Pesticide residues in traditional and industrial honey marketed in Morocco and potential health risk.

This study evaluated the presence of the three pesticides methomyl (MET), carbendazim (CBZ) and chlorpyrifos-ethyl (CPE), as well as the degradation product of CPE (3,5,6-trichloro-2-pyridinol; TCP), in 44 honey samples from all 12 regions of Morocco. With a validated HPLC-UV method occurrence frequencies of 63.6% for MET, 54.5% for CBZ, 95.1% for CPE and 34.1% for TCP were obtained, even at concentrations higher than the maximum residue limits for MET, CPE and TCP. Based on the predominant pesticide, principal component analysis separated sampling regions into three groups. Risk assessment indicated that ingestion of these pesticides, alone or in combination, in honey did not pose a risk to consumers (HQ and HI < 1).

Assessment of methomyl-induced adrenal gland disruption in rat fetuses and pups: Potential protective effects of propolis supplementation.

The present study aimed to unravel the possible adverse effects of methomyl on the developing adrenal gland of rat fetuses and pups. Additionally, this study explored the potential improving effects of propolis against these possible hazards induced by methomyl exposure. To achieve that, pregnant rats were divided into four groups: control group, received 1 mL distilled water, propolis group, received 1 mL propolis at a dose of 300 mg/kg, methomyl group, received 1 mL methomyl at a dose of 2 mg/kg, and combined group, received 1 mL methomyl followed by 1 mL propolis, an hour later at the same previous doses. The results revealed that methomyl exposure, during pregnancy and lactation, induced many histological and ultrastructural changes, caused DNA damage and downregulated the expression of steroidogenic acute regulatory (StAR) and CYP11B2 genes in the adrenal glands of both rat fetuses and pups. Interestingly, propolis supplementation demonstrated a remarkable ability to mitigate these deleterious effects and restored the histology and ultrastructure architecture of the adrenal glands of both fetuses and pups, as well as decreased DNA damage and upregulated the expression of StAR and CYP11B2 genes in the adrenal gland of rat fetuses and pups. In conclusion, our study highlights the potential hazardous impact of methomyl exposure during pregnancy and lactation on the development of the adrenal gland in rat fetuses and pups, moreover, the study presents a new approach to alleviate these effects through propolis administration which could be used as a dietary supplement to mitigate the adverse effects of methomyl exposure.

Effect of environmental level of methomyl on hatching, morphology, immunity and development related genes expression in zebrafish (Danio rerio) embryo.

The extensive use of carbamate pesticides has led to a range of environmental and health problems, such as surface and groundwater contamination, and endocrine disorders in organisms. In this study, we focused on examining the effects of toxic exposure to the carbamate pesticide methomyl on the hatching, morphology, immunity and developmental gene expression levels in zebrafish embryos. Four concentrations of methomyl (0, 2, 20, and 200 µg/L) were administered to zebrafish embryos for a period of 96 h. The study found that exposure to methomyl accelerated the hatching process of zebrafish embryos, with the strongest effect recorded at the concentration of 2 µg/L. Methomyl exposure also trigged significantly reductions in heart rate and caused abnormalities in larvae morphology, and it also stimulated the synthesis and release of several inflammatory factors such as IL-1ß, IL-6, TNF-α and INF-α, lowered the IgM contents, ultimately enhancing inflammatory response and interfering with immune function. All of these showed the significant effects on exposure time, concentration and their interaction (Time × Concentration). Furthermore, the body length of zebrafish exposed to methomyl for 96 h was significantly shorter, particularly at higher concentrations (200 µg/L). Methomyl also affected the expression levels of genes associated with development (down-regulated igf1, bmp2b, vasa, dazl and piwi genes), demonstrating strong developmental toxicity and disruption of the endocrine system, with the most observed at the concentration of 200 µg/L and 96 h exposure to methomyl. The results of this study provide valuable reference information on the potential damage of methomyl concentrations in the environment on fish embryo development, while also supplementing present research on the immunotoxicity of methomyl.

Nexus Advances Using Marine Biopolymeric Gel Material as a Photocatalyst for the Oxidation of Agricultural Wastewater Containing Insecticides.

The attention of the research community is focused not only on waste elimination, but also on waste valorization. The natural marine biopolymer gel substance chitosan, which can be derived from the waste substances of marine life, is a polymer-matrix-based nanocomposite. Chitosan attracts special attention due to its potential applications, especially in wastewater treatment. In this regard, magnetite-incorporated chitosan powders of nanometer scale were synthesized by a simple co-precipitation method to attain the dual functions of chitosan gel and magnetite. The synthesized magnetite-incorporated chitosan nanopowders were verified using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, a vibrating-sample magnetometer (VSM), a scanning electron microscope (SEM), and transmission electron microscopy (TEM) images, which showed that the synthesized magnetite-incorporated chitosan was nanosized. The superior application of such a material to offset the deterioration of the environment caused by insecticides is attained through a photocatalytic reaction. The experimental results verified the function of magnetite-incorporated chitosan, since it increased the composite-specific surface area, resulting in high methomyl molecule oxidation. Methomyl oxidation reached almost complete insecticide removal (99%) within only one hour of irradiance time. The optimal operational conditions were investigated, and the maximal removal rate occurred when the aqueous solution was at an acidic pH of 3.0. The reaction was affected by differing hydrogen peroxide and catalyst doses, and the optimized reagent was recorded at the levels of 40 and 400 mg/L of catalyst and hydrogen peroxide, respectively. Also, catalyst reusability was attained, confirming its sustainability, since it could be used for successive cycles. From the current investigation, it is proposed that magnetite-chitosan nanoparticles could serve as a promising photocatalyst for the elimination of insecticides from wastewater in a green manner.

Features of fatal pesticide ingestion in South Australia.

Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional human fatalities. A rapid increase in pesticide suicides was observed during 'The Green Revolution' after pesticides were introduced into low- and middle-income rural households without appropriate guidelines for safe use and storage. While national pesticide bans have contributed to a significant decrease in pesticide-related suicides, such cases still comprise a large proportion of all suicides around the world. The aim of the current study was to provide a profile of pesticide suicides in a high-income country as a point of comparison against studies from low- and middle-income countries. Statistical analyses were performed using R (version 4.2.3). Over the 20-year study period, there were a low, yet consistent number of pesticide suicides which were most common among males over the age of 40. Paraquat and methomyl pesticides collectively contributed to almost half (48.8%) of all fatalities. Consistent with the literature, such cases often occurred with little premeditation in response to an acute emotional crisis. While interpretation of autopsy findings was mostly limited, there were some pesticides that demonstrated findings consisted with previously reported characteristics (e.g., gastroesophageal erosions with paraquat). Given the high proportion of cases where paraquat and methomyl pesticides were implicated, it may be appropriate to review the availability and accessibility of such compounds to reduce the occurrence of pesticide suicides in South Australia and potentially the wider Australian population.

Toxicity of methomyl insecticides to testicular cells and protective effect of folic acid.

Methomyl is a carbamate insecticide with confirmed testicular toxicity. This study intended to observe the effect of methomyl on testicular cells and the protective effect of folic acid through in vitro experiments. The GC-1 spermatogonia, TM4 Sertoli cells, and TM3 Leydig cells were treated with methomyl (0, 250, 500, and 1000 µM) with or without folic acid (0, 10, 100, and 1000 nM) for 24 h. It was found that methomyl increased cytotoxicity to testicular cells in a dose-dependent manner. In spermatogonia, methomyl significantly inhibited the expression of proliferation genes Ki67 and PCNA at 1000 µM, and increased the expression of apoptosis genes Caspase3 and Bax at each dose. In Sertoli cells, methomyl dose-dependently inhibited the expression of blood-testis barrier function genes TJP1, Cx43, and N-cadherin, but did not affect Occludin and E-cadherin. In Leydig cells, methomyl inhibited the expression of steroid synthase P450scc, StAR, Hsd3b1 and down-regulated the level of testosterone, but did not affect Cyp17a1 and Hsd17b1. Further, folic acid could basically reduce the damage caused by methomyl. This study provided new insights into the toxicity of methomyl and the protective effect of folic acid.

The feasibility of using micro concentrated multiple reflection ATR FTIR accessory in pesticide analysis.

Micro-Multiple Reflection ATR (CMRATR) spectroscopy is a technique, using specialized equipment, which allows the enhanced sensitivity of multiple reflection ATR analysis of small amounts of liquids in a confined area hitherto reserved for single reflection equipment. This technique has demonstrated a high level of sensitivity, especially when used in conjunction with an evaporative technique. In this work, the technique will be used with a miniature CMRATR accessory, which has the added advantage of compatibility with the smallest current FTIR spectrometers, to analyze pesticides. The results presented here indicate that the CMRATR/evaporative technique can serve as both qualitative and quantitative support to the existing standard methodology.

Human Poisoning with Methomyl and Cypermethrin Pesticide Mixture.

There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients intoxicated with methomyl, cypermethrin, or their pesticide mixture were treated at Chang Gung Memorial Hospital. The patients were categorized into three groups based on the type of pesticide, as methomyl (n = 10), cypermethrin (n = 31), or methomyl and cypermethrin (n = 22). Demographic, clinical, laboratory, and mortality data were obtained for analysis. The patients were aged 54.9 ± 18.9 years. Following ingestion, the patients experienced a wide range of clinical symptoms, including aspiration pneumonia (50.8%), acute respiratory failure (41.3%), acute kidney injury (33.3%), multiple organ failure (19.0%), emesis (19.0%), acute hepatitis (12.7%), diarrhea (7.9%), seizures (4.8%), lacrimation (4.8%), etc. After analysis, it was found that patients with methomyl and cypermethrin poisoning suffered higher incidences of acute respiratory failure (p < 0.001), aspiration pneumonia (p = 0.004), acute kidney injury (p = 0.011), and multiple organ failure (p < 0.001) than the other groups. Laboratory analyses revealed that patients with methomyl and cypermethrin poisoning had a higher creatinine level (p = 0.011), white blood cell count (p < 0.001), and neutrophil count (p = 0.019) than the other groups. A total of seven (11.1%) patients died. The average duration of hospitalization was 9.8 ± 10.0 days. In a multivariate logistic regression model, it was revealed that methomyl pesticide (p = 0.045) or methomyl and cypermethrin pesticide mixture (p = 0.013) were significant risk factors for acute respiratory failure. Nevertheless, no mortality risk factor could be identified. Therefore, the analytical results suggest that methomyl pesticide is the major contributor to the toxicity of methomyl and cypermethrin pesticide mixture poisoning. More research is needed.

High-efficiency degradation of methomyl by the novel bacterial consortium MF0904: Performance, structural analysis, metabolic pathways, and environmental bioremediation.

Methomyl is a widely used carbamate pesticide, which has adverse biological effects and poses a serious threat to ecological environments and human health. Several bacterial isolates have been investigated for removing methomyl from environment. However, low degradation efficiency and poor environmental adaptability of pure cultures severely limits their potential for bioremediation of methomyl-contaminated environment. Here, a novel microbial consortium, MF0904, can degrade 100% of 25 mg/L methomyl within 96 h, an efficiency higher than that of any other consortia or pure microbes reported so far. The sequencing analysis revealed that Pandoraea, Stenotrophomonas and Paracoccus were the predominant members of MF0904 in the degradation process, suggesting that these genera might play pivotal roles in methomyl biodegradation. Moreover, five new metabolites including ethanamine, 1,2-dimethyldisulfane, 2-hydroxyacetonitrile, N-hydroxyacetamide, and acetaldehyde were identified using gas chromatography-mass spectrometry, indicating that methomyl could be degraded firstly by hydrolysis of its ester bond, followed by cleavage of the C-S ring and subsequent metabolism. Furthermore, MF0904 can successfully colonize and substantially enhance methomyl degradation in different soils, with complete degradation of 25 mg/L methomyl within 96 and 72 h in sterile and nonsterile soil, respectively. Together, the discovery of microbial consortium MF0904 fills a gap in the synergistic metabolism of methomyl at the community level and provides a potential candidate for bioremediation applications.

A microwave-induced plasma jet for efficient degradation of methomyl in aqueous solution.

As a typical carbamate pesticide, methomyl was once widely used in agriculture for its excellent broad-spectrum insecticidal effect. However, due to its high toxicity, long half-life, and difficult degradation properties, it poses a serious challenge to water environment pollution. In this study, an electrode-free discharge microwave-induced plasma technology was used to rapidly and efficiently degrade methomyl in aqueous solution. In this experiment, the statistical design of experiments (DOE) was adopted to optimize the plasma degradation parameters. Under the optimized parameters (P = 140 W, D = 0 mm, R = 0.5 L/min), 78.4% removal of 50 mg/L of methomyl was achieved after 8 min. The optical emission spectrometry and free radical detection experiments showed that the active substances generated by the collision reaction between plasma and water molecules occurring at the gas-liquid interface were the key factors to exert the degradation effect. The degradation rate of methomyl decreased by 73.2% after the addition of tert-butanol (OH burster), while it decreased by only about 12.0% after the addition of peroxidase. These implied that ∙OH was largely responsible for methomyl degradation. In addition, based on the detected intermediates, possible degradation mechanisms and pathways were analyzed.

First meta-analysis study of cholinesterase inhibition in experimental animals by organophosphate or carbamate insecticides under the influence of diphenhydramine.

Background and Aim: Diphenhydramine is an H1-antihistamine that counteracts the toxic effects of organophosphate and carbamate insecticides that inhibit cholinesterase (ChE) activity. This meta-analysis aimed to investigate the effects of diphenhydramine on ChE inhibition induced by these insecticides in the plasma, erythrocytes, or whole brain of experimental animals. Materials and Methods: A data search was performed on erythrocyte, plasma, and brain ChE inhibition caused by organophosphate and carbamate insecticides in experimental animals (mice, rats, and chicks) treated with the antihistamine diphenhydramine in accordance with preferred reporting items for systematic reviews and meta-analysis, which was done by the two-group random-effects model meta-analysis. The meta-analysis included 18 records extracted from six studies that, appeared from 1996 to 2022. Results: Using the random-effects model, a two-group meta-analysis revealed that the combined effect size (ChE inhibition) was significantly more favorable in the control group than in the diphenhydramine intervention, as shown by a forest plot. The combined effect size (standardized mean difference) was 0.67, with a standard error of 0.3, a lower limit of 0.04, and an upper limit of 1.29 (p = 0.025). The heterogeneity was moderate, as I2 of the combined effect size was 74%, with a significant Cochrane Q-test result (Q = 65, p < 0.0001). Subgroup analysis indicated that, with brain ChE inhibition, the heterogeneity (I2) became 5%, which was lower than ChE inhibition in plasma (84%) and erythrocytes (78%). No publication bias was identified using the funnel plot and Egger's test. Conclusion: This meta-analysis suggests that, in addition to its documented antidotal action against ChE-inhibiting insecticides, diphenhydramine can also reduce the extent of ChE inhibition, especially in the brain, which is the main site of toxicity of these insecticides. There is a need for additional studies to assess such enzyme inhibition in different parts of the brain.

Novel ß-Carotene and Astaxanthin-Producing Marine Planococcus sp.: Insights into Carotenogenesis Regulation and Genetic Aspects.

Astaxanthin and ß-carotene are the most prominent carotenoids extensively used in pharmaceutics. Here, we present a halotolerant bacterium from Lake Wadi El-Natrun capable of producing astaxanthin and ß-carotene analyzed by HPLC, ESI-MS, and infrared spectroscopy. The phenotypic and phylogenetic analyses classified the isolate as a novel strain of the genus Planococcus, for which the name Planococcus sp. Eg-Natrun is proposed. Carotenoid biosynthesis can exceptionally occur in a light-inducible or constitutive manner. The maximum carotenoid yields were 610 ± 13 µg/g (~ 38% ß-carotene and ~ 21% astaxanthin) in a minimal medium with acetate and 1024 ± 53 µg/g dry cells in a rich marine medium. The carotenogenesis incentives (e.g., acetate) and disincentives (e.g., methomyl) were discussed. Moreover, we successfully isolated the CrtE gene, one of the astaxanthin biosynthesis genes, from the unknown genome using a consensus-based degenerate PCR approach. To our knowledge, this is the first report elucidating astaxanthin and ß-carotene in the genus Planococcus.

Immunochromatographic assay for the analysis of methomyl in cabbage and tomato.

In this study, a hapten of methomyl was designed and used to produce monoclonal antibodies (mAbs) against methomyl. Based on these mAbs, we developed an enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay (ICA) strip for the determination of methomyl residues. Results from the ELISA showed that mAb 1D10 exhibited higher affinity with an affinity constant of 2.76 × 1010 L/mol and higher sensitivity with a limit of detection (LOD) was 8.12 ng/mL. After optimizing the ICA, a visible limit of detection (vLOD) was found to be 100 ng/g and the cut-off value was 500 ng/g for methomyl in cabbage and tomato. The calculated LODs were 3.2 ng/g and 5.4 ng/g in cabbage and tomato, respectively. Moreover, results from the ICA were consistent with those of the ELISA in our recovery assay using spiked samples. Hence, the ICA method has a bright future and great prospects for the detection of methomyl in food samples.

[A case of intramuscular injection of methomyl poisoning].

Methomyl is a carbamate insecticide widely used in pesticides. Most of the poisoning methods are through digestive tract, respiratory tract and skin contact. At present, there is no report of poisoning caused by intramuscular injection. A case of poisoning caused by intramuscular injection of methomyl was analyzed retrospectively. About 4 minutes later, cholinergic crisis and central inhibition occurred. Venovenous-Extracorporeal Membrane Oxygenation (VV-ECMO) and atropine were given quickly. Finally, the patient was successfully rescued and had a good prognosis. After intramuscular injection of methomyl, cholinergic crisis can occur rapidly, and the onset rate is significantly faster than that of digestive tract, respiratory tract and skin contact.

Postmortem sampling time effect on toxicity biomarkers in rats exposed to an acute lethal methomyl dose.

Regulations often are imposing long postmortem times before autopsy leading to certain toxicity-unrelated changes in biomarkers, which in turn may affect the reliability of toxicity evaluation during forensic investigations. Since methomyl pesticide shows significant toxicity and is frequently encountered in poisoning cases, the current study evaluated different parameters in methomyl intoxicated rats at three different postmortem intervals (Hour 0, Hour 3 and Hour 6). Eighteen adult Sprague Dawley rats were poisoned with methomyl to simulate actual methomyl poisoning cases. The time of death was assigned as Hour 0. The animals were divided into 3 groups (n = 6) to collect blood and tissue samples at the selected time points. Body weight, relative organ weight, protein concentration, methomyl concentration and acetylcholinesterase activity (AChE) were assessed in blood and different tissues (liver, spleen, kidney, brain, eye, and bone marrow) to evaluate the effect of postmortem sampling time. Outcomes revealed significant decreases in methomyl concentration in blood and bone marrow with advanced sampling time (P < 0.001). Similarly, there were significant reductions in AChE activity in the kidney (P < 0.01), while the enzyme activity significantly increased in brain samples (P < 0.05). Findings illustrated the importance of sampling time in toxicity studies because it could alter experimental results and impact consequent interpretations, as well as it may alter postmortem biomarkers in related forensic cases.

Exposure of Pisum sativum L. Seeds to Methomyl and Imidacloprid Cause Genotoxic Effects in Pollen-Mother Cells

Pesticides are commonly used in modern agricultural systems to protect the plants from pests. Even though they potentially increase the crop yield, they have undesirable toxic effects on the consumers of plant products and nontarget host plants. However, there are limited studies to demonstrate the cytological changes induced by pesticides on plant cells. In the present study, we assess the cytological changes induced by two most commonly used insecticides, methomyl (ME) and imidacloprid (IM), using Pisum sativum L. as model plant system. P. sativum seeds were exposed to various concentrations of ME and IM (0.1, 0.2, 0.3, 0.4 and 0.5%) for 1, 3, and 6 h, and their effects on seed germination (SG), radicle length (RL), mitotic index (MI), chromosomal aberrations frequency (CAF), and micronucleus frequency (MNF) were studied. The results indicate that these insecticides decrease MI in root-tip cells, and increase in the MNF in pollen-mother cells in a dose-dependent manner. Additionally, insecticide-treated groups showed a dose- and time-dependent increase in the percentage of aberrant meiotic cells. Clumped nuclei (CNU), stickiness (STC), bridges (BRs), laggards (LGs), secondary association (SA), and precocious separation (PS) were among the frequently observed anomalies. The findings of this study indicate that commonly used insecticides ME and IM have substantial genotoxic effects on the root-tip and pollen-mother cells of P. sativum L.

Effect of methomyl on water quality, growth performance and antioxidant system in liver of GIFT (Oreochromis niloticus) in the presence of peppermint (Mentha haplocalyx Briq.) as a floating bed.

This study was conducted to investigate the effect of methomyl (MET) on water quality, growth and antioxidant system of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) in the presence of peppermint as a floating bed. The concentration of NH3-N, NO2--N, NO3--N and TP in T3 (with 200 g wet peppermint) was significantly lower (P < 0.05) than that in T2 (100 g), T1 (50 g) and control, and the nutrient removal rates were 61.90%, 31.59%, 59.86% and 45.92% in 20 days, respectively. Juveniles GIFT (5.1 ± 0.2 g) were exposed to sub-lethal concentrations of 0.2, 2.0, 20 and 200 µg/L of MET for 45 days. After 6 weeks of a feeding trial, percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR) were significantly decreased in 0.2, 2.0, 20 µg/L MET groups respectively and increased in the 200 µg/L MET group. Compared with the control, no significant changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were detected in the 0.2 µg/L group. The significant increase in activities of SOD, CAT and GPx was accompanied by a diminution in reduced glutathione (GSH) levels resulting with tilapia exposed to 2.0, 20, or 200 µg/L for 45 days. The highest rates observed in SOD, CAT, GPx were 157.63%, 164.05% and 167.46% of the control respectively, and the lowest inhibition rate in GSH was 66.42% of the control. Peppermint as a floating bed can alleviate the adverse effects of MET, such as growth retardation and oxidative stress.

Methomyl, imbraclaobrid and clethodim induced cytomixis and syncytes behaviors in PMCs of Pisum sativum L: Causes and outcomes.

Cytomixis is a common phenomenon observed in meiotic cells such as anther which is influenced by various factors. Use of pesticides is a common practice in agriculture. However, it is not known whether pesticides can induce cytomixis in plant cells and induce genetic variation. To understand this, the present study was planned to assess the cytomixis and syncytes behaviors in PMCs of Pisum sativum L. Seeds of P. sativum (Family: Fabaceae) were treated with different concentrations of commonly used pesticides methomyl (ME), imbraclaobrid (IM) and clethodim (CL). Seeds were treated with various concentrations (0.1, 0.2, 0.3, 0.4 and 0.5% of ME, IM and CL prepared in water) for 1 and 3 h. Effect of pesticides on pollen fertility, frequency of cytomixis, and kind of cytomixis cells was assessed. In the cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), and various stages of meiosis (PI, MI, AI and TI) with cytomixis cells were observed. In addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) was assessed. During the microsporogenesis in P. sativum, the occurrence of cytomixis and syncytes at various stages of meiosis I were seen. The formation of cytoplasmic channels and direct fusing of pollen mother cells (PMCs) were both seen to cause cytomixis, with the former being more common than the latter. The percentage of PMCs with cytomixis and syncytes cells increased with increase in the concentration of pesticides. The result of the present investigation indicates that commonly used pesticides ME, IM, and CL have a significant effect on pollen fertility, frequency of cytomixis, and kind of cytomixis cells, the cytomictic channel (CC) and direct fusion (DF), in addition, frequency of syncytes cell and their various stages of meiosis I (PI, MI, AI and TI) in pollen mother cells (PMCs) on P. sativum.

Appraisal of sub-chronic exposure to lambada-cyhalothrin and/or methomyl on the behavior and hepato-renal functioning in Oreochromis niloticus: Supportive role of taurine-supplemented feed.

The existing study was designed to inspect the toxicological consequences of two pesticides; lambda-cyhalothrin (LCT) and methomyl (MTM) and their combination on Nile tilapia (Oreochromis niloticus) behaviors, oxidative stress, hepato-renal function indices and microarchitectural alterations. In addition, the efficiency of taurine (TUR) to rescue their toxicity was also considered. Juvenile O. niloticus were assigned into eight groups. The control and TUR groups were fed on a basal diet and TUR-enriched (10 g kg1) diet, respectively. The other groups were fed on a basal diet, and exposed to LCT (0.079 µg L-1), MTM (20.39 µg L-1 and (LCT + MTM). The last three groups were (LCT + TUR), (MTM + TUR), and (LCT + MTM + TUR) and fed on a TUR-enriched diet during exposure to LCT and/or MTM for 60 days. The exposure to LCT and/or MTM resulted in several behavioral alterations and stress via enhanced cortisol and nor-epinephrine levels. A significant elevation of serum 8-hydroxy-2- deoxyguanosine, aspartate and alanine aminotransferases, lactate dehydrogenase, Alkaline phosphatase, urea, creatinine was also observed in these groups. Furthermore, reduced antioxidant enzymes activities, including (catlase, glutathione peroxidase, and superoxide dismutase) with marked histopathological lesions in both liver and kidney tissues were detected. The up-regulated Bax and down-regulated Bcl-2 proteins were expressed in the liver and kidney tissues of LCT and/or MTM -exposed groups. Interestingly, all the observed alterations in behaviors, biochemical indices, and histo-architecture of renal and hepatic tissues were mitigated by TUR supplementation. The findings suggest that feeding O. niloticus dietary TUR may help to reduce the negative effects of LCT and/or MTM, and can also support kidney and liver health in O. niloticus, making it a promising aquaculture feed supplement.

Neurotoxicity of singular and combined exposure of Oreochromis niloticus to methomyl and copper sulphate at environmentally relevant levels: Assessment of neurotransmitters, neural stress, oxidative injury and histopathological changes.

Aquatic organisms are concomitantly exposed to multiple noxious chemicals that can be discharged into water bodies. We aimed to investigate the single and simultaneous sub-acute exposure to copper and methomyl on juvenile Oreochromis niloticus. Compared to the controls, the outcomes revealed that brain of methomyl-exposed fish displayed significant declines in the activities of SOD, CAT, and GST in addition to higher MDA and lower GSH levels. Methomyl induced notable declines in levels of GABA and acetylcholine esterase in brain and muscle of exposed fish. Noteworthy downregulated gene expression levels of TNF-α, HSP-70 together with upregulated c-fos were evident in brain of fish expose to either of tested compounds. Marked apoptotic changes were observed in fish brain exposed to copper and methomyl indicated by augmented immune expression of caspase-3. Conclusively, the results indicated the possible interaction between both compounds with subsequent toxic effects that differ from their single exposure.