Enzyme Activities Glutathione Reductase Research Articles

Genotoxicity and oxidative stress assessment among farmers occupationally exposed to pesticides in El-Behira Governorate, Egypt

ABSTRACT Background Recently, pesticide usage has rapidly increased worldwide and consequently, there is a great worry about their adverse health effects. In literature, there is paucity of research regarding the relationship between occupational pesticide exposure and genotoxicity. The current study aimed to detect sociodemographic and occupational characteristics of the participants and to assess biomarkers of genotoxicity and oxidative stress and reveal their association with exposure to pesticides. Methods A comparative cross-sectional approach was carried out at a randomly selected village where 58 farmers exposed to pesticides were compared with another 58 individuals not exposed to pesticides. Participants were interviewed; blood samples were withdrawn for measuring the following: deoxyribonucleic acid (DNA) fragmentation percentage, serum thiobarbituric acid reactive substances (TBARS) level, serum activity levels of glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD), and butyrylcholinesterase (BChE) enzymes. Results Farmers had significantly higher levels of DNA fragmentation, TBARS, and SOD [8.07 ± 2.38, 1.42 (0.79), and 350.09 (30.03), respectively] than the comparison group [4.41 ± 1.35, 0.37 (0.72), and 281.25 (130.37), respectively]; While they had a lower GR, CAT, and BChE levels [14.53 ± 8.53, 21.7 (41.04), and 2707.77 ± 651.24, respectively] than the comparison group [24.92 ± 9.44, 37.8 (41.72), and 5694.3 ± 1175.76, respectively]. Exposure to pesticides was found to be independently associated with an increase in the percentage of DNA fragmentation by 3.146%; an increase in TBARS level by 0.717 nmol/dL; an increase in the SOD enzyme activity level by 72.614 IU/mL and a decrease in the GR enzyme activity level by 10.094 IU/mL. Conclusion Pesticide exposure is associated with genotoxicity and oxidative stress.

Dose rate dependent genotoxic and metabolic effects predict onset of impaired development and mortality in Atlantic salmon (S. salar) embryos exposed to chronic gamma radiation

Release of radionuclides to the environment from either nuclear weapon and fuel cycles or from naturally occurring radionuclides (NORM) may cause long term contamination of aquatic ecosystems and chronic exposure of living organisms to ionizing radiation, which in turn could lead to adverse effects compromising the sustainability of populations. To address the effects of chronic ionizing radiation on the development of fish, Atlantic salmon embryos were exposed from fertilization until hatching (88 days, 550 day-degree) to dose rates from 1 to 30 mGy·h−1 gamma radiation (60Co). The lowest adopted dose rate was similar to the highest doses measured in some water bodies right after the Chernobyl accident (1 mGy·h−1), however, well above current environmentally realistic scenarios (20 μGy·h−1), or the threshold assumed for significant effects on fish population (40 μGy·h−1). Dose dependent effects were observed on survival, hatching, morbidity, DNA damage, antioxidant defenses, and metabolic status. Histopathological analysis showed dose rate dependent impairment of eye and brain tissues development and establishment of epidermal mucus cell layers accompanied by increased DNA damage at doses ≥1.3 Gy (dose rates ≥1 mGy·h−1).At ≥32.8 Gy (dose rates ≥20 mGy·h−1) deformities and developmental growth defects resulted in respective 46 and 95 % pre-hatch mortality. The 10 mGy·h−1 exposure (≥ 12 Gy total dose) caused significantly increased DNA damage, impaired eye development, and both premature and delayed hatching, while no deformities or effect on survival were observed. We observed a dose rate dependent reduction from dose rate ≥ 20 mGy·h−1 (≥ 27 Gy total dose) on antioxidant SOD, catalase and glutathione reductase enzyme activities. The reduction of antioxidant enzyme activities was in line with observed developmental delay and disturbance to time of hatching. Metabolomic profiles showed a clear shift at dose rates ≥10 mGy·h−1 (≥ 12 Gy total dose) in pathways related to oxidative stress, detoxification, DNA damage and repair. Due to gamma radiation exposure, a switch of central metabolism from glycolysis, citric acid cycle and lactate production towards pentose phosphate pathway indicated a rewiring mechanism for increased production of reductive equivalents to maintain redox homeostasis at the expense of energy output and thus embryonic development.

Preparation of spore-immobilized glutathione reductase and its application in inhibiting browning of pear wine.

Browning is the key problem hindering the industrialization of pear wine. The use of high-yield glutathione Saccharomyces cerevisiae in the fermentation of pear wine can inhibit browning. Glutathione reductase (GR) can ensure the reduction of glutathione. Spore immobilization of enzymes is a new technology. It is a new attempt to apply spore-immobilized GR in combination with high-yield glutathione S. cerevisiae to inhibit browning of pear wine. Saccharomyces cerevisiae spore immobilization enzyme technology was used to immobilize GR in the spores of mutant S. cerevisiae dit1∆, osw2∆ and chs3∆ and wild-type S. cerevisiae. The enzyme activity of GR immobilized by chs3∆ spores was the highest of 3.08 U mg-1 min-1. The chs3∆ spore-immobilized GR had certain resistance to ethanol, citric acid, sucrose, glucose and proteinase K. Electron microscopy analysis showed that the spore wall of chs3∆ had moderate size holes, which might be the main reason why it immobilized GR with the highest enzyme activity. And the GR was immobilized between the prespore membrane and mannoprotein layer of the spore wall. When chs3∆ spore-immobilized GR (chs3∆-GR) was added to Dangshan pear wine fermented by high-yield glutathione S. cerevisiae JN32-9, the presence of chs3∆-GR could further protect amino acids, polyphenols and glucose from oxidation, thereby reducing the browning of the pear wine during storage by 47.32%. GR immobilized by S. cerevisiae spores was effective in inhibiting the browning of pear wine. The method was simple, green and effective and did not increase the production cost of pear wine. © 2024 Society of Chemical Industry.

Changes in Cortisol and in Oxidative/Nitrosative Stress Indicators after ADHD Treatment.

Although ADHD is one of the most prevalent diseases during childhood, we still do not know its precise origin; oxidative/nitrosative stress and the hypothalamic-pituitary-adrenal axis are suggested contributors. Methylphenidate, among others, is the main drug used in ADHD patients, but its effects on relevant markers and structures remain unclear. This study, involving 59 patients diagnosed with ADHD according to DSM-5 criteria, aimed to assess changes in cortisol levels (using cortisol awakening response, CAR) and oxidative/nitrosative status with the treatment. Blood samples before and 3 months after treatment with methylphenidate were used to measure oxidative and inflammatory markers, as well as the endogenous antioxidant activity, while saliva samples tracked cortisol awakening response (CAR). The results showed a treatment-related improvement in the redox profile, with the reduction in advanced oxidation protein products (AOPP), lipid peroxidation (LPO), and nitrite plus nitrate (NOx) levels, and the increase in the enzymatic activities of glutathione reductase (GRd) and catalase (CAT). Moreover, the area under the curve (AUC) of CAR increased significantly, indicating increased reactivity of the HPA axis. These results support, for the first time, the involvement of the endogenous antioxidant system in the pathophysiology of ADHD.

Study of the state of intermediate metabolism and antiradical defense of the body of meat quail during the elimination of mycotoxin

In the last decade, a new promising direction to reduce the risk of T-2 toxicosis at domestic poultry enterprises has been the rational use of antioxidants in the formulation of compound feeds. The purpose of the research is to determine the effect of the antioxidants santoquin (santoquin) and vitamin E in the composition of feed based on wheat grain, sorghum and rapeseed meal with a tolerant level of T-2 toxin on the state of intermediate metabolism and anti-radical protection of the body of meat quails. We have substantiated new data on the advisability of jointly introducing the antioxidants santoquin at a dose of 150 g/t and vitamin E at a dose of 25 thousand IU/t of feed into the composition of feed based on wheat grain, sorghum and rapeseed meal with a tolerant level of T-2 toxin to optimize the meat quail hematopoietic function of the body. The tested antioxidants, when fed in combination, contributed to the improvement of protein, carbohydrate, lipid and mineral metabolism in quails of the 3rd experimental group. Due to the synergistic effect of antioxidants in the composition of diets, an increase in protective functions in the body of quails of the 3rd experimental group was noted due to an increase in lysozyme activity in blood samples by 3,00% (P>0,95) and bactericidal activity - by 8,30% (P>0,95) than in the control group. While ensuring better detoxification of T-2 toxin in comparison with control analogues, meat quails of the 3rd experimental group improved the antioxidant defense of the body due to an increase in the enzymatic activity of glutathione reductase in the blood by 25,34% (P>0,95), alkaline phosphatase - by 18,34% (P>0,95) with a parallel decrease in catalase activity - by 9,54% (P>0,95), the level of conjugated dienes - by 2,28 times (P>0,95) and malondialdehyde - by 1,33 times (P>0,95).

Maternal Caffeine Consumption during Gestation and Lactation Abolishes Cortical Oxidative Stress and Restores Na+/K+-ATPase Activity in Neonates Exposed to Hyperthermia-Induced Seizures.

Caffeine is a psychoactive substance that is widely consumed by individuals of various demographics, including pregnant women. It can readily cross the blood-brain and placental barriers, easily reaching the fetal brain. In addition, caffeine has also shown antioxidant properties, as its consumption reduces oxidative stress in various pathologies, including epilepsy. Febrile seizures (FS) are among the most common convulsive disorders in infants and young children. Here, we used an animal model of FS to learn whether maternal caffeine (1 g/L) intake consumption during gestation and lactation could exert beneficial effects on the rat cortex. Neonatal development was analyzed by measuring pinna opening, eye opening, righting reflex on the surface, and geotaxis reflex. Five and twenty days after HIS, the rats were euthanized, and plasma membranes and cytosolic fractions were isolated from their cortex brain. The enzymatic activities of glutathione reductase, glutathione S-transferase, Na+/K+-ATPase, and Mg2+-ATPase, as well as the levels of thiobarbituric acid reacting substances, were quantified. Results showed that maternal caffeine intake eliminates oxidative stress and normalizes Na+/K+-ATPase activity disrupted by HIS and also affects some parameters relating to the neurodevelopment of neonates. As FS in infants has been related to epilepsy in adults, the antioxidant properties of caffeine could prevent potential damage from hyperthermia.

Effects of Full-Spectrum Cannabis Oil with a Cannabidiol:Tetrahydrocannabinol 2:1 Ratio on the Mechanisms Involved in Hepatic Steatosis and Oxidative Stress in Rats Fed a Sucrose-Rich Diet

Introduction: This study aimed to analyze the effects of cannabis oil (cannabidiol:tetrahydrocannabinol [CBD:THC], 2:1 ratio) on the mechanisms involved in hepatic steatosis and oxidative stress in an experimental model of metabolic syndrome (MS) induced by a sucrose-rich diet (SRD). We hypothesized that noninvasive oral cannabis oil administration improves hepatic steatosis through a lower activity of lipogenic enzymes and an increase in carnitine palmitoyltransferase-1 (CPT-1) enzyme activity involved in the mitochondrial oxidation of fatty acids. Furthermore, cannabis oil ameliorates liver oxidative stress through the regulation of the main regulatory factors involved, nuclear factor erythroid 2 (NrF2) and nuclear factor-kB (NF-κB) p65. For testing this hypothesize, a relevant experimental model of MS was induced by feeding rats with a SRD for 3 weeks. Methods: Male Wistar rats were fed the following diets for 3 weeks: reference diet: standard commercial laboratory diet, SRD, and SRD + cannabis oil: noninvasive oral administration of 1 mg/kg body weight cannabis oil daily. The full-spectrum cannabis oil presents a total cannabinoid CBD:THC 2:1 ratio. Serum glucose, triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol, uric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (AP), N-arachidonoylethanolamine or anandamide and 2-arachidonoylglycerol endocannabinoids levels, thiobarbituric acid reactive substance (TBARS) levels, and non-enzymatic antioxidant capacity (ferric ion-reducing antioxidant power [FRAP]) were evaluated. In the liver tissue: histology, nonalcoholic fatty liver disease activity score (NAS), triglycerides and cholesterol content, lipogenic enzyme activities (fatty acid synthase, acetyl-CoA carboxylase, malic enzyme, and glucose-6-phosphate dehydrogenase), enzyme related to mitochondrial fatty acid oxidation (CPT-1), reactive oxygen species, TBARS, FRAP, glutathione, catalase, glutathione peroxidase, and glutathione reductase enzyme activities. 4-hydroxynonenal, NrF2, and NF-κB p65 levels were analyzed by immunohistochemistry. Results: The results showed that SRD-fed rats developed dyslipidemia, liver damage, hepatic steatosis (increase of key enzymes related to the novo fatty acid synthesis and decrease of key enzyme related to mitochondrial fatty acid oxidation), lipid peroxidation, and oxidative stress. Hepatic NrF2 expression was significantly decreased and NF-κB p65 expression was increased. Cannabis oil administration improved dyslipidemia, liver damage, hepatic steatosis, lipid peroxidation (improving enzymes involved in lipid metabolism), and oxidative stress. In the liver tissue, NrF2 expression increased, and NF-κB p65 expression was reduced. Conclusion: The present study revealed new aspects of liver damage and steatosis, lipid peroxidation, and oxidative stress in dyslipidemic insulin-resistant SRD-fed rats. We demonstrated new properties and molecular mechanisms of cannabis oil (CBD:THC, 2:1 ratio) on lipotoxicity and hepatic oxidative stress in an experimental model of MS.

Effects of Arbutin on Potassium Bromate-Induced Erythrocyte Toxicity in Rats: Biochemical Evaluation of Some Metabolic Enzyme Activities In Vivo and In Vitro.

In the present study, the inhibitory effect of potassium bromate on the pentose phosphate pathway and intracellular antioxidant systems enzymes (glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), glutathione reductase (GR), glutathione S-transferase (GST), and thioredoxin reductase (TrxR)) and the role of arbutin in ameliorating this inhibition were investigated. In the in vivo phase of the study, Wistar Albino rats (28 male adults) were randomly divided into four groups. Control (n = 7): isotonic serum (0.5 mL, i.p), potassium bromate group (n = 7): potassium bromate (100 mg/kg), arbutin group (n = 7): arbutin (i.p.) (50 mg/kg/day), potassium bromate + arbutin, and Group (n = 7): potassium bromate (100 mg/kg) + arbutin (50 mg/kg/day) (i.p). The results of in vivo study showed that the activities of G6PD, 6PGD, GR, and TrxR enzymes were strongly inhibited in potassium bromate groups (p < 0.05). It was determined that GST enzyme activity decreased in the potassium bromate group, but this decrease was not statistically significant compared to the control group (p ⩾ 0.05). A statistically significant increase was found in G6PD, 6PGD, GST, and TrxR enzyme activities in the arbutin group compared to the control group (p < 0.05). The increase in GR enzyme activity was not statistically significant (p ⩾ 0.05). The potassium bromate + arbutin group's enzyme activity increased in comparison to the potassium bromate group and was discovered to be closer to the control group. It was found that potassium bromate inhibited the 6PGD enzyme obtained from rat erythrocyte tissues with IC50 = 346 μM value and Ki = 434.4 μM ± 6.1 value, and the inhibition was noncompetitive.

Göynük Çayı'nda (Bingöl, Türkiye) Garra rufa'nın (Heckel, 1843) antioksidan enzim aktivitelerindeki mevsimsel değişimleri

In this study, seasonal variations of antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glucose 6-phosphate dehydrogenase (G6PD)) and malondialdehyde (MDA) levels in gill, kidney, muscle and liver tissues of Garra rufa (Heckel, 1843) caught from Göynük Stream, one of the most important branch of Murat River, were investigated. Fish samples were caught from two stations (Garip and Ilıcalar), which are determined regularly every month, and brought to the laboratory. The levels of biomarkers in tissues were determined by spectrophotometric methods. It was determined that the difference between the parameters in the studied tissues was statistically significant (P &lt; 0.05) between the two stations, but the difference between the stations in the liver tissue in all seasons in GR enzyme was not statistically significant. However, it was determined that the differences between the seasons were significant in both stations. GR and G6PD enzyme activities were found to be lower than other enzyme activities among the enzyme groups studied, but CAT and SOD enzyme activities were found to be higher than the other enzymes., enzyme activities in muscle tissue are lower than activities in the other tissues among tissues.

Exogenous glutathione maintains the postharvest quality of mango fruit by modulating the ascorbate-glutathione cycle.

Mango fruit is prone to decay after harvest and premature senescence, which significantly lowers its quality and commercial value. The mango fruit (Mangifera indica L.cv. Guixiang) was treated with 0 (control), 2, 5, and 8 mM of reduced glutathione (GSH) after harvest. The fruit was stored at 25 ± 1 °C for 12 days to observe the changes in the antioxidant capacity and postharvest quality. Compared with the control, the 5 mM GSH treatment significantly decreased the weight loss by 44.0% and 24.4%, total soluble solids content by 25.1% and 4.5%, and soluble sugar content by 19.0% and 27.0%. Conversely, the 5 mM GSH treatment increased the firmness by 25.9% and 30.7% on days 4 and 8, respectively, and the titratable acidity content by 115.1% on day 8. Additionally, the 5 mM GSH treatment decreased the malondialdehyde and hydrogen peroxide contents and improved the antioxidant capacity of mango fruit by increasing the superoxide dismutase and peroxidase activities and upregulating the expression of the encoding genes. Meanwhile, the higher levels of monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase enzyme activities and gene expressions accelerated the AsA-GSH cycle, thereby increasing the accumulation of AsA and GSH and maintaining the redox balance. Overall, the experimental results suggest that 5 mM GSH maintains high antioxidant capacity and postharvest quality of mangoes and can use as an effective preservation technique for postharvest mangoes.

Effect of hexavalent chromium exposure on the reproductive status and biomarker responses of female Geloina erosa.

Hexavalent chromium (Cr (VI)) is widely distributed in the marine environment of Hainan Province, China and poses a potential threat to its mangrove ecosystems. However, the mechanisms underlying Cr-induced stress and reproductive toxicity in clams remain largely unknown. In this study, the clams, Geloina erosa, were exposed to 4.34, 8.69, 17.38 and 34.76 mg/L Cr (VI) for 24, 48 and 72 h. The gonad-somatic index (GSI) was determined and histological alterations of the ovaries were quantified by light microscopy. The micronucleus test was performed which quantifies the genotoxic presence of small cytoplasmic bodies in eukaryotic cells. Enzymatic assays for catalase (CAT), glutathione reductase (GR), and malondialdehyde (MDA) activities were done. Quantitative real-time PCR (qRT-PCR) was used to quantify the expression of glutathione-S-transferase (GST), heat shock protein 70 (HSP70) and vitellogenin (Vtg) in ovaries of G. erosa. The results showed that the micronucleus frequency was significantly increased when clams were exposed to Cr (VI). Cr (VI) exposure induced the accumulation of MDA and affected CAT and GR enzyme activities. The high Cr (VI) concentration of 34.76 mg/L significantly increased the levels of GR activity, GST expression and HSP70 expression and inhibited Vtg expression and CAT activity. MDA content was significantly increased after 72 h at the high Cr (VI) exposure (34.76 mg/L). Therefore, Cr (VI) exposure may be toxic to the development of ovaries of G. erosa.

Propentofylline Improves Thiol-Based Antioxidant Defenses and Limits Lipid Peroxidation following Gliotoxic Injury in the Rat Brainstem.

Propentofylline (PROP) is a methylated xanthine compound that diminishes the activation of microglial cells and astrocytes, which are neuronal cells strongly associated with many neurodegenerative diseases. Based on previously observed remyelination and neuroprotective effects, PROP has also been proposed to increment antioxidant defenses and to prevent oxidative damage in neural tissues. Since most neurodegenerative processes have free radicals as molecular pathological agents, the aim of this study was to evaluate the antioxidant effects of 12.5 mg·kg-1·day-1 PROP in plasma and the brainstem of Wistar rats exposed to the gliotoxic agent 0.1% ethidium bromide (EB) for 7-31 days. The bulk of the data here demonstrates that, after 7 days of EB treatment, TBARS levels were 2-fold higher in the rat CNS than in control, reaching a maximum of 2.4-fold within 15 days. After 31 days of EB treatment, lipoperoxidation in CNS was still 65% higher than that in the control. Clearly, PROP treatment limited the progression of lipoperoxidation in EB-oxidized CNS: it was, for example, 76% lower than in the EB-treated group after 15 days. Most of these effects were associated with PROP-induced activity of glutathione reductase in the brainstem: the EB + PROP group showed 59% higher GR activity than that of the EB or control groups within 7 days. In summary, aligning with previous studies from our group and with literature about MTXs, we observed that propentofylline (PROP) improved the thiol-based antioxidant defenses in the rat brainstem by the induction of the enzymatic activity of glutathione reductase (GR), which diminished lipid oxidation progression and rebalanced the redox status in the CNS.

In vitro evaluation of dioscin and protodioscin against ER-positive and triple-negative breast cancer.

Women's breast cancer is one of the most significant healthcare issues for the human race that demands a proactive strategy for a cure. In this study, the cytotoxic activity (MTT assay) of two natural steroidal compounds, protodioscin and dioscin, against two major subtypes of human breast cancer estrogen receptor-positive (ER-positive)/MCF-7 and triple-negative breast cancer (TNBC)/MDA-MB-468), was assessed. The clonogenic capacity was evaluated using the clonogenic assay. Oxidative stress was determined by measuring the formation of malondialdehyde and H2O2 and the assessment of total antioxidant enzyme activities (SOD, GPx, GR, and TrxR). Protodioscin and dioscin were highly cytotoxic against the tested cell lines (1.53 μM <IC50< 6 μM) with low cytotoxicity on normal cells (PBMC; IC50 ≥ 50 μM). Interestingly, these compounds were responsible for a substantial decrease in the clonogenic capacity of both cell lines. Moreover, dioscin was able to reduce the cell motility of the invasive breast cancer cells (MDA-MB-468). At the molecular level, the two treatments resulted in an increase of reactive oxygen species. Notably, both compounds were responsible for decreasing the enzymatic activities of glutathione reductase and thioredoxin reductase. On the basis of such considerations, protodioscin and dioscin may serve as promising natural compounds to treat TNBC and ER-positive breast cancer through the induction of oxidative stress.

Overexpression of tomato glutathione reductase (SlGR) in transgenic tobacco enhances salt tolerance involving the S-nitrosylation of GR

S-nitrosylation, a post-translational modification (PTM) dependent on nitric oxide, is essential for plant development and environmental responsiveness. However, the function of S-nitrosylation of glutathione reductase (GR) in tomato (SlGR) under NaCl stress is yet uncertain. In this study, sodium nitroprusside (SNP), an exogenous NO donor, alleviated the growth inhibition of tomato under NaCl treatment, particularly at 100 μM. Following NaCl treatment, the transcripts, enzyme activity, and S-nitrosylated level of GR were increased. In vitro, the SlGR protein was able to be S-nitrosylated by S-nitrosoglutathione (GSNO), significantly increasing the activity of GR. SlGR overexpression transgenic tobacco plants exhibited enhanced germination rate, fresh weight, and increased root length in comparison to wild-type (WT) seedlings. The accumulation of reactive oxygen species (ROS) was lower, whereas the expression and activities of GR, ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT); the ratio of ascorbic acid/dehydroascorbic acid (AsA/DHA), reduced glutathione/oxidized glutathione (GSH/GSSG), total soluble sugar and proline contents; and the expression of stress-related genes were higher in SlGR overexpression transgenic plants in comparison to the WT plants following NaCl treatment. The accumulation of NO and S-nitrosylated levels of GR in transgenic plants was higher in comparison to WT plants following NaCl treatment. These results indicated that S-nitrosylation of GR played a significant role in salt tolerance by regulating the oxidative state.

Evaluation of Effects of Titanium Dioxide and Zinc Oxide Nanoparticles on Baker’s Yeast (Saccharomyces cerevisiae) Glutathione Reductase Activities

The glutathione reductase (GR) of baker's yeast (Saccharomyces cerevisiae) was exposed to titanium dioxide nanoparticles (TiO2 NPs) and zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 25, 50, 100, 250, and 500mg/L (ppm) in vitro. According to the calculations, the effect of 25, 50, 100, 250, and 500mg/L TiO2 NPs on GR enzyme activities resulted in percentage changes of - 3.12; - 0.87; - 2.12; - 2.12, and - 1.50, respectively. Percentage changes in GR enzyme activities with the effect of 25, 50, 100, 250, and 500mg/L ZnO NPs were calculated as - 2.01; + 1.88; + 0.38; - 2.51, and + 0.75, respectively. It can be deduced from this research that the change in concentrations of TiO2 NPs and ZnO NPs has no statistically significant effect on GR enzyme activities in comparison with the control groups (p > 0.05, N = 3).

Sıçan Eritrositlerinde Karbon Tetraklorürün(CCl4) ve Kuersetinin Bazı Metabolik Enzim Aktiviteleri Üzerine İn Vivo Etkisinin İncelenmesi

In the study; the purpose was to investigate the in vivoimpact of carbon tetrachloride (CCl4) and quercetin (Qu) on activities of important metabolic enzymes such as Glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), glutathione reductase (GR) and glutathione S-transferase (GST) in rat erythrocytes. At the experimental stage, rats were divided into 4 groups. 1.Group (Control): Pure olive oil at a dose determined according to their body weight (1mL/kg) was given to the rats in this group, 2.Group (CCl4: 1.0 mL/kg (ip)(1:1), 3.Group (Ku: 25) mg/kg (ip), 4.Group (CCl4(1.0 ml/kg (ip)+ Ku (25 mg/kg (ip) was injected. The study was continued for 3 days.The results revealed that the activities of; G6PD (p˂0.01), 6PGD (p˂0.01), GR(p˂0.001) and GST (p˃0.05) enzyme activities were decreased in the CCl4group compared to the control group. It was determined that enzyme activities were higher in CCl4+Qu applied groups compared to CCl4group.The application of Qu caused an increase in the enzyme activity value. This can be accepted as an indication that the inhibition caused by CCI4has disappeared. Consequently; It is thought that Qu may be effective in preventing oxidative damage due to CCl4administration.

Nitric oxide overcomes copper and copper oxide nanoparticle-induced toxicity in Sorghum vulgare seedlings through regulation of ROS and proline metabolism.

This study aimed to investigate the phytotoxic effect of copper (Cu) and copper nanoparticles (CuONPs) and ameliorative potential of nitric oxide (NO) against these toxic materials in Sorghum vulgare Pers. seedlings. Data suggested that exposure of Cu and CuONPs significantly reduced growth, chlorophyll, carotenoids and protein in root and shoot, which coincided with increased Cu accumulation. However, addition of sodium nitroprusside (SNP, a donor of NO) lowered Cu and CuONPs mediated toxicity through restricting Cu accumulation and improving photosynthetic pigments and total soluble protein contents. Data further suggested that exposure of Cu and CuONPs significantly increased hydrogen peroxide (H2 O2 ), superoxide radicals (O2 •- ), and malondialdehyde (MDA) contents. Enhanced level of oxidative stress severely inhibited the enzymatic activities of glutathione reductase (GR), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) but enhanced superoxide dismutase (SOD) and catalase (CAT) activity. However, addition of SNP positively regulated antioxidants enzymes activity, particularly the enzymes involved in the ascorbate-glutathione cycle to overcome Cu- and CuONPs-induced stress in Sorghum seedlings. Further, Cu and CuONPs enhanced accumulation of free proline through inducing Δ1 -pyrroline-5-carboxylate synthetase (P5CS) activity while lowering the proline dehydrogenase (PDH) activity. However, addition of SNP reversed these responses. Therefore, overall results revealed that SNP has enough potential of reducing the toxicity of Cu and CuONPs in Sorghum seedlings through regulation of proline metabolism and activity of enzymes of the ascorbate-glutathione cycle. These findings can be employed in developing new resistant varieties of Sorghum having enhanced tolerance against Cu or CuONP stress and improved productivity.

Algaecidal and oxidative effects of metal-free phthalocyanine beta tetra-substituted with sodium 2-mercaptoethanesulfonate

In this study, a water-soluble metal-free phthalocyanine (SPC) containing sodium 2-mercaptoethanesulfonate substituents at the peripheral positions was used to investigate the algaecidal properties and oxidative effects on the growth of two microalgal species, Arthrospira platensis and Chlorella vulgaris. Although OD at 560 nm and chlorophyll-a content were decreased in Arthrospira platensis during 7 days depending on dose and time, increases in both OD at 750 and chlorophyll-a content at 8 ppb (parts per billion) concentration on the 7th day were observed in Chlorella vulgaris. However, total SOD (superoxide dismutase) and GR (glutathione reductase) enzyme activity of A. platensis cultures did not display any alteration in all concentrations, SOD activity displayed an increase significantly at 2 ppb concentration, and GR activity showed increases at 1, 2, and 4 ppb concentrations in C. vulgaris application. In A. platensis application, APX (ascorbate peroxidase) activity decreased at 0.50 ppb, 1 ppb, and 1.5 ppb concentrations. In addition, C. vulgaris application showed decreases at all concentrations. When MDA content increased at all concentrations, the H2O2 content increased only at significatly 0.125 ppb concentration in A. platensis cultures. Both MDA (malondialdehyde) and H2O2 (hydrogen peroxide) content of C. vulgaris cultures showed a statistically significant decrease at all concentrations compared to control. Free proline decreased at 0.25 ppb, 0.50 ppb, 1 ppb, and 1.5 ppb concentrations in A. platensis application, and it decreased at all the concentrations of C. vulgaris application. It concluded that this compound has inhibition effects on A. platensis, but it supports growth in C. vulgaris. Therefore, this synthesized phthalocyanine compound (SPC) should be consumed carefully, and the contamination to aquatic ecosystems should be prevented.

On the Antioxidant Properties of L-Kynurenine: An Efficient ROS Scavenger and Enhancer of Rat Brain Antioxidant Defense.

L-kynurenine (L-KYN) is an endogenous metabolite, that has been used as a neuroprotective strategy in experimental models. The protective effects of L-KYN have been attributed mainly to kynurenic acid (KYNA). However, considering that L-KYN is prone to oxidation, this redox property may play a substantial role in its protective effects. The aim of this work was to characterize the potential impact of the redox properties of L-KYN, in both synthetic and biological systems. First, we determined whether L-KYN scavenges reactive oxygen species (ROS) and prevents DNA and protein oxidative degradation in synthetic systems. The effect of L-KYN and KYNA (0.1–100 µM) on redox markers (ROS production, lipoperoxidation and cellular function) was compared in rat brain homogenates when exposed to FeSO4 (10 µM). Then, the effect of L-KYN administration (75 mg/kg/day for 5 days) on the GSH content and the enzymatic activity of glutathione reductase (GR) and glutathione peroxidase (GPx) was determined in rat brain tissue. Finally, brain homogenates from rats pretreated with L-KYN were exposed to pro-oxidants and oxidative markers were evaluated. The results show that L-KYN is an efficient scavenger of ●OH and ONOO−, but not O2●– or H2O2 and that it prevents DNA and protein oxidative degradation in synthetic systems. L-KYN diminishes the oxidative effect induced by FeSO4 on brain homogenates at lower concentrations (1 µM) when compared to KYNA (100 µM). Furthermore, the sub-chronic administration of L-KYN increased the GSH content and the activity of both GR and GPx, and also prevented the oxidative damage induced by the ex vivo exposure to pro-oxidants. Altogether, these findings strongly suggest that L-KYN can be considered as a potential endogenous antioxidant.

Effects of two synthetic pyrethroids on Arthrospira platensis Gomont growth and antioxidant parameters

The transport of pesticides from application areas to other areas results in pesticide contamination and this sort of contamination has led to unexpected environmental problems worldwide. It is important to determine the responses of phytoplanktonic organisms to these chemicals for an understanding of the effects of pesticides on aquatic ecosystems. In this study, Arthrospira platensis Gomont cyanobacteria were exposed to different concentrations of the pesticides cypermethrin (0-50 µg mL-1) and deltamethrin (0-2 µg mL-1). Changes in chlorophyll-a concentration, the absorbance of OD560, antioxidant parameters (SOD, APX, GR, MDA, H2O2, and proline) were determined under the pesticide exposure. Our results showed that there is a decrease in OD560 absorbance and chlorophyll-a content proportionate to the increase of pesticide levels. Superoxide dismutase enzyme activity decreased with Cyp and Dlm application in A. platensis cultures. Glutathione reductase enzyme activity also decreased with Cyp applications but did not change with Dlm application. Ascorbate peroxidase enzyme activity increased with Cyp treatments but did not change with Dlm applications. Although malondialdehyde and hydrogen peroxide contents did not change with Cyp applications, they increased with Dlm applications. Proline contents increased with Cyp applications but decreased with Dlm applications. In conclusion, deltamethrin is more toxic than cypermethrin in the concentrations applied.