Effects of the insecticide acetamiprid and the fungicide azoxystrobin on locomotion activity and mushroom bodies of solitary bee Centris analis.

Pesticide use is a major factor contributing to the global decline in bee populations. Sublethal effects, such as behavior alterations, are neglected in pesticide regulation for pollinators. However, these effects can bring important information to understanding the impacts of pesticides on bees' daily activities. In this study, we aimed to investigate the effects of the insecticide acetamiprid (7 ng/µL) and the fungicide azoxystrobin (10 ng/µL) on the behavior of the Neotropical solitary bee Centris analis. Female and male bees were exposed to these chemicals continuously for 48 h, followed by an additional 48 h without contaminated food, totaling 96 h of observation. We used five experimental groups: control, solvent control, insecticide, fungicide, and pesticide mixture (insecticide + fungicide). Behavioral alterations based on locomotion and light response were assessed by video tracking at 48 (end of pesticide exposure) and 96 h (end of bioassay). In addition, after recording bees at 96 h, the individuals were anesthetized for brain collection and histological evaluation of mushroom bodies to evaluate if pesticides can damage their neurons and impair the cognitive processes and responses of bees to sensory stimuli. Bees exposed to acetamiprid and pesticide mixture showed lethargic movements and impaired locomotion at 48 h. Notably, these behavioral effects were no longer evident after the bees consumed uncontaminated food for an additional 48 h, totaling 96 h from the start of pesticide exposure. Only fungicide exposure did not result in any behavioral or brain histological changes. Therefore, our study showed that acetamiprid at an estimated residual concentration, despite being classified as having low toxicity for bees, can cause significant initial locomotion disruption in solitary bees. These findings highlight the importance of considering sublethal effects in environmental risk assessment.

Decline pattern and dietary risk assessment of spinetoram in grapes under Egyptian field conditions.

Spinetoram is one of the most extensively used insecticides globally and is a new spinosyn-based insecticide registered for direct treatment of Egyptian grapes. This work established and validated a developed method for determining spinetoram in grape berries and leaves using the QuEChERS coupled LC-MS/MS technique. The average recoveries ranged between 98.52-101.19% and 100.53-104.93%, with RSDs of 2.74-6.21% and 2.79-7.26% for grape berries and leaves, respectively. Spinetoram residues degraded in grape berries and leaves through a first-order kinetic, with an estimated half-life (t1/2) of 4.3 and 2.8 days in grape berries and leaves, respectively, and significant degradation (91.4-97.5%, respectively) after 14 days. Besides, the terminal residues of spinetoram detected in grape berries and leaves samples ranged between 0.017-0.077 mg‧kg-1 and 0.79-0.023 mg·kg-1, respectively, when applied two to three times at a single recommended rate, while it was varied between 0.026-0.44mg‧kg-1 and 0.79-0.023mg‧kg-1 when applied two to three times at a double recommended rate, respectively. A dietary risk assessment was conducted using scientific data from field trials, acceptable daily intake (ADI), and food consumption. It was determined that no noteworthy health hazards were connected to eating grape berries and leaves that had been treated with spinetoram since the risk quotients (RQs) were ≤ 0.4.

The occurrence and mechanism of field resistance to boscalid and pyraclostrobin in Stemphylium solani, the causal agent of tomato gray leaf spot in China.

The destructive disease gray leaf spot, caused by Stemphylium solani, is prevalent in tomato plants in China. A variety of fungicides have been extensively used for controlling the disease, with a particular focus on succinate dehydrogenase inhibitors (SDHIs) and quinone outside inhibitors (QoIs). However, there was a lack of information regarding the resistance of S. solani to boscalid (SDHI) and pyraclostrobin (QoI) in China. In this study, the sensitivity of S. solani to boscalid and pyraclostrobin was monitored. The EC50 values for boscalid ranged from 0.02 to 3.0 µg∙mL-1, with an average value of 0.62 µg∙mL-1, while the EC50 values for pyraclostrobin ranged from 0.21 to 14.71 µg∙mL-1, with an average value of 6.03 µg∙mL-1. Based on these findings, the frequencies of observed resistance were as follows: 36.7% for boscalid and 50% for pyraclostrobin; while the resistance frequency to both boscalid and pyraclostrobin in S. solani was 19.4%. The mutation associated with boscalid resistance in S. solani within tomato fields was identified as SdhB-H277Y, while the mutation related to pyraclostrobin resistance was found in cytochrome b, specifically Cytb-G143A. The resistant mutants displayed diminished fitness in terms of mycelial growth, yet their pathogenicity exhibited no significant disparities. To delay the development of resistance, it is advisable to employ a rotation strategy using alternative fungicides with different modes of action or mix with fungicides with multi-site-contact activity for disease management.

Variation in phytotoxicity of rice seedlings caused by differential accumulation of azoxystrobin and pyraclostrobin in leaves.

The effectiveness of pyraclostrobin (Pyr) and azoxystrobin (Azo) with highly targeting the rice blast is noteworthy, but they have varied toxic levels towards non-target aquatic organisms. Nevertheless, the toxic selectivity and mechanism of non-target plants, specifically rice, remain uncertain. In this study, we investigated the potential phytotoxic effects of Pyr and Azo on rice seedlings, including plant morphology, plant growth, physiological and biochemical changes. The findings revealed that both Pyr and Azo caused toxic effects on rice, resulting in symptoms of chlorosis and inhibited growth. The toxicity of Azo was found to be more severe when applied at the recommended field dose. Disruption of oxidative stress could significantly impact the demonstrated levels of REC, leading to a decrease in photosynthetic pigments and potentially culminating in cell death. Furthermore, the toxic effect of Azo had a greater impact on rice leaves compared to Pyr at treatments of 400, 800, 1600, and 4000 mg/L. However, the in vitro cytotoxicity of Azo on rice leaves was lower than that of Pyr. Therefore, it can be inferred that the mechanism of phytotoxicity of Azo is directly linked to the increased accumulation of the compound on the leaf tips and edges. Additionally, the positive effects observed on plant morphology and growth parameters suggest that the mixed application of plant growth regulators (sodium nitrophenolate aqueous solution of 14 mg/L and diethyl aminoethyl hexanoat of 50 mg/L) can be a promising approach to mitigate the rice phytotoxicity of Azo at 400 and 800 mg/L.

Effect of neonicotinoid and fungicide strobilurin in neotropical solitary bee Centris analis.

The indiscriminate use of pesticides is one of the factors directly impacting bee populations. However, limited information is available on the pesticide effects on solitary bees, especially in Neotropical countries. In this scenario, this study evaluated the survival and histopathological effects caused by the neonicotinoid insecticide acetamiprid (7 ng/µL) and the fungicide azoxystrobin (10 ng/µL) in the midgut and parietal fat body of the solitary bee Centris analis. Female and male newly-emerged bees were orally exposed for 48 h to the pesticides, or alone or in combination, under laboratory conditions. The exposure to the insecticide reduced the survival of males, while the mixture reduced survival in both sexes. Acetamiprid promoted a reduction in the number of regenerative nests in the midgut, alterations of fat body cells by increasing carbohydrates in trophocytes, and reduction of oenocyte size, and increased the frequency of pericardial cells in the advanced activity stage. Both pesticides caused changes in HSP70 immunolabelling of midgut from males at the end of pesticide exposure. Comparatively, the effects on males were stronger than in females exposed to the same pesticides. Therefore, acetamiprid alone and in mixture with fungicide azoxystrobin can be harmful to males and females of Neotropical solitary bee C. analis showing lethal and sublethal effects at a concentration likely to be found in the environment.

Cytochrome c Oxidase Influences Pyraclostrobin Sensitivity in Fusarium graminearum by Regulating FgAox Through Transcription Factors FgAod2 and FgAod5.

Cytochrome c oxidase (Cox) is a crucial terminal oxidase in the electron transport chain. In this study, we generated 14 Cox gene deletion or overexpression mutants in Fusarium graminearum. Fungicide sensitivity tests revealed that 11 Cox gene deletion mutants displayed resistance to pyraclostrobin, while 10 overexpression mutants showed hypersensitivity. RNA-Seq and RT-qPCR analyses demonstrated the upregulation of FgAox (alternative oxidase in F. graminearum), FgAod2, and FgAod5 (alternative oxidase deficiency in F. graminearum) in ΔFgCox4-2 and ΔFgCox17-75 mutants. In 11 Cox gene deletion mutants, FgAox expression was significantly upregulated, whereas in 10 Cox gene overexpression mutants, it was significantly downregulated. FgAox overexpression mutants exhibit resistance to pyraclostrobin, while FgAox deletion mutants show hypersensitivity to pyraclostrobin. FgAod2 and FgAod5 were identified as transcription factors for FgAox. Our findings reveal that FgCox influences pyraclostrobin sensitivity by regulating FgAox through FgAod2 and FgAod5. Understanding pyraclostrobin resistance mechanisms in F. graminearum could help develop better fungicide rotation and application strategies to manage resistance and guide the creation of new fungicides targeting different pathways.

Lignin/Surfactin Coacervate as an Eco-Friendly Pesticide Carrier and Antifungal Agent against Phytopathogen.

Excessive usage of biologically toxic fungicides and their matrix materials poses a serious threat to public health. Leveraging fungicide carriers with inherent pathogen inhibition properties is highly promising for enhancing fungicide efficacy and reducing required dosage. Herein, a series of coacervates have been crafted with lignin and surfactin, both of which are naturally derived and demonstrate substantial antifungal properties. This hierarchically assembled carrier not only effectively loads fungicides with a maximum encapsulation efficiency of 95% but also stably deposits on hydrophobic leaves for high-speed impacting droplets. Intriguingly, these coacervates exhibit broad spectrum fungicidal activity against eight ubiquitous phytopathogens and even act as a standalone biofungicide to replace fungicides. This performance can significantly reduce the fungicide usage and be further strengthened by an encapsulated fungicide. The inhibition rate reaches 87.0% when 0.30 mM pyraclostrobin (Pyr) is encapsulated within this coacervate, comparable to the effectiveness of 0.80 mM Pyr alone. Additionally, the preventive effects against tomato gray mold reached 53%, significantly surpassing those of commercial adjuvants. Thus, it demonstrates that utilizing biosurfactants and biomass with intrinsic antifungal activity to fabricate fully biobased coacervates can synergistically combine the functions of a fungicide carrier and antifungal agent against phytopathogens and guarantee environmental friendliness. This pioneering approach provides deeper insights into synergistically enhancing the effectiveness of agrochemicals from multiple aspects, including fungicide encapsulation, cooperative antifungal action, and droplet deposition.

Response of Soil Microbiota, Enzymes, and Plants to the Fungicide Azoxystrobin.

The present study was aimed at assessing the impact of azoxystrobin-a fungicide commonly used in plant protection against pathogens (Amistar 250 SC)-on the soil microbiota and enzymes, as well as plant growth and development. The laboratory experiment was conducted in three analytical terms (30, 60, and 90 days) on sandy clay (pH-7.0). Azoxystrobin was applied to soil in doses of 0.00 (C), 0.110 (F) and 32.92 (P) mg kg-1 d.m. of soil. Its 0.110 mg kg-1 dose stimulated the proliferation of organotrophic bacteria and actinobacteria but inhibited that of fungi. It also contributed to an increase in the colony development index (CD) and a decrease in the ecophysiological diversity index (EP) of all analyzed groups of microorganisms. Azoxystrobin applied at 32.92 mg kg-1 reduced the number and EP of microorganisms and increased their CD. PP952051.1 Bacillus mycoides strain (P), PP952052.1 Prestia megaterium strain (P) bacteria, as well as PP952052.1 Kreatinophyton terreum isolate (P) fungi were identified in the soil contaminated with azoxystrobin, all of which may exhibit resistance to its effects. The azoxystrobin dose of 0.110 mg kg-1 stimulated the activity of all enzymes, whereas its 32.92 mg kg-1 dose inhibited activities of dehydrogenases, alkaline phosphatase, acid phosphatase, and urease and stimulated the activity of catalase. The analyzed fungicide added to the soil at both 0.110 and 32.92 mg kg-1 doses inhibited seed germination and elongation of shoots of Lepidium sativum L., Sinapsis alba L., and Sorgum saccharatum L.

Graphene Oxide-Based Antifungal Pesticide Delivery System for Tobacco Fungal Disease (Tobacco Target Spot) Control.

In recent years, nanocarrier-based pesticide delivery systems have provided new possibilities for the efficient utilization of pesticides. In this research, we developed a hydroxypropyl-ß-cyclodextrin-modified graphene oxide (GO-HP-ß-CD) nanocarrier for pyraclostrobin (Pyr) delivery and studied its application for tobacco target spot disease control. GO-HP-ß-CD has excellent pesticide-loading performance for Pyr (adsorption capacity of 1562.5 mg/g) and good water dispersibility and stability. Besides, GO-HP-ß-CD shows pH-responsive release performance. In addition, GO-HP-ß-CD also has better leaf affinity than Pyr, and it can effectively adhere to the leaf surface after simulated washing. The results of antifungal experiments indicate that GO-HP-ß-CD-Pyr has a good preventive effect on tobacco target spot disease, and its EC50 value is 0.384 mg/L, which is lower than Pyr. Specifically, this nanopesticide formulation does not contain toxic organic solvent or additive, so it has good environmental friendliness. Therefore, we believe that the GO-HP-ß-CD-Pyr nanopesticide has brilliant potential in the prevention and control of tobacco diseases.

Investigation of the protective role of Ginkgo biloba L. against phytotoxicity, genotoxicity and oxidative damage induced by Trifloxystrobin.

Trifloxystrobin (TFS) is a widely used strobilurin class fungicide. Ginkgo biloba L. has gained popularity due to its recognized medicinal and antioxidant properties. The aim of this study was to determine whether Ginkgo biloba L. extract (Gbex) has a protective role against TFS-induced phytotoxicity, genotoxicity and oxidative damage in A. cepa. Different groups were formed from Allium cepa L. bulbs subjected to tap water (control), 200 mg/L Gbex (Gbex1), 400 mg/L Gbex (Gbex2), 0.8 g/L TFS solution (TFS), 200 mg/L Gbex + 0.8 g/L TFS (TFS + Gbex1) and 400 mg/L Gbex + 0.8 g/L TFS (TFS + Gbex2), respectively. The phenolic composition of Gbex and alterations in the morphological, physiological, biochemical, genotoxicity and anatomical parameters were evaluated. Rutin, protocatechuic acid, catechin, gallic acid, taxifolin, p-coumaric acid, caffeic acid, epicatechin, syringic acid and quercetin were the most prevalent phenolic substances in Gbex. Rooting percentage, root elongation, weight gain, chlorophyll a and chlorophyll b decreased by approximately 50%, 85%, 77%, 55% and 70%, respectively, as a result of TFS treatment compared to the control. In the TFS group, the mitotic index fell by 28% compared to the control group, but chromosomal abnormalities, micronuclei frequency and tail DNA percentage increased. Fragment, vagrant chromosome, sticky chromosome, uneven chromatin distribution, bridge, vacuole-containing nucleus, reverse polarization and irregular mitosis were the chromosomal abnormalities observed in the TFS group. The levels of proline (2.17-fold) and malondialdehyde (2.71-fold), as well as the activities of catalase (2.75-fold) and superoxide dismutase (2.03-fold) were increased by TFS in comparison to the control. TFS-provoked meristematic disorders were damaged epidermis and cortex cells, flattened cell nucleus and thickened cortex cell wall. Gbex combined with TFS relieved all these TFS-induced stress signs in a dose-dependent manner. This investigation showed that Gbex can play protective role in A. cepa against the phytotoxicity, genotoxicity and oxidative damage caused by TFS. The results demonstrated that Gbex had this antioxidant and antigenotoxic potential owing to its high phenolic content.

Impacts of UV light on the effects of either conventional or nano-enabled azoxystrobin on Daphnia magna.

Agri-chemicals such as fungicides are applied in natural settings and hence are exposed to the environment's ultraviolet (UV) light. Recently, many fungicides in commerce are being modified as nano-enabled formulations to increase agricultural productivity and reduce potential off-target effects. The present study investigated the impacts of sunlight-grade UV emission on the effects of either conventional or nano-enabled azoxystrobin (Az or nAz, respectively), a commonly applied agricultural fungicide, on Daphnia magna. Daphnids were exposed to increasing concentrations of Az or nAz under either full-spectrum (Vis) or full-spectrum Vis + UV (Vis + UV) lighting regimes to evaluate LC50s. Az LC50 was calculated at 268.8 and 234.2 µg/L in Vis or Vis + UV, respectively, while LC50 for nAz was 485.6 and 431.0 µg/L under Vis or Vis + UV light, respectively. Daphnids were exposed to 10% LC50 of either Az or nAz under Vis or Vis + UV lighting regime for 48 h or 21 d (acute and chronic, respectively). By 48 h, both Az and nAz reduced O2 consumption and increased TBARS. Heart rate was increased in Az-exposed daphnids but not in nAz groups. Neither of the two chemicals impacted thoracic limb activity. In 21 d exposures, Az significantly reduced biomass production and fecundity, but nAz groups were not significantly different from controls. The results of the present study demonstrate that conventional Az is more toxic to D. magna at lethal and sub-lethal levels in acute and chronic exposures, and sunlight strength UV can potentiate both acute and chronic effects of Az and nAz on D. magna.

Sublethal exposure to thiamethoxam and pyraclostrobin affects the midgut and Malpighian tubules of the stingless bee Frieseomelitta varia (Hymenoptera: Apidae: Meliponini).

The stingless bee Frieseomelitta varia Lepeletier 1836 (Hymenoptera: Apidae) is an essential pollinator in natural and agricultural ecosystems in the Neotropical region. However, these bees may be exposed to pesticides during foraging, which can affect both individuals and their colonies. One example comes from the use of pyraclostrobin (a fungicide) and thiamethoxam (an insecticide) for pest control in pepper crops, which F. varia visits. This study aimed to evaluate the isolated and combined sublethal effects of thiamethoxam (TMX) (0.000543 ng a.i./µL) and pyraclostrobin (PYR) (1.5 ng i.a./µL) on the morphology of the midgut and Malpighian tubules of F. varia workers. Results showed that both pesticides, regardless of the exposure time (through feeding during 48 h or 96 h), disturbed the morphology of the analyzed organs. Specifically, F. varia exposed orally to sublethal concentrations of thiamethoxam and pyraclostrobin, either alone or in combination, exhibited a higher rate of damage to the midgut (e.g., vacuolization, apocrine secretion, and cellular elimination) compared to the bees in the control groups, both after 48 h and 96 h of exposure. In Malpighian tubules, vacuolation is the only damage present. As the observed morphological alterations likely compromise the excretion and absorption functions, exposure to pyraclostrobin and thiamethoxam may lead to disturbances at both the individual and colony levels. These results highlight the urgent need for a future reassessment of the safety of fungicides and insecticides regarding their potential effects on bee populations.

Development and validation of stability indicating assay method for mitapivat: Identification of novel hydrolytic, photolytic, and oxidative forced degradation products employing quadrupole-time of flight mass spectrometry.

Mitapivat is a novel, first-in-class orally active pyruvate kinase activator approved by the US Food and Drug Administration in 2022 for the treatment of hemolytic anemia. There is no literature available regarding the identification of degradation impurities of mitapivat. The present study deals with the degradation behavior of mitapivat under various stress conditions such as hydrolytic, photolytic, thermal, and oxidative stress. The multivariate analysis found that the independent variables, that is, molarity, temperature, and time, are interacting with each other to affect the degradation of mitapivat. A specific, accurate, and precise high-performance liquid chromatographic (HPLC) method was developed to separate mitapivat from its degradation products. The separation was achieved on the C-18 column (250 mm × 4.6 mm × 5 µm) using the combination of 0.1% formic acid buffer and acetonitrile in gradient elution profile. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use Q2(R2) guideline. LC-electrospray ionization-Quadrupole-time of flight was employed to identify degradation products. A total of seven novel degradation products of mitapivat were identified based on tandem mass spectrometry and accurate mass measurement. In-silico toxicity of mitapivat and its degradation products was qualitatively evaluated by the DEREK toxicity prediction tool.

Amino acid mutation of succinate dehydrogenase complex induced resistance to benzovindiflupyr in Magnaporthe oryzae.

Magnaporthe oryzae is a rice blast pathogen that seriously threatens rice yield. Benzovindiflupyr is a succinate dehydrogenase inhibitor (SDHI) fungicide that effectively controls many crop diseases. Benzovindiflupyr has a strong inhibitory effect on M. oryzae; however, control of rice blast by benzovindiflupyr and risk of resistance to benzovindiflupyr are not well studied in this pathogen. In this study, six benzovindiflupyr-resistant strains were obtained by domestication induced in the laboratory. The MoSdhBH245D mutation was the cause of M. oryzae resistance to benzovindiflupyr, which was verified through succinate dehydrogenase (SDH) activity assays, molecular docking, and site-specific mutations. Survival fitness analysis showed no significant difference between the benzovindiflupyr-resistant and parent strains. Positive cross-resistance to benzovindiflupyr and other SDHIs and negative cross-resistance to azoxystrobin were observed. Therefore, the risk of benzovindiflupyr resistance in M. oryzae might be medium to high. It should be combined with other classes of fungicides (tebuconazole and azoxystrobin) to slow the development of resistance.

Honey bee colonies can buffer short-term stressor effects of pollen restriction and fungicide exposure on colony development and the microbiome.

Honey bees (Apis mellifera) have to withstand various environmental stressors alone or in combination in agriculture settings. Plant protection products are applied to achieve high crop yield, but residues of their active substances are frequently detected in bee matrices and could affect honey bee colonies. In addition, intensified agriculture could lead to resource limitation for honey bees. This study aimed to compare the response of full-sized and nucleus colonies to the combined stressors of fungicide exposure and resource limitation. A large-scale field study was conducted simultaneously at five different locations across Germany, starting in spring 2022 and continuing through spring 2023. The fungicide formulation Pictor® Active (active ingredients boscalid and pyraclostrobin) was applied according to label instructions at the maximum recommended rate on oil seed rape crops. Resource limitation was ensured by pollen restriction using a pollen trap and stressor responses were evaluated by assessing colony development, brood development, and core gut microbiome alterations. Furthermore, effects on the plant nectar microbiome were assessed since nectar inhabiting yeast are beneficial for pollination. We showed, that honey bee colonies were able to compensate for the combined stressor effects within six weeks. Nucleus colonies exposed to the combined stressors showed a short-term response with a less favorable brood to bee ratio and reduced colony development in May. No further impacts were observed in either the nucleus colonies or the full-sized colonies from July until the following spring. In addition, no fungicide-dependent differences were found in core gut and nectar microbiomes, and these differences were not distinguishable from local or environmental effects. Therefore, the provision of sufficient resources is important to increase the resilience of honey bees to a combination of stressors.

Pyraclostrobin induces developmental toxicity and cardiotoxicity through oxidative stress and inflammation in zebrafish embryos.

Pyraclostrobin, a typical representative of strobilurin fungicides, is extensively used in agriculture to control fungi and is often detected in water bodies and food. However, the comprehensive toxicological molecular mechanism of pyraclostrobin requires further study. To assess the toxic effects and underlying mechanisms of pyraclostrobin on aquatic organisms, zebrafish embryos were exposed to pyraclostrobin (20, 40, and 60 µg/L) until 96 h post fertilization (hpf). These results indicated that exposure to pyraclostrobin induces morphological alterations, including spinal curvature, shortened body length, and smaller eyes. Furthermore, heart developmental malformations, such as pericardial edema and bradycardia, were observed. This indicated severe cardiotoxicity induced by pyraclostrobin in zebrafish embryos, which was confirmed by the dysregulation of genes related to heart development. Besides, our findings also demonstrated that pyraclostrobin enhanced the contents of reactive oxygen species (ROS) and malondialdehyde (MDA), up-regulated catalase (CAT) activity, but inhibited superoxide dismutase (SOD) activity. Subsequently, the NF-κb signaling pathway was further studied, and the results indicated that the up-regulation of tnf-α, tlr-4, and myd88 activated the NF-κb signaling pathway and up-regulated the relative expression level of pro-inflammatory cytokines, such as cc-chemokine, ifn-γ, and cxcl-clc. Collectively, this study revealed that pyraclostrobin exposure induces developmental toxicity and cardiotoxicity, which may result from a combination of oxidative stress and inflammatory responses. These findings provide a basis for continued evaluation of the effects and ecological risks of pyraclostrobin on the early development of aquatic organisms.

Synergistic toxic effects and mechanistic insights of beta-cypermethrin and pyraclostrobin exposure on hook snout carp (Opsariichthys bidens): A biochemical, transcriptional, and molecular approach.

The extensive utilization of pesticides results in their frequent detection in aquatic environments, often as complex mixtures, posing risks to aquatic organisms. The hook snout carp (Opsariichthys bidens) serves as a valuable bioindicator for evaluating the impacts of environmental pollutants in aquatic ecosystems. However, few studies examined the toxic effects of pesticides on O.bidens, let alone the characterization of the combined effects resulting from their mixtures. This study aims to elucidate the toxic effects of beta-cypermethrin and pyraclostrobin on O.bidens, individually and in combination, focusing on biochemical, transcriptional, and molecular responses. By organizing and analyzing the toxicogenomic databases, both pesticides were identified as a contributor to processes such as apoptosis, oxidative stress, and inflammatory responses. The acute toxicity test revealed comparable acute toxicity of beta-cypermethrin and pyraclostrobin on O.bidens, with LC50 being 0.019 and 0.027 mg/L, respectively, whereas the LC50 decreased to 0.0057 and 0.0079 mg/L under the combined exposure, indicating potential synergistic effects. The activities of enzymes involved in oxidative stress and detoxification were significantly altered after exposure, with superoxide dismutase (SOD) and catalase (CAT) increasing, while malondialdehyde (MDA) levels decreased. The activity of CYP450s was significantly changed. Likewise, the expression levels of genes (mn-sod, p53, esr, il-8) associated with oxidative stress, apoptosis, endocrine and immune systems were significantly increased. Combined exposure to the pesticides significantly exacerbated the aforementioned biological processes in O.bidens. Furthermore, both pesticides can modify protein activity by binding to the surface of SOD molecules and altering protein conformation, contributing to the elevated enzyme activity. Through the investigation of the synergistic toxic effects of pesticides and molecular mechanisms in O.bidens, our findings highlight the importance of assessing the combined effects of pesticide mixtures in aquatic environments.

Effects of captan, mancozeb and azoxystrobin fungicides on motility, oxidative stress and fatty acid profiles in rainbow trout (Oncorhynchus mykiss) spermatozoa.

An in vitro study using rainbow trout spermatozoa was designed to evaluate the toxic effects of different concentrations of captan (CPT), mancozeb (MCZ), and azoxystrobin (AZX) fungicides on motility parameters, lipid peroxidation, SOD activity, total antioxidant capacity (TAC), and DPPH inhibition. Moreover, changes in fatty acids profiles caused by the fungicides were determined for the first time. The results revealed that motility parameters, SOD activities, TAC values, and DPPH inhibitions decreased significantly while lipid peroxidation increased after ≥2 µg/L of CPT, ≥1 µg/L of MCZ, and ≥5 µg/L of AZX incubations for 2 h at 4 °C. Additionally, 10 µg/L CPT, 5 µg/L MCZ, and 200 µg/L AZX reduced motility to the 50 % level. Our results clearly demonstrated significant changes in the fatty acids profiles of spermatozoa exposed to these concentrations of the fungicides. The highest lipid peroxidation and the lowest monounsaturated and polyunsaturated saturated fatty acids (MUFA and PUFA, respectively) were detected in AZX. Even though the susceptibility of spermatozoa to oxidative damage is generally attributed to PUFA contents, the results of this study have represented that MUFA content could play a part in this tendency. Moreover, the lower concentration of MCZ reduced motility to the % 50 level while it deteriorated the fatty acids profile less than did AZX. Overall, the present study demonstrated that the detrimental effects of the fungicides on mitochondrial respiration and related enzymes have more priority than oxidative stress in terms of their toxicities on spermatozoa. It has also been suggested that fish spermatozoa are a good model for determining changes in the fatty acid profiles by fungicides, probably, by other pesticides and environmental contaminants as well.

Unveiling the ecotoxicological effects of azoxystrobin-based fungicides at realistic concentrations on the land snail, Theba pisana.

The ecotoxicological consequences of azoxystrobin on land snails have not yet been addressed. Therefore, the present study aims to provide novel data on the threat of a commercial grade azoxystrobin (AMISTAR) at two environmentally relevant concentrations (0.3 µg/ml) and tenfold (3 µg/ml) on the model species, Theba pisana by physiological, biochemical, and histopathological markers for 28 days. Our results showed a reduction in animal food consumption and growth due to exposure to both azoxystrobin concentrations. It also induced oxidative stress and led to a significant decrease in lipid peroxidation (LPO) levels after 7 days of exposure, while the opposite effect occurred after 28 days. Except for the 7-day exposure, all treated snails had significantly reduced glutathione (GSH) content and increased catalase (CAT) activity at all-time intervals. Glutathione peroxidase (GPx), glutathione-S-transferase (GST) activities, and protein content (PC) were elevated in treated snails at all-time intervals. Moreover, alterations in acetylcholinesterase (AChE) activity between a decrease and an increase were noticed. Additionally, azoxystrobin exerted changes in T. pisana hepatopancreas architecture. Our study suggests that azoxystrobin may have negative ecological consequences for T. pisana and highlights its potential risks to the natural environment.

Systematic health risks assessment of chiral fungicide famoxadone: Stereoselectivities in ferroptosis-mediated cytotoxicity and metabolic behavior.

Famoxadone is a chiral fungicide frequently found in the environment and agricultural products. However, the health risks of famoxadone enantiomers are not well understood. This study investigated the stereoselective cytotoxicity and metabolic behavior of famoxadone enantiomers in mammals. Results showed that R-famoxadone was 1.5 times more toxic to HepG2 cells than S-famoxadone. R-famoxadone induced more pronounced ferroptosis compared to S-famoxadone. It caused greater upregulation of genes related to iron transport and lipid peroxidation, and greater downregulation of genes related to peroxide clearance. Furthermore, R-famoxadone induced more severe lipid peroxidation and reactive oxygen species (ROS) accumulation through ACSL4 activation and GPX4 inhibition. Additionally, the bioavailability of R-famoxadone in mice was six times higher than that of S-famoxadone. Liver microsome assays, cytochrome P450 (CYP450) inhibition assays, human recombinant CYP450 assays, and molecular docking suggested that the lower binding affinities of CYP2C8, CYP2C19, and CYP2E1 for R-famoxadone caused its preferential accumulation. Overall, R-famoxadone poses a higher risk than S-famoxadone due to its greater cytotoxicity and persistence. This study provides the first evidence of ferroptosis-induced stereoselective toxicity, offering insights for the comprehensive health risk assessment of chiral famoxadone and valuable references for the application of high-efficiency, low-risk pesticide enantiomers.