Deltamethrin Research Articles

Green photosensitisers for the degradation of selected pesticides of high risk in most susceptible food: A safer approach.

Pesticides are the leading defence against pests, but their unsafe use reciprocates the pesticide residues in highly susceptible food and is becoming a serious risk for human health. In this study, mint extract and riboflavin were tested as photosensitisers in combination with light irradiation of different frequencies, employed for various time intervals to improve the photo-degradation of deltamethrin (DM) and lambda cyhalothrin (λ-CHT) in cauliflower. Different source of light was studied, either in ultraviolet range (UV-C, 254 nm or UV-A, 320–380 nm) or sunlight simulator (> 380–800 nm). The degradation of the pesticides varied depending on the type of photosensitiser and light source. Photo-degradation of the DM and λ-CHT was enhanced by applying the mint extracts and riboflavin and a more significant degradation was achieved with UV-C than with either UV-A or sunlight, reaching a maximum decrement of the concentration by 67–76%. The light treatments did not significantly affect the in-vitro antioxidant activity of the natural antioxidants in cauliflower. A calculated dietary risk assessment revealed that obvious dietary health hazards of DM and λ-CHT pesticides when sprayed on cauliflower for pest control. The use of green chemical photosensitisers (mint extract and riboflavin) in combination with UV light irradiation represents a novel, sustainable, and safe approach to pesticide reduction in produce.

Deltamethrin Microencapsulation in Emulsion Paint Binder and Its Long-Term Efficacy Against Dengue Vector Aedes aegypti.

Various control interventions have been effective in the control of arthropod vectors to a certain extent; still, sustained vector control is an existing problem globally. Insecticide-based formulations have been found to be useful, however the proper delivery of active molecules to target vectors is important. Currently, synthetic pyrethroid deltamethrin (DM) has been microencapsulated in the emulsion paint binder and evaluated for long-term effectiveness against dengue vector Aedes aegypti. Different compositions of emulsion binder were prepared by varying the content of monomer and DM. A selection was made for the composition yielding the best combination of properties like solid content, intrinsic viscosity, and DM content. Developed formulation was tested against laboratory-reared and pathogen-free Ae. aegypti mosquitoes. Encapsulation of DM in emulsion binder during polymerization showed a uniform distribution. The optimized formulation was stable and did not have a considerable plasticizing effect. Scanning electron microscopy revealed that grain-like micro crystals of DM and surfactant sodium lauryl sulfate (SDS) were uniformly distributed on the formulation surface. The best optimized formulation was highly effective against dengue vector Ae. aegypti and found to provide efficacy for up to 18 months of application. The knockdown time (KDT) values KDT10 and KDT50 were 7.4 min (95% CI: 5.6–9.1) and 22.1 min (95% CI: 19.7–24.3) respectively, whereas 24 h corrected mortality was 90% (95% CI: 82.5–97.5) after 18 months of application (T18). The probit model used to determine knockdown values did not deviate from the linearity and displayed normal distribution of knockdown % with time for different formulations (p ≥ 0.1). Presently developed DM microencapsulated emulsion binder was stable, smooth, and uniform. The binder displayed excellent anti-insect property and was capable of providing long-term effectiveness against dengue vectors Ae. aegypti. Such a formulation after field-scale evaluation could be very useful in attaining long-term protection from arthropod vectors.

Neurotoxicity of a pyrethroid pesticide deltamethrin is associated with the imbalance in proteolytic systems caused by mitophagy activation and proteasome inhibition

Pyrethroids are one of the most commonly used classes of synthetic pesticides in the world. Recent laboratory and epidemiological evidence suggested that pyrethroids have potential adverse effects in the mammalian brain; however, the underlying mechanisms of the neurotoxic effects of pyrethroids have not been fully elucidated. In the present study, we investigated the mechanisms of effects of a type II pyrethroid deltamethrin (DM) in a neuronal cell model focusing on the proteolytic function, including autophagy and the ubiquitin-proteasome system. We confirmed that a micromolar concentration of DM dose-dependently decreased the cell viability and induced apoptotic cell death. Our results showed that DM enhanced autophagy in association with an accumulation of autophagosomes and increase in the levels of autophagy markers LC3-II/LC3-I ratio and p62 which were much elevated in the presence of lysosomal inhibitors bafilomycin A1 and chloroquine. We also found that DM caused a dysfunction of mitochondria with a decrease of mitochondrial membrane potential and mitochondrial DNA copy number as well as colocalization with autophagosomes. Moreover, a decrease in the activities of three major proteasomal enzymes and an accumulation of ubiquitinated proteins were observed by the exposure to DM. Transcriptome analysis revealed that up-regulated genes supported the activation of autophagy with induction of cellular stress responses including oxidative stress and endoplasmic reticulum stress, while down-regulated genes related to the cell cycle and DNA replication. These findings provide novel insights into the neurotoxicity of DM which underlie the imbalance in proteolytic function caused by mitophagy activation and proteasome inhibition.

Effects of acute deltamethrin exposure on kidney transcriptome and intestinal microbiota in goldfish (Carassius auratus)

As a widely used synthetic pyrethroid insecticide, deltamethrin (DM) causes serious health problems to aquatic organisms. However, the comprehensive understanding of the adverse effect of DM on aquatic organisms has received limited attention. In this study, goldfish (Carassius auratus) were exposed to 0 (control group), 0.2 and 2 µg/L DM for 96 h. The kidney transcriptome and intestinal microbiota were investigated. Comparative transcriptome analysis identified 270 and 711 differentially expressed genes (DEGs) in goldfish kidneys after exposure to 0.2 and 2 µg/L DM, respectively. KEGG pathway analysis revealed that the apoptosis pathway was markedly regulated and the regulation of programmed cell death was significantly enriched by the GO analysis. Several apoptosis-related genes including cathepsin L and cytochrome c were also detected. These results indicated that apoptosis occurred in the goldfish kidney after acute exposure to sublethal concentration of DM. Besides, some immune and drug metabolism-related DEGs were identified, indicating that exposure to DM caused immunotoxicity and metabolic disruption in goldfish. Additionally, 16 S rRNA gene sequencing analysis revealed a remarkable alteration in the composition of the intestinal microbial community of DM-treated goldfish. At the phylum level, the abundance of Proteobacteria, Firmicutes and Fusobacteria was increased, whereas the abundance of Bacteroidetes was reduced significantly after DM exposure. At the genus level, the abundance of Aeromonas, Cetobacterium, Dielma and Pseudorhodobacter was reduced, whereas Akkermansia was increased after DM exposure. In summary, exposure to DM could induce apoptosis and immunotoxicity in goldfish kidneys and affect the composition of the intestinal microbiota in goldfish. This study provides a comprehensive analysis of the adverse effect of DM exposure on the goldfish and will be helpful for understanding the toxicological mechanisms of DM in fish.

Estrogen receptor: A potential linker of estrogenic and dopaminergic pathways in zebrafish larvae following deltamethrin exposure

Deltamethrin (DM), a type II pyrethroid insecticide, is widely used to control agricultural pests. However, its excessive use exerts a detrimental effect on the ecological environment and human health, indicating the need to study its potential risks in detail. In the present study, zebrafish embryos were exposed to varying concentrations of DM (0.1, 1, 10, and 25 μg/L) for 96 h to assess the alterations in the transcript levels of proteins of the estrogenic and dopaminergic pathways. In addition, its effect on zebrafish locomotor activity was studied. The mRNA expression of cyp19a1b, erα, erβ2, fshr, gnrh2, gnrhr3, vtg3, dat, and dr1 significantly changed after exposing the embryos to DM. Deltamethrin at 10 and 25 μg/L significantly reduced the average swimming speed of zebrafish larvae. In addition, embryos injected with zebrafish estrogen receptor α (erα) and β (erβ) morpholinos and co-exposed to 25 μg/L DM for 96 h showed reduced expression of vtg3 mRNA compared to embryos exposed to 25 μg/L DM only. The locomotor activity of erα and erβ knockdown zebrafish following DM exposure was increased significantly when compared with that of larvae exposed to 25 μg/L DM only. Our results demonstrated that DM altered the locomotor activity of zebrafish larvae and the transcript levels of the components of estrogenic and dopaminergic pathways; erα and erβ knockdown weakened these effects.

Bioaccessibility and Intestinal Transport of Deltamethrin in Pacific Oyster (Magallana Gigas) Using Simulated Digestion/NCM460 Cell Models.

Deltamethrin (DEL) can be introduced into the food chain through bioaccumulation in Pacific oysters, and then potentially threaten human health. The objective of this study was to investigate the bioaccessibility of DEL in oysters with different cooking methods after simulated digestion. DEL content in different tissues of oysters going from high to low were gills, mantle, viscera, and adductor muscle. Bioaccessibility of DEL in oysters decreased after steaming (65%) or roasting (51%) treatments compared with raw oysters (82%), which indicated that roasting can be used as a recommended cooking method for oysters. In the simulated digestion process, the concentration of DEL in the digestive juice and the bioaccessibility of DEL were affected by the pH in the gastric phase. And the transport efficiency of DEL through the monolayer molecular membrane of NCM460 cells ranged from 35 to 45%. These results can help assess the potential harm to consumers of DEL in shellfish. Furthermore, it provides a reference for the impact of lipophilic toxins in seafood.

The Protective Role of Wheat Germ Oil Against Adverse Effect of Deltamethrin on Reproductive Aspects of Male Albino Rats

Deltamethrin (DLM) is a synthetic pyrethroid type-II known to cause many adverse effects in experimental animals such as endocrine disruption, reproductive toxicity, and negative impact on gametogenesis. The present study was conducted to evaluate the protective role ofwheat germ oil against reproductive toxicity induced by Deltamethrin (DLM) in male albino rats through evaluation of semen picture, measuring the testosterone levels,DNA fragmentation percentage and pathologic changes of the testes. Thirty male rats were divided into three groups (10 each); the first group (C) was administered with normal saline, the second group was given (DLM) at a dose of (6 mg/kg. B.W. of rats) andthe third group (DLM+WGO) was treated with wheat germ oil (1.5 ml/Kg. B.W. of rats),and after one h DLM (6 mg/kg. B.W. of rats) was administered. All treatments were orally given using stomach gavage for 30 days. The rats were left for 65 days of treatment to complete time of one spermatogenesis and maturation of sperms in epididymis then sacrificed and blood samples were collected, testes and epididymis were removed, weighted, and examined histopathologically. DLM administration significantly decreased the weight of testes and adversely affected the semen quality. Testosterone levels were significantly reduced. There is a significant elevation in the DNA laddering percentage in the DLM group compared to the C group. Histopathological examination of the testes revealed that DLM induced changes in the form of distorted seminiferous tubules with intraluminal sloughing degenerated spermatogenic cells. Also there is marked interstitial edema and congestion. The co-administration of DLM with wheat germ showed improvement in weight of testes, semen pictures, testosterone level and a significant reduction in the DNA laddering percentage compared to DLM group. It can be concluded that, the wheat germ oil can mitigate the adverse effects of DLM on male fertility, and leads to improvement of male reproductive performance.

Inhibition of the Nrf2/p38MAPK pathway involved in deltamethrin-induced apoptosis and fibrosis in quail kidney

Deltamethrin (DLM) is a broad-spectrum and effective pyrethroid insecticide. However, DLM has good residual activity on most surfaces and many insects, so it poses a threat to the environment and health of animals and human. Exposure to DLM can cause kidney injury, but the mechanism is not well understood. Therefore, we investigated the possible mechanism of quail kidney injury induced by chronic exposure to different doses of DLM for 12 weeks. The results showed that chronic exposure to DLM induced apoptosis and fibrosis of quail kidney through the promotion of oxidative stress by down-regulating nuclear factor erythroid 2 related factor 2 (Nrf2), up-regulating the phosphorylation of p38 mitogen-activated protein kinases (p38MAPK). Furthermore, DLM-induced kidney apoptosis in quails as evidenced by increased expression of B-cell lymphoma gene 2-associated X while decreased expression of B-cell lymphoma-extra large. Simultaneously, DLM-induced kidney fibrosis in quails as evidenced by increased expression of fibrosis maker proteins. Overall, the results demonstrate that chronic DLM exposure induces kidney apoptosis and fibrosis via inhibition of the Nrf2/p38MAPK pathway. This study provides a new understanding for the mechanism of DLM-induced quail kidney injury and also provides a theoretical basis for treatment of the DLM poisoning.

Dietary Synbiotics Can Help Relieve the Impacts of Deltamethrin Toxicity of Nile Tilapia Reared at Low Temperatures.

Simple SummaryThe toxic impacts of pesticides and insecticides are strongly correlated with water temperature. Water temperature can increase or decrease the efficacy of toxins and their influence on aquatic organisms. An alternate approach to augmenting fish resistance to ambient deltamethrin (DMT) toxicity and low water temperature via synbiotic feeding was proposed. In this study, fish were allocated into four groups and kept at suboptimal water temperature (21 ± 2 °C): control, DMT, synbiotic, and DMT + synbiotic. The results illustrate that including synbiotics in the Nile tilapia diet stimulates the immunity and antioxidant systems in fish, enabling the fish reared at a suboptimal temperature to counteract the immunity suppression and oxidative stress caused by DMT exposure.The optimal water temperature for the normal growth of Nile tilapia is between 26 and 28 °C, and the toxicity of pesticides is strongly related to water temperature. An alternate approach to augmenting the resistance of fish to ambient water toxicity and low water temperature via synbiotic feeding was proposed. In this study, fish were allocated into four groups with 10 fish in each replicate, where they were fed a basal diet or synbiotics (550 mg/kg) and kept at a suboptimal water temperature (21 ± 2 °C). The prepared diets were fed to Nile tilapia for 30 days with or without deltamethrin (DMT) ambient exposure (15 μg/L). The groups were named control (basal diet without DMT toxicity), DMT (basal diet with DMT toxicity), synbiotic (synbiotics without DMT toxicity), and DMT + synbiotic (synbiotics with DMT toxicity). The results displayed upregulated transcription of catalase, glutathione peroxidase, and interferon (IFN-γ) genes caused by DMT exposure and synbiotic feeding when compared with the controls. Moreover, HSP70 and CASP3 genes displayed increased transcription caused by DMT exposure without synbiotic feeding. However, fish fed with synbiotics showed downregulated HSP70 and CASP3 gene expressions. The transcription of IL-1β and IL-8 genes were also decreased by DMT exposure, while fish fed synbiotics showed upregulated levels. DMT exposure resulted in irregular histopathological features in gills, intestine, spleen, and liver tissues, while fish fed synbiotics showed regular, normal, and protected histopathological images. Our results indicated that dietary synbiotics ameliorated histopathological damages in DMT-exposed tilapia through alleviation of oxidative stress and inflammation as well as enhancing the immunity.

Bioremediation role of Spirulina platensis against deltamethrin-mediated toxicity and its chemical residues in chicken meat.

Deltamethrin (DM) is a synthetic pyrethroid insecticide commonly used in veterinary and agriculture. However, both animal and human exposure are associated with hepatorenal toxicity. Our experimental goal was to assess the protective effects of Spirulina platensis (SP) against DM-induced hepatorenal injury, growth performance, meat chemical composition, and its residues in meat, liver, and skin of broiler chickens. Sixty 1-day-old Cobb broiler chicks were assigned to 4 experimental groups; each was divided into 3 replicates with five chicks each; the 1st group received basal diet alone (control), 2nd group supplemented with SP 20 g/kg diet, 3rd group supplemented with DM 300 mg/kg diet, and 4th group supplemented with DM and SP diet. All groups have received the treatment for 35 days. DM, decreased body weight, weight gain, and increased feed conversion rate. DM showed a significant increase in ALT, AST, urea, creatinine, and MDA and a significant decrease in SOD, and GSH levels. Also, SPsignificantly reduced DM levels in meat, skin, and liver with a reduction 63.01, 63.00, and 62.90 %, respectively.The DM intoxicated group showed a significant decrease in protein and a marked increase in fat, cholesterol, and triglycerides when compared to the control group. Histopathological changes were also recorded. Dietary SP improved these parameters. Dietary inclusion of SP can be recommended due to the protective effects on DM-induced toxicity in broiler chickens.

Effects of dietary curcumin inhibit deltamethrin-induced oxidative stress, inflammation and cell apoptosis in Channa argus via Nrf2 and NF-κB signaling pathways

The current study evaluated the ameliorative effects of dietary curcumin (CUR) on oxidative stress, inflammation and cell apoptosis in Channa argus exposed to deltamethrin (DEL) for 28 d. This study was divided into five groups: the first group served as a control group, and the second, third, fourth and fifth groups were exposed to DEL (0.242 ppb) in water and fed CUR-supplemented diets at 0, 100, 200 and 400 mg/kg, respectively. The results showed that the biochemical parameter levels (ADA, COR, LDH, AST and ALT) and the innate immune parameter levels (LYS, CRP, MPO, C3, C4 and IgM) in the serum of fish exposed to DEL were notably increased (P < 0.05), and dietary supplementation with 200 and 400 mg/kg CUR in the DEL exposure period significantly reduced the levels of these parameters (P < 0.05). The levels of ROS, CAT, GSH, SOD, GSH-Px, GST and GSH-Rt in the gill, kidney, spleen, and liver of fish exposed to DEL were significantly decreased (P < 0.05), and there were notable increases (P < 0.05) in the 200 and 400 mg/kg CUR treatments. MDA content exhibited an opposite trend. The results of RT-qPCR analysis showed that dietary supplementation with CUR attenuated the inflammatory response of fish after DEL exposure by downregulating the expression of pro-inflammatory genes (NF-κB p65, IL-1β, IL-6, IL-8, IL-12 and TNF-α) in the liver and spleen and upregulating the expression of anti-inflammatory genes (TGF-β, IκBα and IL-10). Dietary supplementation with CUR was observed to improve the level of oxidative stress of fish after DEL exposure by downregulating the mRNA levels of Keap1 in the liver and spleen and upregulating the mRNA levels of Nrf2, Cu/Zn SOD, GSH-Px, GST and CAT. Dietary supplementation with CUR was determined to improve the cell apoptosis of fish after DEL exposure by downregulating the expression of pro-apoptotic genes (Bcl-2) in the liver and spleen and upregulating the expression of anti-apoptotic genes (Bax, Cas-3, Cas-8, Cas-9, and p53). In brief, the results of our study indicated that supplying optimal dietary CUR could attenuate deltamethrin-induced oxidative stress, inflammation and cell apoptosis in C. argus via the Nrf2 and NF-κB signaling pathways.

Short-term intake of deltamethrin-contaminated fruit, even at low concentrations, induces testicular damage in fruit-eating bats (Artibeus lituratus)

Deltamethrin (DTM) is a pyrethroid insecticide widely used for agricultural purposes. Exposure to DTM has proven to be harmful to humans, but whether low, environmental concentrations of this pesticide also poses a threat to wild mammals is still unknown. In Neotropical areas, bats play important roles in contributing to forest regeneration. We investigated the effects of DTM exposure on the reproductive function of male Neotropical fruit-eating bats (Artibeus lituratus), known for contributing to reforestation through seed dispersal in Neotropical Forests. Bats were assigned to 3 groups: control (fed with papaya); DTM2 (fed with papaya treated with DTM at 0.02 mg/kg) and DTM4 (fed with papaya treated with DTM at 0.04 mg/kg) for seven days. Bats from DTM2 and DTM4 groups showed increased testicular levels of nitric oxide and superoxide dismutase and catalase activities. The germinal epithelium from DTM4 bats showed non-viable cells and cell desquamation, indicating microscopic lesions and Leydig cells atrophy. Our results demonstrate the onset of cell degeneration that may affect the reproductive function in DTM exposed bats.

Dietary Lactobacillus plantarum Relieves Nile Tilapia (Oreochromis niloticus) Juvenile From Oxidative Stress, Immunosuppression, and Inflammation Induced by Deltamethrin and Aeromonas hydrophila

Aeromonas hydrophila infection is one of the major diseases that cause inflammation and immunodepression in aquatic animals. Likewise, waterborne toxins are known for their negative impact on the immunity and antioxidant responses of aquatic organisms. In this study, Lactobacillus plantarum (LP20) was incorporated in Nile tilapia, Oreochromis niloticus, diets (50 mg/kg) to investigate its role in the antioxidant capacity, immunity, and anti-inflammation induced by deltamethrin (DLM) toxicity (96-h LC50 was 14.9 μg/L) and A. hydrophila (LD50, 2 × 108 CFU/ml). One hundred and twenty healthy fish with an initial weight of 28.21 ± 1.34 g were allotted in 12 glass aquaria (60 L) and divided randomly into four groups (triplicates, 10 fish per aquarium). The control fish neither received LP20 nor were exposed to DLM. The second group of fish was fed the control diet and subjected to DLM (DLM group). The third group of fish was provided with LP20 without DLM toxicity (LP20 group), and the fourth group of fish was fed LP20 and subjected to DLM (DLM + LP20 group). After 30 days, fish were intraperitoneally injected with A. hydrophila. Ten days post infection, the survival rate was lower in fish exposed to DLM than those exposed to LP20. Further, fish fed on LP20 had elevated serum total protein (sTP), albumin (ALB), globulin (GLB), phagocytic index (PI), phagocytic (PA), and lysozyme activities (LZM), but they had lower urea, uric acid bilirubin, creatinine, glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) activities after 24 h, 48 h, and 1 week post A. hydrophila challenge. However, fish exposed to DLM had lower sTP, ALB, GLB and higher urea, uric acid, bilirubin, creatinine, glucose, ALT, AST, and ALP after 24 h, 48 h, and 1 week post A. hydrophila challenge. Markedly, after the A. hydrophila challenge, fish exposed to DLM + LP20 displayed upregulated levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) genes. The transcription of interferon gamma (IFN-γ), interleukin 12 (IL-12), and tumor necrosis factor alpha (TNF-α) was upregulated in DLM and DLM + LP20 groups. Fish exposed to DLM downregulated interleukin 8 (IL-8) gene expression after A. hydrophila challenge. Further, fish displayed upregulation of heat shock protein 70 (HSP70) gene expression after DLM toxicity. Besides, fish exposed to DLM toxicity and A. hydrophila infection had severe inflammatory features in the liver, spleen, gills, and intestine, while dietary LP20 relieved the inflammatory features. In summary, dietary LP20 relieves Nile tilapia from oxidative stress, immunosuppression, and inflammation induced by DLM and A. hydrophila infection.

Multi-biomarker assessment in the giant freshwater prawn Macrobrachium rosenbergii after deltamethrin exposure

Deltamethrin (DM) is a synthetic pyrethroid used for agricultural purposes to control insects. However, its extensive use contaminates the aquatic environment and results in serious health problems in aquatic organisms. Knowledge about the toxic effect of DM in freshwater prawns is limited; therefore, this study aims to assess the toxicity of DM in Macrobrachium rosenbergii based on multiple biomarkers. Four-day acute toxicity tests showed that DM was highly toxic to M. rosenbergii with the 24 h, 48 h, 72 h and 96 h LC50 values to be 1.919, 0.603, 0.539, and 0.449 μg/L, respectively. According to 96 h LC50, prawns were exposed to DM at three concentrations (0.02, 0.08, and 0.32 μg/L) for 4 days, and then moved into fresh water for decontamination to investigate the toxic effect of DM in M. rosenbergii. At low concentration (0.02 μg/L and 0.08 μg/L), DM did not cause obvious histopathological damage to hepatopancreas and gill tissue, while at high concentration (0.32 μg/L), the histopathological harm was serious and the damage did not recover to the initial level after 7-day decontamination. 0.02 μg/L DM exposure did not induce significant changes in most of the biomarkers except the increased lactate dehydrogenase (LDH) activity, lactic acid (LD) level, and the first increased then decreased mRNA expression of immune-related genes, indicating the stimulation of DM on energy production and immunity. 0.08 μg/L and 0.32 μg/L DM exposure resulted in varying degrees of damage on prawns, but overall, their toxic effects showed similar trends based on the biomarkers. Increase in malonaldehyde (MDA) and hydrogen peroxide (H2O2) content and decrease in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity after DM exposure demonstrated the oxidative stress caused by DM. The significantly increased acid phosphatase (ACP), alkaline phosphatase (AKP), LDH activity and LD level indicated hepatopancreatic dysfunction and respiration disruption. The first increased and then decreased expression pattern of immune-related genes indicated the immunosuppression caused by DM. After 7-day decontamination in freshwater, the activity/level of the biomarkers partly recovered. This study revealed the severe toxic effect of DM on Macrobrachium rosenbergii based on multiple biomarkers, providing fundamental knowledge for the establishment of DM toxicity assessment system with proper parameters in freshwater crustaceans.

Effects of Permethrin or Deltamethrin Exposure in Adult Sprague Dawley Rats on Acoustic and Light Prepulse Inhibition of Acoustic or Tactile Startle.

The effects of permethrin (PRM) and deltamethrin (DLM) on acoustic or light prepulse inhibition of the acoustic startle response (ASR) and tactile startle response (TSR) were studied in adult male Sprague Dawley rats. Preliminary studies were conducted to optimize the parameters of light and acoustic prepulse inhibition of ASR and TSR. Once these parameters were set, a new group of rats was administered PRM (0 or 90mg/kg) or DLM (0 or 25mg/kg) by gavage in 5mL/kg corn oil. ASR and TSR were assessed using acoustic or light prepulses 6, 8, and 12h after PRM and 2, 4, and 6h after DLM exposure. PRM increased ASR 6h post-treatment with no interaction with acoustic prepulse levels and with no effect on TSR. When light was used as the prepulse, PRM increased ASR and TSR at 6h with no interaction with prepulse levels. DLM decreased ASR and TSR on trials without prepulses but not on trials with acoustic prepulses. DLM also decreased ASR when light prepulses were present 4h post-treatment. A final experiment assessed whether the house light in the test cabinet affected ASR and TSR after PRM or DLM exposure. Rats had increased ASR and TSR when house lights were on compared with when they were off, but lighting did not differentially interact with PRM or DLM. Light and acoustic prepulses of ASR and TSR have different effects depending on the test agent and the test parameters.

Deltamethrin resistance status of Rhipicephalus (Boophilus) Microplus ticks in gaddi goats of north-western Himalayas, India

In this study, adult immersion test (AIT) and larval packet test (LPT) were employed for the evaluation of deltamethrin resistance status in Rhipicephalus (Boophilus) microplus ticks collected from organised and unorganised goat farms of Palampur (Himachal Pradesh). On AIT, the mean mortality varied significantly (P<0.05) fromnil (controland upto 200 ppm delta methrin) to 40.0±0.24% (800 ppm delta methrin). The inhibition of oviposition varied significantly (P<0.05) from nil (control) to 28.83% (800 ppm deltamethrin). The RF (resistance factor) values on AIT and LPT were 23.98 and 10.2, respectively, suggesting level II of resistance (moderate) against deltamethrin in Rhipicephalus (Boophilus) microplus ticks from Gaddi goats of north-western Himalayas.

Efficacy of Synthetic Pyrethroids on Camel Ticks Hyalomma dromedarii “Acari: Ixodidae” in Saudi Arabia

Arthropods are highly effective vectors for a number of life threatening pathogens, parasites, viruses etc., across the world. Hyalomma dromedarii Koch is the prominent tick species infesting camels. Therefore, in this research we studied the insecticidal efficacy of commercially available deltamethrin (DM), Cypermethrin (Cym) and &alpha;-Cypermethrin (&alpha;-Cym) in the fight against the adult of H. dromedarii through in vitro immersion bioassays. In this study, different concentrations of all

Neuromodulatory effect of cinnamon oil on behavioural disturbance, CYP1A1, iNOStranscripts and neurochemical alterations induced by deltamethrin in rat brain

The objective of this study was to investigate the influence of deltamethrin (DLM)on brain function and to find whether DLM-induced neurotoxicity is prevented by the treatment with cinnamon oil. Four groups of ten Wistar albino male rats each were used. Group I (control) received saline only. Group II received cinnamon oil alone at 0.5 mg/kg B.W. intraperitonally, whereas Group III received orally DLM alone at 6 mg/kg B.W. Groups IV was treated with cinnamon oil plus DLM for 21 days to induce neurotoxicity. Rat behaviour, brain acetylcholine esterase (AChE), serotonin, oxidative stress profile were assessed. Serum sampling for the assessment of corticosterone concentration was also carried out. Finally, we demonstrate the gene expression of CYP1A1 and iNOS and the histological picture of the brain. Considering the behaviour assessment, DLM administration alone caused neurobehavioral deficits manifested by anxiety-like behavior which represented ina marked decrease in the sleeping frequency and duration, and marked increase the digging frequency and a wake non-active behavior duration. Moreover, the open field result showed a significant decrease in central square entries and duration. The neurochemical analysis revealed that DLM significantly suppressed AChE activity and elevated serotonin and corticosterone concentrations. Furthermore, results revealed thatthe brain reduced glutathione (GSH) content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration were significantly altered in DLM treated rats. Neurochemical disturbances were confirmed by histopathological changes in the brain. Furthermore, DLM up-regulates the mRNA expression of brain CYP1A1 and iNOS. Co-treatment with cinnamon oil exhibited significant improvement in behavioural performance and the brain antioxidant capacities with an increase in AChE activity and diminished the concentration of serotonin, serum corticosterone and MDA. Cinnamon oil treatment resulted in down-regulation of CYP1A1 and iNOS and improve the histologically picture. In conclusion, cinnamon oil ameliorated DLM-induced neurotoxicity through preventing oxidative stress-induced genotoxicity and apoptosis of brain in rats.

Mesoporous molecularly imprinted polymer core@shell hybrid silica nanoparticles as adsorbent in microextraction by packed sorbent for multiresidue determination of pesticides in apple juice

In this work, we report the synthesis of a mesoporous molecularly imprinted polymer on the surface of silica nanoparticles (core@mMIP) to be applied as adsorbent in microextraction by packed sorbent (MEPS) for selective determination of pesticides in apple juice. The core@mMIP was properly characterized, showing good adhesion of the polymer to the silica core. The best extraction conditions were: 200 µL of ultrapure water as washing solvent,150 µL of acetonitrile as eluent, 100 µL of sample at pH 2.5, five draw-eject cycles and 8 mg of adsorbent. Thereby, recoveries of 96.12 ± 1.05%, 76.88 ± 6.18% and 76.18 ± 5.57% were obtained for pyriproxyfen (PPX), deltamethrin (DTM) and etofenprox (ETF), respectively. After validation, the method presented linearity in the range of 0.02–10 µg mL−1 (r > 0.99), limit of detection of 0.005 µg mL−1, satisfactory selectivity, and proper precision and accuracy. The method was successfully applied real samples of processed and fresh apple juice.

Changes of embryonic development, locomotor activity, and metabolomics in zebrafish co-exposed to chlorpyrifos and deltamethrin.

Organophosphates (OPs) and pyrethroids (PYRs) are extensively used pesticides and often occur in the form of mixture, whereas little was known about their joint toxicities. We aim to investigate the individual and joint effects of OPs and PYRs exposure on zebrafish embryo by employing chlorpyrifos (CPF) and deltamethrin (DM) as representatives. Zebrafish embryos at 2hours post fertilization (hpf) were exposed to CPF (4.80, 39.06, and 78.13μg/L), DM exposure (0.06, 1.60, and 3.19μg/L), and CPF+DM (4.80+0.06, 39.06+1.60, and 78.13+3.19μg/L) until 144hpf. Embryonic development, locomotor activity, and metabolomic changes were recorded and examined. Results displayed that individual exposure to CPF and DM significantly increased the mortality and malformation rate of zebrafish embryos, but decreased hatching rate was only found in CPF+DM co-exposure groups (p<.05). Meanwhile, individual CPF exposure had no detrimental effect on locomotor activity, high dose of individual CPF exposure decreased the swimming speed but had adaptability to the conversion from dark to light, whereas high dose of CPF+DM co-exposure exhibited not only significant decline in swimming speed but also no adaptability to the repeated stimulations, suggesting deficit in learning and memory function. In metabolomic analysis, individual CPF exposure mainly influenced the metabolism of glycerophospholipids and amino acids, individual DM exposure mainly influenced glycerophospholipids, and CPF+DM co-exposure mainly influenced glycerophospholipids and amino acids. Taken together, our findings suggested the embryonic toxicities and neurobehavioral changes caused by CPF and/or DM exposure. The disorder metabolomics of glycerophospholipids and amino acids might be involved in the underlying mechanism of those toxicities.