Increased Glutathione Reductase Research Articles

Methylglyoxal-Induced Protection Response and Toxicity: Role of Glutathione Reductase and Thioredoxin Systems.

Thioredoxin (Trx) and glyoxalase (Glo) systems have been suggested to be molecular targets of methylglyoxal (MGO). This highly reactive endogenous compound has been associated with the development of neurodegenerative pathologies and cell death. In the present study, the glutathione (GSH), Trx, and Glo systems were investigated to understand early events (0.5-3h) that may determine cell fate. It is shown for the first time that MGO treatment induces an increase in glutathione reductase (GR) protein in hippocampal slices (1h) and HT22 nerve cells (0.5 and 2.5h). Thioredoxin interacting protein (Txnip), thioredoxin reductase (TrxR), Glo1, and Glo2 were markedly increased (2- to 4-fold) in hippocampal slices and 1.2- to 1.3-fold in HT22 cells. This increase in protein levels in hippocampal slices was followed by a corresponding increase in GR, TrxR, and Glo1 activities, but not in HT22 cells. In these cells, GR and TrxR activities were decreased by MGO. This result is in agreement with the idea that MGO can affect the Trx/TrxR reducing system, and now we show that GR and Txnip can also be affected by MGO. Impairment in the GR or TrxR reducing capacity can impair peroxide removal by glutathione peroxidase and peroxiredoxin, as both peroxidases depend on reduced GSH and Trx, respectively. In this regard, inhibition of GR and TrxR by 2-AAPA or auranofin, respectively, potentiated MGO toxicity in differentiated SH-SY5Y cells. Overall, MGO not only triggers a clear defense response in hippocampal slices and HT22 cells but also impairs the Trx/TrxR and GSH/GR reducing couples in HT22 cells. The increased MGO toxicity caused by inhibition of GR and TrxR with specific inhibitors, or their inhibition by MGO treatment, supports the notion that both reducing systems are relevant molecular targets of MGO.

Water exchange rate in RAS and dietary inclusion of micro-minerals influence growth, body composition and mineral metabolism in common carp

Recirculation aquaculture systems (RASs) operated at low water exchange rates are known to accumulate minerals in the water. This study examined the dietary mineral requirement and metabolism in common carp reared in RAS of contrasting water exchange rates. Two independent RAS (water exchange rates, 70 vs. 2000L/kg feed) and five experimental diets with graded levels of micro-mineral premix inclusion (0.0, 0.3, 0.6, 1.0 and 1.5%) were tested in a 2×5 factorial arrangement. Common carp fingerlings (8.5g) were reared in either of the RAS and fed the experimental diets in triplicates for 8weeks at 24°C. Water quality, fish growth, body composition, tissue mineral concentrations, blood haemoglobin and haematocrit levels, biochemical and molecular markers of oxidative stress, mineral uptake and metabolism were studied. RAS operated at low water exchange rate showed significantly high conductivity, nitrate, nitrite and dissolved mineral concentrations in water. A tendency for higher growth, significantly higher whole body mineral levels except Cu and Zn were observed in fish reared in RAS with high accumulation of minerals (H-RAS). Of the micro-minerals studied, effect of RAS on the minimal dietary inclusion level was significant only for Se; lower in fish reared in the H-RAS (0.28mg/kg) compared to L-RAS (0.32mg/kg). Increasing premix inclusion decreased growth and feed efficiency, increased the whole body concentration of Cu, Se and Zn, while Fe and Mn were unaffected. Plasma P, Ca, K and Mn were higher and haematocrit was lower in H-RAS reared fish; plasma mineral levels were also influenced by premix inclusion. Enzymes involved in micro-mineral uptake and metabolism (ferric reductase, cupric reductase and alkaline phosphatase) and oxidative stress markers (glutathione peroxidase, catalase, glutathione reductase and glutathione S-transferase) were analysed in gill, intestine and liver. In fish reared in H-RAS, reduced glutathione peroxidase (GPx) and increased glutathione reductase (GR) activities were observed in liver and intestine, respectively. Activity of GPx in all the analysed tissues increased with premix supplementation. Differential regulation in mRNA expression of molecular markers related to micro-mineral uptake, metabolism and oxidative stress were observed in the tissues in response to RAS and premix inclusion. To conclude, fish reared in high accumulation RAS had higher mineral levels in whole body and vertebrae, but did not result in a lower estimate of micro-minerals, except for Se. Difference in rearing system had multiple effects on the physiology and metabolism of fish on the whole, apart from mineral balance alone.

Salidroside as a Novel Protective Agent to Improve Red Blood Cell Cryopreservation.

Glycerol and trehalose have been widely examined as protective agents in the cryopreservation of red blood cells (RBCs). However, the effectiveness of these reagents alone on cell viability is moderate. Here, the addition of salidroside attenuated oxidative damage of sheep RBCs prior to and post cryostorage. The supplementation of salidroside to the cryopreservation media containing 10% glycerol improved RBC survival by approximately 61.1±4.8% vs 37.9±4.6%. A smaller effect was seen in RBCs cryopreserved in 300 mM trehalose where the addition of salidroside improved survival by 7.6±0.3%. Furthermore, the addition of salidroside to cold storage solution demonstrated a significant reduction of haemolysis after 4 days for RBCs loaded with either glycerol or trehalose, compared to cells incubated without salidroside. RBCs survival was 2-fold greater following freezing in trehalose, compared with glycerol. After 10 days, salidroside enabled a lower haemolysis of 16.7±1.3% compared to 29.0±8.4% for cells incubated without salidroside. However, salidroside had no effect on RBCs which had been frozen in glycerol as the resulting haemolysis rate by day 10 was approximately 60%. Salidroside increased glutathione reductase activity and decreased lactate dehydrogenase activity. Furthermore, it led to reduced carbonylation of proteins in both glycerol and trehalose loaded cells. Finally, no effect on lipid peroxidation was found in the glycerol loaded RBCs although this was reduced in RBCs loaded with trehalose and salidroside. The present findings confirm the potential use of salidroside as a novel protective agent in cryopreservation and refrigerated storage of sheep RBCs.

Dietary exposure to honeybush (Cyclopia) polyphenol-enriched extracts altered redox status and expression of oxidative stress and antioxidant defense-related genes in rat liver

Interest in Cyclopia spp. (honeybush) as a source material for production of polyphenol-enriched extracts (PEEs) for the food ingredient and nutraceutical markets requires investigation of their safety. PEEs of Cyclopia subternata (PECsub) and Cyclopia genistoides (PECgen) were fed (2.5g/kg feed) to male Fischer rats for 28days, while PECsub, having the highest total polyphenol content and antioxidant activity, was also fed for 90days. Their dietary intake did not significantly (P≥0.05) affect body weight gain or relative liver and kidney weight. PECsub resulted in a significant (P<0.05) increase in the total serum bilirubin after 28days, while serum alkaline phosphatase levels were only significantly (P<0.05) increased after 90days, suggesting alterations in the biliary system. No effect on serum iron levels was noticed after 28days, but PECsub significantly (P<0.05) reduced serum iron after 90days. Both PECsub and PECgen increased glutathione reductase activity in the liver significantly (P<0.05) after 28days. Reduced glutathione (GSH) content was significantly (P<0.05) decreased after 90days by PECsub resulting in a marked, but not significant (P≥0.05) decrease in the GSH/GSSG ratio. Considering the expression of oxidative stress and antioxidant defense-related genes after 28days, the expression of eleven genes was altered by PECsub and PECgen. Seven genes, mutually affected by PECsub and PECgen, included (i) antioxidant-related genes, prostaglandin-endoperoxide synthase 1 (Ptgs1), kinesin family member 9 (Kif9) and serine (or cysteine) peptidase inhibitor clade B member 1b (Serpinb1b); (ii) genes involved in reactive oxygen species (ROS) metabolism, xeroderma pigmentosum complementation group A (Xpa) and thioredoxin interacting protein (Txnip) as well as (iii) oxygen transporter-related genes, Fanconi anemia complementation group C (Fancc) and vimentin (Vim). The expression of NADPH oxidase organiser 1 (Noxo1) increased 19.97-fold by PECsub and the thyroid peroxidase (Tpo) 372-fold by PECgen. Changes in the expression of the oxidative stress and antioxidant defense-related genes could be indicative of an underlying stress effected by the honeybush PEEs in the liver. Differential gene expression could likely be attributed to the differences in phenolic composition of the extracts. The daily dietary intake of total polyphenol and individual phenolic constituents, recalculated to a human equivalent dose, was much higher, especially for C. subternata, than normally consumed when habitually drinking “fermented” honeybush herbal tea. Subsequent studies verifying the protein-associated changes governing the oxidative status in the liver is required.

Antioxidative response in variegated Pelargonium zonale leaves and generation of extracellular H2O2 in (peri)vascular tissue induced by sunlight and paraquat

In this study we exposed variegated leaves of Pelargonium zonale to strong sunlight (>1100μmolm−2s−1 of photosynthetically active radiation) with and without paraquat (Pq), with the aim to elucidate the mechanisms of H2O2 regulation in green and white tissues with respect to the photosynthetically-dependent generation of reactive oxygen species (ROS). Sunlight induced marked accumulation of H2O2 in the apoplast of vascular and (peri)vascular tissues only in green sectors. This effect was enhanced by the addition of Pq. In the presence of diphenyl iodide, an NADPH oxidase inhibitor, H2O2 accumulation was abolished. Distinct light-induced responses were observed: in photosynthetic cells, sunlight rapidly provoked ascorbate (Asc) biosynthesis and an increase of glutathione reductase (GR) and catalase activities, while in non-photosynthetic cells, early up-regulation of soluble ascorbate peroxidase, dehydroascorbate reductase (DHAR) and GR activities was observed. Paraquat addition stimulated DHAR and GR activities in green sectors, while in white sectors activities of monodehydroascorbate reductase, DHAR and class III peroxidases, as well as Asc content rapidly increased. Differential antioxidative responses in the two tissues in the frame of their contrasting metabolisms, and the possible role of (peri)vascular H2O2 in signaling were discussed.

Antioxidant activity of seedling growth in selected soybean genotypes (Glycine max (L.) Merrill) responses of submergence

In order to better understand the physiological and biochemical responses relating to direct seeding establishment in soybeans, the plant growth rate and antioxidative defense responses of seedlings in seven Indonesian soybean genotypes (Anjasmoro, Detam-1, Detam-2, Dieng, Grobogan, Tanggamus, and Willis) at different submergence periods (4, and 8 days) were examined. Twelve-day old seedlings were hydroponically grown in limited oxygen conditions. The results showed that the chlorophyll content in soybean seedlings was reduced beginning as early as 4 d under submerged condition, except for Detam-1, Detam-2, and Grobogan genotypes. The dry weight and protein concentration of seedlings were significantly higher at control condition (0 d) than those in submerged condition. The activities of superoxide dismutase (SOD) increased linearly until 8 d submerged for all genotypes. On the other hand, our results showed that catalase (CAT) and ascorbate peroxidase (APX) activities did not work together, meaning that CAT is activated and APX deactivated, or vice versa, in response to submergence conditions, except for Grobogan and Tanggamus genotypes which had an effect on both CAT and APX activities. Submergence stress led to a significant increase in glutathione reductase (GR) together with APX activity for Detam-2 and Dieng genotypes at 8 d submerged.

Silicon ameliorates chromium toxicity through phytochelatin-mediated vacuolar sequestration in the roots of Oryza sativa (L.)

ABSTRACTHigh chromium (Cr) in rice causes reduced yield and health hazards. This work investigates how Si alleviates Cr toxicity in rice. Addition of Si under Cr stress restored the growth parameters, total protein content, and membrane stability along with reduced Cr content in shoots, confirming that Si plays critical roles in Cr detoxification in rice. However, Si supplementation under Cr stress caused no significant changes in root Cr content but decreased shoot Cr concentrations compared with Cr-stressed plants, indicating that alleviation of Cr toxicity might be associated with Cr sequestration in roots. Further, concentration of Fe and expression of Fe transporter (OsIRT1) showed no significant changes due to Si supplementation under Cr stress, implying that Fe regulation is not involved with Si-mediated mitigation of Cr toxicity in rice. Further, phytochelatin accumulation and OsPCS1 (phytochelatin synthase) transcripts strongly induced due to the dual treatment of Si and Cr compared with Cr-stressed plants, suggesting that phytochelatin might bind to Cr, which leads to vacuolar sequestration in roots. Furthermore, increased glutathione reductase activity in roots implies that active involvement of ROS scavenging partially ameliorates Cr toxicity in rice plants. The study illustrates first evidences on the effect of Si alleviating Cr toxicity in rice plants.

Oxidative Stress Modulation Through Habitual Physical Activity.

Oxidative stress is involved in different pathophysiological states, such as aging, inflammatory, cardiovascular and neurodegenerative diseases, by damaging several cellular and tissue components including proteins, DNA and lipids. On the other hand, free radicals generated during physical activity are important modulators of muscle contraction, antioxidant protection, and oxidative damage repair. Indeed, ROS, generated during physical activity, are likely main mediators of antioxidant molecules upregulation, as reflected by increased glutathione reductase levels after exercise training. The aim of this review is to summarize the main mechanisms responsible for ROS-dependent adaptations to exercise training. Regular moderate exercise seems to counteract oxidative stress-related detrimental changes and to promote a healthy lifestyle. Conversely, acute and strenuous exercise can generate an excess of free radicals production. Moreover, regular habitual physical activity is related to reduced risk of coronary heart disease and death, whereas vigorous exercise has been shown to favour sudden cardiac death in sedentary individuals with preexisting vascular disease. New specific markers of mitochondrial or ER dysfunction may be better clues of oxidative stress, and their application to clinical practice may help set up the optimal dose, intensity and modality of exercise training for every single subject. The relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. These conflicting effects and outcomes may be explained by the hormesis theory, in which low doses of an agent that is detrimental at high doses, induces an adaptive beneficial effect on the cells or organism.

Oxidative stress response induced in an atrazine phytoremediating plant: Physiological responses of Pennisetum glaucum to high atrazine concentrations

ABSTRACTThis research presented here, for the first time, elucidates the responses of several antioxidants in Pennisetum leaves exposed to varying concentrations of atrazine (0–200 mgkg−1). Pennisetum has been reported to be resistant to atrazine; however, its physiological response to high concentrations (≥50 mgkg−1) of atrazine is not well documented. The contents of reduced (AsA) and oxidized (DHA) ascorbate increased significantly with increase in atrazine concentration and exposure time; but the increase was more evident under higher (50 and 100 mgkg−1) atrazine concentrations. Increase in atrazine concentration to 200 mgkg−1 significantly decreased AsA, but increased DHA content, throughout the experiment. Seedlings treated with 200 mgkg−1 atrazine showed significantly lowest reduced glutathione (GSH) content, while oxidized glutathione (GSSG) was not significantly affected, after 68 d. Seedlings treated with 100 mgkg−1 atrazine showed increased glutathione-S-transferase (GST) activity after 48 d and 68 d, while treatment with 200 mgkg−1 atrazine significantly increased glutathione reductase (GR) after 58 d. This result suggests that Pennisetum may tolerate lower atrazine concentrations. However, higher concentrations (≥50 mg kg−1), which could have longer residency period in the soil, could induce more physiological damage to the plant.

Aerobic Training Increased Glutathione Reductase Activity In Adults With Moderate Psoriasis

PURPOSE:. Recent studies have reported that oxidative stress may play a key role in the pathogenesis of psoriasis. In fact, it has been proposed as a potential theraputic target. Accordingly, this study was conducted to determine the influence of aerobic training on antioxidant enzyme activity in adults with psoriasis. METHODS: A total of 100 sedentary, male-adults with moderate psoriasis, according to the PASI (psoriasis area and severity index) score, volunteered for this interventional study. Psoriatic arthritis was considered as exclusión criteria. Participants were randomly allocated to the intervention (n=50) or control group (n=50) using a concealed method. The intervention consisted of a supervised 12-week treadmill training program, 3 sessions/week. According to this protocol, they performed a warm-up, 40-50 min treadmill exercise (increasing 5-minutes each 4-weeks) at a work intensity of 55-65% of peak heart rate (increasing 5% each 4-weeks) and cooling-down. Erythrocyte glutathione reductase (GR, EC 1.6.4.2) activity was measured spectrophotometrically by following the decrease in absorbance due to the oxidation of NADPH. Lastly, the current protocol was approved by an Institutional Ethics Committee. RESULTS: When compared to baseline, aerobic training significantly increased erythrocyte GR activity (8.8±1.0vs10.2±1.3U/gHb;p=0.028) in the intervention group. On the contrary, no significant changes were found in the control group. CONCLUSION: A 12-week aerobic training programme increased antioxidant enzyme activity in adults with psoriasis. While current results are promising, future studies are still required to consolidate this approach in clinical application.

Proteomic analysis of an environmental isolate of Rhodotorula mucilaginosa after arsenic and cadmium challenge: Identification of a protein expression signature for heavy metal exposure

A metal-resistant Rhodotorula mucilaginosa strain was isolated from an industrial wastewater. Effects on reduced/oxidized glutathione (GSSG/GSH), antioxidant enzymes and proteome were assessed on metal challenge (100mg/L). Increased GSH (mM/g) was found with CdCl2 (18.43±3.34), NaAsO2 (14.76±2.14), CuSO4 (14.73±2.49), and Pb(NO3)2 (15.74±5.3) versus control (7.67±0.95). GSH:GSSG ratio decreased with CdCl2, NaAsO2, and Pb(NO3)2 but not with CuSO4 and cysteine-containing protein levels increased with CdCl2 and NaAsO2. NaAsO2 exposure enhanced glutathione transferase activity but this decreased with CdCl2. Both metals significantly increased glutathione reductase and catalase activities. Metabolism-dependent uptake of Cd and As (12-day exposure) of approximately 65mg/g was observed in live cells with greater cell surface interaction for As compared to Cd. A particular role for arsenic oxidase in As resistance was identified.One dimensional electrophoresis revealed higher oxidation of protein thiols in response to NaAsO2 than to CdCl2. Two dimensional electrophoresis showed altered abundance of some proteins on metal treatment. Selected spots were excised for mass spectrometry and seven proteins identified. Under oxidative stress conditions, xylose reductase, putative chitin deacetylase, 20S proteasome subunit, eukaryotic translation elongation factor 2, valine-tRNA ligase and a metabolic enzyme F0F1 ATP synthase alpha subunit were all expressed as well as a unique hypothetical protein. These may comprise a protein expression signature for metal-induced oxidation in this yeast. SignificanceFungi are of widespread importance in agriculture, biodegradation and often show extensive tolerance to heavy metals. This makes them of interest from the perspective of bioremediation. In this study an environmental isolate of R. mucilaginosa showing extensive tolerance of a panel of heavy metals, in particular cadmium and arsenic, was studied. Several biochemical parameters such as activity of antioxidant enzymes, status of reduced and oxidized glutathione and thiols associated with proteins were all found to be affected by metal exposure. A detailed analysis with arsenic and cadmium pointed to a particular role for arsenic oxidase in arsenic bioaccumulation and tolerance. This is the first time this has been reported in R. mucilaginosa, and suggests that this isolate may have potential in biosorption of these metals in the environment. Proteomic analysis revealed that seven proteins with a variety of roles - ATP synthesis, protein degradation/synthesis, and metabolism of xylose and chitin - were differentially affected by metal exposure in a manner consistent with oxidative stress. These may therefore represent a protein expression signature for exposure to cadmium and arsenic.

PD35-01 RENAL ARTERIAL INFUSION OF ADIPOSE TISSUE-DERIVED STROMAL VASCULAR FRACTION PROTECTS THE RENAL FUNCTION AGAINST ACUTE KIDNEY INJURY INDUCED BY ISCHEMIA-REPERFUSION INJURY

You have accessJournal of UrologyStem Cell Research1 Apr 2016PD35-01 RENAL ARTERIAL INFUSION OF ADIPOSE TISSUE-DERIVED STROMAL VASCULAR FRACTION PROTECTS THE RENAL FUNCTION AGAINST ACUTE KIDNEY INJURY INDUCED BY ISCHEMIA-REPERFUSION INJURY Myoung Jin Jang, Bo Hyun Kim, Chunwoo Lee, Dalsan You, In Gab Jeong, and Chung-Soo Kim Myoung Jin JangMyoung Jin Jang More articles by this author , Bo Hyun KimBo Hyun Kim More articles by this author , Chunwoo LeeChunwoo Lee More articles by this author , Dalsan YouDalsan You More articles by this author , In Gab JeongIn Gab Jeong More articles by this author , and Chung-Soo KimChung-Soo Kim More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1073AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Acute kidney injury (AKI) induced by ischemia-reperfusion injury (IRI) is a major challenge in critical care medicine, with high rates of in-hospital morbidity and mortality. Preclinical studies suggested that administered cultured stem cells protected kidney function against AKI induced by IRI. Due to several concerns regarding the implantation of cultured stem cells into humans, however, recent clinical studies have focused on the use of stromal vascular fraction (SVF) in treating various diseases. The purpose of this study was to determine the therapeutic effects of adipose tissue-derived SVF and the optimal route for SVF delivery in a rat model of AKI induced by IRI. METHODS Fifty male Sprague-Dawley rats were randomly divided into 5 groups (10 animals per group): sham, nephrectomy control, IRI control, intra-renal arterial SVF infusion, and subcapsular SVF injection. To induce AKI induced by IRI, the left renal artery was clamped with a nontraumatic vascular clamp for 40 minutes, and the right kidney was removed. Serum creatinine and glomerular filtration rate were evaluated 1 day prior to IRI, and 2, 4, 7, 14 days after IRI. For histomorphometric studies, the kidney was removed 2 weeks after IRI. RESULTS Intra-renal arterial infusion of SVF significantly reduced the extent of elevation in serum creatinine compared with the IRI control group 4 days after IRI. The glomerular filtration rate of intra-renal arterial SVF infusion group was maintained at a level similar to those of the sham and nephrectomy control groups 14 days after IRI. Masson's trichrome stain for the degree of fibrosis showed that intra-renal arterial infusion of SVF was significantly less fibrosis than that observed in the IRI control group (P<0.001). Staining for alpha-smooth muscle actin showed that the number of small vessels was noticeably higher in the intra-renal arterial SVF infusion and subcapsular SVF injection groups than in the IRI control group (P<0.001). The number of terminal transferase-mediated dUTP nick-end labeling-positive cells increased after IRI, suggesting apoptosis or necrosis had occurred. Terminal transferase-mediated dUTP nick-end labeling assay showed significantly decreased apoptosis in both the intra-renal arterial SVF infusion and subcapsular SVF injection groups compared to the IRI control group (P<0.001). A greater increase in glutathione reductase and glutathione peroxidase was observed in both the intra-renal arterial SVF infusion and subcapsular SVF injection groups than in the IRI control group (P<0.001). These findings further suggest that anti-oxidative responses were elicited by IRI and SVF treatment contributed to further anti-inflammatory and anti-oxidative effects after IRI in this study. CONCLUSIONS Our study showed that renal function is effectively rescued from AKI induced by IRI through administration of SVF in a rat model and intra-renal arterial infusion of SVF was more effective than subcapsular injection. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e844 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Myoung Jin Jang More articles by this author Bo Hyun Kim More articles by this author Chunwoo Lee More articles by this author Dalsan You More articles by this author In Gab Jeong More articles by this author Chung-Soo Kim More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Inhibitory Effect of Yongdamsagan-Tang Water Extract, a Traditional Herbal Formula, on Testosterone-Induced Benign Prostatic Hyperplasia in Rats.

Yongdamsagan-tang, a traditional herbal formula, is used widely for the treatment of inflammation and viral diseases. In this study, we investigated whether Yongdamsagan-tang water extract (YSTE) affects testosterone propionate- (TP-) induced benign prostatic hyperplasia (BPH) in a rat model. To induce BPH, rats were injected subcutaneously with 10 mg/kg of TP every day. YSTE was administrated daily by oral gavage at doses of 200 and 500 mg/kg along with the TP injection. After 4 weeks, prostates were collected, weighed, and analyzed. The relative prostrate weight was significantly lower in both YSTE groups (200 and 500 mg/kg/day) compared with the TP-induced BPH group. YSTE administration reduced the expression of proliferation markers PCNA, cyclin D1, and Ki-67 and the histological abnormalities observed in the prostate in TP-induced BPH rats. YSTE attenuated the increase in the TP-induced androgen concentration in the prostate. The YSTE groups also showed decreased lipid peroxidation and increased glutathione reductase activity in the prostate. These findings suggest that YSTE effectively prevented the development of TP-induced BPH in rats through antiproliferative and antioxidative activities and might be useful in the clinical treatment of BPH.

The role of oxidative protein modification and the gluthatione system in modulation of the redox status of breast epithelial cells

The effects of the SH-group blocker N-ethylmaleimide (NEM) and thiol group protector 1,4-dithioerythritol (DTE) on the redox status of cells HBL-100 cells, oxidative modification of their proteins and the state of glutathione and thioredoxin systems have been investigated. Breast epithelial cells cultivated in the presence of NEM were characterized by decreased redox status, increased glutathione reductase activity, and increased concentrations of products of irreversible oxidative modification of protein and amino acids. Cultivation of HBL-100 cells in the presence of DTE resulted in a shift of the redox status towards reduction processes and increased reversible protein modification by glutathionylation. The proposed model of intracellular redox modulation may be used in the development of new therapeutic approaches to treat diseases accompanied by impaired redox homeostasis (e.g. oncologic, inflammatory, cardiovascular and neurodegenerative disease).

The role of heat shock proteins 27 and 70 in redox-dependent regulation of apoptosis in Jurkat tumor cells

Heat shock proteins Hsp) act as molecular chaperones, protecting enzymes and other proteins against reactive oxygen species. The objective of the study was to investigate the role of Hsp27 in maintaining the balance of the glutathione system and Hsp70 concentrations as well as in implementing Jurkat tumor cell apoptosis. Addition of the Hsp27 inhibitor KRIBB3 (5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxazol) to Jurkat cells resulted in glutathione redox imbalance (increased GSSG and increased glutathione reductase activity), a decrease in Hsp70 concentrations, and also increased cell apoptosis as compared with to the intact cell culture. The proposed selective regulation of chaperone activity is a promising direction in regulating apoptosis at the cellular level.

Daily intake of lead in Wistar rats at different ages: Biochemical, genotoxic and physiological effects.

The effects of the daily intake of feed containing lead (2.0 mg Pb kg(-1)) were evaluated in 45 (Pb45) and 90 (Pb90)-day-old Wistar female rats. Compared to the respective control groups, Pb45 rats consumed more feed and showed greater weight gain, but these parameters returned to control values in Pb90 rats. Higher blood glucose levels were observed in both Pb groups, whereas plasma insulin concentrations were higher in Pb45 but lower in the Pb90 group. Liver glycogen content was lower only in the Pb90 rats. There were no changes in plasma cortisol and acetylcholinesterase activity in the brain. Hematological alterations were observed only in Pb90 rats, which showed lower hemoglobin levels. In the liver, Pb45 rats showed decreased catalase and glutathione peroxidase activities and increased glutathione reductase activity, but in the Pb90 group, glutathione levels were higher. Increased hepatic lipid peroxidation and DNA damage in the lymphocytes were observed in both Pb groups. These results indicate that the daily intake of Pb for different periods results in metabolic changes and in the establishment of oxidative and genotoxic damage in female rats.

Characterisation of lead-induced stress molecular biomarkers in Medicago sativa plants

In this study, we investigated physiological changes and transcriptional responses in four-week-old hydroponically grown Medicago sativa seedlings exposed to (PbNO3)2 (0, 10 and 100μM) for 2 and 7 days. Fresh weight and length were reduced in both shoots and roots after 7 days exposure. Lead accumulation was time and dose-dependent with stronger phytotoxic effects in roots than in shoots, with a relatively low amount of Pb translocated from roots to shoots. Lipid peroxidation augmented remarkably, suggesting the onset of oxidative damages, with increased glutathione reductase (GR), ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities. This result was accompanied by a remarkable up-regulation of APX and SOD genes. In roots, the increase of SOD transcripts was concomitant to an enhanced SOD enzymatic activity in all Pb treatments. However, the 30-fold up-regulation occurred with a remarkable APX activity inhibition, which suggests that there might be post-transcriptional modifications able to regulate root APX. Root glutathione (GSH) and homoglutathione (hGSH) concentrations decreased in a dose dependent manner, while we could not detect the accumulation of phytochelatins (PC), albeit the related gene was up-regulated. The lack of PCs synthesis suggests a post-translational regulation of its enzymatic activity. Heat shock proteins (HSP70 and HSP17.7) were increased in alfalfa shoots, implying the triggering of cellular protection mechanism to cope with lead phytotoxicity. It is concluded that alfalfa plants mitigate the oxidative damage through induction of antioxidant enzymes, and the expression of chaperone proteins to alleviate Pb toxicity; metabolic changes that could be exploited as Pb-stress bioindicators.

Diets supplemented with seaweed affect metabolic rate, innate immune, and antioxidant responses, but not individual growth rate in European seabass (Dicentrarchus labrax)

This study investigated the effects of seaweed dietary supplementation on measures of fish performance including aerobic metabolism, digestive enzymes activity, innate immune status, oxidative damage, and growth rate using European seabass (Dicentrarchus labrax). Fish were fed for 49 days with three different diets: a control diet (CTRL), a Gracilaria-supplemented diet (GR7.5), and a mixed diet (Mix) composed of Gracilaria, Fucus, and Ulva genera representatives. All diets were isoenergetic (22 kJ g−1 adjusted for dry matter (DM)), isoproteic (47 %DM), and isolipidic (18 %DM) and tested in triplicate groups of 20 fish (initial body weight 25.5 ± 4.1 g). Final results showed similar growth rates and digestive activities between diets. Maximum and standard metabolic rates and aerobic metabolic scope revealed comparable results for the three diets. In contrast, fish fed with GR7.5 exhibited elevated routine metabolic rate (190.7 mg O2 kg−1 h−1). Fish fed with the GR7.5 and Mix diets had lower alternative complement pathway (ACH50) (62.5 and 63 units mL−1 respectively) than CTRL (84 units mL−1) GR7.5 increased lipid peroxidation and cholinesterase levels, as well as glutathione s-transferase activity. Mix diet increased glutathione reductase activity when compared to CTRL. Collectively, our findings suggest that dietary seaweed supplementation may alter seabass metabolic rate, innate immune, and antioxidant responses without compromising growth parameters.

Changes in Antioxidant Defense Capability and Lipid Profile after 12-Week Low- Intensity Continuous Training in Both Cigarette and Hookah Smokers: A Follow-Up Study

To examine the impact of low-intensity continuous training program on antioxidant defense capability and lipid profile in male cigarette or hookah smokers. Forty-three male adults participated in a 12-week continuous training program at an intensity of 40% of VO2max. All subjects were subjected to anthropometric, physical and biochemical tests before and after the training program. The increase of Glutathione reductase (GR) and Superoxide dismutase (SOD) is significant only for cigarette smokers (CS) and hookah smokers (HS) groups. The Malondialdehyde (MDA) decrease and α-tocopherol increase are significant only for HS group. GPx was increased in NS, CS and HS by 2.6% (p< 0.01), 2% (p< 0.05) and 1.7% (p< 0.05) respectively. Likewise, significant improvements of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and TC / HDL-C ratio were observed in three groups. En contrast no significant changes were recorded in triglycerides (TG). Also, significant reduction of total cholesterol (TC) for CS group (p< 0.01) and HS groups (p< 0.05). This continuous training program appears to have an important role in lipid levels improving and oxidative stress attenuation.

Beneficial effects of quercetin on oxidative stress in liver and kidney induced by titanium dioxide (TiO2) nanoparticles in rats

TiO2 nanoparticles used as vectors for the delivery of drugs have shown greater effectiveness. However, TiO2 nanoparticles can cause oxidative stress in liver and kidney, so we analyzed if a previous or simultaneous quercetin treatment could counteract this in rats. Five groups of male Wistar rats (200–250 g) were included: (1) healthy controls, (2) TiO2 group, (3) quercetin group, (4) preventive group: quercetin for 5 days prior to exposure of TiO2, and (5) therapeutic group: TiO2 (5 mg/kg, i.v.) plus quercetin single dose for 5 days (5 mg/kg/day, i.p.). Hepatic and renal function tests were made. Five animals from each group were sacrificed (0, 14 and 28 days), and liver and kidney tissue were obtained. Malondialdehyde (MDA), reduced/oxidized glutathione, and activity of glutathione peroxidase/reductase were measured, as well as the level of gene expression by q-PCR. There were no significant changes in serum ALT and AST activities. More damage was observed at 14 versus 28 days, because TiO2 was excreted in urine. Quercetin indeed showed a renal protective effect by increasing glutathione reductase and peroxidase levels and reducing MDA levels. On the other hand, TiO2 liver damage was less pronounced with quercetin as therapeutic treatment. TiO2 induces significantly the glutathione reductase expression and it can be down-regulated by quercetin. Biochemical tests in serum and urine showed a better effect of quercetin administered in the therapeutic group. Care should be taken with the dose and time of administration of quercetin, because this antioxidant could also have a pro-oxidant effect.