Glutathione S-transferase Activity Research Articles

Comparative analysis of active period and oxidative stress of DDVP and ginger (Zingiber officinale) oil on Indian meal moth (Plodia interpunctella Hübner) infesting maize grain

BackgroundIndian meal moth (Plodia interpunctella) is a significant pest infesting stored grains, particularly maize. Over time, synthetic insecticides have been employed to control insect. The residual effects posed on non-target organisms have called for replacement of synthetic insecticides with botanicals. This study therefore aimed at comparing the insecticidal consistency and oxidative stress invoked by dichlorvos (DDVP) and the oil extract of ginger (Zingiber officinale) on Indian meal moth infesting maize. Disinfested maize grains were treated with DDVP and ginger oil extract separately. Adults P. interpunctella were introduced to the treated grains daily using complete replacement method. The percentage mortality was calculated daily for 10 d. Furthermore, the oxidative stress caused by DDVP and ginger oil extract on the moth was evaluated by measuring the level of some oxidative stress biomarkers such as glutathione S-transferase, superoxide dismutase, glutathione peroxidase (GPx), and catalase (CAT) activity in the exposed insects.ResultsPreliminary results indicated that both DDVP and ginger oil extract exhibited insecticidal properties against Indian meal moth infesting maize. However, the insecticidal (active) period of ginger oil extract was found to be longer than that of DDVP. Nevertheless, DDVP provoked greater oxidative stress in the exposed moth.ConclusionsGinger oil extract and DDVP show potential for controlling Indian meal moth infestations in stored maize. Yet, ginger oil offers a longer-lasting effect on pest suppression and control. Consequently, it could be a replacement or synergistic insecticide with DDVP to provide ecofriendly insecticide application.

The Impact of Perfluorooctanoic Acid (PFOA) on the Mussel Mytilus galloprovincialis: A Multi-Biomarker Evaluation

Perfluorooctanoic acid (PFOA) has been widely studied due to its environmental persistence and bioaccumulation potential, raising concerns about its effects on aquatic life. This research evaluates the impact of PFOA on the antioxidant defenses and stress response systems of the mussel Mytilus galloprovincialis. Mussels were exposed to three concentrations of PFOA (1, 10, and 100 µg·L−1) over 28 days. Several biomarkers, including glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), total antioxidant capacity (TAC), vitellogenin (VTG), ubiquitin (UBI), and caspase-3 (CASP) were analyzed. The results suggest stress responses, particularly in animals exposed to higher concentrations, as shown by GST and SOD activities which increased according to PFOA concentrations. Additionally, oxidative stress markers such as MDA and CAT showed variable responses depending on the exposure concentration tested. This study underscores the need for further investigation into the effects of PFOA on mollusks but also the need to unveil gender-specific responses in aquatic organisms exposed to this contaminant. The concentrations of PFOA used in our research are lower than those examined in previous studies, providing crucial insights into the impacts of even minimal exposure levels. It highlights the potential of M. galloprovincialis as a bioindicator in environmental monitoring programs, providing crucial insights for environmental management and policymaking regarding regulating and monitoring PFOA in marine settings. Consequently, in a country where seafood consumption is the second largest in Europe, implementing environmental policies and regulatory measures to manage and monitor PFOA levels in marine environments is crucial.

Short-term exposure to okadaic acid induces behavioral and physiological responses in sea urchin (Strongylocentrotus intermedius)

Massive harmful algal blooms (HABs) have increased the risk of marine organisms encountering the dinoflagellate toxin, okadaic acid (OA). Strongylocentrotus intermedius, a globally significant benthic aquaculture species, has a large appetite for benthic algae. During red tide events, there is a high risk of red tide toxin accumulation. This study systematically evaluated the potential impact of short-term OA exposure on the behavior and physiological functions of juvenile S. intermedius. From typical (5 μg/L) to extreme OA concentrations (20 μg/L) during HAB outbreaks, OA exposure gradually inhibited a series of tube foot-related behaviors (sheltering, foraging, righting, and tube-foot tenacity). At OA concentrations during HAB outbreaks (5 μg/L), the tube foot function of S. intermedius was progressively inhibited. Further physiological indicator analyses revealed that the activity of antioxidants increased over a short period to prevent damage from reactive oxygen species induced by OA. However, OA ultimately suppressed the immune response of S. intermedius, leading to apoptosis. Although HAB-associated concentrations of OA (5 μg/L) did not induce a continuous increase in the integrated biological response index of S. intermedius, this study speculated that HABs pose a future risk to echinoderm species. Notably, principal component analysis results showed that OA exposure eventually induced significant changes in the production of O2-, malondialdehyde, and total glutathione, as well as in glutathione S-transferase activity and caspase-7, -8, and -9 levels. This study provides preliminary evidence of OA’s toxic effects on sea urchins and essential data for urgent risk assessments of algal toxin pollution in aquaculture during HABs.

The toxicity, repellent, and biochemical effects of four wild plant extracts against Aphis gossypii Glover and Phenacoccus solenopsis Tinsley: HPLC analysis of phenolic compounds

The insecticidal and repellent activities of the four wild plant extracts: stinging nettle, Urtica dioica L., white henbane, Hyoscyamus albus L., camphorweeds, Pluchea dioscoridis L., and cocklebur, Xanthium strumarium L. were tested compared to the insecticide spirotetramat against the 3rd nymphal instar of Aphis gossypii Glover and adult females of Phenacoccus solenopsis Tinsley after 24 and 48 h of treatment. Their effects on acetylcholinesterase (AChE) and glutathione-S-transferase (GST) enzyme activities were also assessed to explore their possible mechanisms of action. The phenolic compounds of the plant extracts were investigated by high-performance liquid chromatography (HPLC) analysis. The most abundant compounds in the methanol extract from P. dioscoridis were gallic acid (14.45 µg/mL), and cinnamic acid (11.44 µg/mL); from U. dioica were caffeic acid (15.32 µg/mL) and syringic acid (13.47 µg/mL); from H. albus were syringic acid (7.12 µg/mL) and catechol (5.33 µg/mL); and from X. strumarium were p-coumaric acid (24.53 µg/mL) and pyrogallol (18.35 µg/mL). According to the LC50 values, the contact toxicity of U. dioica, H. albus, P. dioscoridis, and X. strumarium against A. gossypii was 40.3, 60.6, 56.2, and 32.3 mg/L, whereas, the contact toxicity against P. solenopsis was 56.4, 67.5, 64.3, and 36.2 mg/L, compared to the spirotetramat (17.2 and 24.5 mg/L), respectively, at 48 h of treatment. The highest repellency rates were observed with LC50 values for X. strumarium (63.2 and 60.3%), followed by U. dioica (46.2 and 43.5%), P. dioscoridis (45.3 and 42.8%), and H. albus extract (38.8 and 35.2%) compared to the spirotetramat (78.5 and 76.2%) against A. gossypii and P. solenopsis at 24 h, but decreased with time. The AChE and GST activities in pests were significantly inhibited, compared to control and spirotetramat, with dose and time-dependent effects. These findings indicate that tested wild extracts may be suggested as viable alternatives for aphids and mealybugs control.

Fipronil exposure alters oxidative stress responses of Nile tilapia (Oreochromis niloticus) to acute moderate hypoxia

Acute hypoxia is known to increase the generation of reactive oxygen species (ROS), leading to modulation in antioxidant defenses. Pollutant exposure can potentiate ROS generation during hypoxic events and impair antioxidant defenses, increasing the susceptibility of hypoxia-tolerant fishes, such as the Nile tilapia (Oreochromis niloticus), to oxidative stress. The purpose of this study was to evaluate oxidative stress responses of O. niloticus to acute (3 and 8 h) moderate hypoxia (dissolved oxygen ≤2 mg/L−1) and how these responses are affected by simultaneous exposure to the insecticide fipronil (0.1 and 0.5 µg L−1). Hypoxia exposure for 3 h caused an increase in glutathione peroxidase (GPx) activity in the gill and also increased catalase (CAT) and glutathione S-transferase (GST) activities in the liver. After 8 h of hypoxia, glutathione reductase (GR) activity increased. DNA damage (comet assay) in erythrocytes was reduced by hypoxia after 3 and 8 h. Fipronil exposure for 3 h decreased CAT activity in the gill, both under normoxia and hypoxia. After 8h, the combination of fipronil and hypoxia increased GR activity in the gill. In the liver, fipronil exposure under hypoxia for 3 h increased CAT and GR activities; after 8 h, CAT was decreased, and GST increased. GR was also increased by fipronil under normoxia for 8 h. All treatments reduced lipid peroxidation levels in the gills, but in the liver, lipid peroxidation was increased by fipronil after 3 h under normoxia. Moreover, fipronil exposure under hypoxia for 3 and 8h increased DNA damage in erythrocytes, while 8 h of fipronil exposure under normoxia decreased it, suggesting the activation of DNA repair mechanisms. Results show that both fipronil and hypoxia exposure significantly modulate the oxidative stress parameters of O. niloticus and that the combination of these factors produces more pronounced effects.

Disperse Red 1 azo dye: Consequences of low-dose/low-concentration exposures in mice and zebrafish

Color Index Disperse Red 1 (DR1), an azo dye widely used in the textile industry and released into aquatic environments, is genotoxic in somatic cells, but little is known concerning its effects on the reproductive system or the early stages of embryonic development. We have assessed the effects on the spermatozoa of male mice following oral exposure to the dye, at low doses, for 14 days. Measured endpoints were DNA damage (comet assay), miRNA-34c levels, and sperm number, morphology, and motility. Exposure caused decreased miRNA-34c levels. We have also examined dye effects on zebrafish embryos and larvae, which included developmental impairment, altered glutathione transferase activity, and effects on reactive oxygen species and lipid peroxidation levels.

Resistance ratios and enzyme activity of Tetranychus urticae and Tetranychus turkestani (Acari: Tetranychidae) to commonly used acaricides on cotton in Aydin province, Türkiye

This study aims to determine the resistance ratios of Tetranychus urticae Koch red form (RF) and Tetranychus turkestani (Ugarov & Nikolskii) populations collected from cotton fields in Soke, Germencik, Kocarli and Nazilli districts of Aydin province to commonly used acaricides (abamectin, hexythiazox, etoxazole, spiromesifen). The potential role of detoxification enzymes (esterase, glutathione-s-transferase (GST), P450 monooxygenase (P450)) in acaricide resistance was also assessed. Overall populations of T. urticae RF presented varying ratios of resistance to these acaricides with all three populations (G15R21, K24R21, S3R21) showing significant resistance to abamectin (187.1–223.66 fold), hexythiazox (156.31–168.25 fold), etoxazole (409.58–517.20 fold) and spiromesifen (981.77–1246.11 fold). In contrast, all five T. turkestani populations (G4G21, K16G21, N1G21, N11G21, S19G21) were susceptible to abamectin, etoxazole, and spiromesifen, but exhibited some resistance to hexythiazox (164.34–182.39 fold). The resistance ratios of T. turkestani were however lower compared to T. urticae RF. A relationship was also found between detoxification enzymes and resistance. Esterase activity varied among mite populations, with the highest levels recorded in resistant populations of T. urticae (G15R21 and K24R219) with rates ranging between 6.48 and 7 mOD/min/mg protein. GST activity was highest in resistant mite populations (T. urticae S3R21 and T. turkestani K16G21). T. turkestani N11G21 population exhibited the highest P450 enzyme activity, reaching 4.39 RFU/30 min/mg protein. This study was the first to determine the resistance ratios of T. turkestani to hexythiazox in Türkiye, and on a global scale.

Toxicity and Sublethal Effect of Chlorantraniliprole on Multiple Generations of Aedes aegypti L. (Diptera: Culicidae)

Due to the quick development of insecticide resistance, it is crucial to optimize management programs by understanding the sublethal effects of effective insecticides like chlorantraniliprole on Aedes aegypti L. populations. Using age-stage and two-sex life tables, we investigated the sublethal impacts of chlorantraniliprole on Ae. aegypti. Larval duration in the progeny of exposed parents was reduced by 0.33–0.42 days, whereas, the longevity of male and female adults was decreased by 1.43–3.05 days. Similarly, the egg-laying capacity of F1 and F2 progeny of the exposed parents was significantly reduced from 27.3% to 41.2%. The mean generation time (T) increased up to 11.8% in exposed populations, and the net reproduction rate (Ro) decreased by 51.50–55.60%. After 24 h of chlorantraniliprole treatment, there was a significant increase in cytochrome P450 activity. Contrarily, the activity of glutathione S-transferase (GST) initially declined but started increasing after 48 h of treatment. This research highlights the importance of chlorantraniliprole in mosquito management, as well as the importance of considering sublethal effects when developing strategies to handle them. Having a thorough understanding of the harmful effects of insecticides on mosquito populations can greatly enhance the effectiveness of insecticide-based interventions, while also minimizing the risk of pest resurgence.

Associations of GST Gene Polymorphisms and GST Enzyme Activity with the Development of Noise-Induced Hearing Loss in Chinese Han Males

Introduction: In noise-induced hearing loss (NIHL), glutathione S-transferases (GSTs) play a pivotal role as antioxidants in cochlear protection. Nevertheless, the variability in population and environmental factors complicates the interpretation of research findings on the association among GST gene polymorphism, GST enzyme activity, and NIHL, leading to inconsistent results. To explore the potential correlation between them, we took a cross-sectional survey. Methods: For workers with NIHL, standard 1:1 propensity score matching was applied to create a highly comparable control group. Multiplex PCR was used to detect GSTT1 and GSTM1 gene deletions, PCR-restriction fragment length polymorphism was used to detect the GSTP1 rs1695 gene polymorphism, and a GST assay kit was used to measure total plasma GST activity. Furthermore, we analyzed the relationship among GST gene polymorphism, GST enzyme activity, and NIHL. Results: This study included 144 workers with NIHL and 144 workers with normal hearing. The GSTM1 null genotype was significantly higher among workers with NIHL than controls (64.6% vs. 49.3%), regression analysis revealed a significant correlation between GSTM1 null genotype and elevated susceptibility to NIHL (p = 0.013). Workers with NIHL had significantly lower GST activity than healthy controls (p < 0.05). GST enzymes were not affected by GSTT1, GSTM1, or GSTP1 polymorphisms. Conclusion: GSTM1 null genotype but not GSTM1 alone may confer susceptibility to NIHL, and serum GST enzyme activity is linked to NIHL.

Ocean acidification aggravates the toxicity of deltamethrin in Haliotis discus hannai: Insights from immune response, histopathology and physiological responses

Ocean acidification (OA) and other environmental factors can collectively affect marine organisms. Deltamethrin (DM), a type II pyrethroid insecticide, has been widely detected in coastal and estuarine areas, while little attention has been given to the combined effects of DM and OA. In this study, Haliotis discus hannai was exposed to three pH levels (8.1, 7.7 and 7.4) and three DM nominal concentrations (0 μg/L, 0.6 μg/L and 6 μg/L) for 14 and 28 days. The results indicated that experimental acidification and/or DM exposure led to impaired immune function and pathological damage. Additionally, acidified conditions and DM exposure induced oxidative stress, and gills are more sensitive than digestive glands. With increasing pCO2 and DM nominal concentrations, superoxide dismutase (SOD) activity decreased, whereas catalase (CAT) and glutathione S-transferase (GST) activities increased in the gills. Moreover, the expression levels of Toll-like receptor (TLR) pathway-related genes were upregulated after exposure. Integrated biomarker response (IBR) analysis proved that acidified conditions and/or DM detrimentally affected the overall fitness of H. discus hannai, and co-exposure to experimental acidification and DM was the most stressful condition. This study emphasizes the necessity of incorporating OA in future pollutant environmental assessments to better elucidate the risks of environmental disturbance.

Oxidative Stress Associated With Increased Reactive Nitrogen Species Generation in the Liver and Kidney Caused by a Major Metabolite Accumulating in Tyrosinemia Type 1.

Tyrosinemia type 1 (TT1) is caused by fumarylacetoacetate hydrolase activity deficiency, resulting in tissue accumulation of upstream metabolites, including succinylacetone (SA), the pathognomonic compound of this disease. Since the pathogenesis of liver and kidney damage observed in the TT1-affected patients is practically unknown, this study assessed the effects of SA on important biomarkers of redox homeostasis in the liver and kidney of adolescent rats, as well as in hepatic (HepG2) and renal (HEK-293) cultured cells. SA significantly increased nitrate and nitrite levels and decreased the concentrations of reduced glutathione (GSH) in the liver and kidney, indicating induction of reactive nitrogen species (RNS) generation and disruption of antioxidant defenses. Additionally, SA decreased the GSH levels and the activities of glutathione peroxidase, glutathione S-transferase, glutathione reductase, and superoxide dismutase in hepatic and renal cells. Noteworthy, melatonin prevented the SA-induced increase of nitrate and nitrite levels in the liver. Therefore, SA-induced increase of RNS generation and impairment of enzymatic and nonenzymatic antioxidant defenses may contribute to hepatopathy and renal disease in TT1.

Biomarker and adverse outcome pathway responses of Tubifex tubifex(sludge worm) exposed to environmentally-relevant levels of acenaphthene: insights from behavioral, physiological, and chemical structure-activity analyses.

Polycyclic aromatic hydrocarbons (PAHs), including acenaphthene, pose a significant threat to aquatic ecosystems by harming vital organisms such as benthic invertebrates. This study evaluated the impact of environmentally relevant concentrations of acenaphthene on Tubifex tubifex, focusing on sublethal acute toxicity and subchronic biomarker responses. Key biomarkers assessed included histopathological changes and the modulation of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), and malondialdehyde (MDA). Additionally, the study examined structure-activity relationships and species sensitivity distribution (SSD). Concentrations exceeding the solubility threshold of acenaphthene (3.9 mg/L) triggered distinct, concentration-dependent behavioral responses in Tubifex tubifex, such as clumping, mucus secretion, and body wrinkling. Prolonged exposure exacerbated these behavioral dysfunctions, while subchronic exposure resulted in significant histopathological alterations, including epithelial hyperplasia, inflammation, edema, fibrosis, and degenerative changes. The edematic appearance of the body wall suggested a potential immune response to exposure. Furthermore, increased activities of CAT, SOD, and GST indicated oxidative stress in the worms. The study found a 1.5-fold increase in CAT and GST activity, a fivefold increase in SOD, and a striking 100-fold increase in MDA levels compared to controls, signifying an overwhelmed antioxidant defense system and potential cellular disruption. The SSD curve revealed hazard concentrations (HC50 and HC90), indicating that Tubifex tubifex exhibited lower sensitivity to acenaphthene compared to other taxa. In silico analysis and read-across models confirmed the potential of acenaphthene to induce significant oxidative stress upon exposure. The correlation between biomarker responses and structure-activity relationship analysis highlighted the aromatic nature of acenaphthene as a key factor in generating reactive metabolites, inhibiting antioxidant enzymes, and promoting redox cycling, ultimately contributing to adverse outcomes. These findings, coupled with behavioral responses and SSD curve inferences, underscore the importance of the solubility threshold of acenaphthene as a critical benchmark for evaluating its ecological impact in aquatic environments.

Neurotoxicity, Cytotoxicity, and Genotoxicity of Phyto-radio Synthesized Selenium Nanoparticles in Culex pipiens Complex.

Effective mosquito management strategies are crucial to minimize the number of mosquito-borne diseases. Selenium nanoparticles (SeNPs) are promising in mosquito control because they are effective and eco-friendly rather than synthetic insecticides. The current study was conducted to evaluate the impact of SeNPs on the detoxification enzymes, acetylcholine esterase (AChE), glutathione S-transferase (GST), and α-carboxyl esterase (α-CarE), in larval instars of Culex pipiens complex at the LC50 concentration. In 3rd instar larvae treated with microwave-assisted selenium nanoparticles (SeNPs-MW) and gamma-assisted selenium nanoparticles (SeNPs-G), it was found that AChE activity was significantly inhibited. On the other hand, significant increases in GST and α-CarE activities were observed. Additionally, genotoxic and ultrastructure studies of midgut epithelial cells in 3rd instar larvae revealed DNA damage and cell lysis, including destruction of the cell membrane, microvilli, and nuclei. These findings suggest that SeNPs have an adverse effect on AChE gene expression, resulting in its downregulation. This downregulation can be attributed to the formation of reactive oxygen species induced by SeNPs that can modulate the host defense mechanism leading to apoptosis and subsequent larval mortality. The present study was the first to use phyto-microwave-assisted and gamma-assisted synthesis of SeNPs which provides an eco-friendly and cost-effective solution to reduce the risk of chemical insecticides. Furthermore, an integrated pest management program (IPM) using nanocides can be successfully developed for mosquito control.

Effects of freshness of poultry by-product meal on the growth performance, immune response, and hepatopancreatic health of Macrobrachium rosenbergii

A 73-day feeding trial was conducted to determine the effects of the freshness of poultry by-product meal on the growth performance, immune response and hepatopancreatic health of giant freshwater prawn, Macrobrachium rosenbergii. Three semi-purified diets were formulated containing 2.5 % poultry by-product meal with different TVB-N value, designated as L group (untreated poultry by-product meal, TVB-N 10 mg/100 g, i.e., dietary TVB-N 55 mg/100 g), M group (TVB-N 300 mg/100 g, i.e., dietary TVB-N 60 mg/100 g), and H group (TVB-N 450 mg/100 g, i.e., dietary TVB-N 68 mg/100 g), and fed to three groups of prawns (initial weight: 0.82 ± 0.01 g), respectively. Results showed that the weight gain rate (WGR) and specific growth rate (SGR) of prawns significantly decreased with the TVB-N value increased (P < 0.05). The survival rate (SR) and hepatosomatic index (HSI) of prawns in group M and group H were significantly decreased (P < 0.05), while the feed conversion ratio (FCR) was significantly increased (P < 0.05). In addition, the lipase (LPS) and α-amylase (α-AMS) activity of prawns in group L was significantly higher than that in group H (P < 0.05). With the poultry by-product meal TVB-N value increased, the activity of total superoxide dismutase (T-SOD) and glutathione S-transferase (GST) was significantly decreased. RT-qPCR results showed that the expression of bok in group H was significantly higher than that in group L and group M (P < 0.05), the expressions of caspase3, caspase9, bax, and nf-κb in group H were significantly higher than that in group L (P < 0.05). High temperature stress and ammonia nitrogen stress significantly decreased the cumulative survival rate of prawns in group M and group H. Conclusively, it is necessary to guarantee the freshness of the ingredients in prawn formulated diets, and the TVB-N value of diets is recommended not to exceed 60 mg/100 g.

Glutathione and Selenium Supplementation Attenuates Liver Injury in Diethylnitrosamine-Induced Hepatocarcinogenic Mice by Enhancing Glutathione-Related Antioxidant Capacities

Excess oxidative stress and inadequate antioxidant capacities are critical features in the development of hepatocellular carcinoma. This study aimed to determine whether supplementation with glutathione (GSH) and/or selenium (Se), as antioxidants, attenuates diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. C57BL/6J male mice were randomly assigned to control, DEN, DEN + GSH, DEN + Se, and DEN + GSH + Se groups for 20 weeks. Daily supplementation with GSH and/or Se commenced in the first experimental week and continued throughout the study. DEN was administered in weeks 2–9 and 16–19 of the experimental period. DEN administration induced significant pathological alterations of hepatic foci, evidenced by elevated levels of liver function, accompanied by high malondialdehyde (MDA) levels; low GSH levels; and glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) activities. Supplementation with GSH and Se significantly ameliorated liver pathological changes, reducing liver function and MDA levels while increasing GSH levels and GPx, GR, and GST activities. Notably, combined supplementation with GSH and Se more effectively increased the GSH/glutathione disulfide ratio and GPx activity than individual supplementation. Supplementation with GSH and Se attenuated liver injury in DEN-induced hepatocarcinogenic mice by enhancing GSH and its related antioxidant capacities, thereby mitigating oxidative damage.

A multiple biomarker approach to understand the effects of microplastics on the health status of European seabass farmed in earthen ponds on the NE Atlantic coast

The occurrence of microplastics (MPs) in aquaculture environments is a growing concern due to their potential negative effects on fish health and, ultimately, on seafood safety. Earthen pond aquaculture, a prevalent aquaculture system worldwide, is typically located in coastal and estuarine areas thus vulnerable to MP contamination. The present study investigated the possible relation between MP levels of European seabass (Dicentrarchus labrax) farmed in an earthen pond and its health status. More precisely, two groups of fish were established based on the lowest and highest number of MPs found collectively in their gastrointestinal tract (GIT), liver, and dorsal muscle: fish with ≤2 MP/g and fish with ≥4 MP/g. The intestinal integrity and oxidative stress biomarkers in the liver and dorsal muscle were evaluated in the established groups. No significant differences in the biometric and organosomatic parameters between groups were observed. The results indicated a significant increase in the number of acid goblet cells (GC) in the rectum of fish with higher MP levels (p = 0.016). Increased acid GC number may constitute a first defence strategy against foreign particles to protect the intestinal epithelium. No significant differences in oxidative stress biomarkers between the two fish groups were observed, namely in the activity of superoxide dismutase, catalase, glutathione reductase, and glutathione S-transferase in the liver, or in lipid peroxidation levels in the liver and dorsal muscle. The overall results suggest that MP levels were possibly related to an intestinal response but its potential implications on the health status of pond-farmed seabass warrant further investigation. Monitoring MP occurrence across stages of aquaculture production could help to elucidate the potential threats of MPs to fish health.

Elevated temperature increases the susceptibility of D. magna to environmental mixtures of carbamazepine, tramadol and citalopram

The joint risks assessment of thermal stress and rising loads of pharmaceuticals (PhACs) in surface waters is a relevant topic in aquatic ecotoxicology. This study investigated the relevance of increased water temperature to alter the acute toxicity of environmentally relevant carbamazepine (CBZ), citalopram (CIT) and tramadol (TRA) concentrations as mixtures (ECs) and delayed outcomes in Daphnia magna. Responses of detoxification and antioxidant pathways in premature daphnids post an acute 24 h (pulsed) exposure to the PhACs mixtures and delayed responses as the reproductive output over 14 days recovery were investigated under 21- and 26 °C incubation. Biphasic modulation in glutathione S-transferase (GST) activity and significant inhibition of superoxide dismutase (SOD) activity were observed in both thermal regimes with significant shift in effective thresholds from 10-fold ECs at 21 °C to ECs at 26 °C incubation. Significant induction in catalase (CAT) activity and oxidative stress development were recorded at elevated temperatures from the 10-fold ECs dose onward. Pulsed exposures at 26 °C also led to significant decrease in the reproduction of daphnids above the 10-fold ECs of PhACs. The Integrated Biomarker Response scoring (IBRv2) approach outlined a 1.8-fold increase in alterations of daphnids exposed to 100-fold ECs of PhACs at 26 °C.

Integrated Biomarker Response of Oxidative Stress Parameters in the Digestive Glands and Gills of Autochthonous and Invasive Freshwater Mussels from the Sava River, Serbia.

In this study, the activity of oxidative stress parameters superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione S-transferase (GST), as well as the concentrations of vitamin E (Vit E) and SH groups in the digestive glands and gills of freshwater mussels Unio pictorum and Sinanodonta woodiana from the Sava River in Serbia were investigated. These parameters were determined in native and invasive mussels under the same environmental conditions. The activities of GSH-Px and GR and the concentration of Vit E were significantly higher in the digestive glands of the autochthonous species U. pictorum than in the invasive species S. woodiana, while the CAT activity and the concentration of SH groups were lower. In the gills of U. pictorum, GSH-Px activity and Vit E concentration were significantly higher, while CAT, GST, and SH groups were lower. Principal component analysis (PCA) showed that oxidative stress parameters were strictly tissue- and species-specific. In addition, integrated biomarker response (IBR) showed a combined response of enzymatic and non-enzymatic oxidative stress parameters depending on the tissue or species studied, indicating different metabolic activities and behaviors of an autochthonous versus an introduced bivalve species.

Evaluation of the effects of two commercial pesticides on Daphnia magna in different feeding environments using morphological and biochemical markers

ABSTRACT In this study, the impact of exposure to a glyphosate-based herbicide (GBH) and a trifloxystrobin-based fungicide (TBF) on Daphnia magna in diverse feeding environments was assessed through the analysis of morphological and biochemical markers. The test organisms selected for analysis were Chlorella vulgaris and D. magna. First, the 48-hour median lethal concentrations (LC50) of GBH and TBF for D. magna were determined to be 253.1 mg/L and 20.7 µg/L, respectively. Secondly, the lethality, length, width, and spin length of D. magna were evaluated following exposure to sublethal pesticide concentrations, selected based on the LC50 values, in different feeding environments. Thirdly, the activities of glutathione S-transferase (GST), glutathione reductase, catalase (CAT), carboxylesterase, and acetylcholinesterase, as well as the levels of reduced glutathione, were measured in D. magna exposed to sublethal pesticide concentrations in different feeding environments. Both pesticides caused an increase in CAT activity, while GBH also caused an increase in GST activity in the unfed and mixed-fed groups. Conversely, it can be concluded that feeding with C. vulgaris reduces oxidative stress and toxic effects since there was a lesser increase in GST and CAT activities in the C. vulgaris-fed group for both pesticides, similar to the lethality.

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.