Glutathione Peroxidase Gpx Research Articles

Association of Protein Energy Wasting and Oxidative Stress Markers in Peritoneal Dialysis.

Protein-energy wasting (PEW) is highly prevalent among patients undergoing peritoneal dialysis (PD), and it has been proposed that oxidative stress (OS) may contribute to its pathogenesis. This study was an attempt to determine the association between the presence of PEW and OS levels in PD patients. This analytical cross-sectional study involved 62 clinically stable PD patients aged ≥ 18 years, between September 2017 and July 2018. PEW was assessed using PEW definition criteria, 7-point Subjective Global Assessment (SGA), and Malnutrition-Inflammation Score (MIS). Redox state was evaluated through oxidants (lipoperoxides, 8-Isoprostane, nitric oxide), antioxidants (superoxide dismutase, catalase, glutathione peroxidase-GPx, total antioxidant capacity), and oxidative DNA damage [8-hydroxy2'-deoxyguanosine-8-OHdG, 8-Oxoguanine-DNA-N-Glycosylase-1(8-OHdG)]. Among study participants, 38 (61.2%) were males and 24 (38.8%) were females; 22 (35.4%) had diabetes mellitus [males 15 (68.1%) and females 7 (31.8%)]. The average PD duration was 11 (4-27) months, body mass index: 23.5 ± 4.1 kg/m2, energy intake: 1138.4 ± 394.2 kcal/day, and protein intake: 50.2 ± 18.5 g/day. Prevalence of PEW varied based on the assessment method used (50-88.7%). Plasma 8-OHdG levels were higher in patients with PEW evaluated by MIS (0.1 [0.1-56.4] vs. 1.8 [0.1-74.7] ng/mL, P = .028), while GPx activity was lower in the presence of PEW as measured by MIS (3.6 [3.1-7.6] vs. 2.8 [1.2-10] nmol/min/mL, P = .021). No significant differences were observed between PEW markers and remaining OS levels. In PD patients with PEW, assessed by MIS, 8-OHdG was significantly increased, while GPx activity was significantly low.

Hepatic GPx1 and GIT1 expression altered by ethanol exposure during third trimester-equivalent development

Background Ethanol (EtOH) exposure throughout gestation and breastfeeding leads to multiple adverse outcomes in the hepatic system. Under oxidative stress, alterations in the liver are related to the inhibition of induced nitric oxide synthase activity in sinusoidal cells as a consequence of low expression of G-protein-coupled receptor (GPCR)-kinase interacting (GIT1). Here, we hypothesized that both glutathione peroxidase 1 (GPx1) and GIT1 could be altered by EtOH exposure during the third trimester of human equivalent development. Methods We exposed rats during the third trimester equivalent [postnatal days (PD) 2-8] to moderate levels of maternal EtOH (20%). GPx1 and GIT1 expression was detected by western blotting, and the antioxidant activity of glutathione peroxidase GPx and the concentration of hepatic carbonyl groups (CG were determined by spectrophotometry. Serum biochemistry parameters such as alanine aminotransferase (ALT), glucose (gluc), cholesterol (chol), and triglycerides (TG) were also measured. Results We found that ethanol decreased both GIT1 and GPx1 selenoprotein expression, affecting GPx antioxidant activity and increasing protein oxidation. Conclusions These results demonstrate for the first time that the GPx antioxidant system altered by EtOH exposure during the third trimester of development is related to a parallel decrease in GIT1 expression [1].

Hepatic GPx1 and GIT1 expression altered by ethanol exposure during third trimester-equivalent development

Background Ethanol (EtOH) exposure throughout gestation and breastfeeding leads to multiple adverse outcomes in the hepatic system. Under oxidative stress, alterations in the liver are related to the inhibition of induced nitric oxide synthase activity in sinusoidal cells as a consequence of low expression of G-protein-coupled receptor (GPCR)-kinase interacting (GIT1). Here, we hypothesized that both glutathione peroxidase 1 (GPx1) and GIT1 could be altered by EtOH exposure during the third trimester of human equivalent development. Methods We exposed rats during the third trimester equivalent [postnatal days (PD) 2-8] to moderate levels of maternal EtOH (20%). GPx1 and GIT1 expression was detected by western blotting, and the antioxidant activity of glutathione peroxidase GPx and the concentration of hepatic carbonyl groups (CG were determined by spectrophotometry. Serum biochemistry parameters such as alanine aminotransferase (ALT), glucose (gluc), cholesterol (chol), and triglycerides (TG) were also measured. Results We found that ethanol decreased both GIT1 and GPx1 selenoprotein expression, affecting GPx antioxidant activity and increasing protein oxidation. Conclusions These results demonstrate for the first time that the GPx antioxidant system altered by EtOH exposure during the third trimester of development is related to a parallel decrease in GIT1 expression [1].

Microelements, Fatty Acid Profile, and Selected Biomarkers in Grass Carp (Ctenopharyngodon idella) Muscle Tissue: Seasonal Variations and Health Risk Assessment

AbstractThe study assesses associations between microelement levels, fatty acid composition, and oxidative stress markers in grass carp muscle in the summer and autumn seasons. Additionally, various factors were considered, including the estimated daily intake (EDI), target hazard quotient (THQ), total THQ (TTHQ), and metal pollution index (MPI), to evaluate potential health risks for consumers. The microelements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Ni, Pb, Se, Sr, and Zn) were determined using inductively coupled plasma optical emission spectrometry (ICP-OES), and total mercury was determined using cold-vapor atomic absorption spectroscopy (CV-AAS). Fatty acid profiling was realized using gas chromatography (GC) detection with a flame ionization detector (FID). The overall tendency of microelement levels was as follows: Fe > Zn > Al > Sr > Ba > Ni > Se > Cr> Cu > Mn > Pb > As > Li > Hg; <LOQ (below limit of quantification): Cd, and Co. The correlation analysis between concentrations of trace elements (Al, Ba, Cr, Cu, Mn, Li, Sr, Zn, and Hg) and the fatty acids (C16:0, C16:1, C18:1n9c, C18:2n6c, C20:4n6c, EPA, and DHA), as well as between Al, Ba, Fe, or Hg and oxidative stress markers (superoxide dismutase—SOD, glutathione peroxidase—GPx, or total antioxidant status—TAS), revealed statistically significant interactions in different seasons. THQ values were lower than 1; TTHQ values ranged from 0.27 to 0.76. The main toxic elements forming TTHQ were Hg and Ni (49%). The calculated health risk assessment indices indicate a low concentration of observed elements and low risks associated with the consumption of grass carp muscle from the tested location, although concentrations and THQ of mercury and nickel may be of slight concern.

Impact of Adherence to the Mediterranean Diet on Antioxidant Status and Metabolic Parameters in NAFLD Patients: A 24-Month Lifestyle Intervention Study.

The Mediterranean Diet (MedDiet) is recognized as a healthy dietary pattern. Non-alcoholic fatty liver disease (NAFLD) is characterized by the excessive accumulation of fat in the liver. To assess the antioxidant status in erythrocytes, plasma, and peripheral blood mononuclear cells (PBMCs) of NAFLD patients following a 24-month lifestyle intervention based on the MedDiet. Adult patients (n = 40; aged 40-60 years) diagnosed with NAFLD by magnetic resonance imaging were divided into two groups based on their adherence to the MedDiet. Consumption was assessed using a validated 143-item semiquantitative Food Frequency Questionnaire. Anthropometrics, biochemistry parameters, intrahepatic fat contents (IFC), antioxidants, and inflammatory biomarkers were measured in plasma and erythrocytes before and after the intervention. After the intervention, body mass index (BMI) and plasma levels of total cholesterol, low-density lipoprotein cholesterol (LDL-chol), triglycerides, malondialdehyde (MDA), and cytokeratin-18 (CK18) decreased, and high-density lipoprotein cholesterol (HDL-chol) increased. Participants with high adherence to MedDiet showed lower IFC, hepatic enzyme (AST, ALT, and GGT), glycemia, oxidase LDL (oxLDL) plasma levels, and erythrocyte MDA levels. Higher antioxidant activity (erythrocyte catalase-CAT, superoxide dismutase-SOD, glutathione peroxidase-GPx, glutathione reductase-GRd, and total glutathione-GSH as well as PBMCs-CAT gene expression) was observed in these patients, along with a reduction of PBMCs reactive oxygen species production and Toll-like receptor 4 (TLR4) expression. Inverse associations were observed between adherence to the MedDiet and BMI, glycemia, AST, IFC, and CK18 plasma levels and oxLDL, CAT, SOD, and GRd activities in erythrocytes. A significant linear regression was observed between adherence to the MedDiet and antioxidant score. Adherence to the MedDiet is associated with improved plasma and PBMC antioxidant and inflammatory biomarker profiles and high antioxidant defences in erythrocytes.

The Effect of Chronic Bacterial Prostatitis on Levels Antioxidant in Adult Men: A Meta-Analysis of Case-control Studies

Globally, adult males are frequently affected with chronic bacterial prostatitis (CBP), a prevalent urological illness. It is believed that the inflammatory reaction linked to CBP causes oxidative stress, which may change the impacted people's levels of enzyme antioxidants the Effect of Chronic Bacterial Prostatitis on Levels Enzymatic Antioxidant. From October - 2022 to August - 2023, examined 270 clinical samples from subjects males (adults). Two groups were divided: the first group consisted of 180 male patients. In contrast, the second group consisted of 90 healthy males (adults). Blood samples of (3-5) ml were collected from all participants and the levels of zinc, selenium, glutathione peroxidase GPx, superoxide dismutase SOD, and catalase CAT were measured. The results showed that the levels of zinc, selenium, GPx, SOD, and CAT in men with chronic bacterial prostatitis were significantly lower than those in the control group of patients who were visited after ethical treatment at AL-Sader Medical City in Najaf Governorate. Aspects approved by the Medical Ethics Committee of the Iraqi Ministry of Health. The aim of this meta-analysis is to statistically evaluate and in-depth examine the case-control studies conducted so far regarding the effects of CBP on the levels of enzymatic antioxidants in adult men.

Study protective role Camellia sinensis L. (black tea) and silver, Zn oxide nanoparticles on antioxidant-oxidant enzymes and biochemical level against paracetamol overdose in adult male rats

This study aims to measure the preventive effect of the silver, Zn oxide nanoparticles, and Camellia sinensis L. (black tea) on liver toxicity caused by the paracetamol drug. The Nanomaterials, with a practical size range of 33–40nm, black tea was extracted by Soxhlet apparatus using methanol alcohol at a concentration (80%); design in this study, 60 adult male rats weighing between 195 and 330 g and aged 11 to 14 weeks were used. They were kept in a relatively regulated setting with a temperature of 25Co at the University of Karbala’s animal facility. They received food. There were eight rat group divisions. G1: just received saline solution (0,85%) as the control. G2: 250 milligrams of black tea and 250 milligrams of paracetamol per kilogram of body weight. G3: 400 milligrams of C. sinensis L. and 250 milligrams of paracetamol per kilogram of body weight. G4: injection of 0.3 milligrams of zinc nanoparticles and 250 milligrams of paracetamol per kilogram of body weight. G5: injection of 0.5 milligrams of zinc nanoparticles and 250 milligrams of paracetamol per kilogram of body weight. G6: injection of 0.3 milligrams of silver nanoparticles and 250 milligrams of paracetamol per kilogram of body G7: injection of 0.5 milligrams of silver nanoparticles and 250 milligrams of paracetamol per kilogram of body, G8: 250 milligrams of paracetamol per kilogram of body administered intravenously, the blood bled for 30 days after receiving all dosages orally once daily for 21 days. When rats were given injections of 0.5 mg of nanoparticles and when injections of 250 mg of a black tee., it was discovered that the concentration of Malondialdehyde MDA, Lipid Peroxidation LPO, Triacylglycerid, cholesterol levels, and glucose decreased significantly. In contrast, Glutathione peroxidase GPX and protein levels are increased considerably. This was due to the injections’ preventive and antioxidant action against the oxidative stress brought on by the paracetamol height dose. Keywords: silver nanoparticles, Zn oxide nanoparticles, Camellia sinensis L., paracetamol.

Salvia officinalis restores semen quality and testicular functionality in cadmium-intoxicated male rats

The present study investigated the potential ability of Salvia officinalis, one of the oldest medicinal plants, to protect male rats against cadmium reproductive toxicity. Twenty-eight healthy male rats were randomly allocated into four groups (n = 7); control, Salvia-extract treated group, cadmium treated group and a group treated with both Cd and Salvia. Administration of cadmium reduced the relative testis to body weight and significantly affected sperm parameters by decreasing motility, viability, count and increasing morphological aberrations. Comet assay was used to detect DNA fragmentation in sperms of the rats exposed to Cd. Serum levels of testosterone T, follicle stimulating hormone FSH, and luteinizing hormone LH were significantly decreased. The biochemical analysis of testicular tissue showed a significant rise in Malondialdehyde MDA level coupled with a decrease in the activity of antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx and catalase CAT). The histological examination of testis sections after Cd administration revealed severe degeneration of spermatogenic cells. Seminiferous tubules were filled with homogenous eosinophilic fluid associated with atrophy of other seminiferous tubules. Co-treatment with the Salvia officinalis extract restored the oxidative enzymes activities and decreased the formation of lipid peroxidation byproduct, which in turn ameliorated the effect of Cd on sperm parameters, DNA damage and testis histopathology. Taken together, it can be concluded that the synergistic antioxidant and radical savaging activities of Salvia officinalis prevented the effect of Cd on semen quality, sperm DNA damage, along with the oxidative stress and histological abnormalities in the testis tissues.

GPx-1 isoenzyme - biomarker in the assessment of lipid oxidative risk, immunogenesis and arrhythmogenic potential

Abstract Introduction Biomarkers such as glutathione peroxidase-GPx and superoxid dismutase-SOD can assess oxidative status of the body. Oxidative stress imbalances trigger lipid immunogenic modification with important role in atherosclerosis onset process. The present study evaluates GPx-1 because this enzyme isoform is widely expressed in cardiac and vascular structures. Reduction of GPx-1 level indicates the need to correct oxidative imbalance, for prevention of early atherosclerosis onset and cardiovascular diseases. Also, lipid cellular membrane oxidation, under the agression of increased oxidation perturbates calcium transport inside endoplasmattic reticulum, thus affecting normal heart rhyhm (causing arrythmias). Purpose Determination of GPx-1-isoform enzyme in correlation with oxidative status and implicitly with demonstration of oxidative activity on lipids, with the production of oxydized lipoprotein (LDLox) and anti-oxydized lipoprotein autoantibodies (antiLDLox) and the early initiation of atherogenic endothelial dysfunction. Patients and methods: The present study was conducted on 150 patients, aged between 20-45 years old, divided equally into three groups. All the selected patients were without structural cardiovascular pathology. The first two groups presented functional cardiac arrhythmic disorders. The first group (group I) presented only cardiac rhythm disturbances, while the second one (group II) associated also dyslipidemia. The third group (group III) was control, without cardiovascular manifestations or other pathology. Clinical and paraclinical explorations were performed (biochemical, imaging, electocardiogram). In all patients, the GPx-1 isoform was determined, in hemolyzate serum, using standard methods. At the same time, LDLox and antiLDLox antibodies levels were assessed. Results . Mean values of GPx1- isoform were decreased up to 73% in group I, compared to the control and up to 68% in group II, thus implying a proarrhythmogenic oxidative status. In these patients, both dyslipidemic and non-dyslipidemic, the association of decreased GPx enzyme with a high oxidative status for lipids was observed by associating increased lipid oxidation biomarkers - oxidized LDL up to 140% in group I and 177% in group II. Also, as response, a concomitant increase of anti-LDLox autoantibodies was correlated (124% for group I and 156% for group II), indicating increased immunogenesis and the risk of endothelial immune inflammation. Conclusions 1. GPx1 isoenzyme is a biomarker that reflects the existence of oxidative stress and also the risk of early development of lipid oxidation. 2. Decreased GPx level correlates with increased LDLox and antiLDLox autoantibodies levels. 3. GPx evaluation is a necessity in assessing early atherogenic risk and arrhythmogenic potential. 4. Early correction of GPx (through diet, antioxidants) may constitute a prophylaxis of early atherosclerosis and its severe cardiovascular consequences.

Degradation of low-density polyethylene by the bacterium Rhodococcus sp. C-2 isolated from seawater

Low-density polyethylene (LDPE), which accounts for 20% of the global plastic production, is discharged in great quantities into the ocean, threatening marine life and ecosystems. Marine microorganisms have previously been reported to degrade LDPE plastics; however, the exploration of strains and enzymes that degrade LDPE is still limited. Here, an LDPE-degrading bacterium was isolated from seawater of the Changjiang Estuary, China and identified as Rhodococcus sp. C-2, the relative abundance of which was dramatically enhanced during PE-degrading microbial enrichment. The strain C-2 exhibited the degradation of LDPE films, leading to their morphological deterioration, reduced hydrophobicity and tensile strength, weight loss, as well as the formation of oxygen-containing functional groups in short-chain products. Sixteen bacterial enzymes potentially involved in LDPE degradation were screened using genomic, transcriptomic, and degradation product analyses. Thereinto, the glutathione peroxidase GPx with exposed active sites catalyzed the LDPE depolymerization with the cooperation of its dissociated superoxide anion radicals. Furthermore, an LDPE degradation model involving multiple enzymes was proposed. The present study identifies a novel PE-degrading enzyme (PEase) for polyethylene bioremediation and promotes the understanding of LDPE degradation.

Development of an assay pipeline for the discovery of novel small molecule inhibitors of human glutathione peroxidases GPX1 and GPX4

Selenoprotein glutathione peroxidases (GPX), like ubiquitously expressed GPX1 and the ferroptosis modulator GPX4, enact antioxidant activities by reducing hydroperoxides using glutathione. Overexpression of these enzymes is common in cancer and can be associated with the development of resistance to chemotherapy. GPX1 and GPX4 inhibitors have thus shown promise as anti-cancer agents, and targeting other GPX isoforms may prove equally beneficial. Existing inhibitors are often promiscuous, or modulate GPXs only indirectly, so novel direct inhibitors identified through screening against GPX1 and GPX4 could be valuable. Here, we developed optimized glutathione reductase (GR)-coupled GPX assays for the biochemical high-throughput screen (HTS) of almost 12,000 compounds with proposed mechanisms of action. Initial hits were triaged using a GR counter-screen, assessed for isoform specificity against an additional GPX isoform, GPX2, and were assessed for general selenocysteine-targeting activity using a thioredoxin reductase (TXNRD1) assay. Importantly, 70% of the GPX1 inhibitors identified in the primary screen, including several cephalosporin antibiotics, were found to also inhibit TXNRD1, while auranofin, previously known as a TXNRD1 inhibitor, also inhibited GPX1 (but not GPX4). Additionally, every GPX1 inhibitor identified (including omapatrilat, tenatoprazole, cefoxitin and ceftibuten) showed similar inhibitory activity against GPX2. Some compounds inhibiting GPX4 but not GPX1 or GPX2, also inhibited TXNRD1 (26%). Compounds only inhibiting GPX4 included pranlukast sodium hydrate, lusutrombopag, brilanestrant, simeprevir, grazoprevir (MK-5172), paritaprevir, navitoclax, venetoclax and VU0661013. Two compounds (metamizole sodium and isoniazid sodium methanesulfate) inhibited all three GPXs but not TXNRD1, while 2,3-dimercaptopropanesulfonate, PI4KIII beta inhibitor 3, SCE-2174 and cefotetan sodium inhibited all tested selenoproteins (but not GR). The detected overlaps in chemical space suggest that the counter screens introduced here should be imperative for identification of specific GPX inhibitors. With this approach, we could indeed identify novel GPX1/GPX2- or GPX4-specific inhibitors, thus presenting a validated pipeline for future identification of specific selenoprotein-targeting agents. Our study also identified GPX1/GPX2, GPX4 and/or TXNRD1 as targets for several previously developed pharmacologically active compounds.

Abstract 6038: KDM2B regulates Serine-Glycine-One Carbon (SGOC) metabolism by targeting the SGOC enzyme genes via a combination of direct and indirect epigenetic mechanisms

Abstract Our earlier studies had shown that overexpression of the JmjC domain histone demethylase KDM2B renders mouse embryo fibroblasts (MEFs) resistant to oxidative stress due to the role of KDM2B in the regulation of antioxidant mechanisms. Here we present evidence that the knockdown of KDM2B in basal-like breast cancer cell lines results in a decrease of Glutathione (GSH) levels, a secondary increase of intracellular ROS levels and in enhanced sensitivity to deubiquitinase inhibitors. The expression of the Glutamate-Cystine antiporter, the Glutamate-Cysteine Ligase GCLC/GCLM and the Glutathione Peroxidase GPX4, all of which regulate GSH abundance was not affected. To address the mechanism of the GSH regulation we carried out RNA-Seq, quantitative proteomics and metabolomics analyses in shKDM2B- and empty vector-transduced MDA-MB-231 cells. The results showed that the KD of KDM2B causes major shifts in metabolism and that one of the metabolic pathways whose activity depends on KDM2B is the SGOC pathway, which has a major role in GSH biosynthesis. Experiments in cultured cells confirmed the importance of KDM2B in the regulation of this pathway and they also showed that the inhibition of the pathway via the KD of KDM2B is partly responsible for the shKDM2B-induced inhibition of cell proliferation in culture and in xenograft experiments in NSG mice. More important, the transcriptomic signature of the SGOC pathway correlates with the expression of KDM2B in basal like mammary adenocarcinomas in the TCGA database. The genes encoding the majority of the enzymes in the SGOC pathway are known to be regulated by MYC and ATF4 and our data show that both MYC and ATF4 are under the regulatory control of KDM2B. ATAC-Seq and ChIP-Seq experiments in shKDM2B and control MDA-MB-231 cells also showed that KDM2B binds the promoter region of not only MYC and ATF4, but also of the genes encoding the SGOC enzymes and that it regulates chromatin accessibility and the abundance of H3K4me3/H3K27Ac active histone marks in these promoters. Overall, our data indicate that KDM2B regulates the SGOC pathway by targeting MYC and ATF4 and by making the promoters of the genes encoding the SGOC enzymes accessible to these regulators. Overall, our data provide new evidence on SGOC regulation, and identify novel KDM2B-dependent metabolic vulnerabilities in basal like breast cancer. Citation Format: Evangelia Chavdoula, Vollter Anastas, Allesandro La Ferlita, Julian Aldana, Giuseppe Carota, Mariarita Spampinato, Sameer Parashar, Ilaria Cosentini, Burak Soysal, Giovanni Nigita, Michael Freitas, Philip Tsichlis. KDM2B regulates Serine-Glycine-One Carbon (SGOC) metabolism by targeting the SGOC enzyme genes via a combination of direct and indirect epigenetic mechanisms. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6038.

Antioxidant enzymes activity and gene expression in wheat-stripe rust interaction at seedling stage

The current study was designed to determine the activity of antioxidant enzymes: superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione peroxidase GPX and catalase (CAT) and the expression of their genes in 10 wheat isogenic differential lines showing compatible and incompatible interactions with Puccinia striiformis. The enzyme activity was determined at 24 h after inoculation (24hai), 48 h after inoculation (48hai), and 72 h after inoculation (72hai). However, enzyme gene expression was determined only at 72hai. To fulfill the objectives, 12-day-old wheat seedlings of isogenic differential lines were inoculated with stripe rust race (race 574232). The results of the study showed that enzyme activity and gene expression was significantly high in incompatible interaction as compared to compatible interaction. The enzyme activity of SOD was high at 24hai in resistant isogenic differential lines. High enzyme activity (97.54 ± 4.84) was recorded in was recorded Yr5/6* Avocet S. Enzyme activities of CAT and APX were higher at 72hai in resistant isogenic differential lines. CAT, APX genes were significantly upregulated and while gene expression of SOD was low at 72hai.The results indicate a unique pattern of enzyme activity and gene expression of the antioxidant enzymes in the compatible and incompatible interaction is playing a crucial role in the plant defense system.

A study to assess the health effects of an anticancer drug (cyclophosphamide) in zebrafish (Danio rerio): eco-toxicity of emerging contaminants.

Cyclophosphamide (CP) is widely used for treating various kinds of cancer. Because of its high intake, metabolism and excretion, these anticancer medications have been detected in the aquatic environment. There is very limited data on the toxicity and effects of CP on aquatic organisms. The present study aims to assess the toxic effect of CP on certain oxidative stress biomarkers (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione-GSH, glutathione S-transferases-GST and lipid peroxidation-LPO), protein, glucose, metabolising enzymes (aspartate aminotransferase-AST, alanine aminotransferase-ALT), and ion-regulatory markers (sodium ions-Na+, potassium ions-K+, and chloride ions-Cl-), and histology in the gills and liver of Danio rerio at environmentally relevant concentrations (10, 100 and 1000 ng L-1). Exposure to CP for 42 days led to a significant decrease in SOD, CAT, GST, GPx and GSH levels in the gills and liver tissues of zebrafish. The level of lipid peroxidation in the gills and liver tissues of zebrafish was significantly increased compared to the control group. Chronic exposure significantly changes protein, glucose, AST, ALT, Na+, K+ and Cl- biomarkers. Fish exposed to different levels of CP showed necrosis, inflammation, degeneration and hemorrhage in the gills and hepatic tissues. The observed changes in the studied tissue biomarkers were proportional to both dose and time. In conclusion, CP at environmentally relevant concentrations causes oxidative stress, energy demand, homeostasis disturbances, and enzyme and histological alterations in the vital tissues of zebrafish. These alterations were similar to the toxic effects reported in mammalian models.

In vitro Antioxidant Response of the Equine Blood Treated by Leaf Extract of Ficus drupacea Thunb.

The present study aimed to evaluate the antioxidant potential of the aqueous extract derived from the leaves of Ficus drupacea Thunb. using oxidative stress biomarkers (2-thiobarbituric acid reactive substances (TBARS), aldehydic and ketonic derivatives of oxidatively modified proteins, and total antioxidant capacity) and antioxidant defences (activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase GPx), ceruloplasmin (CP) on the model of equine erythrocytes and plasma after incubation in vitro. Freshly collected leaves were washed, weighed, crushed, and homogenized in 0.1M phosphate buffer (pH 7.4) (in the proportion of 1:19, w/w). The equine erythrocytes and plasma were used in the current study. A volume of 0.1 mL of the F. drupacea extract was added to 1.9 mL of equine erythrocytes or plasma. For positive control (blank), 0.1 mL of phosphate buffer was used. The treatment of equine plasma and erythrocytes by extract derived from leaves of F. drupacea resulted in reduced lipid peroxidation and oxidatively modified protein. Treatment by extract resulted in a reduced erythrocyte TBARS level of 21.9% (p = 0.017) compared to the untreated samples. The levels of aldehydic and ketonic derivatives of oxidatively modified proteins were non-significantly decreased. The incubation of equine plasma with an extract derived from leaves of F. drupacea increased antioxidant defences. The activity of SOD and GPx were increased by 41.6% (p = 0.000) and 61.5% (p = 0.000) in the equine plasma after in vitro incubation with an extract derived from leaves of F. drupacea compared to the untreated samples. The level of total antioxidant capacity was non-significantly increased. However, further detailed investigation, especially in vivo and in vitro antioxidant studies is needed to justify the use of extract derived from leaves of F. drupacea as a natural source of antioxidants.

Antioxidant Potential of Diosmin and Diosmetin against Oxidative Stress in Endothelial Cells

Phlebotropic flavonoids, including diosmin and its aglycone diosmetin, are natural polyphenols widely used in the prevention and treatment of chronic venous insufficiency (CVI). As oxidative stress plays an important role in the development of pathophysiology of the cardiovascular system, the study aimed to investigate the protective effects of diosmin and diosmetin on hydrogen peroxide (H2O2)-induced oxidative stress in endothelial cells. The cells were pretreated with different concentrations of the flavonoid prior to the H2O2 exposure. The cell viability, the level of intracellular reactive oxygen species (ROS), the activity of cellular antioxidant enzymes-including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase GPx-and the malondialdehyde (MDA) level were assessed. It was found that the H2O2-induced oxidative stress was ameliorated by diosmin/diosmetin in a concentration-dependent manner. The flavonoids restored the activity of cellular antioxidant enzymes and lowered the MDA level upregulated by the H2O2 exposure. These results indicate that diosmin and diosmetin may prevent oxidative stress in endothelial cells; therefore, they may protect against the development and progression of oxidative-stress-related disorders.

Göynük Çayı'nda (Bingöl) yakalanan Cyprinion macrostomus dokularında antioksidan savunma sistemi göstergelerindeki mevsimsel değişiklikler

In this study, antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase GPx), glutathione reductase (GR) and glucose 6-phosphate dehydrogenase (G6PD)) and malondialdehyde (MDA) levels occurring throughout the year were examined in Cyprinion macrostomus tissues (kidney, gill, liver and gonad) captured from Göynük Stream (Bingöl, Turkey). For this purpose, two locations (Ilıcalar and Garip) where fish can be caught regularly in summer, autumn, winter and spring were determined. Fish were caught regularly from these two locations every month and brought to the laboratory. Spectrophotometric methods were used to determine enzyme activities and MDA levels in the study. As a result of the study, it was determined that the MDA level and enzyme activities between Ilıcalar and Garip stations, in general, were statistically different from each other in all tissues. However, it was observed that there were important differences in general between the seasons at both stations. In addition, while GR and G6PD activities were lower than other enzyme activities throughout the study, CAT and SOD activities were higher.

Bioaccumulation and biochemical responses in the peppery furrow shell Scrobicularia plana exposed to a pharmaceutical cocktail at sub-lethal concentrations

Pharmaceutical drugs in the aquatic medium may pose significant risk to non-target organisms. In this study, the potential toxicity of a mixture of three compounds commonly detected in marine waters (ibuprofen, ciprofloxacin and flumequine) was assessed, by studying bioaccumulation, oxidative stress and neurotoxicity parameters (catalase CAT, superoxide dismutase SOD, glutathione reductase GR, glutathione S-transferase GST, lipid peroxidation LPO, glutathione peroxidase GPX, metallothionein MT and acetylcholinesterase AChE) in the clam Scrobicularia plana. Temporal evolution of selected endpoints was evaluated throughout an exposure period (1, 7 and 21 days) followed by a depuration phase. The accumulation of all drugs was fast, however clams showed the ability to control the internal content of drugs, keeping their concentration constant throughout the exposure and reducing their content after 7 days of depuration. The induction of biochemical alterations (SOD, CAT, LPO, MT, AChE) was observed in gills and digestive gland probably related to an imbalance in the redox state of clams as a consequence of the exposure to the drug mixture. These alterations were also maintained at the end of the depuration week when the high levels of SOD, CAT, GST and LPO indicated the persistence of oxidative stress and damage to lipids despite the fact that clams were no longer exposed to the mixture.

Copper-induced Genotoxicity, Oxidative Stress, and Alteration in Transcriptional Level of Autophagy-associated Genes in Snakehead Fish Channa punctatus.

Copper (Cu) is an essential and important trace element for some significant life processes for most organisms. However, an excessive amount of Cu can be highly toxic. The present study was conducted to elucidate the oxidative stress-induced alteration in transcriptional level of autophagy-related genes in the liver and kidney tissue of fish Channa punctatus after treatment with three different sublethal concentrations of CuSO4for 28days. All the studied enzymatic and non-enzymatic oxidative stress markers viz. superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione reductase-GR, and glutathione-GSH showed an increase in their activity levels in the treated groups in a dose-dependent manner. Particularly SOD and CAT have shown a significant hike in activity levels. ROS levels in blood cells increased significantly (p < 0.05) in all the treated groups, i.e., Group II-1/20th of 96h-LC50 (0.2mg/L), Group III-1/10th of 96h-LC50 (0.4mg/L), and Group IV-1/5h of 96h-LC50 (0.8mg/L) of Cu2+ in a dose-dependent manner as compared to control (Group I). The upregulation in mRNA levels of autophagy-related genes Microtubule-associated protein 1 light chain 3 (LC3), Gamma-aminobutyric acid receptor-associated protein precursor (Gabarap), and Golgi-associated ATPase enhancer of 16kDa (GATE16), autophagy-related 5 (ATG5) was observed while mammalian target of rapamycin (mTOR) showed downregulation in the liver and kidney tissue of fish. The decrease in mTOR and increase in ATG5 gene expression projects autophagic vesicle formation due to oxidative stress. There was significant induction in micronuclei (MN) frequency in all the treated groups. The highest frequency of MN induced by Cu2+ was recorded in Group IV after 28days of the exposure period. Thus, it can be concluded that the available information about Cu2+-induced oxidative stress-mediated autophagy in the liver and kidney of fish C. punctatus remains largely unclear to date, so to fill the aforesaid gap, the present study was undertaken, which gives an insight for the mechanisms of autophagy induced by Cu2+ in fish.

MO929: Oxidative Stress in Hemodialysis Patients

Abstract BACKGROUND AND AIMS It is known that chronic kidney disease (CKD) is associated with complications such as anaemia, mineral bone disorders (CKD-MBD) or diselectrolytemia.Therefore, the diet of renal patients is restricted in different nutrients such as potassium or phosphorus, a fact that could potentially increase oxidative stress [1]. We investigated the relationship between an oxidative damage marker (malondialdehyde-MDA) on the one hand, and plasma antioxidant status (glutathione peroxidase-GPx) activity on the other hand with the nutritional status and with complications associated with CKD (anaemia, CKD-MBD). METHOD We conducted a single-centre cross-sectional study that included 58 CKD G5D patients (mean age of 60.39 ± 11.73 years; 33 males, 25 females; mean haemodialysis vintage of 6.43 ± 4.89 years). All patients have been assessed regarding dialysis status (medical history). We performed analysis before the dialysis session using standard methods blood biochemistry, complete blood count and using spectrophotometry (HPLC)-malondialdehyde and glutathione peroxidase. RESULTS The studied patients’ mean malondialdehyde was 1.41 ± 0.42 mcmol/L, while mean glutathione peroxidase was 58.65 ± 12.15 U/g Hg. The oxidative stress markers did not show any statistically significant correlation with age, gender, dialysis vintage or with predialysis urea and bicarbonate. Patients with a BMI &amp;gt; 30 kg/sqm (21 versus 37 patients) showed a significantly higher level of MDA 1.57 ± 0.51 mcmol/L versus 1.31 ± 0.33 mcmol/L, P = 0.02. We have also found a negative statistically significant correlation between MDA level and serum K (r = –0.29, P = 0.02) and serum phosphorus (r = –0.29, P = 0.03). Patients with predialysis K of higher then 5.5 mEq/L had a statistically significant lower MDA (1.29 ± 0.4 mcmol/L versus 1.54 ± 0.4 mcmol/L, P = 0.025) and a non-significant higher GPx (59.0 ± 12.58 U/g Hg versus 58.2 ± 11.87 U/g Hg, P = 0.8). We found a negative statistically significant correlation of the MDA level with haemoglobin (r = –0.39, P = 0.002) and with haematocrit (r = –0.35, P = 0.006). No statistically significant correlation of the plasma antioxidant GPx with the studied parameters of anaemia and CKD-MBD has been found. CONCLUSION In our study, we found that increased oxidative stress (expressed through the malondialdehyde level) is associated with obesity and more severe anaemia. The indirect relationship found with serum K and phosphorus could indicate the risk of oxidative stress, and therefore it could be useful to take into account the dietary antioxidants when recommending low potassium and low phosphorus diet.