Ferulic acid attenuates difenoconazole exposure induced liver injury in carp by modulating oxidative damage, inflammation and apoptosis

Difenoconazole (DFZ) is a widely used triazole fungicide in agricultural production. However, the presence of DFZ residue in the environment poses a significant risk to non-target organisms. Ferulic acid (FA) is a phenolic compound known for its antioxidant and anti-inflammatory properties. This study aims to investigate the hepatic damage caused by DFZ in carp and explore the mechanism through which FA alleviates this damage. The findings revealed that FA enhanced the antioxidant capability of the carp's liver and reduced the accumulation of reactive oxygen species (ROS) in the liver tissue. Moreover, FA regulated the transcriptional levels of inflammation-related factors, effectively preventing the inflammatory response triggered by the NF-κB signaling pathway. Additionally, TUNEL results demonstrated that DFZ initiated apoptosis, while dietary supplementation with FA decreased the protein expression levels of Bax and Cytochrome C (Cyt c) and the transcriptional levels of bax, caspase3, caspase9, p53 genes. Furthermore, FA increased the protein expression and transcriptional levels of Bcl-2. In conclusion, FA protects against liver injury induced by DFZ exposure in carp by modulating oxidative damage, inflammation, and apoptosis.

Tracing the dissipation of difenoconazole, its metabolites and co-formulants in tomato: A comprehensive analysis by chromatography coupled to high resolution mass spectrometry in laboratory and greenhouse trials

The study evaluated Ceremonia 25 EC®, a plant protection product (PPP) containing difenoconazole, in tomato crops, to identify potential risks associated with PPPs, and in addition to this compound, known metabolites from difenoconazole degradation and co-formulants present in the PPP were monitored. An ultra high performance liquid chromatography coupled to quadrupole-Orbitrap mass analyser (UHPLC-Q-Orbitrap-MS) method was validated with a working range of 2 μg/kg (limit of quantification, LOQ) to 200 μg/kg. Difenoconazole degradation followed a biphasic double first-order in parallel (DFOP) kinetic model in laboratory and greenhouse trials, with high accuracy (R2 > 0.9965). CGA-205374, difenoconazole-alcohol, and hydroxy-difenoconazole metabolites were tentatively identified and semi-quantified in laboratory trials by UHPLC-Q-Orbitrap-MS from day 2 to day 30. No metabolites were found in greenhouse trials. Additionally, 13 volatile co-formulants were tentatively identified by gas chromatography (GC) coupled to Q-Orbitrap-MS, detectable up to the 7th day after PPP application. This study provides a comprehensive understanding of difenoconazole dissipation in tomatoes, identification of metabolites, and detection of co-formulants associated with the applied PPP.

Immunoprotective effect of silybin through blocking p53-driven caspase-9-Apaf-1-Cyt c complex formation and immune dysfunction after difenoconazole exposure in carp spleen

As a broad-spectrum and efficient triazole fungicide, difenoconazole is widely used, which not only pollutes the environment but also exerts toxic effects on non-target organisms. The spleen plays an important role in immune protection as an important secondary lymphoid organ in carp. In this study, we assessed the protective impact of silybin as a dietary additive on spleen tissues of carp during exposure to difenoconazole. Sixty carp were separated into four groups for this investigation including control group, difenoconazole group, silybin group, and silybin and difenoconazole group. By hematoxylin-eosin staining, dihydroethidium staining, immunohistochemical staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, quantitative real-time PCR assay, Western blot analysis, biochemical assays, and immune function indicator assays, we found that silybin could prevent difenoconazole-induced spleen tissue damage, oxidative stress, and immune dysfunction, and inhibited apoptosis of carp spleen tissue cells by suppressing the formation of p53-driven caspase-9-apoptotic protease activating factor-1-cytochrome C complex. The results suggested that silybin as a dietary additive could improve spleen tissue damage and immune dysfunction induced by difenoconazole in aquaculture carp.

Quercetin alleviates the toxicity of difenoconazole to the respiratory system of carp by reducing ROS accumulation and maintaining mitochondrial dynamic balance

Difenoconazole (DFZ) is a fungicidal pesticide extensively employed for the management of fungal diseases in fruits, vegetables, and cereal crops. However, its potential environmental impact cannot be ignored, as DFZ accumulation is able to lead to aquatic environment pollution and harm to non-target organisms. Quercetin (QUE), a flavonoid abundant in fruits and vegetables, possesses antioxidant and anti-inflammatory properties. In this article, carp were exposed to 400 mg/kg QUE and/or 0.3906 mg/L DFZ for 30 d to investigate the effect of QUE on DFZ-induced respiratory toxicity in carp. Research shows that DFZ exposure increases reactive oxygen species (ROS) production in the carp's respiratory system, leading to oxidative stress, inflammation, and damage to gill tissue and tight junction proteins. Further research demonstrates that DFZ induces mitochondrial dynamic imbalance and gill cell apoptosis. Notably, QUE treatment significantly reduces ROS levels, alleviates oxidative stress and inflammation, and mitigates mitochondrial dynamics imbalance and mitochondrial apoptosis. This study emphasizes the profound mechanism of DFZ toxicity to the respiratory system of common carp and the beneficial role of QUE in mitigating DFZ toxicity. These findings contribute to a better understanding of pesticide risk assessment in aquatic systems and provide new insights into strategies to reduce their toxicity.

Bioavailability assessment of difenoconazole to earthworms (Eisenia fetida) in soil by oleic acid-embedded cellulose acetate membrane

Passive sampling technology is widely used to evaluate the bioavailability of pollutants. However, relatively few studies have used passive sampling membranes (PSMs) to evaluate the environmental risks of pollutants in soil, particularly pesticides. Here, the bioavailability of difenoconazole to earthworms (Eisenia fetida) was evaluated using an oleic acid-embedded cellulose acetate membrane (OECAM) for the first time. Difenoconazole reached 94 % equilibrium (T94%) within 1 d in OECAM. For soil pore water, the freely dissolved concentration (Cfree) of difenoconazole was determined using OECAM (R2 = 0.969). In the soil system, a strong linear correlation between the difenoconazole concentration in OECAM and earthworms was observed (R2 = 0.913). The bioavailability of difenoconazole was affected by the soil type and biochar content. The higher the content of soil organic matter and biochar, the lower the concentration of difenoconazole in earthworms, OECAM, and soil pore water. The concentrations of difenoconazole in pore water, earthworms, and OECAM decreased by 65.3, 42.0, and 41.6 %, respectively, when 0.5 % biochar was added. Difenoconazole mainly enters OECAM and earthworms through passive diffusion with similar uptake pathways. Therefore, the bioavailability of difenoconazole to earthworms in different soils can be evaluated using the OECAM.

Sodium alginate-carboxymethyl chitosan hydrogels loaded with difenoconazole for pH-responsive release to control wheat crown rot

Increasing concern about environmental pollution has driven the development of controlled release formulations for agrochemicals. Due to the advantages of degradability and responsiveness to environmental stimuli, polysaccharide-based hydrogel is an ideal carrier for agrochemicals controlled release. In this study, a method-easy polysaccharide hydrogel for controlled release of difenoconazole (DZ) was prepared with sodium alginate (SA) and carboxymethyl chitosan (CMCS). Due to its three-dimensional crosslinked mesh structure, the prepared hydrogels (CSDZ) showed an agrochemical load capacity of 9.03 % and an encapsulation efficiency of 68.64 %. The release rate is faster in alkaline solution, followed by neutral solution, and slowest in an acid environment, which is consistent with the swelling behavior. Furthermore, leaching studies showed that CSDZ hydrogels have excellent protective properties for encapsulated agrochemicals. Compared with technical DZ, the results of in vitro and pot antifungal testing showed that CSDZ had a better control effect against wheat crown rot (Fusarium pseudograminearum). Safety assessment studies indicated that CSDZ hydrogels exhibit good biocompatibility on nontargeted organisms (Daphnia magna, zebrafish and Eisenia fetida) and wheat. This study aims to provide a potentially promising approach for the preparation and application of biocompatible polysaccharide-based hydrogels for agrochemical-controlled release in sustainable disease management.

Bioavailability evaluation of epoxiconazole and difenoconazole in rice and the influence of dissolved organic matter in reducing uptake and translocation

The aim of this study was to assess the bioavailability of epoxiconazole (EPO) and difenoconazole (DIF) in rice plants by evaluating their uptake, translocation, and accumulation. The results showed that the concentration of DIF in the roots was approximately three times higher than EPO, and both accumulated mainly in the roots. In addition, EPO continued to be transported from stems to leaves, causing a rise in its concentration in leaves. Contrastingly, only a minimal amount of DIF was transported to the leaves. This phenomenon is mainly governed by their differing octanol-water partition coefficient. The effects of dissolved organic carbon (DOC) on the accumulation of EPO and DIF in the roots were similar to those of the freely dissolved concentration measured by OECAMs. The concentrations of EPO and DIF in the roots and OECAMs consistently decreased with increasing DOC levels. Furthermore, a significant linear relationship was observed between the EPO and DIF concentrations in root and OECAMs. We also confirmed the accuracy and usefulness of the OECAMs method in predicting the bioavailability of EPO and DIF in rice roots. Therefore, OECAMs show good potential for use as a passive sampler to evaluate the bioavailability of EPO and DIF.

Ferulic acid attenuated difenoconazole-induced immunotoxicity in carp by inhibiting TRAF/TAK1/NF-κB, Nrf2 and p53 pathways

Difenoconazole (DFZ) is a classical triazole fungicide that causes immunosuppression in non-target organisms. Ferulic acid (FA) is a polyphenolic molecule found in nature that has antioxidant and anti-inflammatory activities. The purpose of this investigation was to see if FA could prevent DFZ-induced immunosuppression and to identify the potential mechanisms. Carp were exposed to 1/10 LC50 of DFZ as well as fed normal feed or feed containing dietary additive FA for 30 d. It was found that DFZ-induced immunosuppression could be improved by FA, as evidenced by upregulation of Hb, C3 and IgM and downregulation of LDH. It was then investigated that FA could ameliorate DFZ-induced splenic injury through p53-mediated apoptosis. At the same time, enhancing the levels of CAT, GSH and T-AOC in spleen and transcription levels Nrf2 signaling pathway related genes indicated that FA reduced oxidative damage caused by DFZ by blocking the Nrf2 signaling pathway. In addition, FA inhibited the inflammatory response triggered by TRAF/TAK1/NF-κB signaling pathway, downregulated the transcript levels of pro-inflammatory factors (il-1β, tnf-α, il-6) and the level of NLRP3 inflammasome (NRLP3, ASC, Caspase 1), and upregulated the transcript levels of anti-inflammatory factors (tgf-β1, il-10). In conclusion, the above results suggested that FA mediated TRAF/TAK1/NF-κB, Nrf2, and p53 pathways to attenuate DFZ-induced inflammation, oxidative stress, and apoptosis thereby enhancing the immune capacity of carp.

Difenoconazole disrupts carp intestinal physical barrier and causes inflammatory response via triggering oxidative stress and apoptosis

As a common fungicide, difenoconazole (DFZ) is widespread in the natural environment and poses many potential threats. Carp makes up a significant proportion of China's freshwater aquaculture population and are vulnerable to the DFZ. Therefore, this study investigated the effects of DFZ (0.488 mg/L and 1.953 mg/L) exposure for 4 d on the intestinal tissues of carp and explored the mechanisms. Specifically, DFZ exposure caused pathological damage to the intestinal tissues of carp, reducing the expression levels of intestinal tight junction proteins, and leading to damage to the intestinal barrier. In addition, DFZ exposure activated the NF-κB signaling pathway, increasing the levels of pro-inflammatory factors (TNF-α, IL-1β, IL-6) and decreasing the levels of anti-inflammatory factors (IL-10, TGF-β1). As disruption of the intestinal barrier is closely linked to oxidative stress and apoptosis, we have conducted research in both areas for this reason. The results showed that DFZ exposure elevated reactive oxygen species in carp intestines, decreased antioxidant enzyme activity, and suppressed the expression of oxidative stress-related genes. TUNEL results showed that DFZ induced the onset of apoptosis. In addition, the expression levels of apoptosis-related genes and proteins were examined. Western blotting results showed that DFZ could upregulate the protein expression levels of Bax, Cytochrome C and downregulate the protein levels of Bcl-2. qPCR results showed that DFZ could upregulate the transcript levels of Bax, Caspase-3, Caspase-8 and Caspase-9 and downregulate the transcript levels of Bcl-2 transcript levels. This suggests that DFZ can induce apoptosis of mitochondrial pathway in carp intestine. In conclusion, DFZ can induce oxidative stress and apoptosis in carp intestine, leading to the destruction of intestinal physical barrier and the occurrence of inflammation. Our data support the idea that oxidative stress and apoptosis are important triggers of pesticide-induced inflammatory bowel illness.

Identifying fungicide difenoconazole as illegal growth regulator in vegetable: Computer-aided hapten similarity to enhance immunoassay sensitivity

Difenoconazole, a fungicide with broad-spectrum properties, has recently been found to have been used illegally used as a plant growth regulator in Brassica campestris, with the intent of inducing thick stems and dark green leaves. However, analysts have encountered challenges in implementing a rapid surveillance screening approach for this purpose. In this study, a novel hapten was designed to improve the analytical performance of difenoconazole immunoassay. Specifically, the triazole of the original hapten was replaced with a benzene ring, guided by molecular simulation. This led to the development of a very sensitive antibody and the subsequent development of a competitive indirect enzyme linked immunosorbent assay (ciELISA) for the detection of difenoconazole in vegetable samples. The assay exhibited a working range of 0.16 ng mL^-1 to 9.64 ng mL^-1, with a detection limit of 0.05 ng mL^-1. Upon analysis of blind samples, a strong correlation was observed between the ciELISA and HPLC-MS/MS methods. As a result, the proposed technique may prove to be an excellent tool for the rapid detection of difenoconazole overuse and adulteration in vegetables.

Understanding the ecological effects of the fungicide difenoconazole on soil and Enchytraeus crypticus gut microbiome

Increasing knowledge of the impacts of pesticides on soil ecological communities is fundamental to a comprehensive understanding of the functional changes in the global agroecosystem industry. In this study, we examined microbial community shifts in the gut of the soil-dwelling organism Enchytraeus crypticus and functional shifts in the soil microbiome (bacteria and viruses) after 21 d of exposure to difenoconazole, one of the main fungicides in intensified agriculture. Our results demonstrated reduced body weight and increased oxidative stress levels of E. crypticus under difenoconazole treatment. Meanwhile, difenoconazole not only altered the composition and structure of the gut microbial community, but also interfered with the soil-soil fauna microecology stability by impairing the abundance of beneficial bacteria. Using soil metagenomics, we revealed that bacterial genes encoding detoxification and viruses encoding carbon cycle genes exhibited a dependent enrichment in the toxicity of pesticides via metabolism. Taken together, these findings advance the understanding of the ecotoxicological impact of residual difenoconazole on the soil-soil fauna micro-ecology, and the ecological importance of virus-encoded auxiliary metabolic genes under pesticide stress.

Developmental defects and potential mechanisms in F1 generation of parents exposed to difenoconazole at different life stages of zebrafish (Danio rerio)

As a typical triazole fungicide, difenoconazole is extensively used to control plant diseases; however, its residue in environmental waters poses a risk to aquatic organisms. In this study, we investigated the acute toxicity of different life stages and sub-lethal toxicity in embryonic yolk sac stage of difenoconazole to zebrafish, and the developmental toxicity in F1 generation of parents exposed to difenoconazole at different life stages of zebrafish. Furthermore, we used transcriptomics to explore the potential mechanisms of difenoconazole on the F1 larvae of parents exposed to the chemical at the embryonic stage. The results of this study showed that developmental defects were observed in the F1 embryo/larvae of parents exposed to 3, 30, and 300 μg/L of difenoconazole at different (embryo, larval, juvenile, and adult) life stages, and exposure to difenoconazole at the embryonic stage caused more severe developmental toxicity than those at other life stages. Developmental defects (malformation, inhibition of heartbeat and body length) were observed in the F1 embryos and larvae of parents exposed to difenoconazole at the embryonic stage. In addition, the total cholesterol and triglyceride contents were significantly reduced in the F1 larvae, and RNA-seq analysis revealed significant alterations in the expression of nine genes (msmo1, hsd17b7, sc5d, tm7sf2, ebp, cyp2r1, lss, cyp51, and cyp27b1) in the steroid synthesis pathway. This is suggested that F1 larvae of parents exposed to difenoconazole at the embryonic stage show abnormalities in the steroid biosynthetic pathway. These results reveal the differences in toxicity of difenoconazole to zebrafish at different life stages, improve studies on difenoconazole toxicity to zebrafish, and provide a new perspective for assessing the risk of contaminants to aquatic organisms.

Mechanisms regarding respiratory toxicity triggered by accumulation of ROS in carp exposed to difenoconazole

Difenoconazole is a widely used but difficult-to-degrade fungicide that can directly affect aquatic ecosystems. Here, two doses (0.488 mg/L, 1.953 mg/L) of difenoconazole were used to study the toxicity to the respiratory system of carp at an exposure time of 96 h. The results showed that difenoconazole exposure resulted in severe structural damage to carp gill tissue with extensive inflammatory cell infiltration. Mechanistically, difenoconazole exposure led to excessive accumulation of ROS in carp gill tissue, which induced an inflammatory response in the gill tissue. Meanwhile, the activities of SOD and CAT were reduced and the NRF2 signaling pathway was activated to regulate the imbalance between oxidation and antioxidation. In addition, difenoconazole exposure further activated the mitochondrial pathway of apoptosis by upregulating cytochrome C, BAX, cleaved-caspase 9, and downregulating Bcl-2. More interestingly, exposure to difenoconazole increased autophagosomes, but lysosomal dysfunction prevented the late stages of autophagy from proceeding smoothly, resulting in a protective autophagic response that is not properly initiated. In summary, difenoconazole exposure caused respiratory toxicity including inflammation response, oxidative stress, apoptosis, and autophagy in carp through the accumulation of ROS. The present study expanded our understanding of the toxic effects of difenoconazole on organisms and its possible threat to the aquatic environment.

Deposition and dissipation of difenoconazole in pepper and soil and its reduced application to control pepper anthracnose

The initial deposition amount, dissipation dynamics, retention rate, and field control efficacy of difenoconazole in pepper-soil system were studied with different application dosages, planting regions and patterns. The initial deposition amount of difenoconazole under the same application dosage showed the following order: fruits < cultivated soils < lower stems < upper stems < lower leaves < upper leaves, open field < greenhouse, and Changjiang < Cixi < Hefei < Langfang, respectively, which increased with increasing application dosage. The dissipation rates in leaves, stems, fruits and cultivated soils exhibited an initially fast and then slow trend, while the retention rates displayed a tendency of first increasing and then stabilizing with increasing application dosages. After 7 d of difenoconazole application, the retention rates at five concentrations were 10.3%- 39.1%, and the field efficacy mostly reached the minimum effective dose. These results suggested that difenoconazole could be reduced by 25% based on the minimum recommended dose meeting the requirements of field control efficacy for controlling pepper anthracnose.

Nano-TiO2 aggravates bioaccumulation and developmental neurotoxicity of difenoconazole in zebrafish larvae via oxidative stress and apoptosis: Protective role of vitamin C

Titanium dioxide nanoparticles (n-TiO₂) could enhance the bioavailability and toxicity of coexisting organic contaminants in the aquatic environment. This study attempted to investigate the combined effects of n-TiO₂ and difenoconazole (DIF) on the neurodevelopment of zebrafish and the underlying mechanisms. In this study, zebrafish embryos were exposed to n-TiO₂ (100 μg/L), DIF (0, 0.1 and 0.5 mg/L) and their mixtures from 4 to 96 h post fertilization (hpf) and neurotoxicity was evaluated. Our results indicated that n-TiO₂ adsorbed DIF into the brain of zebrafish and significantly enhanced the bioaccumulation of DIF and n-TiO₂ in the 0.5 mg/L co-exposure group. 100 μg/L n-TiO₂ was not developmentally toxic to the zebrafish larvae, but it exacerbated DIF-induced neurobehavioral alterations in the zebrafish larvae. n-TiO₂ also aggravated DIF-induced suppression of central nervous system (CNS) neurogenesis in Tg (HuC:egfp) zebrafish, motor neuron axon length in Tg (hb9:egfp) zebrafish, and downregulation of neurodevelopmental genes (elavl3, ngn1, gap43, gfap and mbp). In addition, DIF elevated oxidative stress by accumulation of reactive oxygen species (ROS) and inhibition of antioxidant enzymes, and triggered apoptosis by upregulation of p53, bax, bcl-2 and caspase-3, which were markedly intensified in the presence of n-TiO₂. Moreover, vitamin C (VC) ameliorated n-TiO₂/DIF-induced abnormal locomotor behaviors and neurotoxicity by inhibiting oxidative stress and apoptosis, indicating that oxidative stress and apoptosis are involved in n-TiO₂/DIF-induced neurotoxicity. Taken together, our data indicated that n-TiO₂ enhanced the accumulation of DIF and heightened oxidative stress and apoptosis, thereby inducing neurotoxicity. This study exemplifies the importance of the toxicity assessment of chemical mixtures and novel insights to mitigate their combined toxicity.

Crosstalk of oxidative stress, inflammation, apoptosis, and autophagy under reactive oxygen stress involved in difenoconazole-induced kidney damage in carp

Difenoconazole is a commonly used triazole fungicide in agricultural production. Because of its slow degradation and easy accumulation in the environment, it seriously endangers both animal health and the ecological environment. Therefore, it is hoped that the effects on carp kidneys can be studied by simulating difenoconazole residues in the environment. The experiment was designed with two doses (0.488 mg/L, 1.953 mg/L) as exposure concentrations of difenoconazole for 4 d. Histopathological results showed that difenoconazole could cause severe damage to the kidney structure and extensive inflammatory cell infiltration in carp. Elevated levels of Creatinine, and BUN suggested the development of kidney damage. The DHE fluorescence probe's result suggested that difenoconazole might cause reactive oxygen species (ROS) to accumulate in the kidney of carp. Difenoconazole was found to increase MDA levels while decreasing the activities of CAT, SOD, and GSH-PX, according to biochemical indicators. In addition, difenoconazole could up-regulate the transcription levels of inflammatory factors tnf-α, il-6, il-1β, and inos. At the same time, it inhibited the transcription level of il-10 and tgf-β1. The TUNEL test clearly showed that difenoconazole induced apoptosis in the kidney and vastly raised the transcript levels of apoptosis-related genes p53, caspase9, caspase3, and bax while inhibiting the expression of Bcl-2, fas, capsase8. Additionally, TEM imaging showed that clearly autophagic lysosomes and autophagosomes were formed. Elevated levels of LC3II protein expression, increased transcript levels of the autophagy-related gene atg5 as well as decreased transcript levels of p62 represented the generation of autophagy. In conclusion, the study illustrated that oxidative stress, inflammation, apoptosis, and autophagy all played roles in difenoconazole-induced kidney injury in carp, which was closely linked to ROS production. This work provides a valuable reference for studying the toxicity of difenoconazole to aquatic organisms.

Highly efficient in-situ cleaner degradation of difenoconazole by two novel dominant strains: Microflora diversity, monoclonal isolation, growth factor optimization, intermediates, and pathways

The non-point source pollution of difenoconazole (DIF) has become a serious environmental issue, increasingly causes indelible damages to eco-environment and human health due to its toxicity, persistence, and biomagnification. An eco-friendly, cost-effective, and efficient control technology is imperative towards a cleaner and sustainable agricultural production. Herein, a dominant microflora of efficiently degrading DIF was successfully screened, and its microbial diversity was investigated. Two novel degrading strains were isolated and identified as Phyllobacterium sp. (T-1) and Aeromonas sp. (T-2). The results of growth factor optimization indicated that the degradation rates of DIF (C₀ = 20 mg/L) by strain T-1 and T-2 were up to 96.32% and 97.86% within 14 d, respectively, under the optimal conditions. Moreover, there no obvious synergy between strain T-1 and strain T-2. From catalytic kinetics of enzymes, the intracellular enzyme of strain T-1 dominated the degradation of DIF (C₀ = 20 mg/L) entirely with the degradation rate of 82.4% (48 h), the extracellular enzyme showed little catalytic activity. However, the degrade rates of DIF (C₀ = 20 mg/L) by both intracellular and extracellular enzymes of strain T-2 were 77.99% and 26.73% within 48 h, respectively. Moreover, these enzymes remained an undiminished catalytic activity within 48 h. DIF was degraded by strain T-1 to three main transformation products (DIF-TPs 406, DIF-TPs 216, and DIF-TPs 198) undergoing hydroxyl substitution, hydrolysis, cleavage of ether bond between benzene rings, and rearrangement, while two additional products (DIF-TPs 281 and DIF-TPs 237) were generated with the biodegradation of strain T-2, excepting for DIF-TPs 406 and DIF-TPs 216, involving hydrolysis, hydroxylation, and ether bond cleavage between benzene rings. Moreover, QSAR simulation showed that the by-products were almost much lower toxicity or even non-toxic to three typical aquatic organisms (fish, daphnia, and green algae) than DIF. This study not only provides an in depth understanding of DIF bioelimination, but also be instrumental in cleaner management of DIF-contaminated soil. This study can promote the sustainable development of agriculture.

High contamination of a sentinel vertebrate species by azoles in vineyards: a study of common blackbirds (Turdus merula) in multiple habitats in western France

Azoles represent the most used family of organic fungicides worldwide and they are used in agriculture to circumvent the detrimental impact of fungi on yields. Although it is known that these triazoles can contaminate the air, the soil, and the water, field data are currently and dramatically lacking to assess if, and to what extent, the use of triazoles could contaminate non-target wild vertebrate species, notably in agroecosystems. In this study, we aimed to document for the first time the degree of blood contamination of a generalist wild bird species by multiple azoles which are used for plant protection and fungi pest control in various habitats. We deployed passive air samplers and captured 118 Common blackbirds (Turdus merula) in an agroecosystem (vineyard), a protected forest, and a city in western France. We collected blood and analyzed the plasma levels of 13 triazoles and 2 imidazoles. We found that a significant percentage of blackbirds living in vineyards have extremely high plasma levels of multiple azoles (means (pg.g^-1); tebuconazole: 149.23, difenoconazole: 44.27, fenbuconazole: 239.38, tetraconazole: 1194.16), while contamination was very limited in the blackbirds from the protected forest and absent in urban blackbirds. Interestingly, we also report that the contamination of blackbirds living in vineyard was especially high at the end of Spring and the beginning of Summer and this matches perfectly with the results from the passive air samplers (i.e., high levels of azoles in the air of vineyards during June and July). However, we did not find any correlation between the levels of plasma contamination by azoles and two simple integrative biomarkers of health (feather density and body condition) in this sentinel species. Future experimental studies are now needed to assess the potential sub-lethal effects of such levels of contamination on the physiology of non-target vertebrate species.

Multifaceted effects of difenoconazole in tomato fruit ripening: Physiology, flavour and nutritional quality

Difenoconazole is widely used in crop growth, however, its effects on the quality of agricultural products are poorly studied. In this study, the application of difenoconazole on tomato plants could increase soluble sugar content, reduce organic acid and raise accumulation of nutrient-related metabolites during late fruit ripening. Consumer surveys in our study showed that the treatment of difenoconazole tomatoes group had higher sweetness and lower acidity, and those tomatoes were preferred by consumers. Alterations in fruit flavor-related attributes were at least in part corroborated by the abundance of transcripts related to sucrose (SlLin5, SlLin7, SlSuS2, SlSuS6, SlSPS1, SlSPS3) and organic acids (CS, ICDH, cMDH) anabolism. Furthermore, the difenoconazole also significantly promoted the expression of phytohormones synthesis genes, and consequently increased abscisic acid and ethylene levels. Our study not only provides theoretical support for the use of difenoconazole on tomatoes at the level of flavor quality and nutritional health, but also provides valuable information on the mechanism of triazole fungicides in the flavor quality of tomato fruits.

Effect of tank-mixed adjuvant on the behavior of chlorantraniliprole and difenoconazole in soil

In this study, both laboratory and field studies were performed to analyze the effect of the presence of tank-mixed methylated plant oil adjuvant on the adsorption and degradation of chlorantraniliprole (CAP) and difenoconazole (DIF) in soil. Adsorption kinetics and isotherms experiments were conducted according to the equilibrium oscillation method. Fourier transform infrared spectroscopy (FT-IR) analysis, soil contact angle, and zeta potential were used to research the interaction mechanism of adsorption. Fluorescence excitation emission matrix (FEEM) measurements were conducted to characterize soil dissolved organic matter. Field experiment was conducted to investigate the degradation of CAP and DIF combined with adjuvant. DIF exhibited a significantly higher Freundlich maximum adsorption capacity than CAP, which is consistent with the higher octanol-water partition coefficient of DIF. The sorption of CAP and DIF under laboratory conditions was significantly increased with the presence of adjuvant. Soils with high humic acids have strong adsorption capacity and contribute to significant adsorption of CAP and DIF. The half-lives of CAP and DIF tested in fluvo-aquic soil under field conditions were slightly reduced by the adjuvant. Adjuvant reduced the Groundwater Ubiquity Score (GUS) indices of CAP from 1.51 to 1.31, whereas that of DIF from 0.39 to 0.25. Combination between the pesticides and soil molecules can be enhanced, thereby promoting the adsorption and degradation of CAP and DIF in soil, and further reducing their potential to leach into groundwater when 0.1% methylated plant oil adjuvant was mixed and applied.

Difenoconazole causes cardiotoxicity in common carp (Cyprinus carpio): Involvement of oxidative stress, inflammation, apoptosis and autophagy

Difenoconazole, a commonly used broad-spectrum triazole fungicide, is widely applied to fish culture in paddy fields. Due to its high chemical stability, low biodegradability, and easy transfer, difenoconazole persists in aquatic systems, raising public awareness of environmental threats. Difenoconazole causes cardiotoxicity in carp, however, the potential mechanisms of difenoconazole-induced cardiotoxicity remain unclear. Here, common carp were exposed to difenoconazole, and cardiotoxicity was evaluated by measuring the creatine kinase (CK) and the lactate dehydrogenase (LDH) in the serum. Cardiac pathological injury was determined by HE staining. The content and expression of oxidative stress indicators were detected using biochemical kits and qPCR analysis. Changes in inflammation-related cytokines were examined by qPCR. Apoptosis levels were assessed by TUNEL assay and qPCR. The occurrence of autophagy was measured by western blotting detection of autophagy flux LC3II/LC3I, and autophagy regulatory pathways were detected using qPCR. The results showed that difenoconazole exposure induced cardiotoxicity accompanied by obviously elevated LDH and CK levels and caused myocardial fibers to swell and inflammatory cells to increase. Elevated peroxide MDA and reduced transcriptional and activity levels of the antioxidant enzymes CAT, SOD and GSH-Px were dependent on the Nrf2/Keap-1 pathway. Moreover, the proinflammatory cytokines IL-1β, IL-6, and TNF-α were upregulated, iNOS activity was enhanced, whereas the anti-inflammatory cytokines TGF-β1 and IL-10 were downregulated after exposure to difenoconazole. Moreover, apoptosis was observed in the TUNEL assay and mediated through the p53/Bcl-2/Bax-Caspase-9 mitochondrial pathway. Furthermore, difenoconazole increased the autophagy markers LC3II, ATG5 and p62 and regulated them through the PI3K/AKT/mTOR pathway. Altogether, this study demonstrated that difenoconazole exposure caused common carp cardiotoxicity, which is regulated by oxidative stress, inflammation, apoptosis and autophagy, providing central data for toxicological risk assessment of difenoconazole in the ecological environment.

Environmental Hormone Effects and Bioaccumulation of Propiconazole and Difenoconazole in Procypris merus

Studying the bioaccumulation behavior and toxicity of triazole fungicides is a crucial part of comprehensively evaluating the environmental fate and aquatic toxicity.The current research aimed to reveal the toxic effects of propiconazole and difenoconazole on fish through acute toxicity test, bioaccumulation test and oxidase system activity determination. Here, the propiconazole and difenoconazole concentrations were 11.3 mg/L and 31.2 mg/L for LC₅₀-96 h, both having low toxicity. LC-MS/MS was used to determine the propiconazole and difenoconazole concentrations in five organs (muscle, gill, liver, intestine, and kidney) of Procypris meru. The findings indicate that the bioconcentration coefficients of propiconazole and difenoconazole in grass flower carp were 0.66-27.08 and 2.43-22.72, which belonged to medium enrichment pesticides. The bioconcentration coefficients decreased with the increase of exposure concentration. The two fungicides could induce oxidative stress in fish liver, and the activities of three antioxidant enzymes were inhibited in varying degrees (p < 0.05). The results showed that the content of T3 increased, and T4 decreased when exposed to one-tenth LC₅₀ for 7 days. This study shows that triazole pesticides have bioaccumulation risks on aquatic organisms and clear environmental hormonal effects.

Difenoconazole disrupts the blood-brain barrier and results in neurotoxicity in carp by inhibiting the Nrf2 pathway mediated ROS accumulation

Excessive use of hard-to-degrade pesticides threatens the ecological health of aquatic systems. This study aimed to investigate difenoconazole (DFZ) residues in the environment induced neurotoxicity in carp and the underlying mechanisms. A total of thirty-six carps were divided into three groups and exposed to 0, 0.5, and 2.0 mg/L DFZ for 96 h, respectively. The alterations in behavior and blood-brain barrier (BBB) were examined, and potential mechanisms were explored using immunological assays and biochemical methods. The results showed that DFZ exposure caused behavioral freezing, reduced feeding, and neuronal necrosis in carp. Mechanistically, DFZ triggered ROS accumulation and destroyed the balance between oxidation and antioxidation with increased lipid peroxidation product MDA contents and reduced antioxidant enzymes SOD and CAT activities in the carp brain by inhibiting the NF-E2-related factor 2 (Nrf2) pathway. The activation of oxidative stress further reduced tight junction proteins and MMP levels, thereby destroying BBB and leading to DFZ leakage into the brain. Increased BBB permeability additionally led to DFZ activation of nuclear factor kappa-B signaling-mediated inflammatory cytokine storm, exacerbating neuroinflammation. Meanwhile, DFZ exposure activated mitochondria-associated apoptosis in the carp's brain by up-regulating Bcl-2 associated X protein, cleaved-caspase3, and cytochrome C and decreasing B-cell lymphoma-2 levels. Interestingly, the carp's brain initiated a protective autophagic response via the PI3K/AKT/TOR pathway intending to counteract the neurotoxicity of DFZ. Overall, we concluded that accumulation of DFZ at high concentrations in the aquatic systems disrupted the BBB and resulted in neurotoxicity in carp through inhibition of Nrf2 pathway-mediated ROS accumulation. This study provides a reference for monitoring DFZ residues in the environment and a new target for the treatment of DFZ-induced neurotoxicity in carp.

Exposure to difenoconazole induces reproductive toxicity in zebrafish by interfering with gamete maturation and reproductive behavior

Difenoconazole (DCZ) is a triazole fungicide that negatively affects aquatic organisms and humans. However, data regarding the reproductive toxicity of DCZ are insufficient. In this study, we used zebrafish (from 2 h post-fertilization [hpf] to adulthood) as a model to evaluate whether DCZ at environmentally relevant concentrations (0.1, 1.0, and 10.0 μg/L) induces reproductive toxicity. After exposure to DCZ, egg production and fertilization rates were reduced by 1.0 and 10.0 μg/L. A significant decrease in gamete frequency (late vitellogenic oocytes and spermatozoa) was observed at 10.0 μg/L. The concentrations of 17β-estradiol (E2), testosterone (T), and vitellogenin (VTG) were disrupted in females and males by 1.0 and 10.0 μg/L. Exposure to 10.0 μg/L DCZ significantly inhibited the contact time between female and male fish, which was mainly achieved by affecting male fish. The transcription of genes involved in the hypothalamus-pituitary-gonad (HPG) axis was significantly changed after treatment with DCZ. Overall, these data show that the endocrine-disrupting effect of DCZ on the zebrafish HPG axis inhibited gamete maturation and disrupted reproductive behavior, reducing fertility.

Surface-enhanced Raman scattering (SERS) from low-cost silver nanoparticle-decorated cicada wing substrates for rapid detection of difenoconazole in potato

Potato is one of the most important food crops worldwide in terms of human consumption. However, potato farmers employ a variety of pesticides to protect crops from harmful insects and illnesses, and difenoconazole is a commonly used one that has severe effects on human health and the environment. Therefore, detecting difenoconazole quickly and correctly is critical. In this work, we fabricated AgNPs/cicada wing substrates using natural cicada segments, decorated with silver nanoparticles for surface-enhanced Raman scattering (SERS) measurements to detect trace amounts of difenoconazole in potatoes. Results indicated that a linear relationship with the coefficient of detection (R²) of 0.987 and the detection limit (LOD) of 0.016 ppm was observed by targeting a distinctive peak at 808 cm^-1 and logarithmic difenoconazole concentrations of 0.1 to 100 ppm. In addition, difenoconazole LODs in potatoes were 63 μg/kg, lower than those specified by the EU (0.1 mg/kg) and Vietnam (4 mg/kg) utilizing this new technique. Therefore, this proposed SERS method could be used to detect difenoconazole in potatoes at trace levels.

Occurrence of azole and strobilurin fungicides in indoor dust from three cities of China

Widespread use of fungicides has raised the concern of exposure to them among the general population. However, there are extremely limited studies reporting the occurrence of fungicides in indoor dust in China. This study aimed to determine ten agricultural fungicides in indoor dust samples collected in three cities of China from 2016 to 2019, assess spatial and seasonal variations, and estimate the related exposure via dust ingestion. Six out of ten fungicides including difenoconazole, prochloraz, tebuconazole, tricyclazole, azoxystrobin, and pyraclostrobin were frequently detected in the dust samples (ranged 65.8-97.7%) and the concentrations of some fungicides showed a strong correlation with each other. Difenoconazole was the most abundant one among the selected fungicides. The highest level of the selected fungicides was observed in the indoor dust collected from Wuhan in summer 2019 (median cumulative concentration of the fungicides: 62.6 ng/g), while the relatively low concentrations of fungicides were found in the dust from Taiyuan (2.08 ng/g). Heavier fungicide contamination was observed in urban districts compared to that in rural districts. Seasonal variations in the fungicide residuals were also identified. The exposure assessment suggested that intake of the selected fungicides via dust ingestion was much lower than dietary intake reported in other studies. This study filled the data gap of fungicide residuals in the indoor dust in China and further studies are needed to identify the sources and determinants of indoor fungicide contamination.

Cellulose polymers with β-amino ester pendant group: design, synthesis, molecular docking and application in adsorption of toxic metals from wastewater

BACKGROUND

Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively.

RESULTS

The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption rate, the calculated qe values (2.675, 15.252, 20.856 mg/g) were close to the experimental qe values (2.133, 13.91, 18.786 mg/g) for the three polymers Cell-AA, Cell-β-AG and Cell-β-AN, respectively. Molecular Dynamic (MD) and Monte Carlo (MC) simulations were performed on the three polymers complexed with Pb(II).

CONCLUSION

The waste material of the olive industry was used as a precursor for making the target cellulose polymers with β-Amino Ester Pendant Group. The polymer was characterized by SEM, proton NMR, TGA, and FT-IR spectroscopy. The efficacy of adsorption was quantitative for metal ions present in a real sample of wastewater and the efficiency didn't drop even after 7 cycles of use. The results indicate the existence of strong complexation. The thermodynamic study results showed a spontaneous bonding between of Pb(II) and the polymers pendant groups expressed by the negative value of the Gibbs free energy.

Difenoconazole causes spleen tissue damage and immune dysfunction of carp through oxidative stress and apoptosis

As the use of pesticides increases year after year, so does the level of residual pesticides in the aquatic environment, posing a serious threat to non-target organisms. Difenoconazole (DFZ), a class of long-lasting fungicides and residues in the marine environment, has been shown to cause damaging effects on different organs of aquatic organisms. However, there is no research on the damage of DFZ to carp spleen tissue. This study aimed to investigate the acute toxic effects of DFZ on the spleen tissue of carp (Cyprinus carpio) by exposing juvenile carp to environmentally relevant concentrations of DFZ. We randomly selected 30 carp, divided them into the Control, Low, and High groups, and then exposed the three groups to 0, 0.488 mg/L DFZ, and 1.953 mg/L DFZ for 96 h respectively. We then investigated the toxic effects caused by DFZ on carp and spleen tissues by detecting changes in spleen histopathologic damage, apoptosis, oxidative stress, inflammation, and blood biochemical parameters. We found that DFZ causes severe histopathology in spleen tissue, including ballooning, structural relaxation, and giant mitochondria. In addition, we found that DFZ caused excessive apoptosis in spleen tissue by TUNEL staining and expression levels of apoptosis-related genes (caspase3, caspase8, caspase9, fas, bax, bcl-2, and p53). The activities and transcript levels of the antioxidant enzymes SOD, CAT, and GSH-Px were significantly down-regulated. In addition, DFZ led to a significant increase in activation of the NF-κB signaling pathway and mRNA levels of pro-inflammatory cytokines il-6, il-1β, and tnf-α, and a substantial decrease in mRNA levels of anti-inflammatory cytokines il-10 and tgf-β1 in spleen tissue. Blood biochemical parameters showed that DFZ exposure significantly reduced erythrocyte, leukocyte, hemoglobin, C3, and IgM levels. Collectively, DFZ exposure induced apoptosis, immunosuppression, oxidative stress, and inflammatory responses in the spleen tissue of carp, resulting in spleen tissue damage.

Uptake and distribution of difenoconazole in rice plants under different culture patterns

The effects of spraying and root irrigation on the uptake and transport of the fungicide difenoconazole under hydroponic and soil cultivation were investigated. Rice was used as the crop for a short-term exposure experiment. A modified QuEChERS pre-treatment combined with ultra-high-performance liquid chromatography-tandem mass spectrometry was used to extract and detect difenoconazole from rice plants, water and soil. The recoveries of difenoconazole were in the range of 72.8-110.5%, with a relative standard deviation of 2.4-19.5% for all the samples when spiked with 0.01, 0.1 and 1 mg kg^-1 of difenoconazole, respectively. The limit of quantitation (LOQ) of this method was 0.01 mg kg^-1. The exposure results showed that difenoconazole could be absorbed by rice plants and transmitted to different parts of rice plants in all the treatments. In the hydroponic experiment, difenoconazole was mainly distributed in the roots of rice regardless of whether irrigation or spraying was used. For rice cultivated in soil, difenoconazole mainly accumulated in leaves after the root irrigation treatment, whereas after the spraying treatment, the rice roots were the main site of accumulation of difenoconazole. This experiment extends our knowledge of the influence of the cultivation system and application mode on the translocation of difenoconazole in rice plants.

Microplastics reduce the bioaccumulation and oxidative stress damage of triazole fungicides in fish

Microplastics (MPs) and pesticides are typical representatives of harmful chemicals in polluted waters. It is understood that the combined toxicity may differ from that of a single toxic substance. Although their combined toxicities on aquatic organisms have practical significance and research value, they have received little attention due to their complicated interaction, and the mechanism has rarely been reported. In this paper, we designed a study to investigate the single and combined effects of polystyrene microplastics (PS-MPs) and the triazole fungicide difenoconazole on zebrafish, and to explore the mechanism of this effect. The results showed that PS-MPs could reduce the bioaccumulation of difenoconazole in zebrafish to a certain extent and alleviate the oxidative stress damage of difenoconazole in the zebrafish liver. The transcriptome and qRT-PCR data revealed the association of multiple pathways in the difenoconazole response, while the presence of PS-MPs ameliorated this effect in gene expression changes. Due to the properties of PS-MPs and the interaction between them, the toxic effect of difenoconazole when combined with PS-MPs is more prominent. These results provide a novel aspect to understand the environmental behavior of MPs and to evaluate the combined effect of MPs and pesticides on aquatic food.

Ecological risk assessment for difenoconazole in aquatic ecosystems using a web-based interspecies correlation estimation (ICE)-species sensitivity distribution (SSD) model

Difenoconazole is a typical triazole fungicide that can inhibit demethylation during ergosterol synthesis. Due to its wide use, difenoconazole is frequently detected in surface water, paddy water, agricultural water, and other aquatic environments. Presently, an assessment of the ecological risk posed by difenoconazole in aquatic ecosystems is lacking. Here, a web-based interspecies correlation estimation (ICE)-species sensitivity distribution (SSD) model was first applied to assess the ecological risk of difenoconazole in aquatic environments. Meanwhile, maximum acceptable concentration (MAC), maximum risk-free concentration (MRFC), and risk quotient (RQ) values were used to evaluate the potential risk of difenoconazole to aquatic organisms. Our results showed that an aquatic MAC value of 0.31 μg/L was acceptable for difenoconazole in aquatic environments. Further, the detected concentration of difenoconazole was lower than the MRFC value of 0.09 μg/L indicating no risk to aquatic organisms. Assessment data suggested that difenoconazole exhibited potential risks to eight studied aquatic ecosystems (including surface water, paddy water, and agricultural water) in different countries (RQ > 1), indicating that difenoconazole overuse could cause adverse effects to aquatic organisms in these aquatic ecosystems. Thus, restricted use and rational use of difenoconazole are recommended.

Stereoselective effects of fungicide difenoconazole and its four stereoisomers on gut barrier, microbiota, and glucolipid metabolism in male mice

Difenoconazole is a commonly used triazole fungicide that consists of four stereoisomers [(2S,4S)-, (2S,4R)-, (2R,4R)-, and (2R,4S)-isomers] with different bioactivity. For example, the toxicity of the (2R,4S)-isomer to fish is approximately seven times higher than that of the (2S,4S)-isomer. However, the stereoselective toxic effects of difenoconazole stereoisomers on mammals have received little attention. In the present study, adult male mice were orally treated with a mixture of the four stereoisomers or each stereoisomer individually (0, 30, or 100 mg/kg/d) by gavage for 28 days. Pathological staining of the liver sections showed that the (2R,4R)-isomer caused lipid droplet accumulation. The mixture or each individual stereoisomers decreased the levels of amino acids and acyl-carnitine in serum. Moreover, the (2S,4R)-, (2R,4R)-, and (2R,4S)-isomers affected intestinal permeability, causing decreases in mucus secretion and tight junction protein expression in colon. Analysis of the gut microbiota composition showed that the stereoisomers caused decreases of OTU numbers and observed species at different levels. Interestingly, difenoconazole and its four stereoisomers reduced the relative abundance of Bacteroidetes at the phylum level and some short-chain fatty acid (SCFA)-producing bacteria. Taking the findings together, 2R-difenoconazole with strong bioactivity against pathogenic fungi also had significant effects in mammals, disrupting hepatic lipid metabolism, intestinal permeability, and gut microbiota. It is concluded that the health risks of the four difenoconazole stereoisomers to mammals should not be overlooked.

Insights into the effects of difenoconazole on the livers in male mice at the biochemical and transcriptomic levels

Difenoconazole (DFZ) is a broad-spectrum triazole fungicide, that is extensively used in agriculture. Studies have shown that residues of DFZ and other fungicides have toxic effects on nontarget organisms. However, its hepatoxicity in mammals remains unclear. Here, we characterized the toxic hepatic effects in male C57BL/6 mice exposed to 30 and 100 mg/kg bw DFZ for 14 and 56 days, respectively. The results revealed that DFZ could increase the relative liver weights, however, the relative fat and spleen weights decreased. More importantly, DFZ exposure changed the hepatic morphology and induced hepatic oxidative stress. Gene expression analysis suggested that DFZ could induce a glycolipid metabolism disorder. Moreover, hepatic transcriptomic analysis revealed the effects of DFZ exposure on the transcriptional levels of various genes, and enrichment analysis of differentially expressed genes (DEGs) showed that energy metabolism and immune-associated pathways were mainly affected. We validated the results from transcriptomic analysis and found that some key genes related to energy metabolism were affected. In addition, flow cytometry showed that the CD3+/CD4+ and CD3+ /CD8+ levels declined in the spleen of mice. Taken together, these findings combined with transcriptome analysis highlighted that DFZ caused different endpoints in the liver, which could provide more evidence for investigating the toxic effects of DFZ in mammals.

Sub-Chronic Difenoconazole Exposure Induced Gut Microbiota Dysbiosis in Mice

Difenoconazole (DIF) is a widely separated triazole fungicide in many countries. The excessive usage of DIF increases the high volume of residues in agriculture production and water bodies. Some previous studies demonstrated the toxic effects of DIF on non-target animals, however, there were still some gaps in the knowledge of the potential hazards of DIF to mammals and human health. Herein, 7-week-old male mice were exposed to 30 and 100 mg/kg/day DIF for 14 and 56 days. We observed that 56 days of DIF exposure decreased the colonic mucus expression of alcin blue-periodic acid-schiff (AB-PAS) stain and the immunochemical stain of muc2 protein. The transcript levels of mucin protein (muc1, muc2 and muc3) decreased significantly in the gut of mice followed 56 days of 100 mg/kg/day DIF exposure. In addition, the gut microbiota composition was also affected after 14 or 56 days of DIF exposure. Although the mucus expression after 14 days of DIF exposure only decreased slightly, the gut microbiota composition compared with the control group was changed significantly. Moreover, the DIF-30 and DIF-100 caused respectively different changes on the gut microbiota. The relative abundance of Bacteroidetes decreased significantly after 14 days and 56 days of DIF exposure. After 14 days of DIF exposure, there were 35 and 18 differential genera in the DIF-30 and DIF-100 group, respectively. There were 25 and 32 differential genera in the DIF-30 and DIF-100 group after 56 days of exposure, respectively. Meanwhile, the alpha diversity indexes, including observed species, Shannon, Simpson, Chao1 and ACE, in gut microbiota decreased significantly after 56 days of DIF exposure. Interestingly, the relative abundance of Akkermansia increased significantly after 56 days of 100 mg/kg/d DIF exposure. Although Akkermansia was considered as one probiotic, the phenomenon of dramatic Akkermansia increase with the decrease in gut microbiota diversity needed further discussion. These results provided some new insights on how DIF exposure impacts the mucus barrier and induces gut microbiota dysbiosis.

Histology and multi-omic profiling reveal the mixture toxicity of tebuconazole and difenoconazole in adult zebrafish

The combination effects of triazole fungicides on aquatic organisms remain largely unknown. In current study, an integrated histological, transcriptome, metabonomics and microbiology was applied to investigate the mixture effects and risk of tebuconazole (TEB) and difenoconazole (DIF) co-exposure on zebrafish liver and gonad at aquatic life benchmark. TEB and DIF mixture showed additive effect on the acute toxicity to adult zebrafish, the combined toxicity on liver was less than the additive effect of individual TEB and DIF, and TEB and DIF mixture also reduced the toxic effects on gonad and intestinal microflora. Transcriptomics and metabolomics further showed TEB and DIF mixture could induce more differentially expressed genes (DEGs) to regulate the metabolic pathways involved in energy metabolism, steroid hormone biosynthesis, retinol metabolism and microbial metabolism, to balance the energy metabolism and supplies, and maintain the steroid hormone and RA level, further reduced the toxic effect on liver and gonad caused by TEB and DIF. Our results showed the different responses and patterns on transcriptional and metabolic profiles mediated in the diverse toxicity and combination effects of TEB and DIF. The present results provided a deep mechanistic understanding of the combined effects and mode of action of DIF and TEB mixture on aquatic organisms, suggesting the concept of additive effects might sufficiently protective when evaluated the combination effects and ecological risk of TEB and DIF at aquatic life benchmarks.

Difenoconazole induces oxidative DNA damage and mitochondria mediated apoptosis in SH-SY5Y cells

Difenoconazole is one of the most typical triazole fungicides. Difenoconazole is widely used in the field of agricultural production, and its health and safety problems need to be further studied. The main purpose of this paper is to verify the neurotoxicity of Difenoconazole at the cellular level. In this study, SH-SY5Y cell line of human neuroblastoma was used to evaluate its potentially toxic effects and molecular mechanism in vitro. The research indicated that Difenoconazole could reduce cell viability and inhibit cell proliferation, induce DNA damage and accelerate programmed cell death. Further studies showed that Difenoconazole induced DNA double-strand breaks, intracellular generation of ROS, cleaved PARP, mitochondrial membrane potential collapse, induced Cyt c release, and Bax/Bcl-2 ratio increase in SH-SY5Y cells. In conclusion, the cytotoxicity of Difenoconazole revealed its toxic effect on SH-SY5Y cells, and the IC₅₀ value was 55.41 μM after 24 h exposure. Meanwhile, the genetic toxicity of Difenoconazole has revealed that it can induce DNA damage and apoptosis of SH-SY5Y cells. Through this study, the toxic effects of Difenoconazole on SH-SY5Y cells are further understood, which provides a more scientific basis for its safe use and risk control.

Degradation of difenoconazole in water and soil: Kinetics, degradation pathways, transformation products identification and ecotoxicity assessment

Difenoconazole is a widely used triazole fungicide that has been frequently detected in the environment, but comprehensive study about its environmental fate and toxicity of potential transformation products (TPs) is still lacking. Here, laboratory experiments were conducted to investigate the degradation kinetics, pathways, and toxicity of transformation products of difenoconazole. 12, 4 and 4 TPs generated by photolysis, hydrolysis and soil degradation were identified via UHPLC-QTOF/MS and the UNIFI software. Four intermediates TP295, TP295A, TP354A and TP387A reported for the first time were confirmed by purchase or synthesis of their standards, and they were further quantified using UHPLC-MS/MS in all tested samples. The main transformation reactions observed for difenoconazole were oxidation, dechlorination and hydroxylation in the environment. ECOSAR prediction and laboratory tests showed that the acute toxicities of four novel TPs on Brachydanio rerio, Daphnia magna and Selenastrum capricornutum are substantially lower than that of difenoconazole, while all the TPs except for TP277C were predicted chronically very toxic to fish, which may pose a potential threat to aquatic ecosystems. The results are important for elucidating the environmental fate of difenoconazole and assessing the environmental risks, and further provide guidance for scientific and reasonable use.

Degradation of pesticides present in tomato rinse water by direct photolysis and UVC/H2O2: optimization of process conditions through sequential Doehlert design

The degradation of three pesticides, azoxystrobin (AZO), difenoconazole (DFZ), and imidacloprid (IMD), commonly found in the tomato rinse water, was studied through UVC (251-257 nm) and UVC/H₂O₂ photolysis. The results showed that direct photolysis follows pseudo-first-order kinetics, with total AZO and IMD removals within 15 min, using 21.8 and 28.6 W m^-2, respectively, while the highest percentage of DFZ degradation was 51.7% at 28.6 W m^-2 UVC. The estimated quantum yields were 0.572, 0.028, and 0.061 mol Einstein^-1 for AZO, DFZ, and IMD, respectively. With regard to UVC/H₂O₂, total pesticide removal was achieved after 10 min, while optimal treatment conditions in relation to the pesticide removal rates, estimated through the sequential Doehlert design, were about [H₂O₂]₀ = 130 mg L^-1 and 26 W m^-2. Cytotoxicity and genotoxicity assays carried out with Allium cepa, for real industrial tomato rinse water sampled from washing belts did not show abnormalities during cell division, with total pesticides degradation after 15 min, demonstrating the potential application of the UVC/H₂O₂ process as a viable localized treatment with a focus on the possible reuse of treated water.

Integrated ecosystem models (soil-water) to analyze pesticide toxicity to aquatic organisms at two different temperature conditions

In order to increase the knowledge about pesticides considering the soil-water interaction, ecosystem models (mesoscosms) were used to analyze the of leachate on the immobility and feeding rate of the cladocerans, Ceriodaphnia silvestrii and D. similis and algae Raphidocelis subcapitata, at two different temperatures. Mesocosm were filled with natural soil (latosolo) that were contaminated with insecticide/acaricide Kraft 36 EC® and fungicide Score 250 EC®, using the recommended concentration for strawberry crops (10.8 g abamectin/ha and 20 g difenoconazole/ha). Pesticides were applied once (hand sprayers) and the precipitation was simulated twice a week (Days 1, 4, 8, 11, 15 and 18). The mesocosm were kept in a room with a controlled temperature (23 and 33 °C) and photoperiod (12h light/12h dark). The Kraft 36 EC® insecticide showed toxicity for both species of cladocerans tested, with effects on immobility and feeding rate, both at 23 and 33 °C. Score 250 EC® showed to be toxic only for the experiments that analyzed the immobility of C. silvestrii at 23 °C and the feeding of D. smilis at 33 °C, demonstrating that the effects are species-specific and related to the temperature at which they are tested. While for species R. subcapitata there was an effect only for mixture treatments of the pesticides analyzed at both temperatures. Thereby, zooplanktonic organisms may be at risk when exposed to this compound even after percolating in a soil column, which could lead to effects on the entire aquatic trophic chain and that temperature can influence the organism response to the contaminant.

Difenoconazole induces cardiovascular toxicity through oxidative stress-mediated apoptosis in early life stages of zebrafish (Danio rerio)

Difenoconazole (DIF), a common broad-spectrum triazole fungicide, is associated with an increased risk of cardiovascular diseases. Unfortunately, little attention has been paid to the mechanisms underlying this association. In this study, zebrafish embryos were exposed to DIF (0, 0.3, 0.6 and 1.2 mg/L) from 4 to 96 h post fertilization (hpf) and cardiovascular toxicity was evaluated. Our results showed that DIF decreased hatching rate, survival rate and heart rate, with increased malformation rate. Cardiovascular deformities are the most prominent, including pericardial edema, abnormal cardiac structure and disrupted vascular pattern in two transgenic zebrafish models (myl7:egfp and fli1:egfp). DIF exacerbated oxidative stress by via accumulation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme. Cardiovascular apoptosis was triggered through increased expression of p53, bcl-2, bax and caspase 9, while DIF suppressed the transcription of key genes involved in calcium signaling and cardiac muscle contraction. These adverse outcomes were restored by the antioxidant N-acetyl-L-cysteine (NAC), indicating that oxidative stress played a crucial role in DIF-induced cardiovascular toxicity caused by apoptosis and inhibition of cardiac muscle contraction. Taken together, this study revealed the key role of oxidative stress in DIF-induced cardiovascular toxicity and provided novel insights into strategies to mitigate its toxicity.

Exposure to fungicide difenoconazole reduces the soil bacterial community diversity and the co-occurrence network complexity

Difenoconazole is a triazole fungicide that is widely used worldwide and has been frequently detected in agricultural soils, but its ecotoxicological effect on soil bacterial community remains unknown. Here, the degradation of difenoconazole and its effect on soil bacterial communities were investigated at three concentrations in five different agricultural soils. Difenoconazole degraded faster in non-sterilized soils than in sterilized soils, suggesting that biodegradation is a major contributor to the dissipation of difenoconazole in soils. Exposure to high concentrations of difenoconazole decreased the soil bacterial community diversity in most soils, and this influence was aggravated with the increasing concentration. The effect of difenoconazole on soil bacterial community diversity was also enhanced with the increasing content of organic matter and total nitrogen in soils. Moreover, difenoconazole exposure also reduced the soil bacterial community network complexity and exhibited a concentration-dependent characteristic. In addition, a core bacterial community (57 operational taxonomic units, OTUs) was identified, and some core OTUs were strongly linked to the degradation of difenoconazole in soils. It is concluded that high concentrations of difenoconazole may have a significant effect on the soil bacterial communities, and co-occurrence networks may improve the ecotoxicological risk assessment of fungicides on soil microbiome.

Enantioselective Analysis and Degradation Studies of Four Stereoisomers of Difenoconazole in Citrus by Chiral Liquid Chromatography-Tandem Mass Spectrometry

Four difenoconazole stereoisomers were well separated on a Superchiral S-OX column. The absolute configurations of the four stereoisomers of difenoconazole eluted in an orderly fashion with the chiral column were confirmed as (2S,4S), (2S,4R), (2R,4R), and (2R,4S)-difenoconazole, respectively, by single-crystal X-ray diffraction. For the first time, a simple and efficient trace detection method for the determination of residues of the four stereoisomers of difenoconazole in a plant sample by HPLC-MS/MS was developed. The mean recoveries were 78.23-104.38% with RSDs of 0.33-9.95%. The limits of detection for the four difenoconazole enantiomers were 0.0002-0.0004 mg/kg, and the limits of quantitation were 0.0044-0.011 mg/kg in citrus leaves and whole fruits. There was no obvious enantioselectivity upon degradation of the four stereoisomers in citrus leaves and whole fruits in Hunan and Guizhou. In Guangzhou, the rate of degradation of (2R,4R)-difenoconazole was the slowest among the four stereoisomers of difenoconazole.

Increased triazole-resistance and cyp51A mutations in Aspergillus fumigatus after selection with a combination of the triazole fungicides difenoconazole and propiconazole

Triazole-resistance in Aspergillus fumigatus is widespread. We evaluated whether triazole-resistance in A. fumigatus and its related cyp51A mutations, induced by a combination of the triazole fungicides difenoconazole and propiconazole, differs from resistance induced by the individual fungicides. Both difenoconazole and propiconazole can induce triazole-resistance in A. fumigatus. Resistance is much easier induced by formulated fungicides or a combination of these two fungicides compared with standard fungicides or individual fungicides, respectively. Six different mutations (G138S, G138D, H147Y, I246M, M263I and D430N) were identified in the induced resistant strains. The H147Y, I246M and M263I mutations were associated with triazole-resistance. This implies that the application of a combination of difenoconazole and propiconazole may result in higher triazole-resistance in A. fumigatus and more mutations in the cyp51A gene.

Competitive Adsorption and Mobility of Propiconazole and Difenoconazole on Five Different Soils

Propiconazole (PPC) and difenoconazole (DFC) are often combined for field applications. The resulted co-exsistence of PPC and DFC may have an effect on the fate of their individuals in soil. In this study, adsorption, desorption and leaching of PPC and DFC alone and their combinations were investigated in five different soils. Adsorption of PPC and DFC was significantly different on each soil with the Freundlich adsorption coefficients of 2.86-28.69 and 14.86-98.93 negatively correlated with soil pH, respectively. In addition, adsorption of PPC and DFC was declined by 27.12-37.59% and 17.28-25.35% with the presence of coexisting DFC and PPC, respectively. Mobility of PPC and DFC in tested soils was enlarged in coexisting system. The results indicate that adsorption, desorption and mobility of PPC and DFC were mainly affected by soil pH, and these behaviors of individual PPC and DFC were obviously altered by their co-existence.

Comparative efficacy of mitigation techniques for the detoxification of Prunus persica (L.) from selected pesticide residues

Fruits are the valuable and important components of human diet. Among them, Prunus persica is a rich source of different minerals and dietary fibers. In Pakistan, the total annual production of P. persica is approximately 837,000 tons. In order to enhance agricultural yield and quality, the plant protection agents are employed during fruit production. Ultimately, this in turn leads to the incorporation of pesticide residues in fruits. In present study, an effort has been made for the determination of three selected pesticide residues, i.e., chlorpyrifos (CPF), difenoconazole (DFN), and carbendazim (CRB) in samples of P. persica collected from Swat territory. Samples were analyzed through high performance liquid chromatography (HPLC). Results revealed the occurrence of all three pesticides in studied samples; however, levels of CPF and DFN were found to be higher than MRLs. Moreover, the effects of different mitigation techniques revealed that highest reduction of CPF, DFN, and CRB (86%, 97%, 89%) residues was obtained by treatment with 10% CH₃COOH followed by 10% NaCl (74%, 78%, 84%). The lowest reduction was obtained by treatment with 10% solution of NaOH (52%, 55%, 63%).

Effects of difenoconazole on hepatotoxicity, lipid metabolism and gut microbiota in zebrafish (Danio rerio)

In current study, larvae and adult zebrafish were exposed to difenoconazole to assess its effect on hepatotoxicity, lipid metabolism and gut microbiota. Results demonstrated that difenoconazole could induce hepatotoxicity in zebrafish larvae and adult, 0.400, 1.00, 2.00 mg/L difenoconazole caused yolk retention, yolk sac edema or liver degeneration after embryos exposure for 120 h, hepatocyte vacuolization and neoplasm necrosis were observed in adult liver after 0.400 mg/L difenoconazole exposure for 21 d. RNA sequencing showed that the 41 and 567 differentially expressed genes in zebrafish larvae and liver induced by 0.400 mg/L difenoconazole, were concentrated in pathways related to protein digestion and absorption, pancreatic secretion, steroid biosynthesis, and different metabolic pathways including galactose or sugar metabolism. Difenoconazole exposure caused lipid accumulation in larval yolk sac, and the elevated triglyceride (TG), malondialdehyde (MDA) and reactive oxygen species (ROS) levels in larvae and liver, which further confirmed the lipid metabolism disorders induced by difenoconazole. The results further showed that difenoconazole increased the abundance of gut microbiota such as Firmicutes, Aeromonas, Enterobacteriaceae and Bacteroides, further suggested that gut microbiota might participate in lipid metabolism and hepatotoxicity during zebrafish development. These findings advanced the field of the difenoconazole-induced developmental toxicity in larvae and adult zebrafish, and the imbalance of gut microbiota provided the plausible mode of action for the liver damage and disordered lipid metabolism in zebrafish.

Dissipation and distribution of difenoconazole in bananas and a risk assessment of dietary intake

The dissipation and terminal residues of difenoconazole in whole bananas and pulp were investigated under field conditions. The residual levels of difenoconazole in various parts of bananas grown in Guangdong, Hainan and Yunnan were determined by a GC-ECD detection method after simple, rapid pretreatment. The mean recovery was 80.66~107.40%, and the relative standard deviation was 3.36~9.84%. The results showed that the half-lives of difenoconazole in whole bananas and in the pulp were 12.16~13.33 days and 17.77~20.38 days, respectively. At harvest intervals of 28 and 35 days after the last application, the terminal residues of difenoconazole in whole bananas and pulp were 0.45~0.84 mg/kg and 0.19~0.37 mg/kg, respectively, which were lower than the maximum residue level established in China. The distribution of difenoconazole in banana pulp and peels was studied. The results showed that until harvesting, the residue in the peels was always 2.19~12.30 times larger than that in the pulp. Difenoconazole was mainly absorbed by the banana peels but did not easily penetrate into the pulp. Based on dietary risk assessment results, the residual levels of difenoconazole at the sampling interval of 28 days after the last application were within acceptable limits for chronic and acute dietary risks in different populations in China. This study can provide a reference for the safe and rational use of difenoconazole as a fungicide and for the future research and application of banana pulp and peels.

Hormonal and enzymatic responses of maize seedlings to chilling stress as affected by triazoles seed treatments

Triazole fungicides have been used for seed treatment to control soilborne diseases of maize, but seedlings coming from triazole-coated seed show serious phytotoxicity under chilling stress. To understand this phytotoxic impact, maize seed was treated with four triazoles fungicides and the corresponding seedlings were analysed on growth and gene expression. We found that maize seed coated with difenoconazole and tebuconazole exhibited either no or increased effects on germination and growth of maize at 25 °C, regardless of chemical concentrations. When maize seedlings were subjected to chilling treatment, however, their growth was significantly inhibited, and the inhibition was positively correlated with the rate of triazole application. Mesocotyl length decreased by 32.19-44.73% by difenoconazole, and 23.53-32.08% by tebuconazolet at rates of 1:50 and 1:25, respectively. However, myclobutanil did not have any effects at any temperatures. The contents of the gibberellin GA12 and abscisic acid in maize seedlings developed from difenoconazole- or tebuconazole-coated seed were significantly increased under chilling stress. The expression of two key catabolic enzyme genes, GA2ox3 and GA2ox4, was significantly up-regulated immediately following chilling stress and 2 days after recovery at 25 °C in the seedlings treated with difenoconazole or tebuconazole. This imbalance in phytohormones may explain why difenoconazole- or tebuconazole-coated seed more likely results in the phytotoxicity of maize seedlings under a low temperature condition during seed emergence and seedling growth. Since myclobutanil did not have this negative effect, it can be applied for seed coating in areas where temperatures are low during early seedling growth.

Hemp to limit diffusion of difenoconazole in vegetable garden soils

Triazole molecules are used to manage invasive aspergillosis, a fungal infection mainly due to Aspergillus fumigatus. A. fumigatus is not a phytopathogen, but, as it is widespread in soils, triazole fungicides have an unintended impact on it, selecting resistant populations’ in environment. Thus, to maintain our ability to control fungal infections, whether in human health or agriculture, reduce the impact of the use of triazoles in the environment is important, notably limiting their diffusion in soils. Here we tested a hemp-based material as adsorbent to limit the spread of difenoconazole, a triazole fungicide, in vegetable soils. We studied the effects of contact time, material dose, difenoconazole concentration, and organic content of the soil using batch mode and percolation methods. Batch experiments showed that the material exhibited high adsorption capacities toward difenoconazole. Removal from the soil water increased from 46.6% using 0.35 g hemp per kg of soil to 77.0% using 1.75 g hemp per kg, for a contact time of 15 min and an initial difenoconazole concentration of 1.2 mg/L. For a contact time of 240 min, the removal was 93.5%. Percolation experiments showed that the quantity of difenoconazole removed was greater than the amount obtained by batch method: 41.9% of removal with only one passes of solution at a concentration of 12 mg/L is obtained through percolation technique whereas, with similar conditions, only 20% of removal is obtained by batch method, i.e. after 1 min of contact. The removal was strongly dependent on the number of passes: the values increased from 57.0% to 91.0% with increasing the number of passes from 1 to 15. Addition of hemp to soils allows to remove efficiently the difenoconazole fungicide from soil water. Hemp-based felt is a new and safe adsorbent that can be applied in agriculture to limit crop contamination.

Enantioselective Behavior of Chiral Difenoconazole in Apple and Field Soil

Difenoconazole is a universal chiral fungicide which is widely used in apples. Recently, it is still employed as racemic mixtures without distinction of the enantiomers, which may lead to an incomplete risk assessment. Here, we analyzed the stereoselective degradation of difenoconazole in apple fruits and open-field soil using an HPLC-UV system. Different trends were established in various apple varieties under identical environmental conditions. No significant differences were found in its enantioselectivity of the degradation processes applied in the field soil of an apple orchard. However, preferential dissipation of (2R,4R)-difenoconazole and (2R,4S)-difenoconazole was observed in Hanfu and Fuji apples, resulting in the enrichment of stereoisomers of (2S,4S)-difenoconazole and (2S,4R)-difenoconazole. Meanwhile, no significant enantioselectivity was detected in Huahong apples. The present study will provide additional information that contributes to the comprehensive evaluation of the risks posed by the application of chiral difenoconazole in agricultural production practices.