Insight of neonicotinoid insecticides: Exploring exposure, mechanisms in non-target organisms, and removal technologies.

Neonicotinoid insecticides (NEOs) have garnered global attention due to their selective toxicity to insects and minimal impact on mammals. However, growing concerns about their extensive use and potential adverse effects on the ecological environment and non-target organisms necessitate further investigation. This study utilized bibliometric tools to analyze Web of Science data from 2003 to 2024, elucidating the current research landscape, identifying key research areas, and forecasting future trends related to NEOs. This paper provides an in-depth analysis of NEO exposure in non-target organisms, including risk assessments for various samples and maximum residue limits established by different countries. Additionally, it examines the impacts and mechanisms of NEOs on non-target organisms. Finally, it reviews the current methods for NEO removal and degradation. This comprehensive analysis provides valuable insights for regulating NEO usage and addressing associated exposure challenges.

Establishment of a rapid and sensitive ic-ELISA for the detection of thiacloprid residues in honey and medicinal herbs using a novel highly specific monoclonal antibody.

Thiacloprid is one of the first generation of neonicotinoid insecticide with a chloropyridine structure like imidacloprid and acetamiprid. Recent studies have revealed its environmental and non-target organism toxicity, leading to restrictions on its use in many countries and regions. Despite limitations, thiacloprid has been detected in various environmental samples, food sources, and biological specimens, posing a significant threat to human health, necessitating advanced detection methods for monitoring. In this study, a highly specific monoclonal antibody against thiacloprid via a multi-immunogen strategy was prepared and a rapid and sensitive enzyme-linked immunosorbent assay for the detection of thiacloprid residues in honey and medicinal herbs was established. The half maximal inhibitory concentration (IC50) of this method was 0.38 ng/mL, improving the sensitivity by 1.2-480.6 times compared to existing reports, and the limit of detection (IC20) was 0.097 ng/mL. The method was successfully applied to the determination of thiacloprid residues in honey and medicinal herbs (Crataegi fructus, Citri reticulatae pericarpium), achieving recovery rates ranging from 87.50 % to 116.11 %. The obtained results were verified using the LC-MS/MS method. The multi-immunogen strategy proposed in this study provides an approach for the preparation of highly sensitive and specific monoclonal antibodies, and immunoassay established based on it has good application prospects in complex matrices.

Unveiling the Contamination Patterns of Neonicotinoid Insecticides: Detection, Distribution, and Risk Assessment in Panax notoginseng across Plant Parts.

This study analyzed neonicotinoid insecticides (NEOs) and metabolite (m-NEOs) residues in 136 Panax notoginseng samples via ultra-performance liquid chromatography-tandem mass spectrometry. Imidacloprid was the most detected NEO (88.24% of samples), ranging from 1.50 to 2850 µg/kg. To the best of our knowledge, some novel NEOs were detected in P. notoginseng for the first time. NEO clustering patterns varied among plant parts, with higher contamination in leaves and flowers. Fourteen NEO/m-NEOs, including cycloxaprid and acetamiprid, showed site-specific behavior, indicating the possibility of using multiple NEOs simultaneously during planting, resulting in formation of distinct metabolites in different plant parts. Transfer rates in decoction and infusion ranged from 10.06 to 32.33%, reducing residues postprocessing. Dietary risk assessment showed low hazard quotients (HQa: 7.05 × 10-7 to 2.09 × 10-2; HQc: 3.74 × 10-7 to 2.38 × 10-3), but risk-ranking scores indicated potential hazards with imidacloprid and acetamiprid in flowers and leaves. The findings are expected to promote safety assessment and distribution research of NEOs in plants.

A colloidal gold immunochromatographic method for rapid screening of imidacloprid residues in Chinese herbal medicines.

An imidacloprid colloidal gold immunochromatographic strip was developed in this work, and systematic analytical conditions were deeply investigated. The test strips were used for rapid screening of imidacloprid residues in Chinese herbal medicines. The performance of the colloidal gold test strips was investigated by using five selected Chinese herbal medicines (malt, Coix seed, lotus seed, dried ginger and honeysuckle). As a result, the developed imidacloprid colloidal gold immunochromatographic test strips could be used for rapid screening of imidacloprid residues in 60 kinds of different herbs (including 26 kinds of root/rhizome medicines, 20 kinds of seed/fruit/pericarp medicines, 11 kinds of flower/leaf/whole herb medicines, and 3 kinds of bark/aboveground issues of herb medicines), and the cut-off value was 50 µg/kg. The development of this method can achieve the goal of on-site, rapid and low-cost screening of imidacloprid residues in different herbs, which is of great significance for the quality assurance of herbs.

27-Hydroxycholesterol/liver X receptor/apolipoprotein E mediates zearalenone-induced intestinal immunosuppression: A key target potentially linking zearalenone and cancer.

Zearalenone (ZEN) is a mycotoxin that extensively contaminates food and feed, posing a significant threat to public health. However, the mechanisms behind ZEN-induced intestinal immunotoxicity remain unclear. In this study, Sprague-Dawley (SD) rats were exposed to ZEN at a dosage of 5 mg/kg/day b.w. for a duration of 14 days. The results demonstrated that ZEN exposure led to notable pathological alterations and immunosuppression within the intestine. Furthermore, ZEN exposure caused a significant reduction in the levels of apolipoprotein E (ApoE) and liver X receptor (LXR) (P < 0.05). Conversely, it upregulated the levels of myeloid-derived suppressor cells (MDSCs) markers (P < 0.05) and decreased the presence of 27-hydroxycholesterol (27-HC) in the intestine (P < 0.05). It was observed that ApoE or LXR agonists were able to mitigate the immunosuppressive effects induced by ZEN. Additionally, a bioinformatics analysis highlighted that the downregulation of ApoE might elevate the susceptibility to colorectal, breast, and lung cancers. These findings underscore the crucial role of the 27-HC/LXR/ApoE axis disruption in ZEN-induced MDSCs proliferation and subsequent inhibition of T lymphocyte activation within the rat intestine. Notably, ApoE may emerge as a pivotal target linking ZEN exposure to cancer development.

Comprehensive analysis of neonicotinoids in Chinese commercial honey and pollen: A corresponding health risk assessment for non-targeted organisms.

Neonicotinoids are broad-spectrum and highly effective insecticides that work by affecting neural activity in insects. Neonicotinoids are systemic pesticides that are absorbed by plants, transported, and accumulated in plant tissues, including nectar and pollen. Currently, there is a lack of a comprehensive assessment of the level of neonicotinoid contamination and the associated health risks to non-targeted organisms in commercial honey and pollen produced in China. This study collected 160 batches of honey and 26 batches of pollen from different regions and plant sources in China, analyzed the residue patterns of neonicotinoid pesticides, and comprehensively evaluated the exposure risks to non-targeted organisms including bees (adults and larvae) and humans. Furthermore, this study addresses this imperative by establishing a high-throughput, rapid, and ultra-sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on broad-spectrum monoclonal antibodies to detect and quantify neonicotinoids, with validation conducted using the LC-MS/MS method. The findings indicated that 59.4 % of honey samples contained at least one of eight neonicotinoids, and the ic-ELISA rapid detection and calculation method could detect all the samples containing neonicotinoids. Additionally, the dietary risk assessment for humans and honeybees indicates that the consumption of a specific quantity of honey may not pose a health risk to human due to neonicotinoid intake. However, the Risk Quotient values for imidacloprid to adult bees and bee larvae, as well as clothianidin to bee larvae, were determined to be 2.22, 5.03, and 1.01, respectively-each exceeding 1. This highlights the elevated risk of acute toxicity posed by imidacloprid and clothianidin residues to honey bees. The study bears significant implications for the safety evaluation of non-targeted organisms in the natural food chain. Moreover, it provides scientific guidance for protecting the diversity and health of the ecosystem.

Determination of mycobiota and aflatoxin contamination in commercial bee pollen from eight provinces and one autonomous region of China.

The co-occurrence of fungi and mycotoxins in various foods has been frequently reported in many countries, posing a serious threat to the health and safety of consumers. In this study, the mycobiota in five types of commercial bee pollen samples from China were first revealed by DNA metabarcoding. Meanwhile, the content of total aflatoxins in each sample was investigated by high-performance liquid chromatography with fluorescence detection. The results demonstrated that Cladosporium (0.16 %-89.29 %) was the most prevalent genus in bee pollen, followed by Metschnikowia (0-81.12 %), unclassified genus in the phylum Ascomycota (0-81.13 %), Kodamaea (0-73.57 %), and Penicillium (0-36.13 %). Meanwhile, none of the assayed aflatoxins were determined in the 18 batches of bee pollen samples. In addition, the fungal diversity, community composition, and trophic mode varied significantly among five groups. This study provides comprehensive information for better understanding the fungal communities and aflatoxin residues in bee pollen from different floral origins in China.

[Mercury species analysis and tissue distribution in rats after continuous administration of Cinnabaris].

Cinnabaris is a traditional Chinese medicine(TCM) commonly used for sedation and tranquilization in clinics, and its safety has always been a concern. This study intends to investigate the species and tissue distribution of mercury in rats after continuous administration of Cinnabaris. In the experiment, 30 rats were randomly divided into the control group(equivalent to 0.5% carboxy-methyl cellulose sodium), low-dose Cinnabaris group(0.2 g·kg~(-1)), high-dose Cinnabaris group(2 g·kg~(-1)), pseudogerm-free control group(equivalent to 0.5% sodium carboxymethyl cellulose), and pseudogerm-free Cinnabaris group(2 g·kg~(-1)). They were orally administered for 30 consecutive days. Ultrasound-assisted acid extraction method combined with high performance liquid chromatography and inductively coupled plasma-mass spectrometry(HPLC-ICP-MS) was adopted to determine inorganic mercury [Hg(Ⅱ)], methylmercury(MeHg), and ethylmercury(EtHg) in different tissue, plasma, urine, and feces of rats. The optimal detection conditions and extraction methods were optimized, and the linearity(R~2>0.999 3), precision(RSD<7.0%), and accuracy(spike recoveries ranged from 73.05% to 109.5%) of all the mercury species were satisfied, meeting the requirements of analysis. The results of mercury species detection showed that Hg(Ⅱ) was detected in all the tissue of the five experimental groups, and the main accumulating organs were the intestinal tract, stomach, and kidney. MeHg existed at a low concentration in most tissue, and EtHg was not detected in all groups. In addition, pathological examination results showed that hepatocyte vacuolar degeneration, loose cytoplasm, light staining, and mononuclear cell infiltration were observed in the high-dose Cinnabaris group, low-dose Cinnabaris group, and pseudogerm-free Cinnabaris group, with slightly milder lesions in the low-dose Cinnabaris group. Hydrous degeneration of renal tubular epithelium could be seen in the high-dose Cinnabaris group and pseudogerm-free Cinnabaris group, but there was no significant difference between the other groups and the control group. No abnormal changes were found in the brain tissue of rats in each group. This paper studied the different mercury species and tissue distribution in normal and pseudogerm-free rats after continuous administration of Cinnabaris for 30 days and clarified its effects on the tissue structure of the liver, kidney, and brain, which provided supporting evidence for the safety evaluation of Cinnabaris.

Insights into the intestinal toxicity of foodborne mycotoxins through gut microbiota: A comprehensive review.

Mycotoxins, which are fungal metabolites, pose a significant global food safety concern by extensively contaminating food and feed, thereby seriously threatening public health and economic development. Many foodborne mycotoxins exhibit potent intestinal toxicity. However, the mechanisms underlying mycotoxin-induced intestinal toxicity are diverse and complex, and effective prevention or treatment methods for this condition have not yet been established in clinical and animal husbandry practices. In recent years, there has been increasing attention to the role of gut microbiota in the occurrence and development of intestinal diseases. Hence, this review aims to provide a comprehensive summary of the intestinal toxicity mechanisms of six common foodborne mycotoxins. It also explores novel toxicity mechanisms through the "key gut microbiota-key metabolites-key targets" axis, utilizing multiomics and precision toxicology studies with a specific focus on gut microbiota. Additionally, we examine the potential beneficial effects of probiotic supplementation on mycotoxin-induced toxicity based on initial gut microbiota-mediated mycotoxicity. This review offers a systematic description of how mycotoxins impact gut microbiota, metabolites, and genes or proteins, providing valuable insights for subsequent toxicity studies of mycotoxins. Furthermore, it lays a theoretical foundation for preventing and treating intestinal toxicity caused by mycotoxins and advancing food safety practices.

Zearalenone Exposure Disrupts STAT-ISG15 in Rat Colon: A Potential Linkage between Zearalenone and Inflammatory Bowel Disease.

Zearalenone (ZEN), a prevalent mycotoxin contaminating food and known for its intestinal toxicity, has been suggested as a potential risk factor for inflammatory bowel disease (IBD), although the exact relationship between ZEN exposure and IBD remains unclear. In this study, we established a rat model of colon toxicity induced by ZEN exposure to investigate the key targets of ZEN-induced colon toxicity and explore the underlying connection between ZEN exposure and IBD. Histological staining of the rat colon revealed significant pathological changes resulting from ZEN exposure (p < 0.01). Furthermore, the proteomic analysis demonstrated a notable upregulation of protein expression levels, specifically STAT2 (0.12 ± 0.0186), STAT6 (0.36 ± 0.0475) and ISG15 (0.43 ± 0.0226) in the rat colon (p < 0.05). Utilizing bioinformatics analysis, we combined ZEN exposure and IBD clinical sample databases to reveal that ZEN exposure may increase the risk of IBD through activation of the STAT-ISG15 pathway. This study identified novel targets for ZEN-induced intestinal toxicity, providing the basis for further study of ZEN exposure to IBD.

Zearalenone-14-glucoside specifically promotes dysplasia of Gut-Associated Lymphoid Tissue: A natural product for constructing intestinal nodular lymphatic hyperplasia model.

INTRODUCTION: Zearalenone-14-glucoside (Z14G) is a modified mycotoxin that widely contaminates food across the world. Our preliminary experiment showed that Z14G degrades to zearalenone (ZEN) in the intestine exerting toxicity. Notably, oral administration of Z14G in rats induces intestinal nodular lymphatic hyperplasia. OBJECTIVES: To investigate the mechanism of Z14G intestinal toxicity and how it differs from ZEN toxicity. We conducted a precise toxicology study on the intestine of rats exposed to Z14G and ZEN using multi-omics technology. METHODS: Rats were exposed to ZEN (5 mg/kg), Z14G-L (5 mg/kg), Z14G-H (10 mg/kg), and pseudo germ free (PGF)-Z14G-H (10 mg/kg) for 14 days. Histopathological studies were performed on intestines from each group and compared. Metagenomic, metabolomic, and proteomic analyses were performed on rat feces, serum, and intestines, respectively. RESULTS: Histopathological studies showed that Z14G exposure resulted in dysplasia of gut-associated lymphoid tissue (GALT) compared to ZEN exposure. The elimination of gut microbes in the PGF-Z14G-H group alleviated or eliminated Z14G-induced intestinal toxicity and GALT dysplasia. Metagenomic analysis revealed that Z14G exposure significantly promoted the proliferation of Bifidobacterium and Bacteroides compared to ZEN. Metabolomic analysis showed that Z14G exposure significantly reduced bile acid, while proteomic analysis found that Z14G exposure significantly reduced the expression of C-type lectins compared to ZEN. CONCLUSIONS: Our experimental results and previous research suggest that Z14G is hydrolyzed to ZEN by Bifidobacterium and Bacteroides promoting their co-trophic proliferation. This leads to inactivation of lectins by hyperproliferative Bacteroides when ZEN caused intestinal involvement, resulting in abnormal lymphocyte homing and ultimately GALT dysplasia. It is noteworthy that Z14G is a promising model drug to establish rat models of intestinal nodular lymphatic hyperplasia (INLH), which is of great significance for studying the pathogenesis, drug screening and clinical application of INLH.

Preparation of a broad-specificity antibody against zearalenone and its primary analogues and development of immunoassay of Coicis Semen and related products.

The purpose of this study was to prepare a highly sensitive and specific zearalenone (ZEN) monoclonal antibody, which was then used to develop an indirect enzyme-linked immunosorbent assay (ic-ELISA) and a colloidal gold immunochromatographic assay (GICA). These techniques were used for the detection of Coicis Semen and related products (Coicis Semen flour, Yimigao, and Yishigao). Immunogens were synthesized by oxime active ester techniques and characterized via ultraviolet spectrophotometry. Immunogens were injected subcutaneously into the abdominal cavities and backs of mice. Using the prepared antibodies, we developed ic-ELISA and GICA rapid detection methods, which were then applied for the rapid detection of ZEN and its analogues from Coicis Semen and related products. For ic-ELISA, the half maximal inhibitory concentration (IC50 ) values for ZEN, α-zearalenol (α-ZEL), ß-zearalenol (ß-ZEL), zearalanone (ZAN), α-zearalanol (α-ZAL), and ß-zearalanol (ß-ZAL) were determined to be 1.13, 1.69, 2.06, 0.66, 1.20, and 0.94 ng•mL-1 , respectively. For GICA, the cutoff values of ZEN, α-ZEL, ß-ZEL, α-ZAL, and ß-ZAL on test strips were 0.5 ng•mL-1 in phosphate buffer saline (0.01 M, pH 7.4), while ZAN was found to be 0.25 ng•mL-1 . Furthermore, the cutoff values of test strips were between 10 and 20 µg∙kg-1 in Coicis Semen and related products. The results of these two detection methods were in good agreement with results from liquid chromatography-tandem mass spectrometry. This study provides technical support for the preparation of broad-specificity monoclonal antibodies against ZEN and lays the foundation for the simultaneous detection of multiple mycotoxins from food and herbal medicines.

Broad-specificity monoclonal antibody against neonicotinoid insecticides via a multi-immunogen strategy and development of a highly sensitive GNP-based multi-residue immunoassay in ginseng and tomato.

Neonicotinoid insecticides (NNIs) are extensively used across the agricultural products and foods. In order to meet the rapid detection requirements, a novel broad-specificity monoclonal antibody against NNIs was developed for the first time using a multi-immunogen strategy. The antibody's high affinity and its ability to bind target molecules were verified by ic-ELISA. Furthermore, molecular docking was used to evaluate the pivotal forces affecting binding affinity and to determine binding sites. Subsequently, a highly sensitive gold nanoparticle-based immunochromatographic assay was established for the rapid detection of eight NNIs and the IC50 values were 0.03-1.61 ng/mL. The limits of detection for ginseng and tomato ranged from 0.76 to 30.19 µg/kg and 0.87 to 31.57 µg/kg, respectively. The spiked recovery ranged from 72.04% to 120.74%, and the coefficient of variation were less than 9.0%. This study provides a new direction for the development of multiple NNIs residue immunoassays.

Residue detection and correlation analysis of multiple neonicotinoid insecticides and their metabolites in edible herbs.

In this work, a green analytical method was established for the simultaneous extraction and detection of 20 analytes-10 neonicotinoid insecticides and their 10 major toxic metabolites in edible herbs. QuEChERS and LC-MS/MS were used to analyze the 20 analytes in five edible herbs. The residues of the 20 neonicotinoid insecticides and their metabolites in 109 herbal samples were detected, of which 90 samples were positive, and the residue of total neonicotinoid insecticides ranged from 0.26 to 139.28 µg/kg. Acetamiprid (77.06 %, ≤85.95 µg/kg), imidacloprid (67.89 %, ≤32.49 µg/kg) and their metabolites (N-desmethyl-acetamiprid (44.04 %, ≤18.42 µg/kg) and desnitro imidacloprid (48.62 %, ≤16.55 µg/kg) were most frequently detected in herbs. Significant positive correlations were found between imidacloprid/acetamiprid and their metabolites in Lycii fructus and Citri reticulatae pericarpium. Therefore, more attention may be given to the neonicotinoid insecticide residues in edible herbs in the future.

Efficient removal of phytochrome using rice straw-derived biochar: Adsorption performance, mechanisms, and practical applications.

Rice straw derived biochar was fabricated and applied as a purification agent. The adsorption kinetics, isotherms, and thermodynamics for adsorbates were determined using the biochar. Adsorption kinetics and isotherms were best fitted by the pseudo-second order and Langmuir models. Biochar could effectively remove chlorophyll in 9 different solutions. Biochar was employed as a clean-up reagent for 149 pesticides detection, which revealed that biochar had a higher phytochrome removal capacity than graphitized carbon black and 123 pesticides had satisfactory recovery values. The biochar was prepared into a sample pad by electrospinning and was then used for online sample clean-up in a test strip, and it showed high ability of removing phytochrome and improving detection sensitivity. Thus, biochar could be applied as a purification agent to remove pigmentation, making it a promising candidate not only for sample pretreatment but also in the fields of food, agriculture and environment.

Further insight into the potential toxicity of zearalenone-14-glucoside based on toxicokinetics, tissue distribution, transformation, and excretion in rats.

Bioaccumulation and biotransformation are critical factors that affect the release of easily metabolizable chemicals to cause human toxicity. The glucoside-type modified mycotoxin Zearalenone-14-Glucoside (Z14G) has attracted global attention for its high occurrence in foodstuffs and the potential threat to humans as its high rate of transformation into parent forms. Given the limited toxicokinetics information, this study assessed the absorption, distribution, biotransformation and excretion of Z14G, aiming to define the potential risk of Z14G. The toxicokinetics of Z14G were assessed after intravenous (IV) or oral administration (PO) in SD rats at doses of 10 mg/kg·b.w. In addition, comparative work with the parent mycotoxin ZEN was performed in parallel. The determination of Z14G and its metabolites (ZEN, α-zearalenol, ß-zearalenol, α-zearalanol, ß-zearalanol) proceeded with a sensitive UHPLC-MS/MS method. Our research indicated that Z14G readily disappeared from the blood, and distributed throughout the tissues via transformation into its parent form ZEN, and excreted primarily through urine. More importantly, the metabolite α-ZEL was observed in most analyzed tissue, urine and feces samples. Overall, our findings highlight the importance of biotransformation with regard to Z14G, providing critical insight for the health risk assessment of co-exposure of humans to glucoside-type modified mycotoxins.

A comprehensive review on the pretreatment and detection methods of neonicotinoid insecticides in food and environmental samples.

In recent years, the residues of neonicotinoid insecticide in food and environmental samples have attracted extensive attention. Neonicotinoids have many adverse effects on human health, such as cancer, chronic disease, birth defects, and infertility. They have substantial toxicity to some non-target organisms (especially bees). Hence, monitoring the residues of neonicotinoid insecticides in foodstuffs is necessary to guarantee public health and ecological stability. This review aims to summarize and assess the metabolic features, residue status, sample pretreatment methods (solid-phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), and some novel pretreatment methods), and detection methods (instrument detection, immunoassay, and some innovative detection methods) for neonicotinoid insecticide residues in food and environmental samples. This review provides detailed references and discussion for the analysis of neonicotinoid insecticide residues, which can effectively promote the establishment of innovative detection methods for neonicotinoid insecticide residues.

CHA-based dual signal amplification immunofluorescence biosensor for ultrasensitive detection of dimethomorph.

Dimethomorph (DMM) is a widely used high-efficiency fungicide which poses unpredictable threats to the ecological environment and public health. It is significant to establish a sensitive and robust analytical method for DMM detection. Here, we fabricated a catalytic hairpin assembly (CHA) - based immunofluorescence (IMF) biosensor by using single-strand DNA and DMM antibody co-modified gold nanoparticles (H0-Ab-Au) as anti-interference probes and DMM antigen coated 96-well plate as the immune recognition element and CHA reaction vessel. Parameters relevant to AuNP probes preparation and CHA reaction environment were optimized. After optimization, the LOD of 0.002 ng/mL was calculated, with a linear correlation in inverse proportion to DMM concentration ranging from 0.01 ng/mL to 50 ng/mL. In addition, the developed biosensor was successfully applied to a variety of complex matrix samples, with satisfactory recoveries over a range of 86.74%-118.60%. Moreover, the detection results of IMF biosensor have a good correlation with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Therefore, our proposed IMF biosensor exhibits ultra-high sensitivity and excellent specificity, as well as great potential for application to other hazards.

Zearalenone-14-Glucoside Is Hydrolyzed to Zearalenone by ß-Glucosidase in Extracellular Matrix to Exert Intracellular Toxicity in KGN Cells.

As one of the most important conjugated mycotoxins, zearalenone-14-glucoside (Z14G) has received widespread attention from researchers. Although the metabolism of Z14G in animals has been extensively studied, the intracellular toxicity and metabolic process of Z14G are not fully elucidated. In this study, the cytotoxicity of Z14G to human ovarian granulosa cells (KGN) and the metabolism of Z14G in KGN cells were determined. Furthermore, the experiments of co-administration of ß-glucosidase and pre-administered ß-glucosidase inhibitor (Conduritol B epoxide, CBE) were used to clarify the mechanism of Z14G toxicity release. Finally, the human colon adenocarcinoma cell (Caco-2) metabolism model was used to verify the toxicity release mechanism of Z14G. The results showed that the IC50 of Z14G for KGN cells was 420 µM, and the relative hydrolysis rate of Z14G on ZEN was 35% (25% extracellular and 10% intracellular in KGN cells). The results indicated that Z14G cannot enter cells, and Z14G is only hydrolyzed extracellularly to its prototype zearalenone (ZEN) by ß-glucosidase which can exert toxic effects in cells. In conclusion, this study demonstrated the cytotoxicity of Z14G and clarified the toxicity release mechanism of Z14G. Different from previous findings, our results showed that Z14G cannot enter cells but exerts cytotoxicity through deglycosylation. This study promotes the formulation of a risk assessment and legislation limit for ZEN and its metabolites.

Rapid screening of imidacloprid residue in grains and medicinal herbs: A newly designed hapten and monoclonal antibody.

Three different imidacloprid hapten structures were designed to conjugate with proteins (bovine serum albumin, BSA; ovalbumin, OVA; keyhole limpet hemocyanin, KLH) for screening the optimal immunogen and coating antigen. Among these, an unreported antigen (hapten 6-KLH) was selected as the optimal immunogen and coating antigen. In addition, an imidacloprid-specific and high titer monoclonal antibody (IMIB7C3) was obtained by using the above-selected immunogen. A sensitive ic-ELISA (indirect competitive enzyme-linked immunosorbent assay) with a half-maximal inhibitory concentration (IC50) of 1.3 ng mL-1 was established by using the IMIB7C3 antibody (only 1.2 ng per well) to detect the residues of imidacloprid in grains (wheat and maize) and different herbs (Notoginseng radix et rhizoma, Dioscoreae rhizoma, Lonicerae japonicae flos, Astragali radix, Jujubae fructus). The detection results of real samples by the developed immunoassay were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), which proved the accuracy and reliability of the established ic-ELISA. These results indicate that the proposed ic-ELISA method is suitable for rapid and high-throughput detection of imidacloprid residues in agricultural products and medicinal herbs. Furthermore, a quantitative risk assessment was conducted for Lonicerae japonicae flos based on the detection results, which indicates an acceptable risk to human health after the intake of Lonicerae japonicae flos polluted by imidacloprid.