Comparative assessment on the probable mechanisms underlying the hepatorenal toxicity of commercial imidacloprid and hexaflumuron formulations in rats

Imidacloprid-induced lung injury in mice: Activation of the PI3K/AKT/NF-κB signaling pathway via TLR4 receptor engagement

Significant impairment of pulmonary function has been demonstrated through long-term exposure to neonicotinoid insecticides, such as imidacloprid (IMI). However, the underlying mechanisms of lung injury induced by IMI remain unclear. In this study, a mouse model of IMI-induced pulmonary injury was established, and the toxicity and lung damage were assessed through mouse body weight, organ index, hematological parameters, and histopathological analysis of lung tissues. Furthermore, metabolomics and transcriptomics techniques were employed to explore the mechanistic aspects. Results from the toxicity assessments indicated that mouse body weight was significantly reduced by IMI, organ index was disturbed, and hematological parameters were disrupted, resulting in pulmonary injury. The mechanistic experimental results indicate that the differences in metabolites and gene expression in mouse lungs could be altered by IMI. Validation of the results through combined analysis of metabolomics and transcriptomics revealed that the mechanism by which IMI induces lung injury in mice might be associated with the activation of the TLR4 receptor, thereby activating the PI3K/AKT/NF-κB signaling pathway to induce inflammation in mouse lungs. This study provided valuable insights into the mechanisms underlying IMI-induced pulmonary damage, potentially contributing to the development of safer pest control strategies. The knowledge gained served as a robust scientific foundation for the prevention and treatment of IMI-related pulmonary injuries.

Role of IRE1α/XBP1/CHOP/NLRP3 Signalling Pathway in Neonicotinoid Imidacloprid-Induced Pancreatic Dysfunction in Rats and Antagonism of Lycopene: In Vivo and Molecular Docking Simulation Approaches

Imidacloprid (IMI) is a commonly used new-generation pesticide that has numerous harmful effects on non-targeted organisms, including animals. This study analysed both the adverse effects on the pancreas following oral consumption of imidacloprid neonicotinoids (45 mg/kg daily for 30 days) and the potential protective effects of lycopene (LYC) administration (10 mg/kg/day for 30 days) with IMI exposure in male Sprague-Dawley rats. The apoptotic, pyroptotic, inflammatory, oxidative stress, and endoplasmic reticulum stress biomarkers were evaluated, along with the histopathological alterations. Upon IMI administration, noticeable changes were observed in pancreatic histopathology. Additionally, elevated oxidative/endoplasmic reticulum-associated stress biomarkers, inflammatory, pyroptotic, and apoptotic biomarkers were also observed following IMI administration. LYC effectively reversed these alterations by reducing oxidative stress markers (e.g., MDA) and enhancing antioxidant enzymes (SOD, CAT). It downregulated ER stress markers (IRE1α, XBP1, CHOP), decreased pro-inflammatory cytokines (TNF-α, IL-1β), and suppressed pyroptotic (NLRP3, caspase-1) along with apoptotic markers (Bax, cleaved caspase-3). It also improved the histopathological and ultrastructure alterations brought on by IMI toxicity.

Associations between neonicotinoids and liver function measures in US adults: National Health and Nutrition Examination Survey 2015-2016

Background

Toxicological studies indicate that neonicotinoids may be associated with disruptions in liver function due to an increase in oxidative stress. There are scant epidemiological studies investigating the chronic hepatotoxic effects of neonicotinoids.

Objective

To examine the association between detectable concentrations of parent neonicotinoids and neonicotinoid metabolites with liver function markers among US adults, and whether sex modifies this association.

Methods

National Health and Nutrition Examination Survey 2015-2016 data were used to estimate associations between detectable neonicotinoids and serum alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transaminase (GGT), albumin, total bilirubin, total protein, and Hepatic Steatosis Index (HSI) using multiple linear regression.

Results

Detectable levels of N-desmethyl-acetamiprid were associated with a decrease in GGT (β = -3.54 unit/l; 95% confidence interval [CI] = -6.48, -0.61) and detectable levels of 5-hydroxy-imidacloprid were associated with a decrease in HSI (β = -1.11; 95% CI = -2.14, -0.07). Sex modified the association between any parent neonicotinoid and ALP (Pint = 0.064) and the association between clothianidin and ALP (Pint = 0.019), with a pattern of positive associations in males and inverse associations in females, though stratified associations did not reach statistical significance. Sex also modified the association between 5-hydroxy-imidacloprid and total protein (Pint = 0.062), with a significant positive association in females (β = 0.14 g/dl; 95% CI = 0.03, 0.25) and a null association in males.

Conclusion

Detectable concentrations of neonicotinoid metabolites were inversely associated with GGT and HSI in US adults. Evidence suggests neonicotinoids may influence liver function differently depending on sex. Future research is recommended to replicate the findings as the study was limited in its cross-sectional nature and inability to examine continuous neonicotinoid concentrations with liver function.

Non-acute exposure of neonicotinoids, health risk assessment, and evidence integration: a systematic review

Neonicotinoid pesticides are utilized against an extensive range of insects. A growing body of evidence supports that these neuro-active insecticides are classified as toxicants in invertebrates. However, there is limited published data regarding their toxicity in vertebrates and mammals. the current systematic review is focused on the up-to-date knowledge available for several neonicotinoid pesticides and their non-acute toxicity on rodents and human physiology. Oral lethal dose 50 (LD50) of seven neonicotinoids (i.e. imidacloprid, acetamiprid, clothianidin, dinotefuran, thiamethoxam, thiacloprid, and nitenpyram) was initially identified. Subsequently, a screening of the literature was conducted to collect information about non-acute exposure to these insecticides. 99 studies were included and assessed for their risk of bias and level of evidence according to the Office of Health and Translation (OHAT) framework. All the 99 included papers indicate evidence of reproductive toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, immunotoxicity, and oxidative stress induction with a high level of evidence in the health effect of rodents and a moderate level of evidence for human health. The most studied type of these insecticides among 99 papers was imidacloprid (55 papers), followed by acetamiprid (22 papers), clothianidin (21 papers), and thiacloprid (11 papers). While 10 of 99 papers assessed the relationship between clothianidin, thiamethoxam, dinotefuran, and nitenpyram, showing evidence of liver injury, dysfunctions of oxidative stress markers in the reproductive system, and intestinal toxicity. This systematic review provides a comprehensive overview of the potential risks caused by neonicotinoid insecticides to humans and rodents with salient health effects. However, further research is needed to better emphasize and understand the patho-physiological mechanisms of these insecticides, taking into account various factors that can influence their toxicity.

Molecular mechanism of kidney damage caused by abamectin in carp: Oxidative stress, inflammation, mitochondrial damage, and apoptosis

Indiscriminate use of pesticides not only leads to environmental pollution problems, but also causes poisoning of non-target organisms. Abamectin (ABM), a widely used insecticide worldwide, is of wide concern due to its persistence in the environment and its high toxicity to fish. The kidney, as a key organ for detoxification, is more susceptible to the effects of ABM. Unfortunately, few studies investigated the mechanisms behind this connection. In this study, carp was used as an indicator organism for toxicological studies to investigate renal damage caused by ABM residues in carp. In this work, carp were exposed to ABM (0, 3.005, and 12.02 μg/L) for 4 d and the nephrotoxicity was assessed. Histopathological findings revealed that ABM exposure induced kidney damage in carp, as well as an increase Creatinine and BUN levels. Meanwhile, ABM as a reactive oxygen species (ROS) stimulator, boosted ROS bursts and lowered antioxidant enzyme activity while activating the body's antioxidant system, the Nrf2-Keap1 signaling pathway. The accumulation of ROS can also lead to the imbalance of the body's oxidation system, leading to oxidative stress. At the same time, NF-κB signaling pathway associated with inflammation was activated, which regulated expression levels of inflammatory cytokines (TNF-α, IL-6, IL-1β, and iNOS increased, while IL-10 and TGF-β1 decreased). In addition, ABM exposure caused structural damage to kidney mitochondria of carp, resulting in decreased mitochondrial membrane potential and ATP production capacity, and mediated apoptosis through endogenous pathways Bax/Bcl-2/Caspase-9/Caspase-3. In conclusion, ABM caused kidney damage in carp by inducing oxidative stress, inflammation, and apoptosis through mitochondrial pathway. These findings will be useful for future research into molecular mechanisms of ABM-induced nephrotoxicity in aquatic organisms.

Dissipation patterns, residue analysis, and risk evaluation of hexaflumuron in turnip and cauliflower under Chinese growth conditions

Hexaflumuron has been globally registered over 2 decades to control the pests in brassicaceous vegetables, while data on its dissipation and residues in turnip and cauliflower is scarce. Herein, field trials were carried out at six representative experimental sites to study the dissipation behaviors and terminal residues of hexaflumuron in turnip and cauliflower. The residual amounts of hexaflumuron were extracted using a modified QuEChERS and analyzed with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the chronic dietary risk to Chinese populations was evaluated, and the maximum residue limit (MRL) in cauliflower, turnip tubers, and turnip leaves was calculated by the OECD MRL calculator. The single first-order kinetics model was the best-fitted kinetics model for hexaflumuron dissipation in cauliflower. The indeterminate order rate equation and first-order multi-compartment kinetic model were the best formulae for hexaflumuron dissipation in turnip leaves. The half-lives of hexaflumuron ranged from 0.686 to 1.35 and 2.41 to 6.71 days in cauliflower and turnip leaves, respectively. The terminal residues of hexaflumuron in turnip leaves of 0.321-9.59 mg/kg were much higher than in turnip tubers of < 0.01-0.708 mg/kg and cauliflower of < 0.01-1.49 mg/kg at sampling intervals of 0, 5, 7, and 10 days. The chronic dietary risk of hexaflumuron in the preharvest interval of 7 days was lower than 100% and much higher than 0.01%, indicating acceptable but nonnegligible health hazards for Chinese consumers. Therefore, MRL values of hexaflumuron were proposed as 2, 0.8, and 10 mg/kg in cauliflower, turnip tubers, and turnip leaves, respectively.

Potential Mechanisms of Imidacloprid-Induced Neurotoxicity in Adult Rats with Attempts on Protection Using Origanum majorana L. Oil/Extract: In Vivo and In Silico Studies

Imidacloprid (IMI) insecticide is rapidly metabolized in mammals and contributes to neurotoxicity via the blocking of nicotinic acetylcholine receptors, as in insects. Origanum majorana retains its great antioxidant potential in both fresh and dry forms. No data is available on the neuroprotective effect of this plant in laboratory animals. In this context, aerial parts of O. majorana were used to prepare the essential oil (OMO) and methanol extract (OME). The potential neuroprotective impact of both OMO and OME against IMI-induced neurotoxicity in rats was explored. Forty-two rats were divided into 6 groups, with 7 rats in each one. Rats were daily administered the oral treatments: normal saline, OMO, OME, IMI, IMI + OMO, and IMI + OME. Our results revealed the identification of 55 components in O. majorana essential oil, most belonging to the oxygenated and hydrocarbon monoterpenoid group. Moreover, 37 constituents were identified in the methanol extract, mostly phenolics. The potent neurotoxic effect of IMI on rats was confirmed by neurobehavioral and neuropathological alterations and a reduction of both acetylcholine esterase (AchE) activity and dopamine (DA), serotonin (5HT), and γ-aminobutyric acid (GABA) levels in the brain. Exposure of rats to IMI elevates the malondialdehyde (MDA) levels and reduces the antioxidant capacity. IMI could upregulate the transcription levels of nuclear factor-κB (NF-κB), interleukin-1 β (IL-1β), and tumor necrosis factor (TNF-α) genes and express strong caspase-3 and inducible nitric oxide synthase (iNOS) immunostaining in most examined brain areas. On the other hand, rats coadministered OMO or OME with IMI showed a marked improvement in all of the studied toxicological parameters. In conclusion, cotreatment of O. majorana extracts with IMI can protect against IMI neurotoxicity via their potent antioxidant, anti-inflammatory, and anti-apoptotic effects. Thus, we recommend a daily intake of O. majorana to protect against insecticide's oxidative stress-mediated neuroinflammatory stress and apoptosis. The molecular docking study of linalool, rosmarinic acid, γ-terpene, and terpene-4-ol justify the observed normalization of the elevated iNOS and TNF-α levels induced after exposure to IMI.

The effect of Alnus incana (L.) Moench extracts in ameliorating iron overload-induced hepatotoxicity in male albino rats

Iron overload causes multiorgan dysfunction and serious damage. Alnus incana from the family Betulaceae, widely distributed in North America, is used for treating diseases. In this study, we investigated the iron chelating, antioxidant, anti-inflammatory, and antiapoptotic activities of the total and butanol extract from Alnus incana in iron-overloaded rats and identified the bioactive components in both extracts using liquid chromatography-mass spectrometry. We induced iron overload in the rats via six intramuscular injections of 12.5 mg iron dextran/100 g body weight for 30 days. The rats were then administered 60 mg ferrous sulfate /kg body weight once daily using a gastric tube. The total and butanol extracts were given orally, and the reference drug (deferoxamine) was administered subcutaneously for another month. After two months, we evaluated the biochemical, histopathological, histochemical, and immunohistochemical parameters. Iron overload significantly increased the serum iron level, liver biomarker activities, hepatic iron content, malondialdehyde, tumor necrosis factor-alpha, and caspase-3 levels. It also substantially (P < 0.05) reduced serum albumin, total protein, and total bilirubin content, and hepatic reduced glutathione levels. It caused severe histopathological alterations compared to the control rats, which were markedly (P < 0.05) ameliorated after treatment. The total extract exhibited significantly higher anti-inflammatory and antiapoptotic activities but lower antioxidant and iron-chelating activities than the butanol extract. Several polyphenolic compounds, including flavonoids and phenolic acids, were detected by ultraperformance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) analysis. Our findings suggest that both extracts might alleviate iron overload-induced hepatoxicity and other pathological conditions characterized by hepatic iron overload, including thalassemia and sickle-cell anemia.

A Comprehensive Study on the Mechanistic Way of Hexaflumuron and Hymexazol Induced Neurobehavioral Toxicity in Rats

Pesticides are widely used in agriculture to kill pests, but their action is non-selective and results in several hazardous effects on humans and animals. Pesticide toxicity has been demonstrated to alter a variety of neurological functions and predisposes to various neurodegenerative diseases. Although, there is no data available for hexaflumuron (HFM) and hymexazol (HML) neurotoxicity. Hence, the present study aims to investigate the possible mechanisms of HFM and HML neurotoxicity. 21 male Wistar rats were divided into three groups and daily received the treatment via oral gavage for 14 days as follows: group (1) normal saline, group (2) HFM (1/100LD50), and group (3) HML (1/100 LD50). Our results revealed that both HFM and HML produced a significant increase in MDA levels and a decrease in GSH and CAT activity in some brain areas. There were severe histopathological alterations mainly neuronal necrosis and gliosis in different examined areas. Upregulation of mRNA levels of JNK and Bax with downregulation of Bcl-2 was also recorded in both pesticides exposed groups. In all studied toxicological parameters, HML produced neurotoxicity more than HFM. HFM targets the cerebral cortex and striatum, while HML targets the cerebral cortex, striatum, hippocampus, and cerebellum. We can conclude that both HFM and HML provoke neurobehavioral toxicity through oxidative stress that impairs the mitochondrial function and activates the JNK-dependent apoptosis pathway.

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.