Enzymes Glutathione S-transferase Research Articles

Toxicity of triclosan, an antimicrobial agent, to a nontarget freshwater zooplankton species, Moina macrocopa.

The toxicity of triclosan (TCS) on the freshwater cladoceran Moina macrocopa was investigated by acute and chronic toxicity assessments followed by genotoxicity and oxidative stress response analyses. The 48-h LC50 of TCS for ≤24-h-old M. macrocopa was determined as 539 μg L-1 . Chronic exposure to TCS at concentrations ranging from 5 to 100 μg L-1 showed a stimulatory effect at low concentrations (≤10 μg L-1 ) and an inhibitory effect at high concentrations (≥50 μg L-1 ) on growth, reproduction, and population-growth-related parameters of M. macrocopa. The genotoxicity test results indicated that TCS concentrations ranging from 50 to 100 μg L-1 can alter individuals' DNA. Analysis of the antioxidant enzymes catalase (CAT) and glutathione s-transferase (GST) demonstrated increased levels of these enzymes at high TCS concentrations. Our results indicated that TCS concentrations found in the natural environment have minimal acute toxicity to M. macrocopa. However, TCS at even low concentrations can significantly affect its growth, reproduction, and population-growth-related characteristics. The observed responses suggest a hormetic dose-response pattern and imply a potential endocrine-disrupting effect of TCS. Our molecular and biochemical findings indicated that high concentrations of TCS have the potential to induce oxidative stress that may lead to DNA alterations in M. macrocopa.

Carbon nanofibers caused oxidative stress and disrupted anti-predator responses in common spiny loach

Carbon nanofibers, recently recognized pollutants, have been heavily used among the nanomaterials in many industries. Due to the poor suspension-stability, carbon nanofibers tend to sediment at the bottom of waterbodies and hence can be consumed by the bottom-dwellers. The current investigation evaluates the impact of carbon nanofibers at concentrations between 0.1 and 10 mg L−1 on the common bottom dweller spiny loach Lepidocephalichthys thermalis inhabiting Indian rivers. Carbon nanofiber exposure elevated the activities of the hepatic antioxidant enzymes superoxide dismutase, catalase, peroxidase and glutathione S-transferase, as oxidative stress markers. The fish behaviour patterns were examined by testing the effect of carbon nanofibers on predator recognition ability using kairomones, conspecific alarm cues, and dietary cues. The carbon nanofiber-exposed fish showed a loss of predator-recognition abilities. The results collectively demonstrated the carbon nanofiber driven hepatic oxidative damage and impaired predator-recognition ability in L. thermalis. The investigation, first of its kind, highlights the toxic potential of the carbon nanofibers on benthic fishes.

The Effect of Pomegranate-Black Carrot Juice on Serum and Erythrocytes of Sedentary Subjects Exposed to Exhausting Exercise

Background. In this study, the effects of pomegranate-black carrot juice mixture on serum and erythrocytes of sedentary individuals who had exhaustion test were investigated. Methods. A total of 20 men voluntarily participated in the study. Blood samples were obtained from participants on three conditions. First, before the study, blood samples of participants were collected (baseline). Second, the same participants performed in the 20-meter shuttle run test for 1 week each day and were subjected to oxidative stress. Lastly, the same participants were given a mixture of pomegranate-black carrot juices (100 ml/100 ml) for a week, 45 minutes prior to the 20-meter shuttle run test, and the stress + supplement was performed. Blood samples were taken at the end of each process. Results. In the erythrocytes, while the oxidative stress condition malondialdehyde (MDA) level and carbonic anhydrase (CA) enzyme activity levels increased compared to the baseline, reduced glutathione (GSH) level, glutathione reductase (GR), and glutathione S-transferase (GST) enzyme activity levels decreased. In stress + supplement conditions, while GSH and GR levels increased according to oxidative stress conditions, CA and MDA levels decreased. While the lactate dehydrogenase (LDH) level of the oxidative stress condition increased compared to the baseline, the LDH level of the stress + supplement decreased compared to the oxidative stress condition. Conclusions. Our results showed that the level of oxidative stress in subjects exposed to the exhaustion test decreased with the mixture of pomegranate-black carrot juices.

Evaluation of oxidative stress cycle in healthy and inflamed dental pulp tissue: a laboratory investigation.

The purpose of this study was to investigate the oxidative stress cycle consisting of reactive oxygen molecules (ROS), glutathione (GSH) and glutathione S-transferase (GST) in caries-related pulp inflammation. Fifty-four pulp tissue samples were collected from healthy donors with the diagnosis of reversible pulpitis, symptomatic irreversible pulpitis, and healthy pulp. Twelve pulp samples from each group were homogenized and total protein, ROS, GSH, and GST were measured by spectrophotometer. The remaining 6 samples from each group were prepared for paraffin block and used for the histopathologic and immunohistochemical evaluation of oxidative stress parameters and TUNEL labeling. Data were analyzed statistically. The results revealed that total protein levels significantly decreased; however, ROS levels increased in both reversible and irreversible pulpitis compared to the healthy pulp (p < 0.01). Also, as inflammation increases, GST enzyme levels decrease while GSH levels increase significantly (p < 0.05). It was found that the number of TUNEL (+) cells was increased in irreversible pulpitis samples compared to healthy and reversible pulpitis groups (p < 0.05). GSTP1 and GSH immunoreactivity were also observed in irreversible pulpitis samples. It has been revealed that caries-related inflammation alters the oxidative stress cycle in dental pulp tissue. The increase in GSH levels in the inflamed dental pulp due to the increase in ROS levels may improve the defensive ability of the dental pulp. There is a relationship between oxidative stress and inflammation. Control of excessive oxidative stress in pulpitis can stimulate reparative and regenerative processes. The present findings may provide an overview of the management of oxidative stress in cases with pulpitis during regenerative treatments.

Glyphosate is Harmful to Early Life Stages of the Viviparous Fish Jenynsia Multidentata: Biochemical and Locomotor Effects.

Glyphosate is the most widely used herbicide worldwide due to its efficacy in weed control in agriculture. This herbicide has been consistently detected in the aquatic environment, causing harmful consequences to nontarget organisms residing in agricultural regions. In this study, we assessed the effects of environmentally relevant concentrations of glyphosate (30-100µg/L) on the early life stages of the viviparous fish Jenynsia multidentata through biochemical and locomotor endpoints. At 96h of exposure, 30 and 65µg/L glyphosate caused an increase in acetylcholinesterase (AChE) activity, and 65µg/L glyphosate also augmented the levels of lipid peroxidation. Glyphosate at 100µg/L did not alter the activity of acetylcholinesterase or the levels of lipid peroxidation, but it stimulated the activity of the cellular detoxification enzyme glutathione S-transferase. In addition, all concentrations affected the swimming of the fish. Under light conditions, glyphosate caused hypolocomotion at all concentrations tested, whereas under dark conditions, this was observed at 30 and 100µg/L. Hyperlocomotion was observed at 65µg/L glyphosate. These findings are alarming for the health of fish, such as J. multidentata that inhabit streams that pass through agricultural areas, especially for the early life stages of these fish. Research studying the effects of pollutants on native species is relevant to improve regulation that protects aquatic ecosystems.

Behavioral and biochemical patterns in the Andean highland macroinvertebrate Nectopsyche sp. after chronic mercury exposure

Environmental pollution by mercury (Hg) is of particular interest in Latin American countries like Ecuador, where artisanal and industrial gold mining has widely expanded. However, classic assessments, either based on water parameters or bioindicators, are not always effective in determining the effect of this type of pollutant on the ecological quality of the rivers. This study analyzed the behavioral and biochemical responses in benthic macroinvertebrate Nectopsyche sp. after sub-lethal Hg exposure emulating the maximum limits allowed by the current legislation in Ecuador (0.0002 mg L−1). Behavioral changes were significant, with an average decrease in the movement (measured as the number of strokes per 15 s of larvae) after 6 days of exposure to the maximum limit concentration of Hg. Furthermore, the antioxidant enzyme Glutathione S-Transferase activity significantly increased when exposed for 7 days to 0.0002 mg L−1 of Hg concentration. These results preliminarily proved that behavioral and biochemical patterns could function as biomarkers that efficiently identify ecological impairment caused by Hg, which would otherwise be neglected by a purely chemical-based or biomonitoring based on the presence/absence of macroinvertebrates type of assessment. Moreover, we demonstrate that the current limits allowed can impair aquatic life.

Effect of Metarhizium anisopliae (MetA1) on growth enhancement and antioxidative defense mechanism against Rhizoctonia root rot in okra

Rhizoctonia solani is an important necrotrophic pathogenic fungus that causes okra root disease and results in severe yield reduction. Many biocontrol agents are being studied with the intent of improving plant growth and defense systems and reducing crop loss by preventing fungal infections. Recently, a member of the Hypocrealean family, Metarhizium anisopliae, has been reported for insect pathogenicity, endophytism, plant growth promotion, and antifungal potentialities. This research investigated the role of M. anisopliae (MetA1) in growth promotion and root disease suppression in okra. The antagonism against R. solani and the plant growth promotion traits of MetA1 were tested in vitro. The effects of endophytic MetA1 on promoting plant growth and disease suppression were assessed in planta. Dual culture and cell-free culture filtrate assays showed antagonistic activity against R. solani by MetA1. Some plant growth promotion traits, such as phosphate solubilization and catalase activity were also exhibited by MetA1. Seed primed with MetA1 increased the shoot, root, leaves, chlorophyll content, and biomass content compared to control okra plants. The plants challenged with R. solani showed the highest hydrogen peroxide (H2O2) and lipid peroxidation (MDA) contents in the leaves of okra. Whereas MetA1 applied plants showed a reduction of H2O2 and MDA by 5.21 and 14.96%, respectively, under pathogen-inoculated conditions by increasing antioxidant enzyme activities, including catalase (CAT), peroxidase (POD), glutathione S-transferase (GST), and ascorbate peroxidase (APX), by 30.11, 10.19, 5.62, and 5.06%, respectively. Moreover, MetA1 increased soluble sugars, carbohydrates, proline, and secondary metabolites, viz., phenol and flavonoid contents in okra resulting in a better osmotic adjustment of diseases infecting plants. MetA1 reduced disease incidence by 58.33% at 15 DAI compared to the R. solani inoculated plant. The results revealed that MetA1 improved plant growth, elevated the plant defense system, and suppressed root diseases caused by R. solani. Thus, MetA1 was found to be an effective candidate for the biological control program.

Novel Mannich bases derived from 1,2,4-triazoles: Design, synthesis, characterization, and glutathione S-transferase inhibition properties investigations

The reaction of variously substituted 1,2,4-triazole derivatives with morpholine and formaldehyde represents an efficient and easy-to-set synthetic entry toward heterocyclic N-Mannich bases. For this purpose, the synthesized Schiff Bases (3a-g) were reacted with formaldehyde and morpholine, a secondary amine, to yield novel N-Mannich bases (6a-g). The structures of the compounds (6a-g) were determined structurally by employing 1H/13C-NMR, IR, and elemental analysis. The synthesized compounds were screened for in vitro biological activity, and the bioanalysis results showed that the newly synthesized compounds had different in vitro enzyme inhibition activities against Glutathione S-transferase (GST). Their Ki values were calculated in the 2.69 ± 0.421–21.58±6.809 µM range. Besides, their IC50 values were calculated in the 1.975–2.753 µM range. Also, the potential inhibitory effects of the synthesized compounds on glutathione S-transferase enzyme were evaluated by in silico method. The highest affinity values for inhibition of glutathione S-transferase enzyme were observed as 6c (−7.7 kcal/mol), 6 g (−7.4 kcal/mol), and 6b (−6.8 kcal/mol), respectively, and they gave better affinity values than standard Ethacrynic acid. Furthermore, the absorption distribution, metabolism, and excretion properties (ADME), molecular properties, toxicity estimation, and compounds' bioactivity scores were evaluated.

Impacts of Nile Tilapia (Oreochromis niloticus) exposed to microplastics in bioflocs system

Microplastics (MPs) are abundant in aquaculture water, including in bioflocs aquaculture systems. Compared with other aquaculture systems, biofloc technology systems have the richest microbes and are beneficial to cultivated organisms. Therefore, this study provides a comprehensive assessment of the potential effects of MPs on aquaculture organisms in bioflocs systems. Here, Nile Tilapia (Oreochromis niloticus) were exposed to MPs (polystyrene; 32–40 μm diameter) with 0, 80 items/L (30 μg/L), and 800 items/L (300 μg/L) for 28 days in a bioflocs aquaculture system. The results showed that the MPs generally had no apparent effect on water quality, tilapia growth, or digestive enzyme activity. However, MPs accumulated the most in the liver (5.65 ± 0.74 μg/mg) and significantly increased the hepato-somatic index of tilapia and reduced the crude protein and lipid of tilapia muscle (p < 0.05). The levels of the antioxidant enzymes catalase and glutathione S-transferase increased significantly in response to MPs (p < 0.05). In contrast, MPs did not affect the content of glutathione, glutathione peroxidase, oxidized glutathione, and malondialdehyde, or the enzyme activity of Na+/K+-ATPase. Moreover, using an improved integrated biomarker response index, growth performance was found to be less responsive to MPs than to oxidative stress and digestive activity. Exposure to MPs did not significantly influence the microbial communities of the bioflocs and tilapia guts (p < 0.05). These results suggest that MPs barely affected tilapia in the bioflocs system. This study contributes to the evaluation of the ecological risk of MPs in aquaculture systems and a better understanding of the integrated response of cultivated vertebrates to MPs in biofloc technology systems.

Single-neuron neurodegeneration as a degenerative model for Parkinson's disease.

The positive effect of levodopa in the treatment of Parkinson's disease, although it is limited in time and has severe side effects, has encouraged the scientific community to look for new drugs that can stop the neurodegenerative process or even regenerate the neuromelanin-containing dopaminergic nigrostriatal neurons. Successful preclinical studies with coenzyme Q10, mitoquinone, isradipine, nilotinib, TCH346, neurturin, zonisamide, deferiprone, prasinezumab, and cinpanemab prompted clinical trials. However, these failed and after more than 50 years levodopa continues to be the key drug in the treatment of the disease, despite its severe side effects after 4-6 years of chronic treatment. The lack of translated successful results obtained in preclinical investigations based on the use of neurotoxins that do not exist in the human body as new drugs for Parkinson's disease treatment is a big problem. In our opinion, the cause of these failures lies in the experimental animal models involving neurotoxins that do not exist in the human body, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, that induce a very fast, massive and expansive neurodegenerative process, which contrasts with the extremely slow one of neuromelanin-containing dopaminergic neurons. The exceedingly slow progress of the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson's patients is due to (i) a degenerative model in which the neurotoxic effect of an endogenous neurotoxin affects a single neuron, (ii) a neurotoxic event that is not expansive and (iii) the fact that the neurotoxin that triggers the neurodegenerative process is produced inside the neuromelanin-containing dopaminergic neurons. The endogenous neurotoxin that fits this degenerative model involving one single neuron at a time is aminochrome, since it (i) is generated within neuromelanin-containing dopaminergic neurons, (ii) does not cause an expansive neurotoxic effect and (iii) triggers all the mechanisms involved in the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson's disease. In conclusion, based on the hypothesis that the neurodegenerative process of idiopathic Parkinson's disease corresponds to a single-neuron neurodegeneration model, we must search for molecules that increase the expression of the neuroprotective enzymes DT-diaphorase and glutathione transferase M2-2. It has been observed that the activation of the Kelch-like ECH-associated protein 1/nuclear factor (erythroid-derived 2)-like 2 pathway is associated with the transcriptional activation of the DT-diaphorase and glutathione transferase genes.

Midgut Cell Damage and Oxidative Stress in Partamona helleri (Hymenoptera: Apidae) Workers Caused by the Insecticide Lambda-Cyhalothrin.

The stingless bee Partamona helleri plays a role in pollinating both native and cultivated plants in the Neotropics. However, its populations can be reduced by the pyrethroid insecticide lambda-cyhalothrin. This compound may cross the intestinal barrier and circulate through the hemolymph, affecting various non-target bee organs. The aim of the present study was to assess the extent of cellular damage in the midgut and the resulting oxidative stress caused by lambda-cyhalothrin in P. helleri workers. Bees were orally exposed to lambda-cyhalothrin. The lethal concentration at which 50% of the bees died (LC50) was 0.043 mg a.i. L-1. The P. helleri workers were fed this concentration of lambda-cyhalothrin and their midguts were evaluated. The results revealed signs of damage in the midgut epithelium, including pyknotic nuclei, cytoplasm vacuolization, changes in the striated border, and the release of cell fragments, indicating that the midgut was compromised. Furthermore, the ingestion of lambda-cyhalothrin led to an increase in the activity of the detoxification enzyme superoxide dismutase and the levels of the NO2/NO3 markers, indicating oxidative stress. Conversely, the activities of the catalase and glutathione S-transferase enzymes decreased, supporting the occurrence of oxidative stress. In conclusion, the ingestion of lambda-cyhalothrin by P. helleri workers resulted in damage to their midguts and induced oxidative stress.

Determination of Constituents of Extract of Celtis tournefortii Lam. by LC-MS/MS, Investigation of Enzyme Inhibition, Antimicrobial and Anticancer Effects

Phytochemicals found in extracts obtained from plants are very important bioactive constituents. In this study, phytochemicals in extract content obtained from Celtis tournefortii .Lam. tree (CT) leaves were determined by a LC-MS method. The constituents with the major concentrations was found rutin (2479.89 µg ml-1), coumarin (1241.68 µg ml-1), biochanin A (1026.42 µg ml-1), shikimic acid (477.32 µg ml-1), chlorogenic acid (300.76 µg ml-1). The suppressive effects of CT extract on the growth of pathogenic strains were studied by microdilution method. It was observed that it caused suppression on the strains in the concentration range of 2.00-8.00 µg ml-1. The inhibition effects of the extract on acetyl cholinesterase and glutathione-S transferase enzyme activities were investigated, and 50% inhibitory values of enzyme activity were found to be 13.58 and 13.86, respectively. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay method, the cell viability suppressive effects of CT leaf extract were studied in healthy skin fibroblast cells as well as ovarian, colon and brain cancer cells. It was observed that they created a 42%, 4.27%, and 14.29% suppression in cells, respectively.

Seed priming with Beauveria bassiana improves growth and salt stress response in rice

One of the most important abiotic factors that hinder plant development, growth, and production is salt stress. In recent years, there has been a lot of interest in the biological treatment of salt stress in plants using beneficial microbes. The fungal endophyte Beauveria bassiana provides a wide variety of ecosystem services, like suppressing insect pests and pathogens and enhancing plant growth. However, the role of B. bassiana in reducing salt stress in plants has not yet been clarified. This study was undertaken to evaluate the performance of B. bassiana isolate BeauA1 primed rice under salt stress by estimating rice growth, stress parameters, and mitigator characteristics. Primarily, rice seeds were primed with BeauA1 and placed in an agar medium with 120 mM NaCl (≈12 dS m−1 salt solution) to observe the role of BeauA1 in the early establishment of rice seedlings in salt conditions. Seed priming with BeauA1 resulted in an enhancement of rice growth attributes under both control and NaCl stress conditions. In the pot experiment, the BeauA1 primed rice seedlings were planted in soil with different concentrations of salt, viz. 8, 10, and 12 dS m−1. The BeauA1 primed rice plants showed improvement in leaf succulence, leaf area, photosynthetic pigments, and shoot relative water content (RWC), leading to enhanced growth under both salt stress and control conditions. The biochemical study found that BeauA1 considerably increased proline content, total soluble sugars, total carbohydrates, and K+/Na+ in leaves. The antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), glutathione S-transferase (GST), and nonenzymatic antioxidants phenol and flavonoid were upregulated in BeauA1-primed plants under both control and stressed conditions. Further significant reductions of the lipid peroxidation products malondialdehyde (MDA) and hydrogen peroxide (H2O2) by BeauA1 under salt stress were consistent with higher antioxidant activities in salt stress conditions. Principal component analysis (PCA) further validated BeauA1-primed plants' modulation of growth, antioxidant defense, and reduction of MDA and H2O2 in rice under salt-stress conditions. Our findings indicated that utilizing BeauA1 to reduce salt stress would be a useful strategy to increase rice yield in salt-affected regions.

Effect of sub-lethal and lethal concentrations of the entomopathogenic fungus Metarhizium anisopliae Sorokin on detoxification enzymes and demographic parameters of Mythimna separata (Walker)

The maize armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae), is a polyphagous, destructive, and migratory pest. Improper pesticide application induced resistance may be an alternative mechanism for pest resurgence. In this study, the efficacy of Metarhizium anisopliae (Sorokin) was estimated, while focusing on sub-lethal (LC15) and lethal (LC50) concentration treatments on the F0 and F1 generations of laboratory-reared M. separata. The results indicated an LC50 value of 2.2 × 106 conidia mL−1 against M. separata larvae after infection with M. anisopliae. The sub-lethal and lethal concentrations and trans-generational effects on demographic parameters were estimated using the age-stage, two-sex life table. After treatment with LC15 (2.1 × 105conidia mL−1) and LC50 (2.2 × 106 conidia mL−1) concentrations, the progeny of M. separata exhibited reduced fecundity, larval duration and adult male and female longevity as compared to the control. Subsequently, population growth parameters such as mean generation time (T) and net reproductive rates (Ro) were reduced in these concentrations. Furthermore, activities of the detoxification enzymes glutathione S-transferases (GST), acetylcholinesterase (AChE) and esterases (EST) were significantly different at the LC50 as compared to LC15 and the control. These findings showed pathogenicity of M. anisopliae even at sub-lethal concentration, with negative effects on the fecundity, biological parameters and also altered the detoxifying enzymes of M. separata which enhanced its potential use as a management tool in eco-friendly and long-lasting management programs.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

Investigation of Effects of Some Metal Ions and Some Pesticides on Glutathione S-Transferase (GST) Enzyme Purified from Van Lake Fish (Chalcalburnus Tarichi) Kidney

Industrial and agricultural processes have brought about the pollution of aquatic systems, and this situation in the water had adverse effects on human health. In order to reduce these negative effects, all mammalian and aquatic species have a defense system. One of these antioxidant systems is the glutathione S-transferase enzyme group, which has detoxification activity against ROS produced by organic pollutants and heavy metals. In this study, the effects of some pesticides and heavy metal ions on the GST enzyme activity purified kidney tissue of the Lake Van fish (C. Tarichii) was analyzed. Firstly, the purification process was carried out as homogenate preparation and glutathione-agarose affinity technique. SDS-PAGE was carried out to check the enzyme purity. The enzyme was obtained in 89% yield (335-fold) with 27.8-specific activity , and kinetic constants was determined for the enzyme; Km for GSH substrate: 0.429 mM Vmax for GSH substrate: 0.207 EU/mL-1; Km for CDNB substrate: 0.276 mM, Vmax for CDNB substrate: 0.161EU/mL-1. Effects of Met-Hg, Fe3+ Cr3+ , Cu2+, Mg2+, Zn2+, atrazine, methomyl ,and dinicanozole were studied on the activity of the purified enzyme and the IC50 values were determined as 34.5 mM, 10 μM, 1.5 μM, 2.4 μM, 63 μM, 0.15 mM, 9.8 μM, 2.67 μM , and 1.3 μM, respectively.

Bioconcentration and cellular effects of emerging contaminants in sponges from Maldivian coral reefs: A managing tool for sustainable tourism

Tourism is the main income source for the Maldives, but concurrently, it represents a growing threat to its marine ecosystem. Here, we monitored the bioaccumulation of 15 emerging contaminants (ECs) in the Maldivian reef sponges Spheciospongia vagabunda collected in two resort islands (Athuruga and Thudufushi, Ari Atoll) and an inhabited island (Magoodhoo, Faafu Atoll), and we analysed their impact on different sponge cellular stress biomarkers. Caffeine and the insect repellent DEET were detected in sponges of all the islands, whereas the antibiotic erythromycin and the UV filter 4-methylbenzylidene camphor were found in resort islands only. Although concentrations were approximately a few ng/g d.w., we quantified various induced cellular effects, in particular an increase of the levels of the enzyme glutathione S-transferase involved in cell detoxification. Our results highlight the importance to increase awareness on ECs pollution, promoting the use of more environmental friendly products to achieving the sustainable development goals.

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.

Spraying Zinc Sulfate to Reveal the Mechanism through the Glutathione Metabolic Pathway Regulates the Cadmium Tolerance of Seashore Paspalum (Paspalum vaginatum Swartz).

Cadmium (Cd) is considered to be one of the most toxic metals, causing serious harm to plants' growth and humans' health. Therefore, it is necessary to study simple, practical, and environmentally friendly methods to reduce its toxicity. Until now, people have applied zinc sulfate to improve the Cd tolerance of plants. However, related studies have mainly focused on physiological and biochemical aspects, with a lack of in-depth molecular mechanism research. In this study, we sprayed high (40 mM) and low (2.5 mM) concentrations of zinc sulfate on seashore paspalum (Paspalum vaginatum Swartz) plants under 0.5 mM Cd stress. Transcriptome sequencing and physiological indicators were used to reveal the mechanism of Cd tolerance. Compared with the control treatment, we found that zinc sulfate decreased the content of Cd2+ by 57.03-73.39%, and that the transfer coefficient of Cd decreased by 58.91-75.25% in different parts of plants. In addition, our results indicate that the antioxidant capacity of plants was improved, with marked increases in the glutathione content and the activity levels of glutathione reductase (GR), glutathione S-transferase (GST), and other enzymes. Transcriptome sequencing showed that the differentially expressed genes in both the 0.5 Zn and 40 Zn treatments were mainly genes encoding GST. This study suggests that genes encoding GST in the glutathione pathway may play an important role in regulating the Cd tolerance of seashore paspalum. Furthermore, the present study provides a theoretical reference for the regulation mechanism caused by zinc sulfate spraying to improve plants' Cd tolerance.

Transcriptomics and metabolomics provide insight into the anti-browning mechanism of selenium in freshly cut apples.

Enzymatic browning has a considerable negative impact on the acceptability and marketability of freshly cut apples. However, the molecular mechanism by which selenium (Se) positively affects freshly cut apples in this regard is not yet clear. In this study, 0.75 kg/plant of Se-enriched organic fertilizer was applied to "Fuji" apple trees during the young fruit stage (M5, May 25), the early fruit enlargement stage (M6, June 25), and the fruit enlargement stage (M7, July 25), respectively. The same amount of Se-free organic fertilizer was applied as a control. Herein, the regulatory mechanism by which exogenous Se exerts its anti-browning effect in freshly cut apples was investigated. The results showed that the M7 treatment applied in Se-reinforced apples could remarkably inhibit their browning at 1h after being freshly cut. Additionally, the expression of polyphenol oxidase (PPO) and peroxidase (POD) genes treated with exogenous Se was significantly reduced compared to controls. Moreover, the lipoxygenase (LOX) and phospholipase D (PLD) genes, which are involved in membrane lipid oxidation, were expressed at higher levels in the control. The gene expression levels of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), and ascorbate peroxidase (APX) were upregulated in the different exogenous Se treatment groups. Similarly, the main metabolites measured during the browning process were phenols and lipids; thus, it could be speculated that the mechanism by which exogenous Se produces its anti-browning effect may be by reducing phenolase activity, improving the antioxidant capacity of the fruits, and alleviating membrane lipid peroxidation. In summary, this study provides evidence regarding and insight into the response mechanism employed by exogenous Se to inhibit browning in freshly cut apples.