Glutathione S-transferase Research Articles

Potential Application of Egg White Peptides for Antioxidant Properties: Perspectives from Batch Stability and Network Pharmacology.

This study investigated the batch stability of egg white peptides (EWPs) during the enzymatic hydrolysis process, and confirmed the potential application of four crucial four peptides inoxidative damage repair. The results revealed that different batches of EWPs had good stability relating to antioxidant activity. With a similar sequence to confirmed antioxidant peptides, four EWPs (QMDDFE, WDDDPTD, DEPDPL, and FKDEDTQ) were identified withhigh repetition rates, and their potential to repair oxidative damage was investigated. Network pharmacology results showed that these four peptides could regulate the targets related to oxidative damage. Enrichment results demonstrated that these four peptides could influence the targets and pathways related to glutathione transferase activity (enrichment score: 148.0) and glutathione metabolism (p value: 9.22 × 10-10). This study could provide evidence for the batch stability of hydrolyzed prepared EWPs, and offer theoretical support for the development of antioxidant damage ingredients derived from foods.

The Role of Arginase and some Parameters in Diabetic Type 2 Patients with and without Retinopathy

Background: Oxidative stress plays a major role in the pathogenesis of diabetes mellitus by damaging cellular organelles and enzymes in blood such as arginase1, insulin and glutathione s-transferase; increasing lipid peroxidation such as malondialdehyde and increasing insulin resistance which can lead to diabetic complications such as diabetic retinopathy. Objectives: To explore the relationship of oxidative stress to the development of diabetic retinopathy by measuring the levels of Arginase1, the activity of glutathione s-transferase enzyme, and the levels of malondialdehyde as a secondary product of lipid peroxidation (biomarker for oxidative stress). Patients and MethodsThis study was conducted from November 2022 to January 2023 at the Ibn Al-Haitham Teaching Eye Hospital in Baghdad, the University of Baghdad / Department of Chemistry and the National Diabetes Centre for Treatment and Research at Al-Mustansyrriah University. This study was conducted on 120 subjects distributed as follows: 40 non-diabetic obese controls, 40 type 2 diabetics with no retinopathy, and 40 type 2 diabetic retinopathy patients, between 30 and 65 years of age. All groups were subjected to tests: measuring fasting blood glucose (FBG), HbA1c, lipid profile (cholesterol, triglycerides, HDL- cholesterol, LDL- cholesterol, and VLDL cholesterol), serum total arginase1, malondialdehyde glutathione s -transferase, body mass index (BMI), and waist-to-hip ratio. Results: Mean arginase1 levels were significantly higher in diabetic patients than in diabetic retinopathy and control groups (p ≤ 0.05). The mean xidative stress marker malondialdehyde concentration was significantly higher in diabetic retinopathy patients than in type 2 diabetics and the control group (P ≤ 0.05). The mean glutathione s-transferase activity in diabetic retinopathy patients was significantly higher than in the control group and type 2 diabetics (P ≤ 0.05). Conclusion: There is a relationship between oxidative stress and the development of diabetic retinopathy, where the levels of arginase1 and malondialdehyde increased and the activity of glutathione s –transferase enzyme increased as a result of oxidative stress and inflammation associated with complications of type 2 diabetes.

Estimating Anticancer Effects of Yohimbine in DMBA-Induced Oral Carcinogenesis Hamster Model: Utilizing Biochemical and Immunohistochemical Techniques.

Yohimbine is a potent bioactive indole alkaloid, isolated from a variety of biological sources and has long been used as a natural stimulant and aphrodisiac, particularly to treat erectile dysfunction. However, some literature also points toward its anticancer effect in different experimental models. The current study aimed to address a clinical concern on the therapeutic utilization of yohimbine as a repurposed drug. We employed 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis model juxtaposed with biochemical investigation of several detoxification and antioxidant markers, such as Cyt p450, Cyt b5, thiobarbituric acid reactive substance (TBARS), glutathione (GSH), glutathione reductase (GR), glutathione S transferase (GST), DT-diaphorase, vitamin C, vitamin E, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). The immunohistochemical assessment of cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), proliferating cell nuclear antigen (PCNA), and cyclin D1 expression were also performed to observe the effect of yohimbine on these markers. The hamsters treated with DMBA presented the growth of tumors in the buccal pouches, accompanied by significant changes in the liver and buccal mucosa levels of Phase I & II detoxification enzymes and lipid peroxidation (LPO). A significant rise in the range of 2- to 3.5-fold was observed in Cyt p450, Cyt b5, and LPO in DMBA-treated animals. However, oral administration of yohimbine significantly restored the LPO, antioxidant, and detoxifying enzyme activities. Additionally, the levels of COX-2, IL-6, PCNA, and cyclin D1 were also found to be downregulated by yohimbine treatment. In conclusion, yohimbine improved the biochemical and immunohistochemical markers of DMBA-induced oral cancer and reverted to near normal values via ameliorating the underlying inflammation and oxidative stress conditions. Our study highlighted the potential of yohimbine as anticancer agent, especially against oral cancer and suggested its possible use as repurposed drug.

Gene-environment interactions and colorectal cancer risk: A case-control study on xenobiotic metabolizing enzyme polymorphisms in the Jammu& Kashmir, India population

BackgroundCancer remains a significant global health concern, with colorectal cancer (CRC) showing a rising incidence, particularly among younger populations. Most CRC cases are linked to a complex interplay of genetic and environmental factors. The cytochrome P450 (CYP) superfamily, including enzymes like CYP2A13 and CYP2A6, plays a vital role in metabolizing environmental carcinogens such as polycyclic aromatic hydrocarbons (PAHs) and nitrosamines. Polymorphisms in these genes, alongside phase II glutathione-S-transferases (GSTs) involved in detoxification, can influence individual cancer risk. This study focuses on the association between these genetic polymorphisms and CRC risk in the Jammu & Kashmir, population, a region with high exposure to dietary and lifestyle-related carcinogens. MethodologyThis hospital-based case-control study was conducted at the Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, J&K, India between March 2019 and March 2022. The study included 246 histopathologically confirmed colorectal cancer (CRC) cases, and an equal number of matched controls based on age (±5 years), gender, and place of residence. Blood samples were collected for DNA extraction, followed by genotyping of xenobiotic-metabolizing enzyme (XME) genes, including CYP2A13, CYP2A6, and GSTs using standard PCR-RFLP and multiplex PCR methods. Statistical analyses were performed using STATA software to assess the association between gene polymorphisms and CRC risk. ResultsThe study revealed key associations between genetic and environmental factors and CRC risk. The analysis demonstrated that cases had significantly lower education levels than controls. Family history of cancer, smoking, and dietary factors like red meat and salt tea consumption were more prevalent among cases. Genetic analysis identified significant interactions between various CYP and GST genotypes, and environmental factors such as smoking, pesticide exposure, and diet, with varying effects on CRC risk. ConclusionThe research underscores the influence of genetic and environmental factors on colorectal cancer (CRC) risk. Lower educational was associated with a heightened risk of CRC. Certain genotype variants of xenobiotic metabolizing enzymes (XME) were found to increase CRC risk, particularly in conjunction with smoking, pesticide exposure, and sun-dried vegetable consumption. A family history of cancer, especially CRC, further amplified the risk. These findings emphasize the importance of developing personalized CRC prevention and screening strategies that account for gene-environment interactions.

Assessment of oxidative stress biomarkers in Palaemon varians exposed to deep eutectic systems.

In recent years, there has been extensive research within the scientific community on deep eutectic systems due to their remarkable versatility in solubilizing diverse substances and serving as effective solvents in catalytic processes. While initially regarded as non-toxic, a comprehensive toxicological assessment is essential to comprehend their behavior within organisms. In this study, seven distinct systems, composed of N,N,N-triethyl-N-(2,3-dihydroxypropyl)ammonium chloride (N00Cl) and glycerol-derived ethers with alkyl chains of varying lengths (100, 200, 3F00, 300, 3i00, and 400), in a 1:2 molar ratio were investigated for their aquatic toxicity in shrimp (Palaemon varians). The assessment involved analyzing oxidative stress biomarkers such as glutathione S-transferase, glutathione peroxidase, catalase, superoxide dismutase, total antioxidant capacity (TAC), and lipoperoxidation (MDA content). Results show an odd-even effect for LC50 values being N00Cl-300, the system showing higher values. Regarding oxidative stress, an imbalance between reactive oxygen species (ROS) and antioxidant capacity in the organisms has been observed, suggesting significant toxicity to shrimps due to the changes in oxidative stress biomarkers at high concentrations. However, at 100mg/l all systems can be considered environmentally safe, and no negative impacts are expected on aquatic ecosystems.

Lethal and sublethal concentrations spirodiclofen stress may increase the adaptation of Panonychus citri (Acari: Tetranychidae).

Panonychus citri is one of the most destructive pests in citrus orchards, exhibiting varying degrees of tolerance to numerous insecticides, such as spirodiclofen. To effectively manage pests, this study explores the response of P. citri to spirodiclofen stress from the perspectives of life history, enzymatic parameters, and reproduction. The effects of two concentrations (LC30 and LC50) of spirodiclofen on the biological parameters of P. citri were evaluated by the life table method. The results showed that the development duration, fecundity, oviposition days, and lifespan were shortened, though the pre-oviposition period of two treatments was prolonged in comparison with the control. A significant decrease was recorded in the net reproductive rate (R0) and the mean generation time (T) for the two treatments. Nevertheless, the intrinsic rate of increase (r) and the rate of increase (λ) were not significantly affected in the LC30 treatment, whereas they declined in the LC50 treatment. The enzyme activity assay resulted in higher activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and carboxylesterase (CarE), among the treatments than the control. In contrast, the treatments recorded lower cytochromeP450 (CYP450) and Glutathione S-transferase (GST) activities than the control. Furthermore, the study detected that relative mRNA expression of Vitellogenin (Vg) and Vitellogenin receptor (VgR) for two treatments were lower than the control. In summary, two concentrations of spirodiclofen inhibited progeny growth and fecundity of P. citri. Additionally, the results of this study may support further research on tolerance of P. citri in response to spirodiclofen stress.

Anti-viral and Apoptotic Induction of m-TOR Inhibitor Drugs against Hepatitis C Virus Activity and Hepatocellular Carcinoma Cell Line: In vitro and in silico.

This study investigated the potential of m-TOR inhibitor drugs (sirolimus, everolimus, and tacrolimus) in combating both hepatocellular carcinoma (HCC) and hepatitis C virus (HCV) replication. After treating HepG2 and PBMCs with the mammalian target of Rapamycin (m-TOR) inhibitors drugs; sirolimus, everolimus, and tacrolimus at different concentrations (1, 5, and 10 µM/µl), cell proliferation was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Antioxidant activities (total antioxidant, glutathione S-transferase, and glutathione reductase), Fas-ligand level, tumor necrosis factor-α (TNF-α) level, caspase-3, -8, and -9 activities, and cell cycle analysis were measured. quantitative Real-time PCR, colony forming assay, molecular docking studies after infection of PBMCs with 1 ml (1.5 × 106 HCV) serum then incubated with m-TOR inhibitor drugs at their respective IC50 concentrations. In HepG2 cells, treatment with these inhibitors resulted in suppressed cell viability, increased dead cell accumulation, and enhanced apoptotic signaling through elevated Fas-ligand and caspase activities. Additionally, cell cycle analysis revealed arrest in G0/G1 and G2/M phases, further hindering HCC progression. Furthermore, m-TOR inhibitor drugs significantly reduced HCV viral load and colony formation in infected PBMCs. This antiviral effect was accompanied by decreased TNF-α activity, suggesting potential modulation of the inflammatory response associated with HCV infection. Molecular docking studies provided theoretical support for these findings, with Sovaldi demonstrating the highest binding affinity towards key HCV targets compared to other m-TOR inhibitors. This suggests its potential as a potent HCV inhibitor, while also highlighting the potential of exploring m-TOR inhibitors for future HCV treatment development. Overall, this study provides encouraging evidence for the potential of m-TOR inhibitor drugs as promising therapeutic agents for both HCC and HCV, warranting further investigation and optimization for clinical applications.

Assessing the impact of weathered polystyrene collected from the marine environment on oxidative stress responses in Zophobas morio larvae: A preliminary study

Foamed polystyrene (PS) is a prevalent material in consumer products and thus represents one of the largest constituents of marine litter. PS may interact with and be ingested by various organisms, including insects, which are starting to be used in biodegradation of plastic wastes. This study examines the physiological performances and the potential oxidative stress related to dietary environmental PS exposure of Z. morio larvae. Experimental groups were fed different diets: bran and oatmeal (control), weathered PS collected from the marine environment, and virgin PS. Over a 30-day feeding period, larvae growth, survival, and PS consumption were measured, together with antioxidant enzymatic activities and gene expression profiles. Results showed that PS ingestion supports larval growth similarly to bran, but the two PS-fed groups consumed a different amount of plastic, suggesting that weathered PS might affect the patterns of PS consumption by larvae. We denoted that PS consumption was associated with a decline in total antioxidant capacity, which showed the highest decrease in the environmental PS group. Marked increases in oxidative stress biomarkers such as superoxide dismutase (SOD) activity/mRNA levels and malondialdehyde content were also observed in the environmental PS-fed group, indicating an elevated oxidative stress response, probably due to pollutants adsorbed/absorbed on PS. Differently to SOD, catalase at both mRNA and enzyme activity levels was found to be significantly reduced by PS digestion, regardless of PS type. The mRNA levels of glutathione s-transferase (GST) were significantly higher in the environmental PS-fed larvae compared to the virgin PS-fed group. In addition, Principal Component Analysis clearly distinguished between larvae fed different PS types, highlighting the enhanced oxidative stress caused by the ingestion of PS collected from marine environments. These results support the potential of insects in plastic biodegradation processes but also demonstrate the health hazards of using environmental PS as principal dietary component in Z. morio larvae, thus questioning their use in downstream productions.

Mapping transcriptomic profiles of seminal vesiculitis and experimental verification

ObjectiveSeminal vesiculitis is a prevalent infectious disease in the genitourinary system, but its intrinsic pathogenesis and molecular features remain unclear. MethodsIn this study, we utilized next-generation sequencing technology to demonstrate the transcriptomic landscapes of clinical specimens from seminal vesiculitis patients. We identified enriched Go Ontology terms, pathway maps, processes, toxicity, and metabolic networks. ResultsGlutathione transferase activity is highly enriched, indicating its essential role in the disease's development. Furthermore, we established inflammation models of the seminal vesicle and validated the crucial function of glutathione transferase activity in these models ConclusionsOur results provide a robust platform for further intensive studies of seminal vesiculitis.

Possible Causes of Extreme Variation of Benzo[a]pyrene Acute Toxicity Test on Daphnia magna.

There are enormous differences in benzo[a]pyrene (BaP) acute toxicity tests on Daphnia magna, according to previous publications. The explanations of the reasons for this extreme variation are necessary. In this context, the acute toxicity tests of different experiment conditions (light/dark, culture medium, and solvent) were conducted on Daphnia magna with BaP as the toxicant of concern. Based on the experiments above, molecular dynamics (MD) simulations were employed to investigate the mechanisms of action. According to our results, the significant influence of light exposure on the acute toxicity test of BaP (p < 0.05) on D. magna was recorded. On the basis of the MD simulations, it was possible that BaP may not affect the normal operation of Superoxide Dismutase and Catalase directly, and it could be quickly transferred from the body through Glutathione S-transferase and Cytochromes P450. Therefore, when exposed to light, the oxidative stress process intensifies, causing damage to Daphnia magna. Apparently, the ecotoxicity tests based on inhibition for D. magna cannot adequately reflect the toxic effects of BaP.

Impact of diethyl phthalate on freshwater planarian behaviour, regeneration, and antioxidant defence

Diethyl phthalate (DEP) has been widely used as a plasticiser in various consumer products, including cosmetics, personal care items, and pharmaceuticals, and recent studies reported a higher abundance of this priority phthalate in the aquatic environment. DEP is a potential endocrine disruptor, affecting immune systems in humans and wildlife even at low-level chronic exposure. As concern over phthalates increases globally, regulatory bodies focus more on their environmental impact. However, limited research is available, particularly using model organisms like planarians. Planarians are ideal for toxicological studies and may provide insightful information on pollutants' neurotoxic, developmental, and ecological effects, especially in freshwater environments where planarians play a vital role in ecosystem balance. Therefore, the objective of the current study was to examine the toxicity of DEP using the freshwater Dugesia sp., as an experimental animal. The LC50 for the test organism was calculated using DEP concentrations of 800, 400, 200, 100, and 50 µM, with an estimated LC50 of 357.24 µM. Furthermore, planarians were exposed to sub-lethal DEP concentration (178.62 µM) for one day as well as eight days to evaluate the impact of DEP on planarian locomotion, feeding behaviour, and regeneration ability. At sub-lethal concentration, locomotion and feeding ability were decreased, and regeneration was delayed. Furthermore, neuro-transmittance in planaria was altered by sub-lethal DEP concentration, as indicated by a reduced acetylcholinesterase (AChE) activity. DEP exposure induced oxidative damage in the tested planarians as shown by a marked increase in stress biomarkers, including lipid peroxidation levels and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and glutathione S-transferase (GST). Our study revealed that DEP exposure may prove fatal to freshwater organisms, such as planarians. The observed alterations in behaviour and regeneration ability demonstrate the severity of the effects exerted by DEP as a toxicant in aquatic ecosystems, thereby indicating the need to restrict its usage to protect aquatic environments.

The homeostasis of ions and reactive oxygen species in root and shoot play crucial roles in the tolerance of alfalfa to salt alkali stress

High pH saline-alkali stress, mainly NaHCO3, limited the development of animal husbandry in Songnen Plain. Ion imbalance and reactive oxygen species (ROS) metabolism disorder caused by saline-alkali stress inhibited plant growth. In this study, we compared the differences in ion absorption, transport and ROS metabolism between saline-tolerant alfalfa (ZD) and saline-sensitive alfalfa (ZM) under NaHCO3 stress using physiology and transcripomics techniques. WGCNA analysis identified key genes associated with NaHCO3 stress-induced changes. NaHCO3 stress inhibited the absorption of K+ and Mg2+, but activated Ca2+ signal. Furthermore, ZD maintained higher K+, Mg2+ and Ca2+ contents and the K+/Na+ ratio than ZM, this is mainly related to the higher expression of proteins or channel-encoding genes involved in ion absorption and transport in ZD. Antioxidant enzyme systems can be activated in response to NaHCO3 stress. Peroxidase (EC 1.11.1.6), catalase (EC 1.11.1.7) and glutathione transferase (EC 2.5.1.18) activities were higher in ZD than ZM, and most genes encoding the relevant enzymes also demonstrated a stronger up-regulation trend in ZD. Although NaHCO3 stress inhibited Trx-Prx pathway, ZD related enzymes and their genes were also inhibited less than ZM. WGCNA results identified many genes involved in ion absorption, transport and antioxidant systems that play an important role in NaHCO3 stress adaptation. Collectively, ZD has the stronger ion homeostasis regulation and ROS scavenging ability, so it's more resistant to NaHCO3. The results provide theoretical guidance for further understanding of the molecular mechanism of NaHCO3 resistance and provide potential genes for research to improve saline-alkali tolerance in alfalfa.

Acaricidal, larvacidal, and repellent activity of Linalool loaded zinc oxide nanoparticles against Hyalomma anatolicum.

Current strategies for tick control have led to the development of resistance and environmental contamination. Consequently, there is an urgent need for research into new and effective acaricides for tick control. The aim of this study was to fabricate and characterize Linalool loaded zinc oxide nanoparticles (Lin@ZNP), and to assess the acaricidal, larvacidal, and repellent activities of Lin@ ZNP against Hyalomma anatolicum, a prevalent tick species infesting cattle in Saudi Arabia. Lin@ ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The adult immersion, the larval packet, and the assessment of vertical movement behavior of tick larvae assays were utilized to examine the acaricidal, larvicidal, and repellent activities of Lin@ZNP against H. anatolicum, respectively. Furthermore, the impact of Lin@ZNP on acetylcholinesterase and oxidant/antioxidant enzyme activities was investigated. Exposure of adult H. anatolicum to different concentrations of Lin@ZNP resulted in noticeable (p<0.001) reductions in the viability rate of adults and the mean number, weight, and hatchability of eggs, compared to the control group. Lin@ZNP demonstrated significant repellent effects on H. anatolicum larvae after 60, 120, and 180 minutes of exposure. Lin@ZNP, particularly at all concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001); but increase in malondialdehyde (MDA) levels (P<0.001) and a decrease in glutathione-S-transferase (GST) levels in H. anatolicum larvae (P<0.001). Lin@ZNP exhibited considerable acaricidal, larvicidal, and repellent effects against H. dromedarii adults and larvae in a manner dependent on the dosage. Additionally, Lin@ZNP notably reduced AChE levels and antioxidant activity, while inducing oxidative stress in H. anatolicum larvae. Nevertheless, further research is necessary to elucidate the precise mechanisms and practical efficacy of Lin@ZNP.

Assessment of the Health Status of Whitefish (Coregonus lavaretus Linnaeus, 1758) and the Quality of Its Habitat in Lake Sevan (Armenia) Using a Multi-Biomarker Approach

Lake Sevan is a freshwater reservoir in the Caucasus region. Since the first half of the 20th century, the lake has undergone significant changes caused by human activity and anthropogenic pressure. To identify the current ecological state of two bays—Lchashen and Lichk—located in different parts of the lake, a study was conducted in 2022–2023 using a multi-biomarker approach. For this purpose, biomarkers for assessing the health status of fish and the quality of their living conditions were used such as the activity of acetylcholinesterase (AChE) in the brain, glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and the concentration of reduced glutathione (RGS) and malondialdehyde (MDA) in the liver and gills of the whitefish (Coregonus lavaretus Linnaeus, 1758). In addition, hydrochemical and ichthyological analyses were conducted. This study demonstrated seasonal dynamics for all biomarkers. Comparative analysis of biomarkers and hydrochemical and ichthyological data showed that the whitefish in Lchashen Bay is in worse health, and its living conditions there are less favorable than in Lichk Bay.

Comparative analysis of transcriptomics of Fasciola hepatica at different developmental stages.

This study explored the transcriptome differences in Fasciola hepatica at different developmental stages and identified functional genes related to growth and development during juvenile stages. DNBSEQ eukaryotic strand-specific transcriptome resequencing technology was used to sequence the transcriptomes of Fasciola hepatica eggs, juveniles, and adults. Additionally, the genes that were highly expressed during the juvenile stage were validated using qRT-PCR. The Q20 values of all three phases of sequencing were above 98%, and the Q30 values were above 94%. The differentially expressed genes (DEGs) in pairwise comparisons were analyzed by GO functional classification and the KEGG pathway database. Many immune-, growth-, and development-related pathways were found, which might be related to cell proliferation, development, and host immune evasion by Fasciola hepatica. In addition, five DEGs with high expression levels during the juvenile stage were identified: Cathepsin B, Glutathione S-transferase mu, heat shock protein 67B2, Kunitz-CH, and Legumain. Validation analyses revealed that these genes play key roles in maintaining normal growth, development, and immunological processes in liver Fasciola hepatica. RNA-seq was used to analyze the biological characteristics of the DEGs at different developmental stages concerning GO functional classification and KEGG metabolic pathways. Five DEGs with high expression during the juvenile stage were identified. These genes are related to the growth, development, and immune function of Fasciola hepatica, which provides a theoretical basis for subsequent research on the proteomics of Fasciola hepatica and the screening of candidate genes for early diagnosis.

An integrative strategy used by the aphid Uroleucon formosanum to counter host sesquiterpene lactone defense: Insights from combined genomic and transcriptomic analysis.

Insect herbivores adapt and develop strategies to counteract plant chemical defenses. The aphid Uroleucon formosanum is a serious sap-sucking pest that infests lettuces containing toxic sesquiterpene lactones (STLs). Herein, we employed a combination of genome sequencing and RNA-seq transcriptome profiling to understand the mechanisms underlying phytotoxin tolerance in U.formosanum. We generated the first chromosome-level genome assembly for U.formosanum, with a total size of 453.26Mb and a scaffold N50 of 33.22Mb. Comparative genomic analyses revealed an enrichment of signals for positive selection and gene family expansion in immune-related pathways. Specifically, the expanded set of heat shock protein70 (HSP70) genes showed upregulation after treatment with lactucin, suggesting that they may play a role in the immune response against STLs. The expression of takeout-like genes and cuticle-associated genes was also significantly increased in the lactucin-treated samples. Additionally, 53 cytochrome P450 monooxygenase, 30 carboxylesterase, 19 glutathione S-transferase, 32 uridine diphosphate glycosyltransferase and 63 ATP-binding cassette (ABC) transporter genes were identified in the U.formosanum genome. CYP4C1, CYP6A13 and 7 ABC genes were strongly upregulated in response to lactucin treatment, indicating the involvement of detoxifying enzymes in the tolerance of U.formosanum to STLs. Our findings suggest that the cuticle barrier, immune response and enzyme-mediated metabolic detoxification jointly enhance the tolerance of U.formosanum to phytotoxins and promote its adaptation to host plants. This study presents a valuable genomic resource and provides insights into insect adaptation to plant chemical challenges and future technological developments for pest management.

A glutathione S-transferase PcGSTMu2 involved in the detoxification of bifenazate in Panonychus citri.

The citri red mite, Panonychus citri (McGregor), is an important citrus pest worldwide, causing enormous economic losses to citrus production. Bifenazate is a widely used acaricide for controlling P. citri. The detoxification mechanism of bifenazate is not clear in P. citri. PcGSTMu2, a significantly upregulated GST gene, was identified by the transcriptome analysis of P. citri after bifenazate exposure. The expression level of PcGSTMu2 was significantly increased after bifenazate exposure. By using RNAi of PcGSTMu2, the susceptibility of P. citri to bifenazate was significantly increased. Protein modeling and docking of PcGSTMu2 with GSH and bifenazate indicated the potential amino acid residues for binding in the active site. Heterologous expression and in vitro functional assays further revealed that PcGSTMu2 could deplete bifenazate. These results indicated that PcGSTMu2 plays an important role in the detoxification of bifenazate in P. citri and provides the molecular foundation for understanding bifenazate metabolism in P. citri. © 2024 Society of Chemical Industry.

Exploring the inhibitory potential of hormone replacement therapy drugs on glutathione transferase P1-1

Aim: Glutathione transferase P1-1 (GST P1-1) plays a crucial role in the human phase II detoxication system and is implicated in drug resistance in certain cancer cells. Analogs of drugs used in Hormone Replacement Therapy (HRT) have been reported to exhibit inhibition of various GSTs. This study aims to investigate the inhibitory potential of several HRT drugs on GST P1-1 for the possible use of counteracting drug resistance and for other therapeutic purposes. Materials and Methods: GST P1-1 was expressed and then purified in a single step using Nickel Sepharose affinity chromatography. Synthetic drugs that are used in HRT were screened for inhibition of GST P1-1 using 1-chloro-2,4-dinitrobenzene as the substrate. The IC50 value of the most potent compound was calculated and binding location and formation of bonds to GST P1-1 were identified through docking analysis. Results: Screening the inhibitory effect of eight synthetic estrogenic drugs reveals that estradiol valerate is the most potent inhibitor, showing 72 ± 4% inhibition of GST P1-1. This effect is followed by estradiol cypionate 53 ± 5%, mestranol 39 ± 4%, and estradiol propionate 35 ± 2%. The most potent compound estradiol valerate has an IC50 value of 30 ± 2 μM. According to docking analysis, it binds to the H-site of the enzyme where the residues Phe9, Arg14, Val36, Trp39, Ile105, Tyr109, Pro203, Asn207, and Gln210 were within 5 Å proximity of the ligand. Estradiol valerate forms Pi-alkyl interactions with Phe9 and Val36, as well as an alkyl interaction with Ile104. Conclusion: Estradiol valerate is a modest inhibitor for hGST P1-1, however it fits in the area of H-site of the enzyme and forms bonds with critical key residues. Understanding its binding site on the enzyme is critical for designing other inhibitors targeting GSTs or possibility for the potential use as a substrate with other GSTs.

Overlooked and misunderstood: can glutathione conjugates be clues to understanding plant glutathione transferases?

Plant glutathione transferases (GSTs) constitute a large and diverse family of enzymes that are involved in plant stress response, metabolism and defence, yet their physiological functions remain largely elusive. Consistent with the traditional view on GSTs across organisms as detoxification enzymes, in vitro most plant GSTs catalyse glutathionylation, conjugation of the tripeptide glutathione (GSH; γ-Glu-Cys-Gly) onto reactive molecules. However, when it comes to elucidating GST functions, it remains a key challenge that the endogenous plant glutathione conjugates (GS-conjugates) that would result from such glutathionylation reactions are rarely reported. Furthermore, GSTs often display high substrate promiscuity, and their proposed substrates are prone to spontaneous chemical reactions with GSH; hence, single-gene knockouts rarely provide clear chemotypes or phenotypes. In a few cases, GS-conjugates are demonstrated to be biosynthetic intermediates that are rapidly further metabolized towards a pathway end product, explaining their low abundance and rare detection. In this review, we summarize the current knowledge of plant GST functions and how and possibly why evolution has resulted in a broad and extensive expansion of the plant GST family. Finally, we demonstrate that endogenous GS-conjugates are more prevalent in plants than assumed and suggest they are overlooked as clues towards the identification of plant GST functions. This article is part of the theme issue 'The evolution of plant metabolism'.

Genome-Wide Identification and Expression Analysis of GST Genes during Light-Induced Anthocyanin Biosynthesis in Mango (Mangifera indica L.).

Anthocyanins are important secondary metabolites contributing to the red coloration of fruits, the biosynthesis of which is significantly affected by light. Glutathione S-transferases (GSTs) play critical roles in the transport of anthocyanins from the cytosol to the vacuole. Despite their importance, GST genes in mango have not been extensively characterized. In this study, 62 mango GST genes were identified and further divided into six subfamilies. MiGSTs displayed high similarity in their exon/intron structure and motif and domain composition within the same subfamilies. The mango genome harbored eleven pairs of segmental gene duplications and ten sets of tandemly duplicated genes. Orthologous analysis identified twenty-nine, seven, thirty-four, and nineteen pairs of orthologous genes among mango MiGST genes and their counterparts in Arabidopsis, rice, citrus, and bayberry, respectively. Tissue-specific expression profiling highlighted tissue-specific expression patterns for MiGST genes. RNA-seq and qPCR analyses revealed elevated expression levels of seven MiGSTs including MiDHAR1, MiGSTU7, MiGSTU13, MiGSTU21, MiGSTF3, MiGSTF8, and MiGSTF9 during light-induced anthocyanin accumulation in mango. This study establishes a comprehensive genetic framework of MiGSTs in mango fruit and their potential roles in regulating anthocyanin accumulation, which is helpful in developing GST-derived molecular markers and speeding up the process of breeding new red-colored mango cultivars.