF-α, IL-1β, and IL-6) levels. However, co-administration of MEAS significantly (p < .01) reduced their levels, and tissue histopathology confirmed the protective effect of MEAS in maintaining normal tissue architecture following MTX treatment. Protective effect of MEAS is accredited to the antioxidant and anti-inflammatory properties exhibited by bioactive compounds in MEAS. PRACTICAL APPLICATIONS: Amomum subulatum (Black cardamom) is a folkloric and culinary spice used for its organoleptic, nutritional, and medicinal properties. This study demonstrated the phytochemical composition and antioxidant potential of methanolic extract of A. subulatum dry fruits (MEAS). Toxicities associated with MTX therapy limit its clinical application. MEAS attenuated methotrexate-induced oxidative stress, inflammation, and associated organ damages, suggesting the possible therapeutic application of A. subulatum in reducing oxidative stress and associated diseases. Our results showed that A. subulatum is a potential functional food, which may be used for the betterment of health due to its richness in antioxidant and anti-inflammatory phytochemicals.

Dual Enzyme-Like Performances of PLGA Grafted Maghemite Nanocrystals and Their Synergistic Chemo/Chemodynamic Treatment for Human Lung Adenocarcinoma A549 Cells

In recent years, the emergence of non-toxic but catalytically active inorganic nanoparticles has attracted great attention for cancer treatment, but the therapeutic effect has been affected by the limited reactive oxygen species in tumors. Therefore, the combination of chemotherapy and chemodynamic therapy is regarded as a promising therapeutic strategy. In this paper, we reported the preparation and bioactivity evaluation of poly(lactic acid-co-glycolic acid) (PLGA) grafted-γ-Fe₂O₃ nanoparticles with dual response of endogenous peroxidase and catalase like activities. Our hypothesis is that PLGAgrafted γ-Fe₂O₃ nanoparticles could be used as a drug delivery system for the anti-tumor drug doxorubicin to inhibit the growth of lung adenocarcinoma A549 cells; meanwhile, based on its mimic enzyme properties, this kind of nanoparticles could be combined with doxorubicin in the treatment of A549 cells. Our experimental results showed that the PLGAgrafted γ-Fe₂O₃ nanoparticles could simulate the activity of catalase and decompose hydrogen peroxide into H₂O and oxygen in neutral tumor microenvironment, thus reducing the oxidative damage caused by hydrogenperoxide to lung adenocarcinoma A549 cells. In acidic microenvironment, PLGA grafted γ-Fe₂O₃ nanoparticles could simulate the activity of peroxidase and effectively catalyze the decomposition of hydrogen peroxide to generate highly toxic hydroxyl radicals, which could cause the death of A549 cells. Furthermore, the synergistic effect of peroxidase-like activity of PLGA-grafted γ-Fe₂O₃ nanoparticles and doxorubicin could accelerate the apoptosisand destruction of A549 cells, thus enhancing the antitumor effect of doxorubicin-loaded PLGA-grafted γ-Fe₂O₃ nanoparticles. Therefore, this study provides an effective nanoplatform based on dual inorganic biomimetic nanozymes for the treatment of lung cancer.

Selective detection of glutathione by flower-like NiV2O6 with only peroxidase-like activity at neutral pH

In view of the broad application prospect of peroxidase-like nanozymes in biomedical analysis, it is of great significance to eliminate the interference of their oxidase-like activity and enable them to work under neutral conditions. Herein, flower-like NiV₂O₆ was synthesized and their enzyme-mimicking activity was investigated. Through the regulation of pH, NiV₂O₆ nanozyme showed only peroxidase-like activity but not oxidase-like activity under neutral conditions, which could catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine into its blue product in the presence of H₂O₂. Furthermore, based on the competitive effect of glutathione (GSH) on the catalytic activity of nanozymes, a semi-quantitative/quantitative colorimetric assay was established for GSH detection by using peroxidase-like NiV₂O₆. The assay exhibited a good linear relationship in GSH concentration ranging from 3-100 μmol L^-1, with a detection limit of 0.89 μmol L^-1. Moreover, in the presence of formaldehyde as masking agent, this method showed satisfactory specificity for GSH under the interference of a variety of interfering substances and even biothiols. Concerning the practical application, the system was applied to monitor GSH level in fetal bovine serum, human serum and SiHa cells. Satisfyingly, the obtained results were consistent well with those of Ultra performance liquid chromatography (UPLC) and assay kit, indicating the constructed assay has great potential in clinical application.

Glutathione in the Nervous System as a Potential Therapeutic Target to Control the Development and Progression of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rare neurological disorder that affects the motor neurons responsible for regulating muscle movement. However, the molecular pathogenic mechanisms of ALS remain poorly understood. A deficiency in the antioxidant tripeptide glutathione (GSH) in the nervous system appears to be involved in several neurodegenerative diseases characterized by the loss of neuronal cells. Impaired antioxidant defense systems, and the accumulation of oxidative damage due to increased dysfunction in GSH homeostasis are known to be involved in the development and progression of ALS. Aberrant GSH metabolism and redox status following oxidative damage are also associated with various cellular organelles, including the mitochondria and nucleus, and are crucial factors in neuronal toxicity induced by ALS. In this review, we provide an overview of the implications of imbalanced GSH homeostasis and its molecular characteristics in various experimental models of ALS.

Mediation effects of different sulfur forms on solubility, uptake and accumulation of Cd in soil-paddy rice system induced by organic carbon and liming

Liming is a safe and effective remediation practice for Cd contaminated acid paddy soil. The fate of Cd can also be strongly influenced by redox chemistry of sulfur. But it is unclear if, to what extent and how the combination of liming and sulfur mediation could further control Cd uptake by paddy rice. A rice cultivation pot experiment was conducted to evaluate the impact of different sulfur forms (S⁰ and SO₄^2- in K₂SO₄) on the solubility, uptake and accumulation of Cd in the soil-paddy rice system and how liming and reducing organic carbon mediate the process. Results showed that under neutral soil circumstances achieved by liming, co-application of K₂SO₄ and glucose significantly reduced brown rice Cd by 33%, compared to liming alone. They made it more readily for Cd²⁺ to be precipitated into CdS/CdS₂ or co-precipitate with newly formed FeS/FeS₂/iron oxides. The higher pH balancing capability of K₂SO₄ as well as liming kept the newly formed sulfide or iron containing minerals negatively charged to be more prone to adsorb Cd²⁺, that kept the porewater Cd²⁺ the lowest among all the treatments. Individual K₂SO₄ showed significant promoting effect on soil Cd solubility due to SO₄^2- chelation effect. Furthermore, K₂SO₄ had much weaker inhibiting effect on Cd translocation from root to grain, it showed no significant attenuating effect on brown rice Cd. S⁰ containing treatments displayed weaker or no attenuating effect on brown rice Cd due to its strong soil acidification effect. On the basis of liming, organic carbon induced sulfur (K₂SO₄) mediation showed great application potential for safe production on large areas of acid paddy soil contaminated by Cd.

α-Chaconine Affects the Apoptosis, Mechanical Barrier Function, and Antioxidant Ability of Mouse Small Intestinal Epithelial Cells

α-Chaconine is the most abundant glycoalkaloid in potato and toxic to the animal digestive system, but the mechanisms underlying the toxicity are unclear. In this study, mouse small intestinal epithelial cells were incubated with α-chaconine at 0, 0.4, and 0.8 μg/mL for 24, 48, and 72 h to examine apoptosis, mechanical barrier function, and antioxidant ability of the cells using a cell metabolic activity assay, flow cytometry, Western blot, immunofluorescence, and fluorescence quantitative PCR. The results showed that α-chaconine significantly decreased cell proliferation rate, increased apoptosis rate, decreased transepithelial electrical resistance (TEER) value, and increased alkaline phosphatase (AKP) and lactate dehydrogenase (LDH) activities, and there were interactions between α-chaconine concentration and incubation time. α-Chaconine significantly reduced the relative and mRNA expressions of genes coding tight junction proteins zonula occludens-1 (ZO-1) and occludin, increased malondialdehyde (MDA) content, decreased total glutathione (T-GSH) content, reduced the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and γ-glutamylcysteine synthetase (γ-GCS) and the mRNA expressions of SOD, CAT, GSH-Px, and γ-GCS genes. In conclusion, α-chaconine disrupts the cell cycle, destroys the mechanical barrier and permeability of mucosal epithelium, inhibits cell proliferation, and accelerates cell apoptosis.

The protective effect of lycopene against oxidative kidney damage associated with combined use of isoniazid and rifampicin in rats

It is known that the combined use of antibiotics, such as isoniazid and rifampicin, in the treatment of tuberculosis causes oxidative kidney damage. The aim of this study was to biochemically and histopathologically investigate the effect of lycopene on oxidative kidney damage due to the administration of isoniazid and rifampicin in albino Wistar male rats. Lycopene at a dose of 5 mg/kg was orally administered to lycopene+isoniazid+rifampicin (LIR) rats, and normal sunflower oil (0.5 mL) was orally administered to isoniazid+rifampicin (IR) and healthy control (HG) rats as vehicle by gavage. One hour after the administration of lycopene and vehicle, 50 mg/kg isoniazid and rifampicin were given orally to the LIR and IR groups. This procedure was performed once a day for 28 days. Rats were sacrificed by a high dose of anesthesia at the end of this period, and oxidant-antioxidant parameters were measured in the removed kidney tissues. Creatinine and blood urea nitrogen (BUN) levels were measured in blood samples, and kidney tissues were also evaluated histopathologically. The combined administration of isoniazid and rifampicin changed the oxidant-antioxidant balance in favor of oxidants, and it increased blood urea nitrogen and creatinine levels, which are indicators of kidney function. Co-administration of isoniazid and rifampicin also caused oxidative kidney damage. Lycopene biochemically and histopathologically decreased oxidative kidney damage induced by isoniazid and rifampicin administration. These results suggested that lycopene may be beneficial in the treatment of nephrotoxicity due to isoniazid and rifampicin administration.

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.

A Label-Free Fluorometric Glutathione Assay Based on a Conformational Switch of G-quadruplex

In this paper, a label-free fluorescent method for glutathione (GSH) detection based on a thioflavin T/G-quadruplex conformational switch is developed. The sensing assay is fabricated depending on the virtue of mercury ions to form a thymine–thymine mismatch, which collapses the distance between two ssDNA and directs the guanine-rich part to form an intra-strand asymmetric split G-quadruplex. The newly formed G-quadruplex efficiently reacts with thioflavin T and enhances the fluorescent intensity. In the presence of GSH, Hg²⁺ is absorbed, destroying the G-quadruplex formation with a significant decrease in fluorescence emission. The proposed fluorescent assay exhibits a linear range between 0.03–5 μM of GSH with a detection limit of 9.8 nM. Furthermore, the efficacy of this method is examined using human serum samples to detect GSH. Besides GSH, other amino acids are also investigated in standard samples, which display satisfactory sensitivity and selectivity. Above all, we develop a method with features including potentiality, facility, sensitivity, and selectivity for analyzing GSH for clinical diagnostics.

The effects of glutathione ethyl ester in in vitro maturation on the developmental ability of oocytes derived from cattle with liver abnormalities

The main objectives of this study was to identify the effects of a relationship of hyper-concentration of Gamma-glutamyltransferase (γ-GTP) in follicle fluid (FF) on the levels of glutathione (GSH)/reactive oxygen species (ROS) in oocytes and subsequent embryo development in cattle with abnormal livers. Furthermore, we investigated the effect of supplementing in vitro maturation medium with glutathione ethyl ester (GSH-OEt) on the subsequent developmental potential of oocytes from such cattle. We used a control group of cattle (with normal livers) and a liver disorder (LD) group, in which the liver was diagnosed as being abnormal. In experiment 1, the LD group was divided to two subgroups according to the concentration of γ-GTP in FF: a low group (≤50 IU/L; the low LD group), and a high group (>50 IU/L: the high LD group). Cumulus oocyte-complexes (COCs) were matured and fertilized in vitro and then cultured to the blastocyst stage. The levels of GSH and ROS in the matured oocytes after IVM were then assessed in each group. On day 7 after fertilization, embryo cleavage and development were assessed. We found that the rate of development to the blastocyst stage was significantly lower in the high LD group than in the control group and the low LD group. The levels of GSH in matured oocytes were significantly lower in the high LD group than in the control group and low LD group. The levels of ROS in matured oocytes was significantly higher in the high LD group than in the control group and the low LD group. In experiment 2, COCs from cattle in the high LD group were matured in m-199 supplemented with 5 mM GSH-OEt, then IVF and IVC was performed for 7 days. The GSH levels were determined in some COCs after IVM. The supplementation of media with GSH-OEt during IVM increased the levels of GSH in mature oocytes and improved the rate of blastocyst development compared with the control group. In conclusion, GSH-OEt supplementation to media during IVM can improve the developmental potential of oocytes in liver-diseased cattle with high γ-GTP concentrations in the FF by increasing intracellular GSH synthesis and scavenging ROS.