Deltamethrin Research Articles

Ginkgo biloba extract alleviates deltamethrin-induced testicular injury by upregulating SKP2 and inhibiting Beclin1-independent autophagy

BackgroundMale infertility is a worldwide concern that is associated with a decline in sperm quality. Environmental pollutants such as deltamethrin (DM) have harmful effects on male reproductive organs. By maintaining intracellular redox homeostasis, ginkgo biloba extract (GBE) can alleviate male reproductive dysfunction. However, research on the mechanisms by which GBE alleviates reproductive toxicity induced by DM is limited. PurposeIn this study, we investigated whether GBE can alleviate DM-induced testicular and Sertoli cell reproductive toxicity by modulating SKP2 and Beclin1, thus providing a theoretical basis for the development of novel therapeutic approaches. Study DesignWe explored the role of GBE in mitigating DM-induced testicular damage, with a specific focus on the intricate involvement of ubiquitination and autophagy. MethodsAn experimental model was constructed using ICR male mice and the TM4 cell line. Tissue, cellular, and sperm morphological changes were observed through methods such as Hematoxylin and Eosin (H&E) staining, Periodate-Schiff (PAS) staining, ultrastructural observation, immunohistochemistry, and immunofluorescence. Enzyme and hormone levels were measured, and gene and protein levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting techniques. ResultsIn vivo experiments showed that DM exposure led to decreased sex hormone levels, increased seminiferous tubule diameter and impaired spermatogenesis. Meanwhile, DM exposure was found to decrease ubiquitination levels, leading to mitochondrial damage and further escalation of mitochondrial autophagy. Furthermore, in the DM-induced cell model, the upregulation of Beclin1 expression was associated with the inhibition of the ubiquitin‒proteasome system (UPS) and SKP2, thereby exacerbating autophagy. However, GBE has demonstrated notable efficacy in alleviating the reproductive toxicity induced by DM. ConclusionOur findings highlighted that SKP2 is a key regulator of Beclin1-independent autophagy and that GBE exerts therapeutic effects by upregulating SKP2 and inhibiting Beclin1 activation, which ameliorates autophagy and reduces DM-induced testicular damage.

Ocean acidification aggravates the toxicity of deltamethrin in Haliotis discus hannai: Insights from immune response, histopathology and physiological responses

Ocean acidification (OA) and other environmental factors can collectively affect marine organisms. Deltamethrin (DM), a type II pyrethroid insecticide, has been widely detected in coastal and estuarine areas, while little attention has been given to the combined effects of DM and OA. In this study, Haliotis discus hannai was exposed to three pH levels (8.1, 7.7 and 7.4) and three DM nominal concentrations (0 μg/L, 0.6 μg/L and 6 μg/L) for 14 and 28 days. The results indicated that experimental acidification and/or DM exposure led to impaired immune function and pathological damage. Additionally, acidified conditions and DM exposure induced oxidative stress, and gills are more sensitive than digestive glands. With increasing pCO2 and DM nominal concentrations, superoxide dismutase (SOD) activity decreased, whereas catalase (CAT) and glutathione S-transferase (GST) activities increased in the gills. Moreover, the expression levels of Toll-like receptor (TLR) pathway-related genes were upregulated after exposure. Integrated biomarker response (IBR) analysis proved that acidified conditions and/or DM detrimentally affected the overall fitness of H. discus hannai, and co-exposure to experimental acidification and DM was the most stressful condition. This study emphasizes the necessity of incorporating OA in future pollutant environmental assessments to better elucidate the risks of environmental disturbance.

Assessment of sweet whey fortified with Bifidobacteria and selenium on reduction of pesticide liver toxicity in albino rats

Deltamethrin (DLM) represents one of the most commonly used pesticides. It passes through milk, vegetables, and fruits to humans or through animals (veterinary drugs and feeding on contaminated forage) to milk; it can escape from skin to blood and be secreted in breast milk in lactating women. It is believed to have neurotoxic, nephrotoxic, and hepatotoxic properties. To investigate deltamethrin-induced hepatotoxicity, 64 rats were divided into eight groups. The control group did not receive any treatment. The groups were as follows: D 30 mg DLM/kg body weight (BW) dissolved in corn oil; B 1 mL whey (1010 cfu/mL of Bifidobacterium longum ATCC 15707); S 1 mL whey (0.5 ppm selenium); BS 1 mL whey (1010 cfu/mL of B. longum ATCC 15707 + 0.5 ppm selenium); BD 1 mL whey (1010 cfu/mL of B. longum ATCC 15707 + DLM); SD 1 mL whey (0.5 ppm selenium) + DLM; and BSD 1 mL whey (1010 cfu/mL of B. longum ATCC 15707) + 0.5 ppm selenium + DLM. Results revealed that the manipulation of Bifidobacteria with selenium triggered a significant improvement in AST (U/mL), ALT (U/mL), GSH (mg/g), TNF-α (pg/mL), NF-κB (ng/mL), and BCL2 (ng/mL) from 166.7 ± 6.42, 30.67 ± 0.55, 0.252 ± 0.005, 17.18 ± 0.42, 1.14 ± 0.10, and 1.77 ± 0.06 versus 334.9 ± 4.7, 72.83 ± 2.49, 0.108 ± 0.005, 33.57 ± 0.59, 2.58 ± 0.05, and 1.04 ± 0.04, respectively, compared to DLM group. As well as reduction in histopathological necrosis, congestion, and degradation. Whey beverages fortified with B. longum and selenium implicated a reduction in oxidative stress and histopathological degradation that accomplished DLM toxicity. The utilization of whey (a byproduct of cheese making) is considered a recycling process that supports eco-friendly practices and sustainability, thus encouraging its use as a protective tool in animal feed or manipulation by humans, especially workers in pesticide plants.

Deltamethrin exposure caused renal inflammation and renal fibrosis via upregulating endoplasmic reticulum stress-mediated TXNDC5 level in mice

Deltamethrin (DLM) is a type II pyrethroid insecticide that is extensively applied to agriculture, veterinary medicine and livestock pest control. Excessive accumulation of DLM in the body can lead to nephrotoxicity, but the precise toxic mechanism remains obscure. Therefore, we established in vivo models of DLM-exposed mice for 30 days and in vitro models of DLM-exposed renal tubular epithelial cells of mice. The results revealed adverse effects on renal function in mice exposed to excessive DLM, manifested as endoplasmic reticulum (ER) swelling, local inflammatory infiltration in renal tissue and increased collagen fibers, suggesting renal inflammation and fibrosis, etc. Subsequently, in vivo experiments, we found that DLM exposure increased expression levels of endoplasmic reticulum stress (ERS)-related factors, significantly upregulated the expression of TXNDC5, and enhanced the colocalization of GRP78 with TXNDC5. Notably, DLM exposure also strengthened the co-localization of TXNDC5 with NF-κB p65 and TGF-β1, upregulated the expression levels of TLR4/MYD88/NF-κB and TGF-β/SMAD2/3 pathways, alongside inflammation and fibrosis-related factors, these changes exhibited a dose-dependent effect. Meanwhile, in vitro experiments, the results of ERS, inflammation, and fibrosis-related factor expression levels were consistent with those observed in vivo. In conclusion, our results demonstrated that TXNDC5 might played a certain role in DLM-induced nephrotoxicity. Specifically, DLM exposure could trigger ERS, increase TXNDC5 expression, and promote TLR4/MYD88/NF-κB and TGF-β/Smad2/3 pathways, leading to renal inflammation and fibrosis in mice. These discoveries not only deepen our understanding of DLM toxicity but also provide valuable avenues for exploring mitigation strategies and therapeutic interventions.

Deltamethrin increased susceptibility to Aeromonas hydrophila in crucian carp through compromising gill barrier

Pyrethroids serve as a significant method for managing and preventing parasitic diseases in fish. Among these, deltamethrin (DEL) is used extensively in aquatic environments. Our previous work has been confirmed that DEL exposure can induce oxidative stress and immunosuppression on the gill mucosal barrier of crucian carp (Carassius auratus). However, it is not clear whether DEL affects the susceptibility of farmed fish to bacterial infection. In this study, fish was pre-exposed to different DEL concentration (0, 0.3 and 0.6 μg L−1) and then challenged by immersion with Aeromonas hydrophila (1.0 × 10^8 CFU mL−1). After immersion challenge, fish pre-exposed to DEL developed prominent lipopolysaccharides level in gill and serum and had a significantly lower survival rate compared to the control group. In DEL pre-exposure fish after immersion, the gill apoptosis levels were significantly higher and disrupted the tight junction barrier by downregulating the zo1 and claudin12. Furthermore, fish pre-exposed to DEL exhibited increased activities of superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and malonaldehyde (MDA) levels in the early stage after immersion but experiencing decreased activities of glutathione peroxidase (GPx) and lysozyme (LZM) in the later stage after immersion. And this process was regulated by the NRF2 pathway. Additionally, fish pre-exposed to DEL after immersion had significantly lower mRNA levels of immune-related genes tlr4, myd88, tnfα, and il-1β. Overall, these findings indicate that DEL damaged the gill barrier, weakened the immune response, raised LPS levels, and heightened vulnerability to A. hydrophila infection in crucian carp, resulting in mortality. Thus, this work will help social groups and aquaculture workers to understand the potential risk of DEL exposure for bacterial secondary infection in cultured fish.

Nanoporous carbon derived ZIF-67@MWCNTs-Fe3O4 reinforced hollow fiber to performe hollow fiber solid-phase micro extraction (HF-SPME) coupled with high-performance liquid chromatography to determine deltamethrin and cypermethrin

This study presents a novel micro extraction approach by developing a highly porous and stable Co@N-C/MWCNTs sorbent capable to addresses limitations of traditional sorbents. Zeolitic Imidazolate Framework-67 (ZIF-67) interconnected with magnetic Multi-walled Carbon Nanotubes (MWCNTs) selected as the template for the synthesis of sorbent possess distinctive N-doped and metal (Co) active sites coupled with carbon-rich nanotubes, resulting in a sorbent with a strong affinity to target analytes and excellent chemical stability. For the first time, this material integrated into the pores of a hollow fiber (HF) for a simplified and efficient Hollow Fiber Solid Phase Micro extraction (HF-SPME) method. This innovative integration increases the extraction surface area and minimize matrix interference. Under optimal conditions, the method achieved a wide linear range (0.1–200 μg L−1) for the target analytes, deltamethrin (DLT) and cypermethrin (CPM), the coefficient of determination of 0.9945 for DLT and 0.9982 for CPM. Additionally, it demonstrated excellent analytical performance with: Low limits of detection (LODs): 0.03 µg L−1 for DLT and 0.04 µg L−1 for CPM. Good precision: Inter and intra-day relative standard deviations (RSD) within 2.5–3.4 %. High enrichment factors (EFs): 68–58. The novel Co@N-C/MWCNTs coating, integrated with a hollow fiber, offers a promising advancement for HF-SPME due to its unique properties.

Bioaccumulation of Deltamethrin and Piperonyl butoxide in Labeo rohita fish

Deltamethrin (DLM), in combination with the synergist piperonyl butoxide (PBO), is extensively used in pest control programs due to its potent pesticidal properties and appreciable safety margin. However, various research studies report their adverse effects on non-target organisms. In this study, we investigated the toxicity of DLM, PBO, and a DLM-PBO (3:1) combination on Labeo rohita (L. rohita) fish fingerlings. Fish behavior and mortality rates were recorded at different time intervals up to 96 h for concentrations of 0.003, 0.007, 0.015, 0.031, and 0.062 µg/mL, respectively. Biochemical, hematological, and histopathological studies were carried out. High-performance liquid chromatography (HPLC) was used to detect and quantify residues in fish samples. The LC50 values after 48 h for DLM, PBO, and DLM-PBO exposed fish fingerlings were found to be 0.028, 0.066, and 0.007 µg/mL, respectively. At a concentration of 0.003 µg/mL of DLM, PBO, and DLM-PBO, the treated fish fingerlings exhibited similar behavior to the control group. Hematological parameters, such as red blood cell (RBC) and white blood cell (WBC) counts, were reduced in the treated groups compared to the control. Biochemical parameters showed increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), while total serum protein levels decreased in DLM, PBO, and DLM-PBO treated fingerlings. Histopathological examination of liver, gill, and heart tissues revealed lesions with hydropic degeneration in the liver and fusions of gill lamellae in the treated tissues. Fish fingerlings exposed to the DLM-PBO combination appeared highly prone to toxicity compared to those treated with DLM and PBO separately.

Toxicological effect of deltamethrin on enzymatical, apoptosis and immune response, histological morphology in Litopenaeus vannamei

Deltamethrin (DM) use in agricultural production and storage can result in the presence of residues in several feed ingredients, which can then be ingested by aquatic animals, potentially leading to adverse health effects. Although the potential toxicity of the lipophilic deltamethrin has been evaluated in several studies, there is a paucity of comprehensive studies on the negative effects induced by chronic exposure of shrimp to deltamethrin at different dietary lipid levels. A feeding experiment of six weeks was carried out to assess whether alterations in dietary lipid levels have an impact on the toxicity of DM. In a feeding experiment on Litopenaeus vannamei, the effects of dietary fat levels on the toxicity of DM were studied. There were six distinct diets created comprising three levels of DM (0.2 mg⋅kg–1, 1 mg⋅kg–1, 5 mg⋅kg–1), and two lipid levels (6.96 %, 10.88 %). The diets were designated as LF0.2, LF1, LF5, HF0.2, HF1, HF5. The growth performance and whole shrimp body lipid were reduced with the increase of DM addition to the diet, and DM caused abnormal changes in lipoproteins (LDL, HDL, LPS) in shrimp when feeding diets containing high doses of DM. Furthermore, GOT, GPT, AKP, and ACP activities were found to be significantly increased by long-term exposure to DM. Meanwhile, the way that genes linked to the nuclear factor kappa-B immune signaling pathway showed a significant increase in the hepatopancreas (dorsal, imd, pelle, ikkβ), intestine (imd, tube, pelle), and muscle (toll, imd, pelle) of shrimp following exposure to DM. Similarly, cellular autophagy genes in the hepatopancreas (atg9, atg12), muscle (atg3, atg9), and intestine (atg3, atg5, atg9, beclin, atg13) were significantly upregulated in a dose-dependent manner after shrimp chronic exposure to DM. Histopathological damage was also induced in the muscles under DM exposure. In summary, chronic exposure to DM resulted in a slowing of growth performance, disruption of lipoprotein metabolism, impairment of hepatopancreatic, intestinal, and muscle-related immune functions, as well as the promotion of autophagy and damage to shrimp muscle.

Impact of sub chronic administration of deltamethrin on autoimmune activity in rat

Deltamethrin (DLM) is a newer kind of insecticide that is used on pets, livestock, and crops, as well as to combat malaria vectors and household pests. It belongs to the synthetic pyrethroid group and is being promoted as an alternative to organophosphate chemicals due to its persistent and destructive effects. The current study aimed to evaluate the impact of sub-chronic oral exposure to DLM on autoimmune activity in rats. Three groups of male albino rats (15 rats/group) including the control group, the ethanol-treated group (1 ml/rat), and the DLM-treated group (5 mg/kg b.w). Samples of blood were taken from all groups at 4-, 8- and 12-week intervals for the determination of hematological, cytokines, and immunological parameters. T lymphocyte subsets and Treg lymphocytes were determined in serum using flow cytometric acquisition. The results revealed that DLM significantly increased TNF-α, IL-33, IL-6, IL-17, IgG, IgM, WBCs, differential count, and platelets while decreasing Hb concentration and RBCs. Additionally, DLM decreased the number of T-cell subsets (CD3, CD4, CD5, and CD8) and Treg lymphocytes. All of these impacts became more severe over time. It is possible to conclude that the sub-chronic oral exposure to DLM disturbed autoimmune activity through the disturbances in immunological indices, CDs subset Treg lymphocytes.

Comparison of the acute toxicity and behavioural effects of two pyrethroids on African catfish Clarias gariepinus fingerlings

Two of the most-commonly used pyrethroid insecticides were subjected to static bioassays to determine their acute toxicity to Clarias gariepinus fingerlings, followed by comparisons of their impact on mortality and behavioural changes in the fish. The LC50 values for deltamethrin (DMT) at exposure durations of 24, 48 and 96 h were 12, 9 and 8 µg l−1, respectively; the LC50 values for cypermethrin (CYP) at the same exposure durations were 55, 44 and 26 µg l−1, respectively. The estimated safe limits ranged from 8×10−1 to 8×10−5 µg l−1 for DMT, and 26×10−1 to 26×10−5 µg l-1 for CYP. The tested substances had an acute toxicity effect on fish development as they caused death, and chronic toxicity effects as they changed fish behaviour. Fish exposed to either one of these pesticides showed behavioural alterations, such as loss of static balance, excessive mucous secretion, irregular swimming, gulping of air and skin discolouration. The results reveal that CYP was less toxic (96-h LC50 = 26 µg l−1) than DMT (96-h LC50 = 8 µg l−1) based on the greater LC50 value and a lower percentage of mortality. To avoid potential ecotoxicological risks to aquatic life, use of these pyrethroids in both terrestrial and freshwater ecosystems must be treated with caution.

Contribution of Immune Responses to the Cardiotoxicity and Hepatotoxicity of Deltamethrin in Early Life Stage Zebrafish (Danio rerio).

Deltamethrin (DM) is a widely used insecticide that has demonstrated developmental toxicity in the early life stages of fish. To better characterize the underlying mechanisms, embryos from Tg(cmlc2:RFP), Tg(apo14:GFP), and Tg(mpx:GFP) transgenic strains of zebrafish were exposed to nominal DM concentrations of 0.1, 1, 10, 25, and 50 μg/L until 120 h post-fertilization (hpf). Heart size increased 56.7%, and liver size was reduced by 17.1% in zebrafish exposed to 22.7 and 24.2 μg/L DM, respectively. RNA sequencing and bioinformatic analyses predicted that key biological processes affected by DM exposure were related to inflammatory responses. Expression of IL-1 protein was increased by 69.0% in the 24.4 μg/L DM treatment, and aggregation of neutrophils in cardiac and hepatic histologic sections was also observed. Coexposure to resatorvid, an anti-inflammatory agent, mitigated inflammatory responses and cardiac toxicity induced by DM and also restored liver biomass. Our data indicated a complex proinflammatory mechanism underlying DM-induced cardiotoxicity and hepatotoxicity which may be important for key events of adverse outcomes and associated risks of DM to early life stages of fish.

Evaluation of Apis mellifera brain morphophysiology in response to titanium dioxide nanoparticles and deltamethrin co‐exposure

AbstractHoneybees are important insects, both economically and as pollinators. While foraging, bees can come in contact with environmental pollutants such as pesticides, possibly in combination with other xenobiotic compounds that may compromise bee health. Our current study investigated the acute exposure to nanosized titanium dioxide, a common additive in food, cosmetics, paints and agricultural products, along with deltamethrin (DLT), a well‐known pyrethroid pesticide. The effects of binary exposure to titanium dioxide nanoparticles (TiO2‐NPs) nanoparticles at concentrations of 25, 50, 75 and 100 μg/mL with DLT were noted on Apis mellifera brain histology along with their possible synergism. In DLT‐ and combined TiO2‐NP‐DLT treated bees, survival rates were lowered and several histological alterations were observed including an increased number of cells with pyknotic nuclei, along with cytoplasmic vacuolization, chromatin compaction and degeneration indicating autophagic activity and a decrease in the cross‐sectional area of nanoparticle‐treated mushroom body calyces. A synergistic relationship between TiO2‐NPs and DLT was revealed, while LD50 for combined TiO2‐NP‐DLT treatment was 0.101, 0.09 and 0.02 μg/bee at 24, 48 and 72 h, respectively. In summary, results demonstrate that TiO2‐NP and DLT co‐exposure can induce damage in bee brain structures at higher concentrations, which indicates an additional risk factor for bee health in the field.

Co-exposure to deltamethrin and cyazofamid: variations in enzyme activity and gene transcription in the earthworm (Eisenia fetida).

Pesticide formulations are typically applied as mixtures, and their synergistic effects can increase toxicity to the organisms in the environment. Despite pesticide mixtures being the leading cause of pesticide exposure incidents, little attention has been given to assessing their combined toxicity and interactions. This survey purposed to reveal the cumulative toxic effects of deltamethrin (DEL) and cyazofamid (CYA) on earthworms (Eisenia fetida) by examining multiple endpoints. Our findings revealed that the LC50 values of DEL for E. fetida, following 7- and 14-day exposures, ranged from 887.7 (728-1095) to 1552 (1226-2298) mg kg-1, while those of CYA ranged from 316.8 (246.2-489.4) to 483.2 (326.1-1202) mg kg-1. The combinations of DEL and CYA induced synergistic influences on the organisms. The contents of Cu/Zn-SOD and CarE showed significant variations when exposed to DEL, CYA, and their combinations compared to the untreated group. Furthermore, the mixture administration resulted in more pronounced alterations in the expression of five genes (hsp70, tctp, gst, mt, and crt) associated with cellular stress, carcinogenesis, detoxification, and endoplasmic reticulum compared to single exposures. In conclusion, our comprehensive findings provided detailed insights into the cumulative toxic effects of chemical mixtures across miscellaneous endpoints and concentration ranges. These results underscored the importance of considering mixture administration during ecological risk evaluations of chemicals.

Whole transcriptomic analysis reveals overexpression of salivary gland and cuticular proteins genes in insecticide-resistant Anopheles arabiensis from Western Kenya

BackgroundEffective vector control is key to malaria prevention. However, this is now compromised by increased insecticide resistance due to continued reliance on insecticide-based control interventions. In Kenya, we have observed heterogenous resistance to pyrethroids and organophosphates in Anopheles arabiensis which is one of the most widespread malaria vectors in the country. We investigated the gene expression profiles of insecticide resistant An. arabiensis populations from Migori and Siaya counties in Western Kenya using RNA-Sequencing. Centers for Disease Control and Prevention (CDC) bottle assays were conducted using deltamethrin (DELTA), alphacypermethrin (ACYP) and pirimiphos-methyl (PMM) to determine the resistance status in both sites.ResultsMosquitoes from Migori had average mortalities of 91%, 92% and 58% while those from Siaya had 85%, 86%, and 30% when exposed to DELTA, ACYP and PMM, respectively. RNA-Seq analysis was done on pools of mosquitoes which survived exposure (‘resistant’), mosquitoes that were not exposed, and the insecticide-susceptible An. arabiensis Dongola strain. Gene expression profiles of resistant mosquitoes from both Migori and Siaya showed an overexpression mainly of salivary gland proteins belonging to both the short and long form D7 genes, and cuticular proteins (including CPR9, CPR10, CPR15, CPR16). Additionally, the overexpression of detoxification genes including cytochrome P450s (CYP9M1, CYP325H1, CYP4C27, CYP9L1 and CYP307A1), 2 carboxylesterases and a glutathione-S-transferase (GSTE4) were also shared between DELTA, ACYP, and PMM survivors, pointing to potential contribution to cross resistance to both pyrethroid and organophosphate insecticides.ConclusionThis study provides novel insights into the molecular basis of insecticide resistance in An. arabiensis in Western Kenya and suggests that salivary gland proteins and cuticular proteins are associated with resistance to multiple classes of insecticides.

Chronic low-dose deltamethrin exposure induces colon injury and aggravates DSS-induced colitis via promoting cellular senescence

ObjectiveDeltamethrin (DLM) is a commonly used insecticide, which is harmful to many organs. Here, we explored the effects of chronic low-dose DLM residues on colon tissue and its potential mechanism. MethodsThe mice were given long-term low-dose DLM by intragastric administration, and the body weights and disease activity index (DAI) scores of the mice were regularly recorded. The colon tissues were then collected for hematoxylin-eosin, immunofluorescence and immunohistochemistry staining. Besides, the RNA sequencing was performed to explore the potential mechanism. ResultsOur results showed that long-term exposure to low-dose DLM could cause inflammation in mice colon tissue, manifested as weight loss, increased DAI score, increased apoptosis of colonic epithelial cells, and increased infiltration of inflammatory cells. However, we observed that after long-term exposure to DLM and withdrawal for a period of time, although apoptosis was restored, the recovery of colon inflammation was not ideal. Subsequently, we performed RNA sequencing and found that long-term DLM exposure could lead to the senescence of some cells in mice colon tissue. The results of staining of cellular senescence markers in colon tissue showed that the level of cellular senescence in the DLM group was significantly increased, and the p53 signalling related to senescence was also significantly activated, indicating that cellular senescence played a key role in DLM-induced colitis. We further treated mice with quercetin (QUE) after long-term DLM exposure, and found that QUE could indeed alleviate DLM-induced colitis. In addition, we observed that long-term accumulation of DLM could aggravate DSS-induced colitis in mice, and QUE treatment could reverse this scenario. ConclusionContinuous intake of DLM caused chronic colitis in mice, and the inflammation persisted even after discontinuation of DLM intake. This was attributed to the induction of cellular senescence in colon tissue. Treatment with QUE alleviated DLM-induced colitis by reducing cellular senescence. Long-term DLM exposure also aggravated DSS-induced colitis, which could be mitigated by QUE treatment.

Maternal exposure to deltamethrin during pregnancy and lactation impairs neurodevelopment of male offspring

Deltamethrin (DM) is a highly effective and widely used pyrethroid pesticide. It is an environmental factor affecting public and occupational health and exerts direct toxic effects on the central nervous system. As the major target organs for neurotoxicity of DM, the hippocampus and the cerebellum are critical to the learning and motor function. Pregnant Wistar rats were randomly divided into four groups and gavaged at doses of 0, 1, 4or 10 mg/kg/d DM from gestational day (GD) 0 to postnatal day (PN) 21. The PC12 cells were selected to further verify the regulatory mechanisms of DM on the neurodevelopmental injury. We found that maternal exposure to DM caused learning, memory and motor dysfunction in male offspring. Maternal exposure to DM induced the decrease in the density of hippocampal dendritic spines in male offspring through the reduced expression of M1 mAchRs, which in turn reduced the mediated AKT/mTOR signaling pathway, contributing to the inhibition of dynamic changes of GluA1. Meanwhile, DM exposure inhibited the BDNF/TrkB signaling pathway, thereby reducing phosphorylation of stathmin and impairing cerebellar purkinje cell dendrite growth and development. Taken together, maternal exposure to DM during pregnancy and lactation could impair neurodevelopment of male offspring.

Time of exposure and assessment influence the mortality induced by insecticides against metabolic resistant mosquitoes

BackgroundIncreasing metabolic resistance in malaria vector mosquitoes resulted in the development of insecticide-treated nets (ITNs) with active ingredients (AI) that target them. Bioassays that accurately measure the mortality induced by these AIs on ITNs are needed. Mosquito metabolic enzyme expression follows a circadian rhythm. Thus, this study assessed (i) influence of the time of day of mosquito exposure and (ii) timing of assessment of mortality post exposure (24 and 72 h) to ITNs against vectors that are susceptible to pyrethroids and those with metabolic and knockdown resistance mechanisms.MethodsTwo cone bioassay experiments were conducted following World Health Organization (WHO) guidelines. Firstly, on ITNs incorporated with 2 g AI/kg of deltamethrin (DM) alone, or combined with 8 g AI/kg piperonyl butoxide (PBO) synergist, during the day (9:00–14:00 h) and repeated in the evening (18:00–20:00 h). This was followed by a confirmatory experiment during the afternoon (12:00–14:00 h) and repeated in the night (22:00–24:00 h) using mosquitoes unexposed or pre-exposed to PBO for 1 h before exposure to DM ITNs. Each net piece was tested with a minimum of eight cones per time (N = 24). The outcome was mortality after 24 h (M24) or 72 h (M72) of holding.ResultsThe cone bioassays performed using metabolic resistant mosquitoes during the evening showed significantly lower M24 than those performed in the day for DM: odds ratio (OR) 0.14 [95% confidence interval (CI) 0.06–0.30, p < 0.0001] and DM PBO [OR 0.29 (95% CI 0.18—0.49, p < 0.0001). M72 was higher than M24 for metabolic resistant mosquitoes exposed to DM [OR 1.44 (95% CI 1.09–1.88), p = 0.009] and DM PBO [OR 1.82 (95% CI 1.42–2.34), p < 0.0001]. An influence of hour of experiment and time of assessment was not observed for mosquitoes that had knockdown resistance or that were pyrethroid-susceptible.ConclusionsTime of day of experiment and hour of assessment of delayed mortality after exposure of mosquitoes are important considerations in evaluating insecticides that interact with mosquito metabolism to counter metabolic resistant mosquitoes. This is important when evaluating field-aged ITNs that may have lower concentrations of AI.Graphical

Extreme gradient boosting-enhanced molecularly imprinted fluorescence nanosensor for rapid identification and visual detection of deltamethrin in seawater and aquatic products

Deltamethrin (DEL), a synthetic pyrethroid insecticide, may have long-term adverse effects on the aquatic environment. Extreme Gradient Boosting (XGBoost) is a classic ensemble boosting algorithm framework known for its high training efficiency, strong prediction performance, and versatile applications. In this study, we successfully developed a highly sensitive molecularly imprinted fluorescence nanosensor (MF-sensor) for DEL determination, enhanced by the XGBoost algorithm. The MF-sensor was fabricated by grafting blue and red CdSe/ZnS quantum dots onto a molecularly imprinted silica layer. The MF-sensor consisted of blue-molecularly imprinted polymer (MIP)-quantum dots (QDs) and r-MIP-QDs, which selectively detected DEL, and unmodified green CdSe QDs, which were not selective for DEL. Under optimized conditions, we observed an excellent linear relationship between the I526/(I450 +I630) ratio and DEL concentration ranging from 0.01 mg/L to 40.0 mg/L (R2 = 0.9944). The limit of detection was determined to be 1.34 µg/L. The recoveries in actual samples ranged from 98.5% to 109.0%, with a relative standard deviation (RSD) below 7.5%. Additionally, we utilized the XGBoost algorithm to establish a DEL prediction model, achieving an accuracy of 95.7%. The recoveries ranged from 96.0% to 102.4%, with a RSD below 5.5%. Overall, the proposed MF-sensor, enhanced by the XGBoost algorithm, was successfully utilized for the detection of DEL in environmental and aquatic products.

Comparative effectiveness of deltamethrin, imidacloprid and emamectin benzoate alone and in binary blends to control Trogoderma granarium: Effect on macronutrients

Trogoderma granarium Everts (Insecta, Dermestidae) severely attacks a variety of stored commodities, and its control has been achieved by conventional insecticides. However, unplanned use of insecticides leads towards emergence of resistance as well as health and environment damage. Previous studies reported insecticidal efficacy of deltamethrin (DL), emamectin benzoate (EB) and imidacloprid (IM) individually but lacking efficacy of mixtures against T. granarium. The study presented here was aimed at investigating the susceptibility of field collected Mandi Bahaud Din (MBD) population (14 years DL exposure history) and a DL susceptible LAB-S population (not exposed to insecticides since 2001) against DL, EB and IM individually and in binary mixtures (DL:EB, DL:IM and EB:IM) at different ratio (1:1, 1:2, 1:3, 2:1 and 3:1). The MBD strain showed greater susceptibility against IM and EB (LC50 473.09 and 556.4 ppm) respectively, but decreased susceptibility (LC50 808.67 ppm) against DL indicating DL resistance. The LC50 values were 251.62, 307.15 and 369.73 ppm against DL, IM and EB, respectively in LAB-S strain. All binary mixtures exhibited synergistic interactions against MBD strain and EB:IM mixture (3:1) was found the most effective (RTU 3.93) among all the tested combinations. In contrast, EB:IM mixture showed antagonistic interactions (1:1, 1:2, 1:3, 2:1) but synergistic interactions were achieved by increasing EB concentration (3:1, RTU 1.23) in mixture against LAB-S strain. However, DL:EB was more effective (RTU 2.1) against LAB-S strain among all the tested combinations. The toxic effect of LC20 of most effective mixture on macronutrients was also investigated. A significant reduction in contents of trehalose, total protein, soluble protein, total lipids and glycogen while an increase in glucose and free amino acids was observed in both strains in comparison with their respective unexposed control. It is concluded that binary mixture reduces the net quantity of conventional insecticides, thus offering more effective approach to control T. granarium.

Deciphering the interplay between LPS/TLR4 pathways, neurotransmitter, and deltamethrin-induced depressive-like behavior: Perspectives from the gut-brain axis

The improper use of deltamethrin (DM) can result in its accumulation in soil, water, food, and even the human body, which is associated with an elevated risk of neurotoxicity and behavioral abnormalities; however, the underlying mechanisms remain insufficiently investigated. Emerging evidence underscores the significance of the gut-brain axis in central nervous system (CNS) dysfunctions. Accordingly, this study investigates the role of the gut-brain axis in DM-induced behavioral anomalies in mice. The results showed that DM exposure induced depressive-like behavior, and the hippocampus, the region that is responsible for the modulation of emotional behavior, showed structural integrity disrupted (neuronal nuclear shrinkage and decreased tight junction protein expression). In addition, DM exposure led to compromised gut barrier integrity (disruptions on crypt surfaces and decreased tight junction protein expression), which might contribute to the gut bacterial-derived lipopolysaccharide (LPS) leakage into the bloodstream and reaching the brain, triggering LPS/toll-like receptor (TLR) 4 -mediated increases in brain pro-inflammatory cytokines. Subsequently, we observed a disturbance in neurotransmitter metabolic pathways following DM exposure, which inhibited the production of 5-hydroxytryptamine (5-HT). Additionally, DM exposure resulted in gut microbiota dysbiosis. Characteristic bacteria, such as Alistipes, Bifidobacterium, Gram-negative bacterium cTPY-13, and Odoribacter exhibited significant correlations with behavior, tight junction proteins, inflammatory response, and neurotransmitters. Further fecal microbiota transplantation (FMT) experiments suggested that DM-induced gut microbiota dysbiosis might contribute to depressive-like behavior. These results provide a new perspective on the toxicity mechanism of DM, indicating that its neurotoxicity may be partially regulated by the microbiota-gut-brain axis.