Oxidative stress and mitochondrial damage in lambda-cyhalothrin toxicity: A comprehensive review of antioxidant mechanisms

Melatonin prevents glyphosate-induced hepatic lipid accumulation in roosters via activating Nrf2 pathway

BACKGROUND

Glyphosate (GLY) is a widely used herbicide with well-defined hepatotoxic effects, in which oxidative stress has been shown to be involved in the pathogenesis of hepatotoxicity. Melatonin (MET), an effective free radical scavenger, has been revealed to alleviate drug-induced liver damage by inhibiting oxidative stress.

METHODS

In this study, a rooster model with primary chicken embryo hepatocytes was applied to elucidate the therapeutic effects of MET against GLY-induced hepatic damage and the potential mechanism. Histopathological examinations, biochemical tests and immunoblotting analysis were used to monitor the protective effects of MET on GLY-induced hepatic lipid accumulation. Molecular docking analysis was used to reveal the key reason of MET-improved hepatic lipid deposition.

RESULTS

Data firstly showed that MET administration markedly improved GLY-induced hepatic injury, as evidenced by normalized liver enzymes and alleviated pathological changes of liver tissues. Moreover, MET supplementation alleviated GLY-induced hepatic lipid accumulation, which was correlated with improved serum and hepatic lipid profiles and normalized expression of lipolysis- and lipogenesis-related proteins. Notably, MET significantly inhibited vital enzymes involved in stimulating oxidative stress. Moreover, MET enhanced GLY-inhibited Nrf2 nuclear transcription and increased the expressions of its downstream target genes HO1 and NQO1. Further studies revealed that MET may interact with Nrf2 to enhance nuclear translocation of Nrf2.

CONCLUSION

Collectively, our results provide the first direct evidence that MET is a novel regulator of Nrf2, highlighting that Nrf2 may be a potential therapeutic target for GLY-induced lipotoxic liver injury.

Assessing ecological responses of exposure to the pyrethroid insecticide lambda-cyhalothrin in sub-tropical freshwater ecosystems

Pyrethroid insecticides are widely detected in aquatic ecosystems due to their extensive use in agriculture and horticulture, which could pose a potential risk to aquatic non-target organisms. While previous ecotoxicological studies have been conducted mainly with standard tests and local species under temperate conditions, scarce information is available on the effects of pyrethroid insecticides on communities and ecosystems under (sub-)tropical conditions. A single application of lambda-cyhalothrin at concentrations of 0, 9, 30, and 100 ng/L was evaluated in outdoor mesocosms under sub-tropical conditions. Lambda-cyhalothrin was found to dissipate rapidly in the water column, with only 11 % and 7 % of the remaining dose measured at 1 and 3 days after application, respectively. Lambda-cyhalothrin concentrations disappeared considerably faster from the water compartment compared to temperate conditions. Consistent decreases in abundance were observed for Lecane lunaris at the medium and higher treatments (NOEC = 9 ng/L) and at the highest treatment (NOEC = 30 ng/L) for Keratella tropica. On the contrary, two taxa belonging to Cladocera (i.e., Ceriodaphnia sp. and Diaphanosoma sp.) showed the most prominent increase in abundance related to the lambda-cyhalothrin treatments. At the community level, a consistent no observed effect concentrations (NOECs) of 9 ng/L could be calculated for the zooplankton community. A marginal significant overall treatment related effect was observed for the macroinvertebrate community. The results of species sensitivity distribution (SSD) analysis based on results of acute toxicity experiments conducted alongside the mesocosm experiment and obtained from the literature indicated that macroinvertebrates from temperate regions may be generally more sensitive than their counterparts in (sub-)tropical regions. Overall, these findings suggest that environmentally relevant concentrations of the pyrethroid insecticide lambda-cyhalothrin may lead to different ecological outcomes in freshwater ecosystems in the (sub-)tropics relative to temperate regions.

The effect of lambda-cyhalothrin nanocapsules on the gut microbial communities and immune response of the bee elucidates the potential environmental impact of emerging nanopesticides

Emerging nanopesticides are gradually gaining widespread application in agriculture due to their excellent properties, but their potential risks to pollinating insects are not fully understood. In this study, lambda-cyhalothrin nanocapsules (LC-NCs) were constructed by electrostatic self-assembly method with iron mineralization optimization, and their effects on bee gut microbial communities and host immune-related factors were investigated. Microbiome sequencing revealed that LC-NCs increase the diversity of gut microbial communities and reduce the complexity of network features, disrupting the overall structure of the microbial communities. In addition, LC-NCs also had systemic effects on the immune response of bees, including increased activity of SOD and CAT enzymes and expression of their genes, as well as downregulation of Defensin1. Furthermore, we noticed that the immune system of the host was activated simultaneously with a rise in the abundance of beneficial bacteria in the gut. Our research emphasizes the importance of both the host and gut microbiota of holobiont in revealing the potential risks of LC-NCs to environmental indicators of honey bees, and provides references for exploring the interactions between host-microbiota systems under exogenous stress. At the same time, we hope that more research can focus on the potential impacts of nanopesticides on the ecological environment.

Eco(geno)toxicity of the new commercial insecticide Platinum Neo, a mixture of the neonicotinoid thiamethoxam and the pyrethroid lambda-cyhalothrin

New mixtures of pesticides are being placed on the market to increase the spectrum of phytosanitary action. Thus, the eco(geno)toxic effects of the new commercial mixture named Platinum Neo, as well as its constituents the neonicotinoid Thiamethoxam and the pyrethroid Lambda-Cyhalothrin, were investigated using the species Daphnia magna, Raphidocelis subcapitata, Danio rerio, and Allium cepa L. The lowest- and no-observed effect concentration (LOEC and NOEC) were measured in ecotoxicological tests. While Thiamethoxam was ecotoxic at ppm level, Lambda-Cyhalothrin and Platinum Neo formulation were ecotoxic at ppb level. The mitotic index (MI), chromosomal aberrations and micronucleus [MN] frequency were measured as indicators of phytogenotoxicity in A. cepa plants exposed for 12 h to the different insecticides and their mixture under different dilutions. There were significant alterations in the MI and MN frequency in comparison with the A. cepa negative control group, with Thiamethoxam, Lambda-Cyhalothrin, and Platinum Neo treatments all significantly reducing MI and increasing MN frequency. Thus, MI reduction was found at 13.7 mg L-1 for Thiamethoxam, 0.8 μg L-1 for Lambda-Cyahalothrin, and 2.7:2 μg L-1 for Platinum Neo, while MN induction was not observed at 14 mg L-1 for Thiamethoxam, 0.8 μg L-1 for Lambda-Cyahalothrin, and 1.4:1 μg L-1 for Platinum Neo. The insecticide eco(geno)toxicity hierarchy was Platinun Neo > Lambda-Cyhalothrin > Thiamethoxam, and the organism sensitivity hierarchy was daphnids > fish > algae > A. cepa. Eco(geno)toxicity studies of new pesticide mixtures can be useful for management, risk assessment, and avoiding impacts of these products on living beings.

Biomarkers at the Individual and Biochemical Level: Effects of Pure and Formulated Lambda-Cyhalothrin in Boana pulchella Tadpoles (Duméril and Bibron, 1841)

We compared the effects of lambda-cyhalothrin as the pure active ingredient and as a formulated product (Zero®), on the larval stage of the autochthonous species Boana pulchella. We evaluated ecotoxicological endpoints, behavioral and developmental alterations, and the biochemical detoxifying, neurotoxic, and oxidative stress responses, covering a wide concentration range from environmental to high application levels. Both pyrethroid preparations displayed similar ecotoxicity (median lethal concentration of ~0.5 mg/L), with the lethal effect of Zero® being more pronounced than that of the active ingredient. Sublethal behavioral alterations in natatory activity were observed at 1000 times lower concentrations, indicating the ecological hazard of tadpole exposure to this pyrethroid at environmentally relevant concentrations. Biochemical endpoints in B. pulchella larvae showed significant responses to lambda-cyhalothrin in the ng/L range; these responses were different for the pure or the formulated product, and they were variable at higher concentrations. Principal components analysis confirmed the prevalence of biochemical responses as early endpoints at the lowest lambda-cyhalothrin concentrations; the Integrated Biomarker Response Index proportionally increased with pyrethroid concentration in a similar way for the pure and the formulated products. We conclude that lambda-cyhalothrin is of concern from an environmental perspective, with particular emphasis on autochthonous anuran development. The battery of biochemical biomarkers included in our study showed a consistent integrated biomarker response, indicating that this is a potent tool for monitoring impacts on amphibians. Environ Toxicol Chem 2024;43:2134-2144. © 2024 SETAC.

Lambda-cyhalothrin induces heart injury in chickens by regulating cytochrome P450 enzyme system and inhibiting Nrf2/HO-1 pathway

Lambda-cyhalothrin (LCT) is a common pyrethroid insecticide widely used for ectoparasite control and hygiene pest prevention in poultry and this study aimed to investigate the mechanisms of LCT-induced cardiac injury in chickens. Low, medium, and high-dose LCT exposure models in chickens were established and hematoxylin and eosin (H&E) staining, dihydroethidium (DHE) staining, TUNEL staining, immunofluorescence, biochemical analysis, and gene expression analysis were used to study the effects of LCT exposure on the chicken heart. The results showed that LCT exposure increased the serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH), led to muscle fiber breakage and inflammatory cell infiltration and caused cardiac tissue damage. The DHE staining and biochemical analysis revealed that LCT exposure resulted in the excessive accumulation of ROS, decreased activities/levels of catalase (CAT), total superoxide dismutase (T-SOD), and glutathione (GSH), and increased levels of the oxidative damage marker malondialdehyde (MDA). The TUNEL staining indicated that LCT exposure increased apoptosis possibly through the elevated expression of pro-apoptotic genes in the mitochondrial pathway, the reduced expression of anti-apoptotic genes, the upregulation of pro-inflammatory factors and the downregulation of anti-inflammatory factors. Here, LCT exposure significantly inhibited the expression of genes in the Nrf2/HO-1 pathway and activated the expression of genes in the CYP450 enzyme system. Compared to the low-dose group, the high-dose LCT exposure group showed lower levels of apoptosis and inflammation, possibly related to the low oxidative stress levels mediated by the decreased expression of the CYP450 enzyme system. In conclusion, LCT exposure induces oxidative stress, apoptosis, and inflammation in chicken hearts, which may be associated with the inhibition of the Nrf2/HO-1 pathway and activation of the CYP450 enzyme system. This study provides a theoretical basis for the safer use of insecticides in poultry production.

Risk Assessment of Fenpropathrin: Cause Hepatotoxicity and Nephrotoxicity in Common Carp (Cyprinus carpio L.)

The synthetic pyrethroid pesticide fenpropathrin (FEN) is extensively used worldwide and has frequently been detected in biota and the environment, whilst the negative effects and toxicological mechanisms of FEN on non-target organisms are still unknown. In the present study, healthy immature common carp were treated with FEN (0.45 and 1.35 μg/L) for a duration of 14 days, and the negative impacts and possible mechanisms of FEN on fish were investigated. Biochemical analyses results showed that FEN exposure altered the levels of glucose (GLU), total cholesterol (T-CHO), triglyceride (TG), albumin (ALB), alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) in carp serum, and caused histological injury of the liver and kidney, indicating that FEN may cause hepatotoxicity and nephrotoxicity in carp. In addition, FEN also altered the activities of superoxide dismutase (SOD) and catalase (CAT) in carp serum, upregulated the levels of reactive oxygen species (ROS), and elevated the levels of malondialdehyde (MDA) in the liver and kidney. Meanwhile, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were also upregulated, indicating that oxidative stress and inflammatory reaction may be involved in the hepatotoxicity and nephrotoxicity caused by FEN. Furthermore, RNA-seq analysis results revealed that FEN treatment induced a diverse array of transcriptional changes in the liver and kidney and downregulated differentially expressed genes (DEGs) were concentrated in multiple pathways, especially cell cycle and DNA replication, suggesting that FEN may induce cell cycle arrest of hepatocytes and renal cells, subsequently inducing hepatotoxicity and nephrotoxicity. Overall, the present study enhances our comprehension of the toxic effects of FEN and provides empirical evidence to support the risk assessment of FEN for non-target organisms.

The toxic effect of 2,6-di-tert-butylphenol on embryonic development in zebrafish (Danio rerio): Decreased survival rate, morphological abnormality, and abnormal vascular development

2,6-di-tert-butylphenol (2,6-DTBP) has been used extensively in plastics, rubber and polymer phenolic antioxidants. It is discharged into the aquatic environment through industrial waste. However, the toxicity assessment of 2,6-DTBP is insufficient. Here, zebrafish embryos were used as an animal model to investigate the toxicological effects of 2,6-DTBP. The results showed that 2,6-DTBP induced mitochondrial dysfunction and reactive oxygen species accumulation, which caused apoptosis, and further led to developmental toxicity of zebrafish embryos, such as delayed incubation, reduced survival rate, and increased malformation rate and heart rate. 2,6-DTBP can also cause morphological changes in the zebrafish endothelial cell (zEC) nucleus, inhibit zEC migration, trigger abnormal angiogenesis and zEC sprouting angiogenesis, and ultimately affect vascular development. In addition, 2,6-DTBP interfered with the endogenous antioxidant system, causing changes in activities of superoxide dismutase, catalase, and glutathione S-transferase and contents of malondialdehyde and glutathione. Transcriptome sequencing showed that 2,6-DTBP altered the mRNA levels of genes associated with vascular development, oxidative stress, apoptosis, extracellular matrix components and receptors. Integrative biomarker response assessment found that 12 μM 2,6-DTBP had the highest toxicity. These results indicated that 2,6-DTBP induced apoptosis through oxidative stress, leading to toxicity of zebrafish embryo development. This study contributes to understanding the effects of environmental 2,6-DTBP exposure on early development of aquatic organisms and draws public attention to the health risks posed by chemicals in aquatic organisms.

Enhancing soil health, microbial count, and hydrophilic methomyl and hydrophobic lambda-cyhalothrin remediation with biochar and nano-biochar

Pesticide contamination and soil degradation present significant challenges in agricultural ecosystems, driving extensive exploration of biochar (BC) and nano-biochar (NBC) as potential solutions. This study examines their effects on soil properties, microbial communities, and the fate of two key pesticides: the hydrophilic methomyl (MET) and the hydrophobic lambda-cyhalothrin (LCT), at different concentrations (1%, 3%, and 5% w w-1) in agricultural soil. Through a carefully designed seven-week black bean pot experiment, the results indicated that the addition of BC/NBC significantly influenced soil dynamics. Soil pH and moisture content (MC) notably increased, accompanied by a general rise in soil organic carbon (SOC) content. However, in BC5/NBC5 treatments, SOC declined after the 2nd or 3rd week. Microbial populations, including total plate count (TPC), phosphate-solubilizing bacteria (PSB), and nitrogen-fixing bacteria (NFB), showed dynamic responses to BC/NBC applications. BC1/NBC1 and BC3/NBC3 applications led to a significant increase in microbial populations, whereas BC5/NBC5 treatments experienced a decline after the initial surge. Furthermore, the removal efficiency of both MET and LCT increased with higher BC/NBC concentrations, with NBC demonstrating greater efficacy than BC. Degradation kinetics, modeled by a first-order equation, revealed that MET degraded faster than LCT. These findings underscore the profound impact of BC/NBC on pesticide dynamics and microbial communities, highlighting their potential to transform sustainable agricultural practices.

From growth inhibition to ultrastructural changes: Toxicological assessment of lambda cyhalothrin and fosetyl aluminium against Bacillus subtilis and Pseudomonas aeruginosa

In modern agricultural practices, agrochemicals and pesticides play an important role in protecting the crops from pests and elevating agricultural productivity. This strategic utilization is essential to meet global food demand due to the relentless growth of the world's population. However, the indiscriminate application of these substances may result in environmental hazards and directly affect the soil microorganisms and crop production. Considering this, an in vitro study was carried out to evaluate the pesticides' effects i.e. lambda cyhalothrin (insecticide) and fosetyl aluminum (fungicide) at lower, recommended, and higher doses on growth behavior, enzymatic profile, total soluble protein production, and lipid peroxidation of bacterial specimens (Pseudomonas aeruginosa and Bacillus subtilis). The experimental findings demonstrated a concentration-dependent decrease in growth of both tested bacteria, when exposed to fosetyl aluminium concentrations exceeding the recommended dose. This decline was statistically significant (p < 0.000). However, lambda cyhalothrin at three times of recommended dose induces 10% increase in growth of Pseudomonas aeruginosa (P. aeruginosa) and 76.8% decrease in growth of Bacillus subtilis (B. subtilis) respectively as compared to control. These results showed the stimulatory effect of lambda cyhalothrin on P. aeruginosa and inhibitory effect on B. subtilis. Pesticides induced notable alterations in biomarker enzymatic assays and other parameters related to oxidative stress among bacterial strains, resulting in increased oxidative stress and membrane permeability. Generally, the maximum toxicity of both (P. aeruginosa and B. subtilis) was shown by fosetyl aluminium, at three times of recommended dose. Fosetyl aluminium induced morphological changes like cellular cracking, reduced viability, aberrant margins and more damage in both bacterial strains as compared to lambda cyhalothrin when observed under scanning electron microscope (SEM). Conclusively the, present study provide an insights into a mechanistic approach of pyrethroid insecticide and phosphonite fungicide induced cellular toxicity towards bacteria.

Placental transcriptome variation associated with season, location, and urinary prenatal pyrethroid metabolites of Thai farm-working women

Prenatal exposure to pyrethroids is linked to adverse health effects in early life and proper placental function is critical to fetal development. This study explores the impact of prenatal pyrethroid exposure, as well as factors impacting exposure and effect, on the placental transcriptome, to understand pyrethroid exposures' relationship to placental function. The study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE) recruited pregnant farm-working women from two agricultural districts in the Chiang Mai province of Thailand between 2017 and 2019. This cohort was predominantly exposed to cypermethrin (type II), alongside pyrethroids such as cyfluthrin (type II) and permethrin (type I). In 253 participants, maternal urinary pyrethroid metabolites, 3-phenoxybenzoic acid (PBA), cis-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (CDCCA), and trans-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (TDCCA) were measured in early, middle, and late pregnancy and adjusted for urinary creatinine. The placental transcriptome was analyzed using RNA-Seq. Using generalized linear regression, we identified differentially expressed genes (DEGs) associated with the sum of each metabolite across pregnancy, as well as those associated with location of residence and season of birth. Pathway and upstream transcription factor analyses were performed to examine potential mechanisms associated with DEGs. Notably, TDCCA and CDCCA levels peaked in late pregnancy, with significant regional differences, particularly higher levels in the Fang region. Placental gene expression analysis showed no DEGs associated with individual metabolites at FDR<0.05. However, 251 DEGs by location, implicating immune response and oxidative phosphorylation pathways, were identified, while season of birth was associated with 2585 DEGs, over-represented in fibrosis signaling and metabolism pathways. Finally, transcription factor analysis identified 226 and 282 transcription factors associated with location and season, respectively, related to cell proliferation, differentiation, and the immune system. These alterations may have significant implications for fetal development and other pathologic processes, highlighting the importance of monitoring environmental exposures during pregnancy.

Combined toxic effects of polyethylene microplastics and lambda-cyhalothrin on gut of zebrafish (Danio rerio)

Microplastics (MPs), which are prevalent and increasingly accumulating in aquatic environments. Other pollutants coexist with MPs in the water, such as pesticides, and may be carried or transferred to aquatic organisms, posing unpredictable ecological risks. This study sought to assess the adsorption of lambda-cyhalothrin (LCT) by virgin and aged polyethylene MPs (VPE and APE, respectively), and to examine their influence on LCT's toxicity in zebrafish, specifically regarding acute toxicity, oxidative stress, gut microbiota and immunity. The adsorption results showed that VPE and APE could adsorb LCT, with adsorption capacities of 34.4 mg∙g-1 and 39.0 mg∙g-1, respectively. Compared with LCT exposure alone, VPE and APE increased the acute toxicity of LCT to zebrafish. Additionally, exposure to LCT and PE-MPs alone can induce oxidative stress in the zebrafish gut, while combined exposure can exacerbate the oxidative stress response and intensify intestinal lipid peroxidation. Moreover, exposure to LCT or PE-MPs alone promotes inflammation, and combined exposure leads to downregulation of the myd88-nf-κb related gene expression, thus impacting intestinal immunity. Furthermore, exposure to APE increased LCT toxicity to zebrafish more than VPE. Meanwhile, exposure to PE-MPs and LCT alone or in combination has the potential to affect gut microbiota function and alter the abundance and diversity of the zebrafish gut flora. Collectively, the presence of PE-MPs may affect the toxicity of pesticides in zebrafish. The findings emphasize the importance of studying the interaction between MPs and pesticides in the aquatic environment.

Fenpropathrin provoked kidney damage via controlling the NLRP3/Caspase-1/GSDMD-mediated pyroptosis: The palliative role of curcumin-loaded chitosan nanoparticles

This study assessed the ability of formulated curcumin-loaded chitosan nanoparticles (CU-CS-NPs) to reduce the kidney damage resulting from fenpropathrin (FPN) in rats compared to curcumin (CU) in rats. Sixty male Sprague Dawley rats were separated into six groups and orally administered 1 mL/kg b.wt corn oil, 50 mg CU/kg b.wt, 50 mg CU-CS-NPs /kg b.wt., 15 mg FPN /kg b.wt, CU+ FPN or CU-CS-NPs + FPN for 60 days. Then, serum renal damage products were assessed. Total antioxidant capacity, reactive oxygen species, interleukin 1β (IL-1β), malondialdehyde, NF-κB P65, cleaved-Caspase-1, and Caspase-8 were estimated in kidney homogenates. The cleaved Caspase-3 and TNF-α immunoexpression and pyroptosis-related genes were determined in renal tissues. The results showed that CU-CS-NPS significantly repressed the FPN-induced increment in kidney damage products (urea, uric acid, and creatinine). Moreover, the FPN-associated hypo-proteinemia, renal oxidative stress and apoptotic reactions, and impaired renal histology were considerably repaired by CU and CU-CS-NPs. Additionally, compared to FPN-exposed rats, CU, and CU-CS-NPs-treated rats had considerably lower immunoexpression of cleaved Caspase-3 and TNF-α in renal tissue. The pyroptosis-related genes NLRP3, GSDMD, IL-18, Caspase-3, Caspase-1, IL-1β, Caspase-8, TNF-α, and NF-κB dramatically upregulated by FPN exposure in the renal tissues. Yet, in CU and CU-CS-NPs-treated rats, the gene above expression deviations were corrected. Notably, CU-CS-NPs were superior to CU in preventing oxidative damage and inflammation and regulating pyroptosis in the renal tissues of the FPN-exposed group. The results of the present study conclusively showed the superior favorable effect of CU-CS-NPs in counteracting renal impairment linked to environmental pollutants.