Glutathione Disulfide Content Research Articles

Microcystin-LR sensitizes the Oncorhynchus mykiss intestinal epithelium and interacts with paralytic shellfish toxins to alter oxidative balance

In the context of harmful algal blooms, fish can be exposed to the combined effects of more than one toxin. We studied the effects of consecutive exposure to Microcystin-LR (MCLR) in vivo and paralytic shellfish toxins (PST) ex vivo/in vitro (MCLR+PST) in the rainbow trout Oncorhynchus mykiss's middle intestine. We fed juvenile fish with MCLR incorporated in the feed every 12 h and euthanized them 48 h after the first feeding. Immediately, we removed the middle intestine to make ex vivo and in vitro preparations and exposed them to PST for one hour. We analyzed glutathione (GSH) and glutathione disulfide (GSSG) contents, glutathione S-transferase (GST), glutathione reductase (GR), catalase (CAT), and protein phosphatase 1 (PP1) activities in ex vivo intestinal strips; apical and basolateral ATP-biding cassette subfamily C (Abcc)-mediated transport in ex vivo everted and non- everted sacs; and reactive oxygen species (ROS) production in isolated enterocytes in vitro. MCLR+PST treatment decreased the GSH content, GSH/GSSG ratio, GST activity, and increased ROS production. GR activity remained unchanged, while CAT activity only increased in response to PST. MCLR inhibited PP1 activity and activated Abcc-mediated transport only at the basolateral side of the intestine. Our results show a combined effect of MCLR+PST on the oxidative balance in the O. mykiss middle intestine, which is not affected by the two toxins groups when applied individually. Basolateral Abcc transporters activation by MCLR treatment could lead to an increase in the absorption of toxicants (including MCLR) into the organism. Therefore, MCLR makes the O. mykiss middle intestine more sensitive to possibly co-occurring cyanotoxins like PST.

Ferroptosis Is Crucial for Cisplatin Induced Sertoli Cell Injury via N6-Methyladenosine Dependent Manner.

This study aimed to investigate the effect of the N6-methyladenosine (m6A) dependent ferroptosis on cisplatininduced Sertoli cell injury. A cisplatin exposure mouse model was established by intraperitoneal injection of cisplatin in our study. TM4 cell lines was used for in vitro study. Ferroptosis was detected according to metabolomic analysis and a series of assays, including malondialdehyde, glutathione, and glutathione disulfide concentration detection, 2',7'-dichlorodihydrofluorescein diacetate and BODIPY 581/591 C11 probe detection, and transmission electron microscope imaging. Key ferroptosis-related genes were identified via transcriptomic analysis, western blot and immunohistochemistry. The m6A modification was demonstrated via m6A RNA immunoprecipitation and luciferase reporter assays. Immune cell infiltration was detected by mass cytometry, and verified by flow cytometry and immunofluorescence. Ferroptosis, but not other types of programmed cell death, is a significant phenomenon in cisplatin-induced testis damage and Sertoli cell loss. Ferroptosis induced by cisplatin in Sertoli cell/TM4 cell is GPX4 independent but is regulated by SLC7A11 and ALOX12. Both SLC7A11 and ALOX12 are regulated via m6A dependent manner by METTL3. Furthermore, overexpressed ALOX12-12HETE pathway may result in macrophage polarization and inflammatory response in cisplatin exposure testis. Cisplatin-induced Sertoli cell injury via ferroptosis and promoted ferroptosis in an m6A dependent manner. m6A modification of both SLC7A11 and ALOX12 mRNA could result in ferroptosis in our in vitro model. Further, overexpressed ALOX12 can cause more production of 12-HETE, which may be responsible for testis inflammation caused by cisplatin.

Impact of Nitrogen and Elemental Sulfur on Formation of Volatile Sulfur Compounds during Fermentation of Pinot Noir Grapes

The influence of yeast assimilable nitrogen (YAN) and elemental sulfur (S0) on the formation of volatile sulfur compounds (VSCs) during fermentation was investigated. Pinot noir fermentations were performed using Saccharomyces cerevisiae strain UCD522 or P1Y2 with an addition of 0, 5, or 15 µg/g elemental sulfur. H2S production during fermentation was measured using lead acetate tubes and additional VSCs measured by GC-PFPD. The addition of S0 resulted in H2S formation during alcoholic fermentation regardless of which yeast strain was used. H2S production was greater in fermentations performed by UCD522 with increasing amounts of S0 resulting in increased production of H2S. Higher S0 resulted in wines containing higher concentrations of methyl thioacetate and glutathione disulfide. Additional experiments examined the impact of nitrogen composition and S0. The addition of diammonium phosphate (DAP) resulted in an increase in H2S formation during fermentation whereas the addition of amino acids did not, whether S0 was added or not. Fermentations where DAP and S0 were both added produced a higher concentration of H2S compared to fermentations where S0 or DAP additions were made individually. VSCs in the wine were also impacted by the addition of nitrogen and/or S0 with the addition of S0 and nitrogen (DAP or amino acids) resulting in elevated concentrations of methyl thioacetate in the wines.

Exogenous Allantoin Confers Rapeseed (Brassica campestris) Tolerance to Simulated Drought by Improving Antioxidant Metabolism and Physiology.

Allantoin is an emerging plant metabolite, but its role in conferring drought-induced oxidative stress is still elusive. Therefore, an experiment was devised to explore the role of allantoin (0.5 and 1.0 mM; foliar spray) in rapeseed (Brassica campestris cv. BARI Sarisha-17) under drought. Seedlings at fifteen days of age were subjected to drought, maintaining soil moisture levels at 50% and 25% field capacities, while well-irrigated plants served as the control group. Drought-stressed plants exhibited increased levels of lipid peroxidation and hydrogen peroxide, electrolyte leakage, and impaired glyoxalase systems. Thus, the growth, biomass, and yield attributes of rapeseed were significantly impaired under drought. However, the allantoin-supplemented plants showed a notable increase in their contents of ascorbate and glutathione and decreased dehydroascorbate and glutathione disulfide contents under drought. Moreover, the activity of antioxidant enzymes such as ascorbate peroxidase, dehydroascorbate reductase, glutathione reductase, glutathione peroxidase, and catalase were accelerated with the allantoin spray and the glyoxalase system was also enhanced under drought. Moreover, the improvement in water balance with reduction in proline and potassium ion contents was also observed when allantoin was applied to the plants. Overall, the beneficial effects of allantoin supplementation resulted in the improved plant growth, biomass, and yield of rapeseed under drought conditions. These findings suggest that allantoin acts as an efficient metabolite in mitigating the oxidative stress caused by reactive oxygen species by enhancing antioxidant defense mechanisms and the glyoxalase system.

Glutathione Depletion Disrupts Redox Homeostasis in an Anoxia-Tolerant Invertebrate.

The upregulation of endogenous antioxidants is a widespread phenomenon in animals that tolerate hypoxia/anoxia for extended periods. The identity of the mobilized antioxidant is often context-dependent and differs among species, tissues, and stresses. Thus, the contribution of individual antioxidants to the adaptation to oxygen deprivation remains elusive. This study investigated the role of glutathione (GSH) in the control of redox homeostasis under the stress of anoxia and reoxygenation in Helix aspersa, an animal model of anoxia tolerance. To do so, the total GSH (tGSH) pool was depleted with l-buthionine-(S, R)-sulfoximine (BSO) before exposing snails to anoxia for 6 h. Then, the concentration of GSH, glutathione disulfide (GSSG), and oxidative stress markers (TBARS and protein carbonyl) and the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose 6-phosphate dehydrogenase) were measured in foot muscle and hepatopancreas. BSO alone induced tGSH depletion by 59-75%, but no other changes happened in other variables, except for foot GSSG. Anoxia elicited a 110-114% increase in glutathione peroxidase in the foot; no other changes occurred during anoxia. However, GSH depletion before anoxia increased the GSSG/tGSH ratio by 84-90% in both tissues, which returned to baseline levels during reoxygenation. Our findings indicate that glutathione is required to withstand the oxidative challenge induced by hypoxia and reoxygenation in land snails.

Interplay between the renin angiotensin system and oxidative stress contributes to alcohol addiction by stimulating dopamine accumulation in the mesolimbic pathway

The brain renin–angiotensin system (RAS) has recently been implicated in the development of substance abuse and addiction. However, the integrative roles of the two counter-regulating RAS arms, including the ACE1/Ang II/AT1R axis and the ACE2/Ang(1–7)/MasR axis, in alcohol addiction remain unclear. Using the 20% ethanol intermittent-access two-bottle-choice (IA2BC) paradigm, we observed significant alcohol preference and addictive behaviors in rats. Additionally, we observed significant disruption in the RAS and redox homeostasis in the ventral tegmental area (VTA), as indicated by upregulation of ACE1 activities, Ang II levels, AT1R expression, and glutathione disulfide contents, as well as downregulation of ACE2 activities, Ang(1–7) levels, MasR expression and glutathione content. Moreover, dopamine accumulated in the VTA and nucleus accumbens of IA2BC rats. Intra-VTA infusion of the antioxidant tempol substantially attenuated RAS imbalance and addictive behaviors. Intra-VTA infusion of the ACE1 inhibitor captopril significantly reduced oxidative stress, alcohol preference, addictive behaviors, and dopamine accumulation, whereas intra-VTA infusion of the ACE2 inhibitor MLN4760 had the opposite effects. The anti-addictive effects of the ACE2/Ang(1–7)/MasR axis were further observed using intra-VTA infusion of Ang(1–7) and a MasR-specific antagonist A779. Therefore, our findings suggest that excessive alcohol intake causes RAS imbalance via oxidative stress, and that a dysregulated RAS in the VTA contributes to alcohol addiction by stimulating oxidative stress and dopaminergic neurotransmission. Breaking the vicious cycle of RAS imbalance and oxidative stress using brain-permeable antioxidants, ACE1 inhibitors, ACE2 activators, or Ang(1–7) mimetics thus represents a promising strategy for combating alcohol addiction.

Combined enteral infusion of glutamine, carbohydrates, and antioxidants modulates gut protein metabolism in humans

Background:Available data suggest that nutrients can affect intestinal protein metabolism, which contributes to the regulation of gut barrier function. Objective:We aimed to assess whether an oral nutritional supplement (ONS) containing glutamine (as the dipeptide Ala-Gln), carbohydrates, and antioxidants would modulate duodenal protein metabolism in healthy humans. Design:Thirty healthy control subjects were included and, over a period of 5 h, received by nasogastric tube either saline or ONS providing 11.7 kcal/kg as 0.877 g Ala-Gln/kg, 3.9 g carbohydrates/kg, and antioxidants (29.25 mg vitamin C/kg, 9.75 mg vitamin E/kg, 195 μg β-carotene/kg, 5.85 mg Se/kg, and 390 μg Zn/kg) or glutamine (0.585 g/kg, 2.34 kcal/kg). Simultaneously, a continuous intravenous infusion of l-[1-13C]-leucine was done until endoscopy. Leucine enrichment was assessed by using gas chromatography–mass spectrometric analysis, and mucosal fractional synthesis rate was calculated by using intracellular amino acid enrichment as precursor. Mucosal proteolytic pathways were also evaluated. Results:ONS infusion resulted in a doubling increase (P < 0.01) of duodenal fractional synthesis rate and a significant (P < 0.05) decrease in cathepsin D–mediated proteolysis compared with saline, whereas proteasome and Ca2+-dependent activities were unaffected. ONS infusion significantly (P < 0.01) decreased duodenal glutathione but not glutathione disulfide concentrations or the ratio of glutathione to glutathione disulfide. Insulinemia increased after ONS infusion, whereas plasma essential amino acids decreased. Infusion of glutamine alone did not reproduce ONS effects. Conclusions:ONS infusion improves duodenal protein balance in healthy humans. Further investigations are needed to study the origin of these effects and to evaluate ONS supply in stressed persons.

Liver fibrosis is a common pathological change in the liver of dairy cows with fatty liver

Fatty liver (i.e., hepatic lipidosis) is a prevalent metabolic disorder in dairy cows during the transition period, characterized by excess hepatic accumulation of triglyceride (TG), tissue dysfunction, and cell death. Detailed pathological changes, particularly hepatic fibrosis, during fatty liver remain to be determined. Liver fibrosis occurs as a consequence of liver damage, resulting from the excessive accumulation of extracellular matrix, which distorts the architecture of the normal liver, compromising its normal synthetic and metabolic functions. Thus, we aimed to investigate liver fibrosis status and its potential causal factors including oxidative stress, hepatocyte apoptosis, and production of inflammatory cytokines in the liver of cows with fatty liver. Forty-five dairy cows (parity, 3-5) were selected, and liver biopsy and blood were collected on the second week postpartum (days in milk, 10-14 d). On the basis of the degree of lipid accumulation in liver, selected cows were categorized into normal (n = 25; TG <1% wet wt), mild fatty liver (n = 15; 1% ≤ TG <5% wet wt), and moderate fatty liver (n = 5; 5% ≤ TG <10% wet wt). Compared with normal cows, blood concentrations of nonesterified fatty acids and β-hydroxybutyrate, along with alanine aminotransferase and aspartate aminotransferase activities, were greater in the cows with fatty liver (mild and moderate). Hepatic extracellular matrix deposition, as indicated by Picrosirius red staining, was greater in cows with fatty liver than those with normal ones. In addition, we observed an increased proportion of collagen type I fiber in extracellular matrix with increased lipid accumulation in the liver. Compared with normal cows, the area of α-smooth muscle actin (α-SMA)-positive staining along with the mRNA abundance of collagen type I α 1 (COL1A1), ACTA2 (gene encoding α-SMA), and transforming growth factor-β (TGFB) were greater in cows with fatty liver. Compared with normal cows, hepatic contents of malondialdehyde, glutathione disulfide, and 8-isoprostane were greater, whereas total antioxidant capacity, the hepatic content of glutathione, and activities of antioxidant indicators, including superoxide dismutase, glutathione peroxidase, and catalase, were lower in cows with fatty liver. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells and abundance of apoptosis-related molecules BAX, CASP3, CASP8, and CASP9 were greater in cows with fatty liver. However, mRNA abundance of the anti-apoptotic gene BCL2 did not differ. The mRNA abundance of pro-inflammatory cytokines including tumor necrosis factor-α (TNFA), interleukin-1β (IL1B), and interleukin-6 (IL6) was greater in the liver of cows with fatty liver. Overall, the present study indicated that fibrosis is a common pathological response to liver damage and is associated with oxidative stress, hepatocyte death, and inflammation.

Glutathione treatment suppresses the adverse effects of microplastics in rice

Oryza sativa is grown worldwide and exhibit sensitivity to different stresses. Exponential increase in microplastics in agroecosystems is damaging and demand pragmatic strategies to protect growth and yield losses. We evaluated exogenous application of different doses of glutathione (GSH) for mediation of physiological traits of rice plants experiencing two different MPs i.e. PET and HDPE in root zone. All the rice seedlings exhibited MP-induced significant (P ≤ 0.001) growth inhibition compared to the control plants. GSH application (T3) significantly increased the shoot fresh weight (8.80%), root fresh weight (19.22%), shoot dry weight (13.705%), root dry weight (25.52%), plant height (5.75%) and 100-grain weight (9.36%), compared to control plants. GSH treated plants (T4) showed a recovery mechanism by managing the marginal rate of reduction of all photosynthetic and gas exchange attributes by showing 34.44, 20.98, 34.83, 42.16, 39.70, and 51.38% reduction for Chl-a, Chl-b, total cholophyll, photosynthetic rate (A), transpiration rate (E), and stomatal conductance (Gs), respectively, compared to control plants. Under 5 mg L−1 HDPE and PET, rice seedlings without GSH treatment responded in terms of increase in total soluble sugar, total free amino acid, glutathione, glutathione disulfide contents, while total soluble protein and ascorbic acid contents decreased significantly, compared with control plants. Corrleation matrix revealed positive relationship between GSH and improvement in studied attributes. Moreover, exogenous GSH improved rice growth and productivity to counter the negative role of MPs. This unique study examined the effects of GSH on rice plants growing in MP-contaminated media and revealed how exogenous GSH helps plants survive MP-stress.

Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation.

Thioredoxin reductase 3 (Txnrd3) plays a crucial role in antioxidant and anti-cancer activities, and sperm maturation. The damage of heavy metals, including Nickel (Ni), is the most prominent harm in social development, and hampering Txnrd3 might exacerbate Ni-induced cardiac damage. In this study, a total of 160 8-week-old C57BL/N male mice with 25-30 g weight of Txnrd3+/+ wild-type and Txnrd3-/- homozygote-type were randomly divided into eight groups. The mice in the control and Ni groups were gavaged with distilled water and a freshly prepared 10mg/kg NiCl2 solution. Melatonin (Mel) groups were administered at a concentration of 2mg/kg for 21 days at the mice's 0.1ml/10g body weight. Ni exposure up-regulated the messenger RNA (mRNA) levels of mitochondrial apoptosis (caspase-3, caspase-9, cytochrome c, p53, and BAX), autophagy (LC3, ATG 1, ATG 7, and Beclin-1), and inflammation (TNF-α, COX 2, IL-1β, IL-2, IL-6, and IL-7)-related markers, but down-regulated the mRNA levels of BCL-2, p62 and mTOR (p < .05). Ni exposure decreased the expression of BCL-2 and p62 protein but increased the expression levels of caspase-3, caspase-9, cytochrome c, p53, BAX, ATG 7, Beclin-1, TNF-α, COX 2, IL-1β and IL-2 protein (p < .05). Ni increased the contents of glutathione disulfide (GSSG) and malondialdehyde (MDA) and decreased the activities of catalase (CAT) and total superoxide dismutase (T-SOD) (p < .05). Decreased Txnrd3 expression significantly exacerbated changes compared to the Ni exposure (p < .05). Mel significantly attenuated these changes, but the effect decreased when Txnrd3 was inhibited (p < .05). In conclusion, decreased Txnrd3 expression promoted Ni-induced mitochondrial apoptosis and inflammation via oxidative stress and aggravated heart damage in mice. Decreased Txnrd3 expression significantly reduced the protective effect of Mel to Ni exposure.

Liensinine Inhibits Osteosarcoma Growth by ROS-Mediated Suppression of the JAK2/STAT3 Signaling Pathway.

Osteosarcoma (OS) is the most common malignancy of bone. Liensinine exerts antitumor effects on cancers of the colon, breast, and gallbladder. However, its antitumor activity in OS remains unclear. This study is aimed at investigating the efficacy of liensinine against OS and the underlying mechanism of action. Cell proliferation, apoptosis, and cycle arrest in OS were detected using the Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays, respectively. The production of reactive oxygen species (ROS), glutathione (GSH) and glutathione disulfide (GSSG) concentrations, and mitochondrial membrane potential (MMP) of OS cells were measured by flow cytometry, colorimetry, and JC-1 staining. The expressions of factors related to apoptosis, cell cycle, and activation of the JAK2/STAT3 pathway were determined by Western blotting. To examine the potential role of ROS, an antioxidant (N-acetyl cysteine, NAC) was used in combination with liensinine. In vivo, we generated a xenograft mouse model to assess its antitumor efficacy. Tissue level expressions of factors related to apoptosis and activation of the JAK2/STAT3 pathway were assessed by immunohistochemistry or Western blotting. Liensinine inhibited the proliferation and induced G0/G1 phase arrest and apoptosis of OS cells in a dose-dependent manner. Additionally, liensinine promoted intracellular ROS production, enhanced the GSSG/GSH ratio, and induced MMP loss and ROS-mediated suppression of the JAK2/STAT3 pathway. NAC significantly attenuated the liensinine-induced antitumor activities and activated the JAK2/STAT3 pathway. In vivo, liensinine effectively inhibited the OS growth and promoted apoptosis; however, it had no negative effect on the internal organs. In conclusion, liensinine-induced ROS production could suppress the activation of the JAK2/STAT3 pathway and inhibit the OS growth both in vivo and in vitro. Our findings provided a new rationale for subsequent academic and clinical research on OS treatment.

NRF2 activation protects against valproic acid-induced disruption of neurogenesis in P19 cells

Valproic acid (VPA) is a commonly prescribed antiepileptic drug that causes fetal valproate syndrome (FVS) in developing embryos exposed to it. Symptoms of FVS include neural tube defects (NTDs), musculoskeletal abnormalities, and neurodevelopmental difficulties. One proposed mechanism of VPA-induced developmental toxicity is via oxidative stress, defined as the disruption of redox-sensitive cell signaling. We propose that redox imbalances caused by VPA exposure result in improper cellular differentiation that may contribute to FVS. In undifferentiated P19 mouse embryonal carcinoma cells treated with VPA, glutathione disulfide (GSSG) concentrations were higher and the glutathione (GSH)/GSSG redox potential (Eh) was more oxidizing compared to vehicle-treated control cells, both of which are indications of potential intracellular oxidative stress. Interestingly, VPA had no effect on GSH or GSSG levels in differentiated P19 neurons. Undifferentiated cells pretreated with 3H-1,2-dithiole-3-thione (D3T), an inducer of the nuclear factor erythroid 2-related factor 2 (NRF2) antioxidant response that combats cellular redox disruption, were protected from VPA-induced alterations to the GSH/GSSG system. To assess differential periods of susceptibility, P19 cells were exposed to VPA at various time points during their neuronal differentiation. Cells exposed to VPA early in the differentiation process did not undergo normal neurogenesis as measured by POU domain, class 5, transcription factor 1 (OCT4) and tubulin beta-3 chain (βIII-tubulin), markers of cell stemness and neuronal differentiation, respectively. Neurogenesis was improved with D3T pretreatments prior to VPA exposure. Furthermore, differentiating P19 cells treated with VPA exhibited increased protein oxidation that was diminished with D3T pretreatment. These findings demonstrate that VPA inhibits neurogenesis and propose NRF2-mediated redox homeostasis as a means to promote normal neuronal differentiation, thereby potentially decreasing the prevalence of FVS outcomes.

Effects of CaCl2 Treatment Alleviates Chilling Injury of Loquat Fruit (Eribotrya japonica) by Modulating ROS Homeostasis.

The effects of calcium chloride (CaCl2) treatment on chilling injury (CI), reactive oxygen species (ROS) metabolism, and ascorbate-glutathione (AsA-GSH) cycle in loquat fruit at 1 °C storage for 35 d were investigated. The results indicated that CaCl2 treatment remarkably suppressed the increase in browning index and firmness as well as the decrease in extractable juice rate. CaCl2 treatment also decreased the production of superoxide radical (), hydrogen peroxide (H2O2) content, but increased the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical () scavenging ability, the activities of superoxide dismutase (SOD), catalase (CAT), and their gene expressions. Moreover, compared to the control loquat fruit, CaCl2-treated fruit maintained higher contents of AsA, GSH, higher levels of activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) and expressions of EjAPX, EjGR, EjMDHAR, and EjDHAR, but exhibited lower glutathione disulfide (GSSG) content. These results suggested that CaCl2 treatment alleviated CI in loquat fruit through enhancing antioxidant enzymes activities and AsA-GSH cycle system to quench ROS.

Evaluating the Effects of MKAVCFSL Derived from Bighead Carp (Hypophthalmichthys nobilis) Flesh on Antioxidant Activity in Caco-2 Cells In Vitro

The effect of an antioxidative peptide Met-Lys-Ala-Val-Cys-Phe-Ser-Leu (MKAVCFSL) on oxidative stress in Caco-2 cell lines was investigated. Caco-2 cells exposed to excess oxidative stress could be restored when pretreated with the peptide. Reactive oxygen species (ROS) and malondialdehyde (MDA) within the cells could be scavenged by MKAVCFSL. The peptide could also enhance the activity of glutathione peroxidase (GPx), glutathione reductase (GR), and superoxide dismutase (SOD), while catalase (CAT) activity did not show a significant difference between treatment and control samples. Meanwhile, it was observed that peptide treatment increased the concentration of glutathione (GSH). Yet the content of glutathione disulfide (GSSG) was hardly affected. The stability of MKAVCFSL was also assessed and an intact peptide was observed after simulated gastrointestinal digestion. Part of the peptide was hydrolyzed into fragments including MKA, FSL, AVCFSL, and MKAVCF. This study demonstrated that MKAVCFSL derived from bighead carp hydrolysates could ameliorate oxidative stress to protect the Caco-2 cells.

Occupational exposure in lead and zinc mines induces oxidative stress in miners lymphocytes: Role of mitochondrial/lysosomal damage

Abstract The purpose of this research was to determine mitochondrial and lysosomal damage and oxidative stress status in blood lymphocytes of lead-zinc miners. This research was performed in 10 mine workers who have been in contact with lead and zinc in comparison to a control group containing 10 healthy volunteers. Lymphocytes were isolated from peripheral blood using the Ficoll standard method and then mitochondrial and lysosomal damage and oxidative stress were evaluated. The level of reactive oxygen species (ROS), collapse in the mitochondrial membrane potential (MMP) collapse, and glutathione disulfide (GSSG) content, and lysosomal damage in miners were higher than the control group. Also, viability and glutathione (GSH) content were decreased. The lymphocytes of workers of a lead-zinc mine are more susceptible to oxidative stress, mitochondrial and lysosomal damage. The proper use of safety equipment can reduce the risk of toxic agents and their subsequent hazards for mine workers.

Cardiac arrhythmia catheter ablation procedures guided by x-ray imaging: N-acetylcysteine protection against radiation-induced cellular damage (CARAPACE study): study design.

Catheter ablation (CA) procedures are characterized by exposure to ionizing radiations (IR). IR can cause DNA damage and may lead to carcinogenesis if not efficiently repaired. The primary endpoint of this study is to investigate whether intravenous administration of N-acetylcysteine prior to CA procedure may prevent systemic oxidative stress and genomic DNA damage induced by exposure to IR. The "Cardiac Arrhythmia catheter ablation procedures guided by x-Ray imaging: N-Acetylcysteine Protection Against radiation induced Cellular damagE" (CARAPACE) study is a prospective, randomized, single-blinded, parallel-arm monocenter study enrolling 550 consecutive patients undergoing CA at the Arrhythmology Unit of Centro Cardiologico Monzino (CCM). Inclusion criteria are age ≥ 18, indication for CA procedure guided by IR imaging, and written informed consent. IR levels will be measured via fluoroscopy time, effective dose, and dose area product. Glutathione and glutathione disulfide concentrations will be measured, and urinary levels of 8-iso-prostaglandin-F2α and 8-hydroxy-2-deoxyguanosine will be quantified. The enrolled patients will be randomized 1:1 to the N-acetylcysteine group or to the control group. We expect that pre-operative administration of N-acetylcysteine will prevent IR-induced systemic oxidative stress. The study will provide data on oxidative DNA damage assessed by urinary 8-hydroxy-2-deoxyguanosine levels and direct evidence of genomic DNA damage in blood cells by comet assay. Catheter ablation procedures can lead to IR exposure and subsequent DNA damage. N-acetylcysteine administration prior to the procedure may prevent them and therefore lead to less possible complications. www.clinicaltrials.gov (NCT04154982).

Tebuconazole and trifloxystrobin regulate the physiology, antioxidant defense and methylglyoxal detoxification systems in conferring salt stress tolerance in Triticum aestivum L.

Fungicides are widely used for controlling fungi in crop plants. However, their roles in conferring abiotic stress tolerance are still elusive. In this study, the effect of tebuconazole (TEB) and trifloxystrobin (TRI) on wheat seedlings (Triticum aestivum L. cv. Norin 61) was investigated under salt stress. Seedlings were pre-treated for 48h with fungicide (1.375µM TEB + 0.5µM TRI) and then subjected to salt stress (250mMNaCl) for 5days. Salt treatment alone resulted in oxidative damage and increased lipid peroxidation as evident by higher malondialdehyde (MDA) and hydrogen peroxide (H2O2) content. Salt stress also decreased the chlorophyll and relative water content and increased the proline (Pro) content. Furthermore, salt stress increased the dehydroascorbate (DHA) and glutathione disulfide (GSSG) content while ascorbate (AsA), the AsA/DHA ratio, reduced glutathione (GSH) and the GSH/GSSG ratio decreased. However, a combined application of TEB and TRI significantly alleviated growth inhibition, photosynthetic pigments and leaf water status improved under salt stress. Application of TEB and TRI also decreased MDA, electrolyte leakage, and H2O2 content by modulating the contents of AsA and GSH, and enzymatic antioxidant activities. In addition, TEB and TRI regulated K+/Na+ homeostasis by improving the K+/Na+ ratio under salt stress. These results suggested that exogenous application of TEB and TRI rendered the wheat seedling more tolerant to salinity stress by controlling ROS and methylglyoxal (MG) production through the regulation of the antioxidant defense and MG detoxification systems.

Protein extracted from symbiotic culture of Chlorella pyrenoidosa and Yarrowia lipolytica shows structure-related detoxifying effects against 2, 2’-azobis (2-methyl-propanimidamidine) dihydrochloride induced oxidative stress

We characterized the co-culture system of Chlorella pyrenoidosa and Yarrowia lipolytica to identify co-culture products of high application value. We first optimized the co-culture parameters using different ratios of algae and Y. lipolytica, which highlighted the competitive relationship between the two organisms. Analysis of pH values indicated that a relatively alkaline symbiotic co-culture might result in undetectable amounts of Y. lipolytica. The ratio of C. pyrenoidosa and yeast did not influence the balance of dissolved oxygen, but showed an influence on the production of chlorophyll A and total protein, with the protein content significantly increasing after 5 days of co-culture. Two protein hydrolysates were extracted from a single culture of C. pyrenoidosa and from a co-culture with Y. lipolytica (3:1 ratio) after 5 days. Structure analysis indicated a high molecular weight and composition of antioxidative-associated amino acids in the co-culture protein, and the two spatial structures were quite diverse; the co-culture protein showed formation of side chain vibrations and unordered structures. Notably, Y. lipolytica could stimulate the formation of superoxide dismutase and the chlorophyll a-b binding protein. In contrast to the protein from C. pyrenoidosa single culture, the co-culture protein showed remarkable protective effects on erythrocytes under oxidative stress, which may be attributed to its specific structure. The activities of antioxidative-associated enzymes were significantly lower than those in the control group (without protein), and the contents of oxidation-related metabolic products, including total glutathione, increased, while the glutathione disulfide content decreased significantly. We hypothesize that this C. pyrenoidosa-specific protein structure obtained from co-culture with Y. lipolytica consists of more exposed hydrophobic residues on the surface of protein molecules, resulting in enhanced antioxidative activity. Therefore, the protein from the yeast-algal symbiotic co-culture has a larger variable structure and shows potent anti-hemolytic activity under oxidative stress.

T-BHQ Protects Against Oxidative Damage and Maintains the Antioxidant Response in Malnourished Rats.

Objective:Tert-butylhydroquinone (t-BHQ) protective effect against oxidative damage in thymus from malnourished pops-rats was evaluated.Methods:Malnutrition in pops-rats was induced during the lactation period and first-, second-, and third-degree malnourished rats were studied (MN1, MN2, and MN3). To determine t-BHQ protective effect, lipid peroxidation (LPx) was assessed, as well as the carbonyl content. The reduced glutathione and glutathione disulfide content were determined and antioxidant enzyme activities were measured.Results:Oxidative protein damage, LPx, and Nuclear Factor-κB (NF-κB) content, increased in the MN2 and MN3 compared to well-nourished rats, associated with lower protein content and antioxidant activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase. Tert-butylhydroquinone treatment induced a protective effect against lipids and proteins oxidative damage, as well as decrease in NF-κB in MN rats and restored the antioxidant mechanisms, mostly GPx and SOD. No differences were found between male and female animals.Conclusions:Results show that higher body weight deficit leads to increased oxidative damage and probably inflammation, attributable to alterations in antioxidant mechanisms. These effects were reversed by the t-BHQ-treatment, which restores the antioxidant response. Our findings suggest that t-BHQ could be an interesting pharmacological intervention, but it needs to be studied further.

Capillary Isotachophoresis Determination of Trace Oxidized Glutathione in Blood

Abstract A capillary isotachophoresis (CITP) method performed in a column-coupling apparatus has been developed for the simultaneous determination of glutathione (GSH) and glutathione disulfide (GSSG) concentrations in blood samples. The determination of GSSG and GSH concentrations in biological samples is important because of their roles in oxidative stress. Different concentrations of a leading ion in the coupled columns (concentration cascade) and a large volume (37 µ ) of the injected sample facilitated a GSSG concentration of between 2 and 25 µmol/l. A reaction between iodoacetate and GSH under alkaline conditions was used to prepare the sample in order to avoid oxidation of GSH to GSSG. This step eliminated the main source of systematic errors with regard to the determination of the GSSG concentration. A linear relationship (R2=0.9969) between the zone length of S-(carboxymethyl)glutathione (the product of the reaction between GSH and iodoacetate) and the concentration of GSH (40-120 µmol/l) was obtained. The method was applied to the analysis of bovine blood samples that had been diluted by a factor of ten with satisfactory results