Glutathione S-transferase Enzyme Activity Research Articles

In Vitro Inhibition Effect and Molecular Docking Study of Curcumin, Resveratrol, and Quercetin on Human Erythrocyte Glutathione Transferase

Background:Chemotherapy has shown varying success rates in the treatment of metastatic cancer in the last 50 years. One of the problems in the use of many chemotherapeutic agents is to increase the expression of glutathione transferase enzyme (GST; EC 2.5.1.18). Therefore, the development of GST inhibitors is important to improve the effectiveness of antitumor drugs and to overcome multi-drug resistance.Introduction:Glutathione S-transferases (GSTs) are a major member of enzymes serving in the detoxification of exogenous and endogenous substances. But, it has been reported that GSTs are overexpressed in many tumour cells, and it has been found to be related to developing resistance to anticancer drugs by these cells. The development of GST inhibitors is important to increase the efficacy of antitumor drugs and overcome multi-drug resistance. The aim of our study was to investigate the effect of natural compounds including curcumin, resveratrol, and quercetin on GST enzyme activity. We also aimed to specify inhibition mechanism of the compounds on human erythrocytes GST (hGST) with in silico study.Method:GST was purified from human erythrocytes using affinity chromatography (glutathione agarose). The enzyme purity was checked with SDS-PAGE. After the inhibitory effect of the curcumin, quercetin, resveratrol was investigated. Lastly, inhibition mechanisms of these natural compound were identified with induced-fit docking method.Result:GST was purified with 19.31% yield from human erythrocytes. In inhibition studies, Ki values of curcumin, quercetin, resveratrol were determined as 0.0021 ± 0.0008, 0.0257 ± 0.0011, 663.3301 ± 0.0936 µM respectively. According to our results, all natural products showed the inhibition effect and the order of inhibition is as follows: curcumin ˃ quercetin ˃ resveratrol.Conclusion:According to the results of the in vitro and in silico studies, it can be said that curcumin, quercetin, resveratrol are the inhibitors of human erythrocyte GST. In conclusion, these observations may be of great importance for the potential use of these natural compounds as chemopreventive agents.

The Toxic Effects of Sulfoxaflor Induced in Earthworms (Eisenia fetida) under Effective Concentrations.

Sulfoxaflor is a new kind of neonicotinoid insecticide that is used to control sap-feeding insect pests. In this study, a hazard assessment of sulfoxaflor on soil invertebrate earthworms was performed under effective concentrations. The results showed that different exposure times and doses had significant influence on the toxicity of sulfoxaflor. Sulfoxaflor degraded quickly in artificial soil with a degradation rate of 0.002–0.017 mg/(kg·d) and a half-life of 12.0–15.4 d. At 0.5 mg/kg and 1.0 mg/kg, the ·OH− content, antioxidant enzyme activeities, thiobarbituric acid reactive substances (TBARS) content and 8-OHdG content had significant differences compared to those in the control group. On the 56th day, significant differences were only observed in the Glutathione S-transferase enzyme (GST) activity and 8-OHdG content at 1.0 mg/kg compared to those in the control group due to the degradation of sulfoxaflor. This indicated that the risk of sulfoxaflor to earthworms was reduced because it was easily degraded in soil. However, because sulfoxaflor is a super toxic pollutant to earthworms, high concentrations of sulfoxaflor should not be released into the soil environment.

A novel sigma class glutathione S-transferase gene in freshwater planarian Dugesia japonica: cloning, characterization and protective effects in herbicide glyphosate stress.

As the top-selling herbicide in the world, glyphosate distributes widely in natural environment and its influence on the ecological security and human health has attracted more and more concern. Glutathione S-transferases (GSTs) are a well-characterized superfamily of isoenzymes for cellular defense against exogenous toxic substances and therefore protect organisms from injury. In this study, the complete cDNA sequence of GST gene (named as Dja-GST) in freshwater planarian Dugesia japonica was firstly cloned by means of RACE method. The full-length Dja-GST comprises of 706 nucleotides which encodes a polypeptide of 200 amino acids. Dja-GST has two representative GST domains at the N- and C-termini. The conservative GST-N domain includes G-site Y8, F9, R14, W39, K43, P52 and S64, while the variable GST-C domain contains H-site K104, V156, D159 and L161. Sequence analysis, phylogenetic tree reconstruction and multiple alignment collectively indicate that Dja-GST belongs to the Sigma class of GST superfamily. Also, GST gene expression profile, GST enzymatic activity and MDA content in response to glyphosate exposure were systematically investigated and the correlations among them were analyzed. The results suggest that glyphosate exposure modified the mRNA transcription and enzymatic activity of GST, as well as the MDA content in planarians, indicating that Dja-GST might play an important part in organisms defending against oxidative stress induced by glyphosate. This work lays a molecular foundation for further exploring the exact functions of Dja-GST and gives an important implication for evaluating the ecological environment effects of herbicide glyphosate.

Caracterization of glutathione S-transferase of Dermacantor marginatus and effect of the recombinant antigen as a potential anti-tick vaccine

Dermacentor marginatus is one of the main tick species in northwestern China, and is a vector of various tick-borne pathogens. Tick control method largely depends on chemical agents, but the disadvantages of using such approach would cause environmental damage and the risk of developing tick resistance to acaricides. Vaccination of tick protective antigen is an eco-friendly approach which is an alternative and promising method to mitigate tick infestation in livestock. In the study, a mu-class glutathione S-transferase (GST) sequence of D. marginatus was cloned and the recombinant protein (rDmGST) was expressed. Transcriptional level of the GST was measured together with native GST activity of the tick. Finally, A vaccine trial on rabbits against D. marginatus was proceeded to evaluate the anti-tick effect of rDmGST. Results reveled that the CDs of the D. margiantus glutathione S-transferase mu 1 gene has 669 base pair nucleotide sequence encoding a 223 amino acid. The deduced GST protein sequence had over 95 % similarity with that of D. variabilis. The rDmGST was efficiently expressed soluble and purified by His trap affinity chromatography. Enzyme activity of native GST and transcriptional profiles of the GST showed up-regulation in different stages and organs of D. marginaus during blood feeding. Polyclonal antibody reacted with rDmGST in Western blotting. Tick challenge on rDmGST inoculated rabbits showed reductions in adult female engorgement rate, total egg mass and egg hatching rate with an overall vaccine efficacy of 43.69 %. The results of the experiment indicated the GST has potential value to be an effective protective antigen of D. marginatus.

The physiological and toxicological effects of antibiotics on an interspecies insect model

Silkworm (Bombyx mori L.) has a clear genetic background, parts of which are highly homologous to certain genes related to human hereditary diseases. Thus, the species presents an excellent interspecies model for drug screening and microbe-host interaction studies. Chloramphenicol (CAM) and vancomycin (VCM) are antibiotics commonly used to treat specific bacterial infections in medical care, animal husbandry, and agriculture. However, inappropriate dosages and prolonged therapy increase their risk of toxicity. In this work, we investigated the physiological and toxicological responses of silkworm to combined oral administration of CAM and VCM. Results showed that antibiotics promote the feeding behavior of silkworm and significantly reduce (P < 0.05) intestinal cultivable bacterial counts. Moreover, antibiotics decreased the antioxidant enzyme activities of superoxide dismutase, catalase, glutathione S-transferase, and thioredoxin reductase and caused oxidative damage to the silkworm intestine; the degree of damage was confirmed by histopathology analysis. The gene expression levels of antimicrobial peptides (attacin, lysozyme, and cecropins) were also perturbed by antibiotics. After antibiotic exposure, 16S rRNA metagenomic sequencing revealed increases in the relative abundance of Sphingobium, Burkholderia, Barnesiella, Bacteroides, Bradyrhizobium, Acinetobacter, Phenylobacterium, Plesiomonas, Escherichia/Shigella, and unclassified bacteria, as well as a reduction of Enterococcus. The metabolic and functional profiles of intestinal microbiota, particularly metabolic processes, such as energy, cofactors and vitamins, lipid, amino acid, and carbohydrate metabolisms, changed after antibiotic exposure. In conclusion, our findings reveal that antibiotics exert substantial effects on silkworm. The present study may promote the applications of silkworm as an interspecies model in the medical and pharmaceutical fields.

Toxicological effects of some antiparasitic drugs on equine liver glutathione S-Transferase enzyme activity

Benzimidazoles are antiparasitic drugs having an extensive application field like agriculture, medicine, and especially in veterinary medicine. In this study, we report the effect of some benzimidazole drugs such as ricobendazole (RBZ), thiabendazole (TBZ), albendazole (ALBA) and oxfendazole (OFZ) on glutathione s-transferase (GST) enzyme activity. The kinetics studies, IC50 and Ki values of the tested drugs on GSTs enzyme activity were investigated. The obtained ranking of IC50 values were found to be approximately RBZ (53.31 μM, r2: 0.9778) < OFZ (57.75 μM, r2: 0.9630) < ALBA (63.00 μM, r2: 0.9443) < TBZ (69.30 μM, r2: 0.9491). And the obtained ranking of Ki values of the tested drugs (RBZ, TBZ, ALBA, and OFZ) for GSTs enzyme activity was found to be approximately 26.37 ± 2.96, 44.01 ± 5.74, 39.82 ± 3.98 and 30.14 ± 3.03 μM, respectively. Experimental results showed that tested the benzimidazoles drugs have some significant inhibitory effect on GSTs enzyme activity. And also, it was determined that RBZ, ALBA, OFZ are competitive inhibition, but TBZ is non-competitive inhibitors on GSTs enzyme activity. RBZ drug showed the best inhibitory effect with the lowest Ki value.

Short-term spatiotemporal biomarker changes in oysters transplanted to an anthropized estuary in Southern Brazil

Estuarine ecosystems are increasingly being affected by pollution caused by anthropogenic activities. In this study, Crassostrea gasar oysters were transplanted and maintained for seven days at three sites (S1, S2, and S3) in the Laguna Estuarine System (LES)—situated in southern Brazil—that has been exposed to multiple anthropic stresses. On the basis of the concentrations of metal and organic pollutants in oysters, we identified marked spatial variations in pollutant levels, with S3 showing the highest concentration of Ag, Fe, Ni, Zn, and total polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and linear alkylbenzenes (LABs), followed by S2 and S1. Along with the concentrations of pollutants, a set of biomarkers was analyzed. Oysters maintained at S3 showed enhanced protective defenses in gills, as observed by the increased levels of superoxide dismutase (SOD-like) and heat shock protein 90 (HSP90-like) transcripts and catalase (CAT) activity, concomitant with reduced lipid peroxidation (MDA) levels. Decreased antioxidant activities together with increased MDA levels are indicative of the digestive gland being more susceptible to pollutant-induced oxidative damage. Oysters transplanted into LES showed lower levels of cytochrome P450 transcripts (CYP356A1-like and CYP2AU1), and decreased glutathione S-transferase (GST) enzyme activity, suggesting lower biotransformation capacity. By integrating information regarding the concentration of metal and organic pollutants with that of molecular as well as biochemical biomarkers, our study provides novel insights into pollutant exposure and the potential biological impacts of such exposure on estuarine organisms in southern Brazil.

Bemisia tabaci (Hemiptera: Aleyrodidae) Insecticide Resistance in Shandong Province, China.

The Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) complex comprises important pests and virus vectors in agricultural crops worldwide. In China, B. tabaci has spread to more than 20 provinces and caused severe losses of vegetables, fruits, and ornamental plants. However, B. tabaci has developed resistance to many insecticidal classes in Shandong Province, eastern China. In this study, we investigated the cryptic species, insecticide resistance and detoxifying enzymes of B. tabaci from six representative locations exhibiting severe damage in Shandong. At four of the six locations, B. tabaci Mediterranean (MED) comprised 100% of the samples collected. In a further two locations, species composition was predominantly (>94%) MED with B. tabaci Middle East-Asia Minor 1 (MEAM1), comprising a low proportion (<6%) of the samples collected. For all field populations, avermectin was the most effective insecticide against adult B. tabaci, pyriproxyfen had a significant effect on B. tabaci eggs and field populations were susceptible to pymetrozine. Six field populations of B. tabaci have developed low-to-moderate resistance to neonicotinoids. The detoxifying enzyme activity of carboxylesterase, glutathione S-transferase, and multifunctional oxidase were quantified. Multifunctional oxidase and glutathione S-transferase activity were positively correlated with insecticide resistance in several B. tabaci populations.

Effects of butylparaben on antioxidant enzyme activities and histopathological changes in rat tissues.

Butyl p-hydroxybenzoic acid, also known as butylparaben (BP), is one of the most common parabens absorbed by the skin and gastrointestinal tract and metabolised in the liver and kidney. Recent in vivo and in vitro studies have raised concern that BP causes reproductive, development, and teratogenic toxicity. However, BP-induced oxidative stress and its relation to tissue damage has not been widely investigated before. Therefore, we aimed to investigate the effects of butyl 4-hydroxybenzoate on enzyme activities related to the pentose phosphate pathway and on glutathione-dependent enzymes such as glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) in kidney, liver, brain, and testis tissues. Male rats were randomly divided into four groups to orally receive corn oil (control) or 200, 400, or 800 mg/kg/day of BP for 14 days. Then we measured G6PD, GR, GST, 6-PGD, and GPx enzyme activities in these tissues and studied histopathological changes. BP treatment caused imbalance in antioxidant enzyme activities and tissue damage in the liver, kidney, brain, and testis. These findings are the first to show the degenerative role of BP on the cellular level. The observed impairment of equivalent homeostasis and antioxidant defence points to oxidative stress as a mechanism behind tissue damage caused by BP.

Protein target identification and toxicological mechanism investigation of silver nanoparticles-induced hepatotoxicity by integrating proteomic and metallomic strategies

BackgroundSilver nanoparticles (AgNPs), as promising anti-microbials and anti-cancer therapeutics, the toxicological effect and killing efficiency towards cells need in-depth investigation for better applications in daily life and healthcare fields. Thus far, limited studies have yet elucidated the protein targets of AgNPs and silver ions (Ag+) released from intracellular AgNPs dissolution in hepatocytes, as well as potential interaction mechanism.ResultsThrough integrating proteomic and metallomic methodologies, six intracellular protein targets (i.e. glutathione S-transferase (GST), peroxiredoxin, myosin, elongation factor 1, 60S ribosomal protein and 40S ribosomal protein) were ultimately identified and confirmed as AgNPs- and Ag+ −binding proteins. Toward a deep understanding the direct interaction mechanism between AgNPs and these protein targets, GST was chosen as a representative for toxicological investigation. The results revealed that AgNPs could remarkably deplete the enzyme activity of GST but did not depress the expressions, resulting in elevated intracellular oxidative stress and cell death. Finally, both “Ag+ effect” and “particle-specific effect” were demonstrated to concomitantly account for the overall cytotoxicity of AgNPs, and the former relatively contributed more via activity depletion of GST.ConclusionsCollectively, our major contribution is the development of an efficient strategy to identify the intracellular AgNPs-targeted protein (e.g. GST) through integrating proteomic and metallomic methodologies, which is helpful to accelerate the interpretation of underlying toxicological mechanism of AgNPs.

Characterisation of GST genes from the Hyphantria cunea and their response to the oxidative stress caused by the infection of Hyphantria cunea nucleopolyhedrovirus (HcNPV)

The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Noctuidae), is a major pest found in forests. In this study, the effects of Hyphantria cunea nucleopolyhedrovirus (HcNPV) infection on the transcription levels and activities of glutathione S-transferases (GSTs) in H. cunea were determined. In the present study, 18 GST family genes were identified from the H. cunea transcriptome dataset by using bioinformatic analyses. These GST genes were classified into cytosolic (15 genes) and microsomal (three genes) classes. The 15 cytosolic GST genes belonged to four different subclasses (epsilon, sigma and delta). The all GST genes, especially GSTe4, showed high expression levels in egg and 1st~4th instar larval stage while their low expression levels in 5th~7th instar larvae using real-time quantitative PCR analysis. However, the expression levels of the 18 GST genes were varied after exposure to sublethal doses of HcNPV. The expression levels of most GSTs were downregulated and upregulated at low and high concentrations of HcNPV, respectively. The corresponding total GST activities also showed similar patterns. In H. cunea, changes in the expression levels and enzymatic activities of GSTs after exposure to HcNPV indicated that they may have important functions in the defense against HcNPV, and the stress, which may be reflected by the high GST enzymatic activities.

Methanolic extract of Nepeta paulsenii as an ameliorative agent against CCl4 induced testicular damage in male albino rats

The issue of male sexual dysfunction arises due to numerous complications linked with sperm motility, imbalance of antioxidant enzymes and hormonal levels. Carbon tetrachloride (CCl4) is widely used as a standard toxin to induce chemical injury and toxicity. A lot of research has been performed on many species of the genus Nepeta in vitro and in vivo but the plant Nepeta paulsenii have been rarely used in this aspect. The current research was designed to explore the impacts of methanolic extract of the Nepeta paulsenii plant on CCl4 induced testicular impairment in male albino rats. Forty-eight rats were distributed equally into 8 groups; Control, Vehicle control, CCl4 treated (1 ml/kg), CCl4 + Silymarine treated, CCl4 + Nepeta paulsenii (200 mg/kg) treated, CCl4 + Nepeta paulsenii (400 mg/kg), Nepeta paulsenii (200 mg/kg) and Nepeta paulsenii (400 mg/kg) treated. Blood and testicles were obtained and analyzed. To check antioxidant enzymes, hormonal concentrations, daily sperm production (DSP), protein content and histopathology various analyses were performed. CCl4 exposure resulted in adverse morphological changes and significant (p < 0.05) reduction in testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) concentrations, the activity of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione-disulfide reductase (GSR) and glutathione S-transferase (GST) enzymes, daily sperm production (DSP), protein content and high-density lipoproteins (HDL). CCl4 increased the TBARS and H2O2 production along with the cholesterol, triglyceride and low-density lipoproteins (LDL) levels, but Nepeta paulsenii restored these changes back to their normal state significantly (p < 0.05). Therefore, it was concluded that Nepeta paulsenii extract has potential to ameliorate the CCl4 induced testicular damage.

TiO2 nanoparticles and multi-walled carbon nanotubes monitoring and bioremediation potential using ciliates Pseudocohnilembus persalinus

In recent years, the release of nanomaterials pollutants to water bodies, to a great extent, attributed to anthropogenic activities. Their impacts on aquatic organisms as well as nanomaterial monitoring and bioremediation using organism have drawn much attentions. However, studies on relationship of nano-contaminants and aquatic organisms are very scarce. Our results showed that titanium dioxide nanoparticles (TiO2-NPs) and Multi-walled carbon nanotubes (MWCNTs) caused an obvious cell decreases on the whole, but a significant increase at 48 h TiO2-NPs exposure, indicating a resistant mechanism in ciliates for nano-toxic. Besides, MWCNTs was more toxic to Pseudocohnilembus persalinus than that of TiO2-NPs in terms of EC50 value. It is firstly found that P. persalinus ingested and released TiO2-NPs through cytostome and cytoproct, which might be the reason that TiO2-NPs less toxic than MWCNTs. The significantly increased superoxide dismutase (SOD) and glutathione S-transferase (GST) enzyme activities and expression levels were evaluated by reactive oxygen species ROS generation, which demonstrated that P. persalinus antioxidant defense enzyme played roles on nano-toxic resistant in ciliates. Moreover, the integrated biomarker response (IBR) was also determined, which demonstrated that MWCNTs had comparatively higher values than those of TiO2-NPs after higher concentration exposure to ciliates. In addition, it was confirmed by the present work that sod, gst and cat played different roles on immunity, and the sensitivity of cat gene expression to these two nanomaterials exposure was dissimilar. Damages of shrunk as well as losses of cilia on the cell surface caused by TiO2-NPs and MWCNTs exposure in P. persalinus using SEM revealed possible physical hazards of aggregated nanomaterials. Our findings will be helpful to understand the effect mechanisms of NPs on ciliates, and also demonstrated the possibility of P. persalinus as bio-indicator of nanomaterials in aquatic and potentials on bioremediation.

Polymorphisms in GSTE2 is associated with temephos resistance in Aedes aegypti

The glutathione S-transferases (GSTs) are enzymes involved in several distinct biological processes. In insects, the GSTs, especially delta and epsilon classes, play a key role in the metabolism of xenobiotics used to control insect populations. Here, we investigated its potential role in temephos resistance, examining the GSTE2 gene from susceptible (RecL) and resistant (RecR) strains of the mosquito Aedes aegypti, vector for several pathogenic arboviruses. Total GST enzymatic activity and the GSTE2 gene expression profile were evaluated, with the GSTE2 cDNA and genomic loci sequenced from both strains. Recombinant GSTE2 and mutants were produced in a heterologous expression system and assayed for enzyme kinetic parameters. These proteins also had their 3D structure predicted through molecular modeling. Our results showed that RecR has a profile of total GST enzymatic activity higher than RecL, with the expression of the GSTE2 gene in resistant larvae increasing six folds. Four exclusive RecR mutations were observed (L111S, I150V, E178A and A198E), which were absent in the laboratory susceptible strains. The enzymatic activity of the recombinant GSTE2 showed different kinetic parameters, with the GSTE2 RecR showing an enhanced ability to metabolize its substrate. The I150V mutation was shown to induce significant changes in catalytic parameters and a 3D modeling of GSTE2 mapped two of the RecR changes (L111S and I150V) near the enzyme's catalytic pocket, also implying an impact on its catalytic activity. Our results reinforce a potential role for GSTE2 in the metabolic resistance phenotype while contributing to the understanding of the molecular basis for the resistance mechanism.

Toxic effects of ornamental stone processing waste effluents on Geophagus brasiliensis (Teleostei: Cichlidae)

The ornamental stone industry generates considerable amounts of waste (OSPW), which may eventually reach natural environments and impact the local ecosystem. The aim of this study was to compare the toxic effects of two OSPW effluents in Geophagus brasiliensis: i) leachate effluent from a lagoon in an OSPW landfill (LE) and ii) decanted effluent from an ornamental stone processing industry (DE). G. brasiliensis were submitted to acute contamination with both OSPW effluents. After contamination, the gills were extracted for evaluation of histopathological alterations and ion concentration, while the liver underwent catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione s-transferase (GST) enzyme activity analysis. An induced biomarker response (IBRv2) index was determined to correlate the multi-biomarker response in G. brasiliensis. Fish gills exposed to DE showed increased concentration of Ca2+, Mg2+, Na+, and K+ when compared to those treated with LE. Histopathological lesions were observed in gills of animals exposed to both effluents. Micronucleus and comet assay were significantly greater in fish exposed to DE, when compared to those contaminated with LE. The evaluation of the enzymatic activity of CAT, GPx and SOD indicate greater oxidative stress in DE and LE-exposed fish, while GST activity was not altered. DE showed an IBRv2 value almost two-times higher in relation to LE, indicating that this waste may present higher toxic potential. The results demonstrate that both contaminants led to substantial toxic effects in G. brasiliensis, although the decanted waste induced the most remarkable responses in G. brasiliensis.

Protective Responses Induced by Chiral 3-Dichloroacetyl Oxazolidine Safeners in Maize (Zea mays L.) and the Detoxification Mechanism.

Herbicide safeners selectively protect crops from herbicide injury while maintaining the herbicidal effect on the target weed. To some extent, the detoxification of herbicides is related to the effect of herbicide safeners on the level and activity of herbicide target enzymes. In this work, the expression of the detoxifying enzyme glutathione S-transferase (GST) and antioxidant enzyme activities in maize seedlings were studied in the presence of three potential herbicide safeners: 3-dichloroacetyl oxazolidine and its two optical isomers. Further, the protective effect of chiral herbicide safeners on detoxifying chlorsulfuron in maize was evaluated. All safeners increased the expression levels of herbicide detoxifying enzymes, including GST, catalase (CAT), and peroxidase (POD) to reduce sulfonylurea herbicide phytotoxicity in maize seedlings. Our results indicate that the R-isomer of 3-(dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine can induce glutathione (GSH) production, GST activity, and the ability of GST to react with the substrate 1-chloro-2,4-dinitrobenzene (CDNB) in maize, meaning that the R-isomer can protect maize from damage by chlorsulfuron. Information about antioxidative enzyme activity was obtained to determine the role of chiral safeners in overcoming the oxidative stress in maize attributed to herbicides. The interaction of safeners and active target sites of acetolactate synthase (ALS) was demonstrated by molecular docking modeling, which indicated that both isomers could form a good interaction with ALS. Our findings suggest that the detoxification mechanism of chiral safeners might involve the induction of the activity of herbicide detoxifying enzymes as well as the completion of the target active site between the safener and chlorsulfuron.

Characteristics of prepared fenpropathrin nano-emulsion and research on glutathione S-transferase enzymatic activity and penetration performance on T. cinnabarinus

In this study, fenpropathrin nano-emulsion (NE) was prepared by phase inversion emulsification method. 8% xylene and 2% solvent oil 150 (The main component is 1,2,4,5-Tetramethylbenzene) were used as solvent, styrylphenolpolyoxyethylene and calcium dodecylbenzenesulfonate were used as surfactants. The particle size, zeta potential, conductivity and contact angle were detected to evaluate the characteristic of the nano-emulsion. Toxicity of fenpropathrin nano-emulsion on the pest mite, Tetranychus cinnabarinus, was analyzed. The particle sizes of 8% fenpropathrin nano-emulsion and 20% fenpropathrin emulsion concentrates (EC) were 31.53 nm and 459.00 nm, zeta potentials were –22 mV and 5.762 mV, respectively, which showed that the size of nanoemulsion was much smaller and its stability was higher than that of EC. The contact angles of these two formulations were tested in concentrations of 500 mg/L to 2000 mg/L. We found that the contact angle of NE at the same concentration was 32% lower than that of EC averagely. The results indicated that the wettability and adhesion ability of nano-emulsion droplets were better than those of EC on the biological targets. According to determination of penetration performance to T. cinnabarinus, it was found that the penetration performance of NE to T. cinnabarinus is 4–6 times higher than that of EC. With the characteristics above, the NE has exhibited higher biological activity on the T. cinnabarinus. The results of Glutathione-S-transferase (GSTs) enzymatic activity of T. cinnabarinus showed nano-emulsion had higher effects than EC. In conclusion, compared with EC, nano-emulsion has better penetration, biological activity and a great application prospect in pesticide field in the future.

Effect of lipoic acid supplementation on gene expression and activity of glutathione S-transferase enzyme in infertile men

Oxidative stress has become the focus of interest as a potential cause of male infertility. We evaluate effects of lipoic acid (LA) supplementation on glutathione S-transferase (GST) expression. This randomized, triple-blind, placebo-controlled clinical trial was conducted on 44 infertile males with idiopathic asthenozoospermia. Men were randomized to receive 600 mg LA or placebo once daily for 12 weeks and semen samples and venous blood samples were obtained. GST expression, reactive oxygen species (ROS) levels, GST activity and reproductive hormone profiles were also measured. GST expression in the intervention group were significantly higher than the control group. Also, at the end of the study, GST activity increased, and ROS levels decreased significantly compared to the baseline. Additionally, the intervention group showed an increase in testosterone and decrease in serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin after 12 weeks, but this difference was not significant. We conclude a 12-week treatment with LA leads to improvements in reproductive hormones in serum, and significantly reduces the generation of ROS and increases the gene expression and activity of GST in seminal fluid.

Effects of phenol on glutathione S-transferase expression and enzyme activity in Chironomus kiiensis larvae.

Detoxifying enzyme mRNAs are potentially useful stress biomarkers. Glutathione S-transferase (GST) metabolises lipophilic organic contaminants and mitigates oxidative damage caused by environmental pollutants. Herein, 12 Chironomus kiiensis GSTs (CkGSTs1-6, CkGSTt1-2, CkGSTd1-2, CkGSTm1-2) were cloned and grouped into sigma, theta, delta and microsomal subclasses. Open reading frames (450-699 bp) encode 170-232 amino acid proteins with predicted molecular masses of 17.31-26.84 kDa and isoelectric points from 4.94 to 9.58. All 12 GSTs were expressed during all tested developmental stages, and 11 displayed higher expression in fourth-instar larvae than eggs. GST activity after 24 h of phenol exposure was used to estimate environmental phenol contamination. After exposure to sublethal concentrations of phenol for 48 h, expression and activity of CkGSTs were inhibited in C. kiiensis larvae. Expression of CkGSTd1-2 and CkGSTs1-2 varied with phenol concentration, indicating potential use as biomarkers for monitoring environmental phenol contamination.

Investigation of the Polyphenol Composition, Biological Activities, and Detoxification Properties of Some Medicinal Mushrooms from Turkey.

Ethanolic extracts of the mushroom species Ganoderma adspersum, Inonotus hispidus, Russula chloroides, and Sarcodon imbricatus were investigated for their polyphenolic contents and biological activities. The radical scavenging activity of the extracts was evaluated by 2,2-diphenyl-1-(2,4,6-trinitrophenyl) (DPPH) method and their polyphenolic compounds were determined by high performance liquid chromatography (HPLC) analysis. Furthermore, the activity effects of mushroom extracts on the enzyme glutathione-S-transferase (GST) were also examined. Additionally, the antimicrobial activity of mushroom extracts was evaluated by disc diffusion method. Ethanolic extract of I. hispidus demonstrated the highest total phenolic content and total flavonoid contents, with 227.23±4.96 mg gallic acid equivalent/g and 42.14±0.20 quercetin equivalent/g, respectively. The highest DPPH radical scavenging activity was observed for ethanolic extracts of I. hispidus, with 10.687±1.643 µg/mL IC50. HPLC analysis demonstrated that R. chloroides was composed of ferulic acid, gallic acid, and myricetin compounds. The highest GST enzyme activity effect was detected with the ethanol extracts of I. hispidus and S. imbricatus. None of the mushroom extracts demonstrated significant inhibition of the bacterial strains used. These results indicate that I. hispidus may be proposed as a new potential source of natural medicine and its potential may be related to its polyphenolic content, which needs further investigation.