Developmental toxicity of fungicide carbendazim in female mice

Effects of the pesticide carbendazim on broiler chicken health and carbendazim residue levels in broiler tissues

Pesticide residues may enter the human body through the food chain when livestock and poultry consume pesticide-contaminated feed. Therefore, monitoring and limiting pesticide residues in animal feed and animal-origin foods is necessary. Carbendazim is one of the most frequently detected pesticides in food and feed and has various toxic effects on non-target animals. This study investigated the effects of varying concentrations of carbendazim contamination in feed on broiler chicken growth performance, serum biochemical indicators, histopathology, and carbendazim residues in broiler muscles and livers. The results demonstrated that contamination of 5-100 mg/kg carbendazim in feed did not affect broiler growth performance or health. Carbendazim contamination in feed at 200-800 mg/kg slightly reduced growth performance. Broiler kidneys showed minor histopathological alterations after 400 mg/kg carbendazim exposure. Furthermore, when the carbendazim content in feed was less than 25 mg/kg, the residual carbendazim in the muscles and livers of broilers did not exceed the maximum residue level set by the European Union and China. Based on the above findings, carbendazim residues in the feed of less than 25 mg/kg can be considered safe for chicken products.

In vitro immunotoxicity effects of carbendazim were inhibited by n-acetylcysteine in microglial BV-2 cells

Carbendazim (CBZ) is a benzimidazole fungicide widely used worldwide in industrial, agricultural, and veterinary practices. Although, CBZ was found in all brain tissues causing serious neurotoxicity, its impact on brain immune cells remain scarcely understood. Our study investigated the in vitro effects of CBZ on activated microglial BV-2 cells. Lipopolysaccharide (LPS)-stimulated BV-2 cells were exposed to increasing concentrations of CBZ and cytokine release was measured by ELISA, and Cytometric Bead Array (CBA) assays. Mitochondrial superoxide anion (O2·-) generation was evaluated by Dihydroethidium (DHE) and nitric oxide (NO) was assessed by Griess reagent. Lipid peroxidation was evaluated by measuring the malonaldehyde (MDA) levels. The transmembrane mitochondrial potential (ΔΨm) was detected by cytometry analysis with dihexyloxacarbocyanine iodide (DiOC6(3)) assay. CBZ concentration-dependently increased IL-1β, IL-6, TNF-α and MCP-1 by LPS-activated BV-2 cells. CBZ significantly promoted oxidative stress by increasing NO, O2·- generation, and MDA levels. In contrast, CBZ significantly decreased ΔΨm. Pre-treatment of BV-2 cells with N-acetylcysteine (NAC) reversed all the above mentioned immunotoxic parameters, suggesting a potential protective role of NAC against CBZ-induced immunotoxicity via its antioxidant and anti-inflammatory effects on activated BV-2 cells. Therefore, microglial proinflammatory over-activation by CBZ may be a potential mechanism by which CBZ could induce neurotoxicity and neurodegenerative disorders.

Design and synthesis of polypyrrole conductive ink based on sulfated chitosan for bactericide carbendazim detection

Conductive polymers (CPs) are typically insoluble in solvents, and devising biocompatible hydrophilic CPs is challenging and imperative to expand the applications of CPs. Herein, sulfated chitosan (SCS) is used as a green dopant instead of toxic poly(styrene sulfonate) (PSS), and SCS:polypyrrole (SCS:PPy) conductive ink is prepared by in situ polymerization. Due to the complex structure between PPy and SCS polyanion, the synthesized SCS:PPy dispersion forms a well-connected electric pathway and confers superior conductivity, dispersion stability, good film-forming ability, and high electrical stability. As proof of our concept, electrochemical sensing utilizing an SCS:PPy-modified screen-printed carbon electrode (SPCE) was performed towards carbendazim (CBZ). The SCS:PPy on the SPCE surface displayed greater sensitivity to CBZ because the conductive complex structure eased the electrocatalytic action of SCS:PPy by dramatically increasing the current intensity of CBZ oxidation and notably ameliorating stability. The sensor unveils the lowest detection value of 1.02 nM with a linear range of 0.05 to 906 μM for sensing trace CBZ by utilizing the pulse voltammetry technique. Interestingly, this senor shows excellent selectivity towards CBZ due to the formation of substantial interactions between SCS:PPy and CBZ, as demonstrated by molecular simulation studies. Furthermore, this sensor can precisely monitor CBZ in actual fruit and river water samples with satisfactory results. This study sheds light on the design and synthesis of sustainable hydrophilic CPs in the fabrication of sensors.

A strategy for the investigation of toxic mechanisms and protection by efflux pumps using Schizosaccharomyces pombe strains: Application to rotenone

Effects not related with the inhibition of complex I of the mitochondrial electron transport chain are studied in S. pombe, which lacks it. This study aims: First, the use of a strategy with S. pombe strains to investigate the toxicity, mechanisms of action, interactions and detoxication by efflux pumps. Second, to investigate the mechanisms of toxic action of rotenone. In the dose-response assessment, the yeast presented a good correlation with the toxicity in Daphnia magna for 15 chemicals. In the mechanistic study, the mph1Δ strain presented marked specificity to the interaction with microtubules by carbendazim. DNA damage caused by hydroxyurea, an inhibitor of deoxynucleotide synthesis, was identified with marked specificity with the rad3Δ strain. The sty1Δ strain was very sensitive to the oxidative and osmotic stress induced by hydrogen peroxide and potassium chloride, respectively, being more sensitive to oxidative stress than the pap1Δ strain. The protection by exclusion pumps was also evaluated. Rotenone presented low toxicity in S. pombe due to the lack of its main target, and the marked protection by the exclusion transporters Bfr1, Pmd1, Caf5 and Mfs1. Marked cellular stress was detected. Finally, the toxicity of rotenone could be potentiated by the fungicide carbendazim and the antimetabolite hydroxyurea. In conclusion, the use of S. pombe strains is a valid strategy to: a) assess global toxicity; b) investigate the main mechanisms of toxic action, particularly spindle and DNA interferences, and osmotic and oxidative stress not related to complex I inhibition; c) explore the detoxication by efflux pumps; and d) evaluate possible chemical interactions. Therefore, it should be useful for the investigation of adverse outcome pathways.

Design and synthesis of nano-iron oxyhydroxide-based molecularly imprinted electrochemical sensors for trace-level carbendazim detection in actual samples

Carbendazim (CBD) is widely used as a fungicide that acts as a pesticide in farming to prevent crop diseases. However, CBD can remain on crops for a long time. When consumed by humans and animals, it produces a range of toxic symptoms and poses a serious threat to their health. Therefore, the detection of CBD is necessary. Traditional assay strategies for CBD detection, although sensitive and practical, can hardly achieve fast, robust monitoring during food processing and daily life. Here, we designed a novel electrochemical sensor for CBD detection. In this method, iron oxyhydroxide nanomaterial (β-FeOOH) was first prepared by hydrothermal method. Then, a molecularly imprinted polymer (MIP) layer was electropolymerized on the surface using CBD as the template and resorcinol (RC) as the functional monomer. The synergistic interaction between β-FeOOH and MIP endows the MIP/β-FeOOH/CC-based electrochemical sensor with high specificity and sensitivity. Under optimal conditions, the MIP/β-FeOOH/CC-based sensor showed a wide linear range of 39 pM-80 nM for CBD and a detection limit as low as 25 pM. Therefore, the as-prepared sensor can be a practical and effective tool for pesticide residue detection.

Carbendazim residue in plant-based foods in China: Consecutive surveys from 2011 to 2020

Carbendazim, a widely used fungicide in China, has been found to have reproductive toxicity and mutagenic effects. However, information on the spatial-temporal variations of carbendazim residues in food in China is limited. Here, we investigated the presence of carbendazim in China's plant-based foods from 2011 to 2020, evaluated the spatial-temporal characteristics, and assessed the associated exposure risks in the Chinese diet. The results revealed a high detection frequency of carbendazim in fruits (26.4%) and high concentrations in vegetables (∼110 mg kg-1), indicating widespread misuse of the fungicide. The acute risks of consuming certain vegetables and cereals exceeded the recommended limits by up to 12 and 5 times, respectively. Although there has been a decline in carbendazim residue levels in food since the implementation of the Chinese government's action plan for zero growth of pesticide use in 2015, some provinces still exhibited high levels of carbendazim in multiple food categories, which were positively correlated with annual pesticide application. We highlight that carbendazim contamination reflects the broader issue of pesticide use in China. It emphasizes the need for committed and targeted national policies to reduce carbendazim residues in food and suggests that such measures could also regulate the use of other pesticides, given that pesticide abuse in China is not limited to specific types. We call for the re-evaluation of maximum residue limits of carbendazim, particularly in highly consumed foods such as cereals.

Fungicides as a risk factor for the development of neurological diseases and disorders in humans: a systematic review

Although studies show that pesticides, especially insecticides, may be toxic to humans, publications on the neurological effects of fungicides are scarce. As fungicides are used widely in Brazil, it is necessary to gather evidence to support actions aimed at safely using of these chemicals. We investigated through a systematic review of publications on the use of fungicides and consequences of exposure related to nervous system diseases or neurological disorders in humans. The protocol review was registered on PROSPERO and followed the guidelines of the PRISMA-Statement. As far as it is known, there is no apparent systematic review in the literature on this topic. The search was comprised of the following databases: PubMed; Web of Science; Scopus and EMBASE, using groups of Mesh terms and strategies specific to each database. Thirteen articles were selected for this review. Regarding the substances analyzed in the studies, some reported the use of fungicides in general, without separating them by type, while others summarized the categories of all pesticides by their function (insecticides, herbicides, fungicides, etc.) or chemical class (dithiocarbamate, dicarboximide, inorganic, etc.). However, most of the articles referred to fungicides that contain the metal manganese (Mn) in their composition. As for neurological disorders, articles addressed Parkinson's disease (PD), neurodevelopmental outcomes, extrapyramidal syndrome resembling PD, cognitive disorders, depression, neural tube defects, motor neurone disease, and amyotrophic lateral sclerosis. Most investigations pointed to exposure to fungicides, mainly maneb and mancozeb, leading to the development of at least one neurological disease, which suggests the need for further multicentric clinical trials and prospective studies for greater clarity of the research problem.

Carbendazim exposure inhibits mouse oocytes meiotic maturation in vitro by destroying spindle assembly

Successful fertilization and early embryonic development heavily depend on the quality of the oocytes. Carbendazim (CBZ), a broad-spectrum fungicide, is widely available in the environment and has adverse effects on organisms. The present study focused on exploring the potential reproductive toxicity of CBZ exposure by investigating its effects on the maturation of mouse oocytes. The results demonstrated that although no disruptions were observed in the G2/M stage transition for meiosis resumption, CBZ did hinder the polar body extrusion (PBE) occurring during oocyte maturation. Cell cycle distribution analysis revealed that CBZ exposure interfered with the meiotic process, causing oocytes to be arrested at the metaphase I (MI) stage. The subsequent investigation highlighted that CBZ exposure impeded the spindle assembly and chromosomal alignment, which was linked to a decline in the level of p-MAPK. Additionally, CBZ exposure adversely affected the kinetochore-microtubule (K-MT) attachment, leading to the persistent activation of the spindle-assembly checkpoint (SAC). The study further noticed a substantial rise in the acetylation of α-tubulin and a reduction in spindle microtubule stability in CBZ-treated oocytes. In addition, the distribution pattern of estrogen receptor alpha (ERα) was altered in oocytes treated with CBZ, with abnormal aggregation on the spindles. CBZ exposure also resulted in altered histone modifications. A notable finding from this research was that the meiotic maturation of some oocytes remained unaffected even after CBZ treatment. However, during the ensuing metaphase II (MII) stage, these oocytes displayed anomalies in their spindle morphology and chromosome arrangement and diminished ability to bind to the sperm. The observations made in this study underscore the potential for CBZ to disrupt the meiotic maturation of oocytes, leading to a decline in the overall quality of oocytes.

Developmental defects induced by thiabendazole are mediated via apoptosis, oxidative stress and alteration in PI3K/Akt and MAPK pathways in zebrafish

Thiabendazole, a benzimidazole fungicide, is widely used to prevent yield loss in agricultural land by inhibiting plant diseases derived from fungi. As thiabendazole has a stable benzimidazole ring structure, it remains in the environment for an extended period, and its toxic effects on non-target organisms have been reported, indicating the possibility that it could threaten public health. However, little research has been conducted to elucidate the comprehensive mechanisms of its developmental toxicity. Therefore, we used zebrafish, a representative toxicological model that can predict toxicity in aquatic organisms and mammals, to demonstrate the developmental toxicity of thiabendazole. Various morphological malformations were observed, including decreased body length, eye size, and increased heart and yolk sac edema. Apoptosis, reactive oxygen species (ROS) production, and inflammatory response were also triggered by thiabendazole exposure in zebrafish larvae. Furthermore, PI3K/Akt and MAPK signaling pathways important for appropriate organogenesis were significantly changed by thiabendazole. These results led to toxicity in various organs and a reduction in the expression of related genes, including cardiovascular toxicity, neurotoxicity, and hepatic and pancreatic toxicity, which were detected in flk1:eGFP, olig2:dsRED, and L-fabp:dsRed;elastase:GFP transgenic zebrafish models, respectively. Overall, this study partly determined the developmental toxicity of thiabendazole in zebrafish and provided evidence of the environmental hazards of this fungicide.

Untargeted Metabolomics Reveals Lipid Impairment in the Liver of Adult Zebrafish (Danio rerio) Exposed to Carbendazim

Carbendazim is a systemic fungicide used in several countries, particularly in Brazil. However, studies suggest that it is related to the promotion of tumors, endocrine disruption, and toxicity to organisms, among other effects. As a result, carbendazim is not allowed in the United States, Australia, and some European Union countries. Therefore, further studies are necessary to evaluate its effects, and zebrafish is a model routinely used to provide relevant information regarding the acute and long-term effects of xenobiotics. In this way, zebrafish water tank samples (water samples from aquari containing zebrafish) and liver samples from animals exposed to carbendazim at a concentration of 120 μg/L were analyzed by liquid chromatography coupled to high-resolution mass spectrometry, followed by multivariate and univariate statistical analyses, using the metabolomics approach. Our results suggest impairment of lipid metabolism with a consequent increase in intrahepatic lipids and endocrine disruption. Furthermore, the results suggest two endogenous metabolites as potential biomarkers to determine carbendazim exposure. Finally, the present study showed that it is possible to use zebrafish water tank samples to assess the dysregulation of endogenous metabolites to understand biological effects. Environ Toxicol Chem 2023;42:437-448. © 2022 SETAC.

Carbendazim: Ecological risks, toxicities, degradation pathways and potential risks to human health

Carbendazim is a highly effective benzimidazole fungicide and is widely used throughout the world. The effects of carbendazim contamination on the biology and environment should be paid more attention. We reviewed the published papers to evaluate the biological and environmental risks of carbendazim residues. The carbendazim has been frequently detected in the soil, water, air, and food samples and disrupted the soil and water ecosystem balances and functions. The carbendazim could induce embryonic, reproductive, developmental and hematological toxicities to different model animals. The carbendazim contamination can be remediated by photodegradation and chemical and microbial degradation. The carbendazim could enter into human body through food, drinking water and skin contact. Most of the existing studies were completed in the laboratory, and further studies should be conducted to reveal the effects of successive carbendazim applications in the field.

Carbendazim toxicity in different cell lines and mammalian tissues

The extensive production and use of harmful pesticides in agriculture to improve crop yield has raised concerns about their potential threat to living components of the environment. Pesticides cause serious environmental and health problems both to humans and animals. Carbendazim (CBZ) is a broad spectrum fungicide that is used to control or effectively kill pathogenic microorganisms. CBZ is a significant contaminant found in food, soil and water. It exerts immediate and delayed harmful effects on humans, invertebrates, aquatic animals and soil microbes when used extensively and repeatedly. CBZ is a teratogenic, mutagenic and aneugenic agent that imparts its toxicity by enhancing generation of reactive oxygen species generation. It elevates the oxidation of thiols, proteins and lipids and decreases the activities of antioxidant enzymes. CBZ is cytotoxic causing hematological abnormalities, mitotic spindle deformity, inhibits mitosis and alters cell cycle events which lead to apoptosis. CBZ is known to cause endocrine-disruption, embryo toxicity, infertility, hepatic dysfunction and has been reported to be one of the leading causes of neurodegenerative disorders. CBZ is dangerous to human health, the most common side effects upon chronic exposure are thyroid gland dysfunction and oxidative hepato-nephrotoxicity. In mammals, CBZ has been shown to disrupt the antioxidant defense system. In this review, CBZ-induced toxicity in different cells, tissues and organisms, under in vitro and in vivo conditions, has been systematically discussed.

Functional analysis, diversity, and distribution of carbendazim hydrolases MheI and CbmA, responsible for the initial step in carbendazim degradation

Strains Rhodococcus qingshengii djl-6 and Rhodococcus jialingiae djl-6-2 both harbor the typical carbendazim degradation pathway with the hydrolysis of carbendazim to 2-aminobenzimidazole (2-AB) as the initial step. However, the enzymes involved in this process are still unknown. In this study, the previous reported carbendazim hydrolase MheI was found in strain djl-6, but not in strain djl-6-2, then another carbendazim hydrolase CbmA was obtained by a four-step purification strategy from strain djl-6-2. CbmA was classified as a member of the amidase signature superfamily with conserved catalytic site residues Ser157, Ser181, and Lys82, while MheI was classified as a member of the Abhydrolase superfamily with conserved catalytic site residues Ser77 and His224. The catalytic efficiency (k_cat /K_m ) of MheI (24.0-27.9 μM^-1 min^-1 ) was 200 times more than that of CbmA (0.032-0.21 μM^-1 min^-1 ). The mheI gene (plasmid encoded) was highly conserved (> 99% identity) in the strains from different bacterial genera and its plasmid encoded flanked by mobile genetic elements. The cmbA gene was highly conserved only in strains of the genus Rhodococcus and it was chromosomally encoded. Overall, the function, diversity, and distribution of carbendazim hydrolases MheI and CbmA will provide insights into the microbial degradation of carbendazim.

Newly synthesized chitosan-nanoparticles attenuate carbendazim hepatorenal toxicity in rats via activation of Nrf2/HO1 signalling pathway

Widespread application of carbendazim (CBZ) is a major environmental impact because of its residues that caused multi-organ dysfunction. Recently, Chitosan nanoparticles (CS-NPs) are extensively used as nanocarriers due to their non-toxic and biodegradable nature. Therefore, the current study aimed to investigate the possible mechanistic pathway of modified CS-NPs to reduce the hepatic and nephrotoxicity of CBZ in rats. CS-NPs were synthesized by the ionic gelation method by using ascorbic acid instead of acetic acid to increase its antioxidant efficiency. Twenty-adult male Wistar rats were grouped (n = 5) as follows: Group (1) negative control, group (2) received CS-NPs, group (3) received CBZ, and group (4) co-administered CS-NPs with CBZ. Rats received the aforementioned materials daily by oral gavage for 28 days and weighed weekly. The results revealed that CBZ receiving group showed severe histopathological alterations in the liver and kidney sections including cellular necrosis and interstitial inflammation confirmed by immunostaining and showed marked immunopositivity of iNOS and caspase-3 protein. There were marked elevations in the serum levels of ALT, AST, urea, and creatinine with a significant increase in MDA levels and decrease in TAC levels. Upregulation of the Keap1 gene and down-regulation of Nrf2 and HO-1 genes were also observed. Co-treatment of rats by CS-NPs with CBZ markedly improved all the above-mentioned toxicological parameters and return liver and kidney tissues to normal histological architecture. We concluded that CBZ caused hepatorenal toxicity via oxidative stress and the Nrf2/HO-1 pathway and CS-NPs could reduce CBZ toxicity via their antioxidant, anti-apoptotic, and anti-inflammatory effects.

Gadolinium sesquisulfide anchored N-doped reduced graphene oxide for sensitive detection and degradation of carbendazim

Agriculture is having a major role in solving issues associated with food shortages across the globe. Carbendazim (CZM) is one of the fungicides which is commonly used in agriculture to grow crops in large quantities and fast. Monitoring CZM content is in high demand for environmental remediation. The present work deals with the synthesis of gadolinium sesquisulfide anchored Nitrogen-doped reduced graphene oxide (Gd₂S₃/NRGO) through a simple microwave-assisted method. X-ray diffraction and morphological studies confirm the formation of the nanocomposite. Gd₂S₃/NRGO showed enhanced activity both in electrochemical detection and light-driven degradation of CZM compared to Gd₂S₃ and NRGO. Gd₂S₃/NRGO modified glassy carbon electrode (GCE) exhibit a wide linear range of 0.01-450 μM CZM with 0.009 μM LOD using differential pulse voltammetry (DPV). Gd₂S₃/NRGO@GCE showed good selectivity, stability, and recovery (98.13-99.10%) in the river water sample. In addition, Gd₂S₃/NRGO has been explored towards the visible-light-induced degradation of CZM. The reactions conditions were optimized to achieve maximum efficiency. 94% of CZM was degraded within 90 min in presence of Gd₂S₃/NRGO. Mechanism of electrochemical redox reaction and degradation of CZM in presence of Gd₂S₃/NRGO has been explored to the maximum extent possible. Degradation intermediates were identified using LC-MS.

A Novel Cu2O/ZnO@PET Composite Membrane for the Photocatalytic Degradation of Carbendazim

The extremely high levels of water pollution caused by various industrial activities represent one of the most important environmental problems. Efficient techniques and advanced materials have been extensively developed for the removal of highly toxic organic pollutants, including pesticides. This study investigated the photocatalytic degradation of the fungicide carbendazim (Czm) using composite track-etched membranes (TeMs) in an aqueous solution. Copper(I) oxide (Cu₂O) and zinc oxide (ZnO) microtubes (MTs) were prepared using an electroless template deposition technique in porous poly(ethylene terephthalate) (PET) TeMs with nanochannels with a density of 4 × 10⁷ pores/cm⁻² and diameter of 385 ± 9 nm to yield Cu₂O@PET and ZnO@PET composite membranes, respectively. A mixed Cu₂O/ZnO@PET composite was prepared via a two-step deposition process, containing ZnO (87%) and CuZ (13%) as crystalline phases. The structure and composition of all composite membranes were elucidated using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) techniques. Under UV–visible light irradiation, the Cu₂O/ZnO@PET composite displayed enhanced photocatalytic activity, reaching 98% Czm degradation, higher than Cu₂O@PET and ZnO@PET composites. The maximum Czm degradation efficiency from aqueous solution was obtained at an optimal pH of 6 and contact time of 140 min. The effects of various parameters such as temperature, catalyst dosage and sample exposure time on the photocatalytic degradation process were studied. The degradation reaction of Czm was found to follow the Langmuir–Hinshelwood mechanism and a pseudo-first order kinetic model. The degradation kinetics of Czm accelerated with increasing temperature, and the activation energy (E_a) levels were calculated as 11.9 kJ/mol, 14.22 kJ/mol and 15.82 kJ/mol for Cu₂O/ZnO@PET, ZnO@PET and Cu₂O@PET composite membranes, respectively. The reusability of the Cu₂O/ZnO@PET catalyst was also investigated at different temperatures for 10 consecutive runs, without any activation or regeneration processes. The Cu₂O/ZnO@PET composite exhibited degradation efficiency levels of over 50% at 14 °C and over 30% at 52 °C after 5 consecutive uses.

Insights overview on the possible protective effect of chitosan nanoparticles encapsulation against neurotoxicity induced by carbendazim in rats

Carbendazim (CBZ) contamination of food and water is a principal factor in many negative impacts on public health. Nanoencapsulation of agrochemicals by nontoxic polymers as chitosan nanoparticles (CS-NPs) is one of the most applications of nanotechnology in agriculture. Despite its many advantages, such as it provides controlled release property, more stability and solubility of the active ingredient, it is not authorized to be used in the market because there are no adequate studies on the nano pesticides induced toxicity on experimental animals. So, we aim to study the possible impacts of CBZ-loading CS-NPs on the whole brain of rats and to explain its mechanism of action. 20 male Wistar rats were partitioned into 4 groups as follows: Group (1), normal saline; group (2), 5 mg/kg CS-NPs; group (3), 300 mg/kg CBZ; group (4) 300 mg/kg CS/CBZ-NCs. After 28 days, some neurobehavioral parameters were assessed to all rats then euthanization was done to collect the brain. Our results revealed that CBZ prompted neurotoxicity manifested by severe neurobehavioral changes and a significant increase of MDA with a decrease of GSH and CAT in brain tissue. In addition, there were severe neuropathological alterations confirmed by immunohistochemistry which showed strong bax, GFAP, and TNF-ὰ protein expression in some brain areas. CBZ also induced apoptosis manifested by up-regulation of JNK and P53 with down-regulation of Bcl-2 in brain tissue. Otherwise, encapsulation of CBZ with CS-NPs could reduce CBZ-induced neurotoxicity and improve all studied toxicological parameters. We recommend using CBZ-loading CS-NPs as an alternative approach for fungicide application in agricultural and veterinary practices but further studies are needed to ensure its safety on other organs.

Novel insights into the potential mechanisms underlying carbendazim-induced hepatorenal toxicity in rats

Carbendazim (CBZ) is a common environmental pollutant that can contaminate food and water and severely damage human health. Some studies revealed the adverse effect of CBZ on different organs, but its detailed toxicity mechanism has not been elucidated yet. Thus, the present study aims to clarify the mechanisms of CBZ-induced hepatorenal toxicity in rats. Therefore, we partitioned 40 male Wistar rats into four groups (n = 10): a negative control group and three treatment groups, which received 100, 300, and 600 mg/kg of CBZ. All rats received the treatment daily by oral gavage. We collected blood and organ samples (liver and kidney) at 14 and 28 days postdosing. CBZ caused extensive pathological alterations in both the liver and kidneys, such as cellular degeneration and necrosis accompanied by severe inflammatory reactions in a dose- and time-dependent manner. All the CBZ-treated groups displayed strong tumor necrosis factor-α and nuclear factor-κB (NF-κB) immunopositivity. Additionally, CBZ dose-dependently elevated the alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea, and creatinine serum levels and reduced the serum albumin levels. Furthermore, CBZ-induced apoptosis, as indicated by the observed Bax gene upregulation and Bcl-2 gene downregulation in both organs. All these changes may be related to oxidative stress, as indicated by the increase in malondialdehyde levels and the decrease in total antioxidant capacity. Our results demonstrate that CBZ-induced dose- and time-dependent hepatorenal damage through oxidative stress, which activated both the NF-κB signaling pathway and Bcl-based programmed cell death.

A novel electrochemical sensor based on molecularly imprinted polymer-modified C-ZIF67@Ni for highly sensitive and selective determination of carbendazim

In this work, we propose a two-step coating method, combining C-ZIF67@Ni with molecular imprinting polymer (MIP), to develop a high-sensitivity and high-selectivity Carbendazim (CBD) electrochemical sensor. ZIF67@Ni was prepared by a simple chemical bath method, and C-ZIF67@Ni was obtained by high-temperature carbonization of ZIF67@Ni. Then, MIP layer was prepared by electrochemical in-situ polymerization, with O-aminophenol as functional monomers, CBD acting as template on the surface of the C-ZIF67@Ni-modified glassy carbon electrode (GCE). During the preparation process, the types of functional monomers, the polymerization solution pH, the ratio of functional monomers to template molecules, and the incubation time are optimized. The morphological characteristics, composition information and electrochemical properties of MIP/C-ZIF67@Ni/GCE were investigated in detail under optimal conditions. Physical characterization and electrochemical tests revealed that ZIF67@Ni significantly improves the electron transmission capacity and surface area of the sensor after high-temperature carbonization. C-ZIF67@ Ni has a good synergistic effect on MIP, allowing rapid and specific identification of the test substance. MIP/C-ZIF67@Ni/GCE showed a good linear relationship with CBD in the concentration range from 4 × 10^-13 M to 1 × 10^-9 M, the lowest detection limit was 1.35 × 10^-13 M (S/N = 3) R² = 0.9983 and RSD = 2.34. Additionally, the sensor showed good repeatability, stability, and selectivity, and can be used for the detection of carbendazim in soil and water with a recovery of 98% above.

Antagonistic Effects of Enrofloxacin on Carbendazim-Induced Developmental Toxicity in Zebrafish Embryos

Carbendazim (CAR) and enrofloxacin (ENF) are frequently detected in fruits and meat products, respectively. Since most people consume fruits, vegetables, and meat products, combined exposure is possible, necessitating further evaluation of toxic interactions. In this study, the developmental toxicity of separate and combined exposure was examined in zebrafish embryos. Carbendazim exposure at 0.79 mg/L and above significantly affected developmental parameters, while enrofloxacin alone had no substantial effects on these developmental parameters within the selected concentration range (0.10-0.40 mg/L). Surprisingly, ENF antagonized the CAR-evoked reduction in the 48 hpf (hours post-fertilization) hatching rate and the increases in the 96 hpf malformation and lethality rates. The results revealed that the antagonism might be associated with reciprocal effects of these compounds on metabolism-related genes, such as cyp7a1 and apoa1a. These results reveal a complex interaction between ENF and CAR on metabolic regulation during development and highlight the importance of combined assessment for agents with the potential for simultaneous exposure.

Insights into the microbial degradation and biochemical mechanisms of carbamates

Carbamate compounds are commonly applied in agricultural sectors as alternative options to the recalcitrant organochlorine pesticides due to their easier breakdown and less persistent nature. However, the large-scale use of carbamates also leads to toxic environmental residues, causing severe toxicity in various living systems. The toxic effects of carbamates are due to their inhibitor activity against the acetylchlolinesterase enzyme. This enzyme is crucial for neurotransmission signaling in living beings. Hence, from the environmental point of view, the elimination of carbamates is a worldwide concern and priority. Microbial technology can be deliberated as a potential tool that can work efficiently and as an ecofriendly option for the dissipation of carbamate insecticides from contaminated environments by improving biodegradation processes via metabolic activities of microorganisms. A variety of bacterial and fungal species have been isolated and characterized and are capable of degrading a broad range of carbamates in soil and water environments. In addition, microbial carbamate hydrolase genes (mcd, cehA, cahA, cfdJ, and mcbA) were strongly implicated in the evolution of new metabolic functions and carbamate hydrolase enzymes. However, the accurate localization and appropriate functions of carbamate hydrolase enzymes/genes are very limited. To explore the information on the degradation routes of carbamates and promote the application of biodegradation, a study of molecular techniques is required to unlock insights regarding the degradation specific genes and enzymes. Hence, this review discusses the deep understanding of carbamate degradation mechanisms with microbial strains, metabolic pathways, molecular mechanisms, and their genetic basis in degradation.

Embryotoxic effects of Rovral® for early chicken (Gallus gallus) development

Rovral® is a fungicide used to control pests that affect various crops and little is known regarding its effects on embryonic development of amniotes. Thus, this study aimed to determine the influence of Rovral® during chicken organogenesis using acute in ovo contamination. Fertilized eggs were inoculated with different concentrations of Rovral® (100, 300, 500 or 750 µl/ml), injected into the egg's air chamber. After 7 days, embryos were examined for possible malformations, staging, weight and mortality. Subsequently, head, trunk, limbs and eyes were measured for morphometry and asymmetry. For blood analysis, eggs were treated with 300 µl/ml Rovral® and glucose, presence of micronuclei and erythrocyte nuclei abnormalities determined. Treatments with Rovral® affected the mortality rate in a concentration-dependent manner. LC₅₀ value was found to be 596 µl/ml which represents 397-fold higher than the recommended concentration for use. Rovral® produced several malformations including hemorrhagic, ocular and cephalic abnormalities. No significant changes were observed in body weight, staging, body measurements, symmetry and glucose levels of live embryos, which indicates this fungicide presents low toxicity under the analyzed conditions. Changes in erythrocyte nuclei were noted; however significant difference was observed only for presence of binucleated erythrocytes. It is important to point out that possibly more significant changes may have occurred at lower concentrations through chronic contamination. Therefore, caution is needed in the use of this fungicide, since it presents teratogenic and mutagenic potential.

Portable and quantitative detection of carbendazim based on the readout of a thermometer

The detection of carbendazim (CBZ) is important for food safety and human health. However, most current analytical methods require large instruments and highly trained operators. In order to solve this problem, herein, an innovative portable and quantitative photothermal assay platform relying on a thermometer readout for the detection of CBZ has been developed. Gold nanoparticles (AuNPs), which exhibit a strong distance-dependent photothermal effect under specific laser irradiation, were utilized as indicators. The CBZ aptamer was introduced to protect AuNPs from salt-mediated aggregation. When CBZ is present, the binding event between CBZ and aptamer leads to the loss of the aptamer protective effect on AuNPs, and AuNP aggregation occurs. Under 650-nm laser irradiation, the increase in temperature associated with an AuNP-dependent photothermal effect is highly related to the CBZ concentration. Having the advantages of user-friendliness, low cost, quick response, and portability, this method has great potential for on-site applications.

Characterization of a novel carbendazim-degrading strain Rhodococcus sp. CX-1 revealed by genome and transcriptome analyses

The persistence and ecotoxicity of carbendazim residues pose a potential risk to environmental ecology and human health. Here, a novel and highly efficient carbendazim-degrading bacterium Rhodococcus sp. CX-1, capable of utilizing carbendazim as its sole source of carbon and energy, was isolated from contaminated soil. The biodegradation characteristics and metabolic pathways were studied by mass spectrometry, genomic annotation, and transcriptome analysis. The degradation rate of carbendazim by strain CX-1 was 3.98-9.90 mg/L/h under different conditions, and the optimum degradation conditions were 40 °C and pH 7.0. The addition of carbon sources (glucose, fructose, and sucrose, 100 mg/L) could accelerate carbendazim degradation. HPLC-MS/MS identification suggested that carbendazim is first hydrolyzed into 2-aminobenzimidazole and then to 2-hydroxybenzimidazole, and is ultimately mineralized to carbon dioxide. The genome of strain CX-1 contained 6,511,628 bp nucleotides, 2 linear plasmids, 2 circular plasmids, and 6437 protein coding genes. Genome annotation and transcriptome analysis indicated that carbendazim degradation may be regulated by the degradation genes harbored in the chromosome and in plasmid 2, and two different degradation pathways of carbendazim by imidazole ring cleavage or benzene ring cleavage were predicted. This study provided new insight to reveal the biodegradation mechanism of carbendazim; furthermore, strain CX-1 is a promising bioresource for carbendazim bioremediation.

Sublethal effects of carbendazim in Jenynsia multidentata detected by a battery of molecular, biochemical and genetic biomarkers

The fungicide carbendazim (CBM) has been applied all around the world but its potential adverse effects other than its recognized activity as endocrine disruptor in non target organisms have been scarcely studied. The aims of this work were (1) to use a battery of biomarkers that can reflect potential negative effects such as oxidative stress, genotoxicity, neurotoxicity or altered immune response; and (2) to examine biomarkers of detoxification by analyzing the gene expression of cytochrome P4501A1 (CYP1A1) and the multi-xenobiotic resistance protein P-glycoprotein (P-gp) in the freshwater fish Jenynsia multidentata exposed to environmentally relevant concentrations of CBM during 24 h. Fish exposed to 5 μg/L showed inhibition of GST activity and an increase of TBARs contents in gills, the organ of direct contact with waterborne contaminants. Genotoxicity - measured in peripheral blood-was evidenced by the increases of micronuclei frequency when fish were exposed to 5, 10 and 100 μg/L CBM and of nuclear abnormalities (NA) frequency at 0.05, 0.5, 5, 10 and 100 μg/L CBM. The expression inhibition of interleukin (IL-1β) and tumor necrosis factor a (TNF-α) at 10, and 5 and 10 μg/L CBM, respectively, indicated an altered immune response. The expression of CYP1A1 was down regulated in liver at 10 μg/L and of P-gp at 5 μg/L CBM, indicating a possible slow on CBM metabolization. On the other hand, in gills CYP1A1 decreased at 5 and 10 μg/L while P-gp was induced at 5 and 100 μg/L CBM. Overall, most of these significant effects were detected below 10 μg/L CBM, in a range of realistic concentrations in aquatic ecosystems worldwide.

The Effects of Carbendazim on Acute Toxicity, Development, and Reproduction in Caenorhabditis elegans

Carbendazim, as a fungicide, was commonly used to control fungal diseases in agriculture, forestry, and veterinary medicines. In this study, the acute and reproductive toxicity of carbendazim was assessed using Caenorhabditis elegans (C. elegans) as a model in order to preliminarily evaluate the potential risks of this fungicide in agricultural production and application. The results showed that the growth of C. elegans was inhibited by 0.01 μg/L carbendazim. The treatment of 0.1 μg/L carbendazim caused a significant decrease in locomotion behavior and significant damage to the reproductive and antioxidant system, causing the lifespan of nematodes to be drastically shortened. These results provide a better understanding of the environmental risk of carbendazim and raise new concerns about safety.

Effect of Nigella sativa and Foeniculum vulgare seeds extracts on male mice exposed to carbendazim

The increasing prevalence of environmental pollutants such as pesticides is a major global problem that affects living organisms. Exposure to environmental pollutants remains a major source of health risk throughout the world. The potential health benefits of various medicinal plants and natural products in relation to protect various diseases are currently receiving considerable attention. A current approach is to develop a new biological compound from natural products that inhibits pain. Ethnopharmacological surveys have been found to be one of the most reliable tools for the discovery of the natural and semi-synthetic drug. The present study was performed to investigate the hematological and biochemical changes induced by carbendazim (CBZ) and the potential protective effect of seeds extracts of Nigella sativa (NSSE) and Foeniculum vulgare (FVSE) against CBZ toxicity in male mice. Mice were distributed into 6 groups. Mice of group 1 were served as control. Group 2 was exposed to CBZ. Group 3 was supplemented with NSSE and exposed to CBZ. Group 4 was treated with FVSE and CBZ. Normal mice of group 5 and 6 were subjected to NSSE and FVSE respectively. Body weight gain was significantly decreased in mice of group 2. In mice of group 2, significant declines of RBC, HB, Hct, WBC, total protein, FSH, LH, testosterone, T4, T3, CAT and SOD were observed. Moreover, the levels of ALT, AST, ALP, total bilirubin, creatinine, BUN, uric acid, glucose, cholesterol, CK, LDH, MDA and GSH were significantly enhanced. Treatment with NSSE and FVSE showed attenuation effects against CBZ induced hematological and biochemical changes. The results suggest that the attenuation effects of NSSE and FVSE attributed to their antioxidant properties.

Fluorescent aptasensor for carbendazim detection in aqueous samples based on gold nanoparticles quenching Rhodamine B

This paper proposes a fluorescent aptasensor for the detection of carbendazim (CBZ) in aqueous solution using CBZ-specific aptamer as sensing probe, gold nanoparticles (AuNPs) and Rhodamine B (RhoB) as indicator, respectively. In the absence of CBZ, CBZ aptamer could wrap AuNPs and maintained it dispersed in NaCl solution basically. Contrarily, the aptamer could specifically combine with CBZ and form a stable aptamer-CBZ complex, leaving AuNPs exposed to be aggregated by NaCl solution. The dispersed AuNPs could efficiently quench the fluorescence of RhoB, but those aggregated AuNPs have poor capability to impair the fluorescent indicator. Thus, the concentration of CBZ could be detected quantitatively through the distinction of the fluorescence intensity. This convenient fluorescent assay for CBZ had a wide linear range from 2.33 to 800 nM and a 2.33 nM limit of detection (LOD). Furthermore, it had high selectivity over pesticides, antibiotics, metal ions and other disrupting chemicals. As for application, the method could determine CBZ in water samples with recoveries in the range of 96.3-111.2%. This fluorescent aptasensor possessed great potential application for CBZ detection in actual aquatic environment.

The role of teratogens in neural crest development

The neural crest (NC), discovered by Wilhelm His 150 years ago, gives rise to a multipotent migratory embryonic cell population that generates a remarkably diverse and important array of cell types during the development of the vertebrate embryo. These cells originate in the neural plate border (NPB), which is the ectoderm between the neural plate and the epidermis. They give rise to the neurons and glia of the peripheral nervous system, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies are a class of congenital diseases resulting from the abnormal induction, specification, migration, differentiation or death of NC cells (NCCs) during embryonic development and have an important medical and societal impact. In general, congenital defects affect an appreciable percentage of newborns worldwide. Some of these defects are caused by teratogens, which are agents that negatively impact the formation of tissues and organs during development. In this review, we will discuss the teratogens linked to the development of many birth defects, with a strong focus on those that specifically affect the development of the NC, thereby producing neurocristopathies. Although increasing attention is being paid to the effect of teratogens on embryonic development in general, there is a strong need to critically evaluate the specific role of these agents in NC development. Therefore, increased understanding of the role of these factors in NC development will contribute to the planning of strategies aimed at the prevention and treatment of human neurocristopathies, whose etiology was previously not considered.

Low dose carbendazim disrupts mouse spermatogenesis might Be through estrogen receptor related histone and DNA methylation

Pesticides, fungicides are reportedly involved in a decline in spermatozoa quality, especially motility, and a consequent increase in the rate of infertility. Fungicide carbendazim (CBZ) is widely used in agriculture and other aspects. Although CBZ is known to disrupt spermatogenesis, causing a decrease in spermatozoa concentration and motility, the mechanisms are not fully understood. We aimed to further explore the underlying mechanisms of CBZ disruption of spermatogenesis. Pubertal mice were exposed to low doses (0.1, 1 and 10 mg/kg body weight) of CBZ for 5 weeks, then many factors related to spermatogenesis have been explored. It was found that 0.1-10 mg/kg body weight of CBZ exposure decreased mouse sperm motility and concentration, diminished the important protein factors (VASA, PGK2, B-Amy and CREM) for spermatogenesis, reduced sperm protein acrosin level, disrupted very vital epigenetic factors H3K27, 5 mC and 5 hmC. Furthermore, CBZ exposure damaged estrogen receptor alpha (ERα) pathway by decreased the protein levels of ERα and its targets PI3K and AKT. In summary low doses of CBZ exposure disrupted mouse spermatogenesis through estrogen receptor signaling; and that histone methylation and DNA methylation might play vital roles in CBZ disturbance of spermatogenesis through intertwining with estrogen signaling pathways. CBZ from the contamination in environment or food chain poses a serious threat to the normal development of spermatozoa. Therefore we strongly recommend to minimise the use of CBZ since it causes the severe issues on spermatogenesis.

Carbendazim induces death in alveolar epithelial cells: A comparison between submerged and at the air-liquid interface cell culture

The fungicide Carbendazim is widely used in agriculture and preservation of films and fibers. In mammals, it can promote germ cell mutagenicity, carcinogenicity, and reproductive toxicity. However, few data about the effects of this toxicant upon the respiratory system are available. In this work, we evaluated Carbendazim toxicity upon A549 alveolar cells both in monolayer and upon air-liquid interface cell system. Monolayer cell exposed to non-cytotoxic concentrations of this fungicide showed cell arrest at G2/M phase, and did not show additional alterations. On the other hand, alveolar 3D reconstructed epithelial model (air-liquid interface cell system) was characterized and exposed to IC₂₅ of Carbendazim using the Vitrocell® Cloud 12 chamber. Expression of Active Caspase-3, α-tubulin and ROS was significantly increased after such exposure. Mitochondrial activity was also reduced after exposed to Carbendazim. The obtained results indicate that besides the environmental and reproductive toxicity concerns regarding Carbendazim exposure, pulmonary toxicity must be considered for this fungicide. In addition, we observed that the way of exposure impacts considerably on the cell response for in vitro assessment of chemicals inhalation toxicity profile.

Silver-Nanocellulose Composite Used as SERS Substrate for Detecting Carbendazim

Nanocellulose is an abundant green resource that, owing to the larger surface area, length, and diameter of the fibers, can be used as a framework for loading Ag nanoparticles and serve as substrate for surface enhancement Raman scattering (SERS). These properties would cause the hydroxyl groups on the surface to adsorb the Ag ions and reduce them to Ag seed to form a load fulcrum. This paper presents a convenient and environmentally friendly method for the fabrication of silver-nanocellulose composites (NCF-Ag). A commonly used pesticide, carbendazim (CBZ), was used as a SERS probe to evaluate the properties of NCF-Ag. The results showed that NCF-Ag possesses good homogeneity, reproducibility, and stability. Additionally, CBZ was found to have a low limit of detection (LOD), i.e., 1.0 × 10⁻⁸ M, which indicates the possibility for trace analysis. Furthermore, it presents good linearity with R² = 0.98 at 1007 and 1270 cm⁻¹ in the range from 10⁻⁴~10⁻⁷ M CBZ.

Molecular identification and biocontrol activity of sugarcane rhizosphere bacteria against red rot pathogen Colletotrichum falcatum

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A total of 226 isolates were screened against three strains (cfNAV, cfCHA and cf8436) of C. falcatum by dual culture technique. Selected Twenty-Six bacteria characterized of morphology, biochemical activity, PGP activity, antifungal potential and 16S rRNA gene sequence. These isolates belonged to proteobacteria (13), firmicutes (10) and bacterioidetes (03) respectively.

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Ochrobactrum intermedium (TRD14), Acinetobacter sp (PK9), Bacillus sp (RSC29 and KR91) and Escherichia sp (VRE34) selected for green house study. The most promising results in suppression of the disease as well as plant growth were observed in treatment withVRE34. The plant height and stem diameter were increased from 13.27 ± 0.67 inches to 24.03 ± 1.40 inches and from 6.07 ± 0.45 mm to 9.87 ± 0.93 mm.

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Isolates identified in this study could be used as an alternative to chemical fungicides to control red rot pathogen of sugarcane plants. However, detailed investigations on their inoculations in the field to confirm its growth promotion potency and biocontrol efficacy under natural environmental and soil conditions shall make these strains as important bioinoculants for integrated disease management of red rot disease in sugarcane.

A total of 226 sugarcane rhizosphere-associated bacterial strains from the six different cultivars were screened against three pathogenic strains of C. falcatum (cfNAV, cfCHA, and cf8436) for the suppression of red rot disease. On the basis of mycelial growth inhibition in dual culture assay, 26 bacteria were selected for further characterization of morphology, biochemical activity, plant-growth-promoting (PGP) activity, antifungal potential and molecular identity by 16S rRNA gene sequence. On the basis of the 16S rRNA gene sequencing, it was found that the isolates belonged to proteobacteria (13), Firmicutes (10), and Bacteroides (3). The antagonistic bacteria tested for PGP traits revealed that 10 strains were able to solubilize tricalcium phosphate, 11 strains were able to produce siderophore, and 14 strains were able to grow in the N-free medium. The quantitative estimation of indole-3-acetic acid production was ranged from 21.58 to 66.31 μg/mL. On the basis of PGP and biocontrol traits, five strains Ochrobactrum intermedium (TRD14), Acinetobacter sp. (PK9), Bacillus sp. (RSC29 and KR91) and Escherichia sp. (VRE34) were further chosen for pot trial under greenhouse conditions on highly susceptible variety CoC671. The results showed that the pathogen-inoculated sugarcane plants were able to germinate but died within one month. However, the CoC671 inoculated with selected biocontrol strains found protected from disease and an increase in plant growth parameters on par with carbendazim fungicides. This study proves that the isolates identified in this study could be used as an alternative to chemical fungicides to control red rot pathogen of sugarcane plants.

Simultaneous Determination of Pesticides in Fruits by Using Second-Order Fluorescence Data Resolved by Unfolded Partial Least-Squares Coupled to Residual Bilinearization

In the present work, a chemometric-assisted spectrofluorimetric method has been developed for the simultaneous determination of natural fluorescent pesticides, carbaryl, carbendazim, and thiabendazole, in orange and banana. Only a simple extraction with methanol was required as sample pretreatment. Emission-excitation fluorescence matrices were obtained and resolved by using a second-order multivariate calibration method based on unfolded partial least-squares combined with residual bilinearization (U-PLS/RBL) for achieving “second-order advantage.” In this way, pesticides were determined in fruits even in the presence of inner filter effects, background interactions, strong spectral overlapping, and unexpected components. U-PLS can cope with effects that cause trilinearity loss such as, inner filter effects, including background in the calibration set; meanwhile, RBL allows to resolve the presence of unexpected components. The extraction technique was validated against a commonly applied technique based on the use of ethyl acetate and sodium sulfate. Besides, results obtained for real samples were statistically compared with those obtained by using HPLC. LODs of 0.038, 0.054, and 0.018 mg·kg−1 and 0.044, 0.072, and 0.020 mg·kg−1 were obtained for carbaryl, carbendazim, and thiabendazole in banana and orange samples, respectively; values were in accordance with the MRLs (Maximum Residue Limits) established by different official control organizations such as National Food Safety and Quality Service (SENASA), Codex Alimentarius (based on Food and Agriculture Organization (FAO) of the United Nations and World Health Organization (WHO), and Environmental Protection Agency (EPA).

Hydrolysis mechanism of carbendazim hydrolase from the strain Microbacterium sp. djl-6F

The carbendazim (MBC) hydrolyzing enzyme gene was cloned and heterologously expressed in Escherichia coli BL21 (DE3) from a newly isolated MBC-degrading bacterium strain Microbacterium sp. strain djl-6F. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis revealed that purified MheI-6F protein catalyzes direct hydrolysis of MBC into 2-aminobenzimidazole (2-AB) with a high turnover rate and moderate affinity (K_m of 6.69μmol/L and k_cat of 160.88/min) without the need for any cofactors. The optimal catalytic condition of MheI-6F was identified as 45°C, pH7.0. The enzymatic activity of MheI-6F was found to be diminished by metal ions, and strongly inhibited by sodium dodecyl sulfate (SDS). Through generating amino acid mutations in MheI-6F, Cys16 and Cys222 were identified as the catalytic groups that are essential for the hydrolysis of MBC. This is the first report on the biodegradation of MBC at the enzymatice level.

Selection and Characterization of DNA Aptamers for Electrochemical Biosensing of Carbendazim

This article reports a novel aptamer-based impedimetric detection of carbendazim, a commonly used benzimidazole fungicide in agriculture. High affinity and specificity DNA aptamers against carbendazim were successfully selected using systematic evolution of ligand by exponential enrichment (SELEX). The dissociation constants (K_ds) of the selected DNA aptamers after 10 in vitro selection cycles were characterized using fluorescence-based assays showing values in the nanomolar range. The aptamer which showed the highest degree of affinity and conformation change was used to fabricate an electrochemical aptasensor via self-assembly of thiol-modified aptamer on gold electrodes. The aptasensor exploits the specific recognition of carbendazim by the aptamer immobilized on the gold surface which leads to conformational changes in the aptamer structure. This conformational change alters the access of a ferrocyanide/ferricyanide redox couple to the aptasensor surface. The aptasensor response is thus measured by following the increase in the electron transfer resistance of the redox couple using Faradaic electrochemical impedance spectroscopy. This method allowed a selective and sensitive label-free detection of carbendazim within a range of 10 pg/mL-10 ng/mL with a limit of detection of 8.2 pg/mL. The aptasensor did not show cross reactivity with other commonly used pesticides such as fenamiphos, isoproturon, atrazine, linuron, thiamethoxam, trifluralin, carbaryl, and methyl parathion. Moreover, the aptasensor has been applied in different spiked food matrixes showing high recovery percentages. We believe that the proposed aptasensor is a promising alternative to the currently used methods for carbendazim monitoring.

Carbendazim exposure induces developmental, biochemical and behavioural disturbance in zebrafish embryos

Carbendazim is a widely used broad spectrum benzimidazole fungicide; however, its effects to non-target aquatic organisms are poorly studied. The aim of this study was to investigate the toxic effects of carbendazim to zebrafish early life stages at several levels of biological organization, including developmental, biochemical and behavioural levels. The embryo assay was done following the OECD guideline 236 and using a concentration range between 1.1 and 1.8mg/L. Lethal and developmental endpoints such as hatching, edemas, malformations, heart beat rate, body growth and delays were assessed in a 96h exposure. A sub-teratogenic range (from 0.16 to 500μg/L) was then used to assess effects at biochemical and behavioural levels. Biochemical markers included cholinesterase (ChE), glutathione-S-transferase (GST), lactate dehydrogenase (LDH) and catalase (CAT) and were assessed at 96h. The locomotor behaviour was assessed using an automated video tracking system at 120h. Carbendazim (96h-LC50 of 1.75mg/L) elicited several developmental anomalies in zebrafish embryos with EC50 values ranging from 0.85 to 1.6mg/L. ChE, GST and LDH activities were increased at concentrations equal or above 4μg/L. The locomotor assay showed to be extremely sensitive, detecting effects in time that larvae spent swimming at concentrations of 0.16μg/L and thus, being several orders of magnitude more sensitive that developmental parameters or lethality. These are ecological relevant concentrations and highlight the potential of behavioural endpoints as early warning signs for environmental stress. Further studies should focus on understanding how the behavioural disturbances measured in these types of studies translate into fitness impairment at the adult stage.

Deleterious effects of benomyl and carbendazim on human placental trophoblast cells

Benomyl and carbendazim are benzimidazole fungicides that are used throughout the world against a wide range of fungal diseases of agricultural products. There is as yet little information regarding the toxicity of benzimidazole fungicides to human placenta. In this study, we utilized human placental trophoblast cell line HTR-8/SVneo (HTR-8) to access the toxic effects of benomyl and carbendazim. Our data showed that these two fungicides decreased cell viability and the percentages of cells in G0/G1 phase, as well as induced apoptosis of HTR-8 cells. The invasion and migration of HTR-8 cells were significantly inhibited by benomyl and carbendazim. We further found that benomyl and carbendazim altered the expression of protease systems (MMPs/TIPMs and uPA/PAI-1) and adhesion molecules (integrin α5 and β1) in HTR-8 cells. Our present study firstly shows the deleterious effects of benomyl and carbendazim on placental cells and suggests a potential risk of benzimidazole fungicides to human reproduction.

Embryonic exposure to carbendazim induces the transcription of genes related to apoptosis, immunotoxicity and endocrine disruption in zebrafish (Danio rerio)

Carbendazim is one of the most widespread environmental contaminant that can cause major concern to human and animal reproductive system. To date, very few studies have been conducted on the toxic effect of carbendazim in the non-target organism zebrafish (Danio rerio). The study presented here aimed to assess how carbendazim triggers apoptosis, immunotoxicity and endocrine disruption pathways in zebrafish during its embryo development. Our results demonstrated that the expression patterns of many key genes involved in cell apoptosis pathway (e.g. P53, Mdm2, Bbc3 and Cas8) were significantly up-regulated upon the exposure to carbendazim at the concentration of 500 μg/L, while the Bcl2 and Cas3 were down-regulated at the same concentration, interestingly, the expression level of Ogg1 decreased at all the exposure concentrations. It was also observed that the mRNA levels of CXCL-C1C, CCL1, IL-1b and TNFα which were closely related to the innate immune system, were affected in newly hatched zebrafish after exposed to different concentrations of carbendazim. Moreover, the expression of genes that are involved in the hypothalamic-pituitary-gonadal/thyroid (HPG/HPT) axis including VTG, ERα, ERβ2, Dio1, Dio2, Thraa and Thrb were all down-regulated significantly after the exposure to carbendazim. The expression levels of two cytochrome P450 aromatases CYP19a and CYP19b were increased significantly after 20 and 100 μg/L carbendazim exposure, respectively. Taken together, our results indicated that carbendazim had the potential to induce cell apoptosis and cause immune toxicity as well as endocrine disruption in zebrafish during the embryo developmental stage. The information presented here also help to elucidate the environmental risks caused by the carbendazim-induced toxicity in aquatic organisms.

Malformações congênitas em municípios de grande utilização de agrotóxicos em Mato Grosso, Brasil

Mato Grosso é o maior produtor agrícola e também o maior consumidor nacional de agrotóxicos. A exposição materna aos agrotóxicos no período periconcepcional tem sido associada com aumento no risco de malformações congênitas. O objetivo deste artigo é analisar a associação entre o uso de agrotóxicos e as malformações congênitas em municípios com maior exposição aos agrotóxicos em Mato Grosso. Estudo de caso-controle realizado com 219 nascidos vivos com malformação congênita e 862 nascidos vivos sadios. Estimou-se a média de utilização dos agrotóxicos nos trimestres anterior e posterior à data da fecundação e durante todo o período periconcepecional segundo município e mês e ano de sua utilização. Posteriormente, estas medidas foram quartilizadas e transformadas em variáveis do tipo indicadoras (dummy ), atribuindo-se um nível de exposição para cada intervalo interquartil. Foi realizada análise bivariada e regressão logística. Foram observadas associações significantes (p < 0,05) no terceiro (OR=1,66, IC95% 0,98 - 2,79) e quarto quartil (OR=1,88, IC95% 1,09 - 3,24) do período pós-fecundação e no quarto quartil (OR=2,04, IC95%1,17-3,56) durante todo o período periconcepecional. A exposição materna aos agrotóxicos foi associada à maior ocorrência de malformações congênitas.

Reproductive and possible hormonal effects of carbendazim

This study aimed to better elucidate reproductive and possible hormonal effects of the fungicide carbendazim (CBZ) through a review of published toxicological studies as well as an evaluation of this fungicide in the Hershberger and uterotrophic assays, which are designed to detect in vivo effects of the sex hormones. The literature review indicates that CBZ induces reproductive and developmental toxicity through alteration of many key events which are important to spermatogenesis. The lower dose of CBZ (100mg/kg) evaluated in the Hershberger test increased prostate weight compared to control group but did not alter the weight of other testosterone-dependent tissues. In the uterotrophic assay, CBZ did not induce an estrogenic or an antiestrogenic effect. In the literature, it has been reported that CBZ may: (1) alter the levels of various hormones (testosterone, LH, FSH, GnRH); (2) negatively influence testicular steroidogenesis; (3) have androgenic effects acting directly in the androgenic receptors and/or increasing the expression of androgen receptors. Despite the contradictory results reported by the different studies that investigated a possible endocrine mode of action of CBZ, it seems that this fungicide may influence the hypothalamus-pituitary-gonad axis in addition to being a testicular toxicant.

Isolation and characterization of carbendazim-degrading Rhodococcus erythropolis djl-11

Carbendazim (methyl 1H-benzimidazol-2-yl carbamate) is one of the most widely used fungicides in agriculture worldwide, but has been reported to have adverse effects on animal health and ecosystem function. A highly efficient carbendazim-degrading bacterium (strain dj1-11) was isolated from carbendazim-contaminated soil samples via enrichment culture. Strain dj1-11 was identified as Rhodococcus erythropolis based on morphological, physiological and biochemical characters, including sequence analysis of the 16S rRNA gene. In vitro degradation of carbendazim (1000 mg·L⁻¹) by dj1-11 in minimal salts medium (MSM) was highly efficient, and with an average degradation rate of 333.33 mg·L⁻¹·d⁻¹ at 28°C. The optimal temperature range for carbendazim degradation by dj1-11 in MSM was 25–30°C. Whilst strain dj1-11 was capable of metabolizing cabendazim as the sole source of carbon and nitrogen, degradation was significantly (P<0.05) increased by addition of 12.5 mM NH₄NO₃. Changes in MSM pH (4–9), substitution of NH₄NO₃ with organic substrates as N and C sources or replacing Mg²⁺ with Mn²⁺, Zn²⁺ or Fe²⁺ did not significantly affect carbendazim degradation by dj1-11. During the degradation process, liquid chromatography-mass spectrometry (LC-MS) detected the metabolites 2-aminobenzimidazole and 2-hydroxybenzimidazole. A putative carbendazim-hydrolyzing esterase gene was cloned from chromosomal DNA of djl-11 and showed 99% sequence homology to the mheI carbendazim-hydrolyzing esterase gene from Nocardioides sp. SG-4G.

A study of proteotoxicity and genotoxicity induced by the pesticide and fungicide on marine invertebrate (Donax faba)

Chlorpyrifos (CPF) and carbendazim (CBZ) are widely used pesticide and fungicide in India. The 96 h LC(50) values of chlorpyrifos and carbendazim for the marine invertebrate Donax faba, were 247.72 μg L(-1) and 200.82 μg L(-1) respectively. CBZ was found to accumulate less than CPF. Gill, body and foot tissues were used as target organs in biomarker and genotoxic studies. The results showed that treatment with chlorpyrifos and carbendazim increased the MDA levels, decreased the GSH levels and changed the total protein, SOD, CAT, GPx and AChE activities in all the tissues compared to those of the control (p<0.05). These results suggest that lipid peroxidation can be a possible pathway for the toxicity of chlorpyrifos and carbendazim. The antioxidant enzyme levels decrease as a result of the consumption of enzymes to neutralize free radicals generated by CPF and CBZ. Comet tail was observed in the first three doses, in all the tissues, of which the mean tail length differed significantly (p<0.01) from those of the unexposed ones. D. faba can be used as an indicator organism to assess the genotoxic risks of chemical contamination in the marine environment using comet assay. Theses biomarkers can be used further to know these agrochemicals impact on coastal marine bivalves.