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Maximiliano JE, Ares I, Martínez M, Lopez-Torres B, Martínez-Larrañaga MR, Anadón A, Martínez MA. Dopaminergic and serotoninergic systems as preferential targets of the pyrethroid tefluthrin exposure in the rat brain. Environ Res 2024; 247:118239. [PMID: 38244974 DOI: 10.1016/j.envres.2024.118239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
The monoaminergic systems dopamine (DA) and serotonin (5-HT) play important roles in neuromodulation, such as motor control, cognitive, affective, and neuroendocrine functions. In the present research study, we addressed the hypothesis that exposure to Type I pyrethroid tefluthrin may specifically target the dopaminergic and serotoninergic systems. Tefluthrin could modify brain monoamine neurotransmitters, DA and 5-HT levels as well as dopaminergic and serotoninergic signaling pathways. Adult male Wistar rats were treated with tefluthrin [2.2, 4.4 and 5.5 mg/kg bw, equivalent to 1/10, 1/5 and 1/4 of the acute oral rat lethal dose 50 (LD50) value] by oral gavage, six days. After last dose of tefluthrin, DA and 5-HT and metabolites levels were determined in brain regions (striatum, hippocampus, prefrontal cortex and hypothalamus). Tefluthrin induced a decrease of DA, 5-HT and metabolites contents, in a brain regional- and dose-related manner. The major decreases in DA and 5-HT contents were observed in prefrontal cortex tissue. Here, we studied that in vivo exposure to tefluthrin may alter DA and 5-HT neurotransmission in prefrontal cortex. Transcripts related to (i) dopaminergic [dopamine transporter 1 (Dat1), tyrosine hydroxylase (TH), dopamine receptors (Drd1, Drd2)], (ii) serotoninergic [serotonin transporter (SERT), tryptophan hydroxylase 2 (TPH2), serotonin receptors (5-HT1A, 5-HT2A)] and (iii) DA and 5-HT degradation [monoamine oxidases (MAOA, MAOB)] signaling pathways were investigated. Results showed that tefluthrin induced down-regulation of transcripts responsible for the synthesis and action of DA (TH, Drd1, Drd2) and 5-HT (SERT, TPH2). In contrast, tefluthrin treatment induced up-regulation of genes involved in DA transporter (Dat1), 5-HT receptors (5-HT1A, 5-HT2A) and monoamine oxidases (MAOA, MAOB). Given the integral roles of mitochondrial dysfunction and dopaminergic and serotoninergic alterations as hallmarks of neurodegenerative diseases, our data suggest that tefluthrin may be a candidate for pesticides contributing to neurodegenerative disorders pathogenesis by causing damage to the DA and 5-HT systems.
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Affiliation(s)
- Jorge-Enrique Maximiliano
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Irma Ares
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain.
| | - Marta Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain.
| | - Bernardo Lopez-Torres
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - María-Rosa Martínez-Larrañaga
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Arturo Anadón
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - María-Aránzazu Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain
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Lai HJ, Lee MJ, Yu HW, Chen KW, Tsai KL, Lin PC, Huang CW. Biophysical mechanisms underlying tefluthrin-induced modulation of gating changes and resurgent current generation in the human Na v1.4 channel. Pestic Biochem Physiol 2024; 200:105833. [PMID: 38582596 DOI: 10.1016/j.pestbp.2024.105833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 02/14/2024] [Accepted: 02/17/2024] [Indexed: 04/08/2024]
Abstract
Human skeletal muscle contraction is triggered by activation of Nav1.4 channels. Nav1.4 channels can generate resurgent currents by channel reopening at hyperpolarized potentials through a gating transition dependent on the intracellular Navβ4 peptide in the physiological conditions. Tefluthrin (TEF) is a pyrethroid insecticide that can disrupt electrical signaling in nerves and skeletal muscle, resulting in seizures, muscle spasms, fasciculations, and mental confusion. TEF can also induce tail currents through other voltage-gated sodium channels in the absence of Navβ4 peptide, suggesting that muscle spasms may be caused by resurgent currents. Further, intracellular Navβ4 peptide and extracellular TEF may show competitive or synergistic effects; however, their binding sites are still unknown. To address these issues, electrophysiological recordings were performed on CHO-K1 cells expressing Nav1.4 channels with intracellular Navβ4 peptide, extracellular TEF, or both. TEF and Navβ4 peptide induced a hyperpolarizing shift of activation and inactivation curves in the Nav1.4 channel. TEF also substantially prolonged the inactivation time constants, while simultaneous application of Navβ4 peptide partially reversed this effect. Resurgent currents were enhanced by TEF and Navβ4 peptide at negative potentials, but TEF more potently enhances resurgent currents and dampens decay of resurgent currents. With longer depolarization, peak resurgent currents decay was fastest with the TEF alone. Molecular docking suggested that TEF and Navβ4 peptide binding site(s) are not in the narrowest part of the channel pore, but rather in the bundle-crossing regions and in the domain linkers, respectively. TEF can induce resurgent currents independently and synergistically with Navβ4 peptide, which may explain the muscle spasms observed in TEF intoxication.
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Affiliation(s)
- Hsing-Jung Lai
- Department of Neurology, National Taiwan University Hospital, Taipei 10617, Taiwan; Department of Physiology, National Taiwan University, Taipei 10617, Taiwan
| | - Ming-Jen Lee
- Department of Neurology, National Taiwan University Hospital, Taipei 10617, Taiwan; Department of Medical genetics, National Taiwan University Hospital, Taipei 10617, Taiwan
| | - Hsin-Wei Yu
- Department of Physiology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Kuan-Wen Chen
- Genetics Generation Advancement Corporation, Taipei 11494, Taiwan
| | - Ke-Li Tsai
- Department of Physiology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Pi-Chen Lin
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan
| | - Chiung-Wei Huang
- Department of Physiology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Department of Post-Baccalaureate Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
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Wang H, Xu W, Li L. Tefluthrin induced toxicities in zebrafish: Focusing on enantioselectivity. Pestic Biochem Physiol 2023; 195:105572. [PMID: 37666624 DOI: 10.1016/j.pestbp.2023.105572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/25/2023] [Accepted: 08/07/2023] [Indexed: 09/06/2023]
Abstract
Tefluthrin is one of widely used chiral pyrethroid pesticides. The potential enantioselective risk posed by tefluthrin to the aquatic ecosystem is still unclear. In this study, the toxicity differences and corresponding mechanism of tefluthrin on zebrafish were investigated at the enantiomeric level. The results indicated that two tefluthrin enantiomers showed different acute toxicity, developmental toxicity and oxidative stress to zebrafish. The acute toxicity of (1R,3R)-tefluthrin was 130-176 fold as that of (1S,3S)-tefluthrin on zebrafish embryos, larvae and adults. (1R,3R)-Tefluthrin presented approximately 10, 3 and 2 times inhibition effect on the deformity rate, hatching rate and spontaneous movements on embryos as that of (1S,3S)-tefluthrin. Meanwhile, (1R,3R)-tefluthrin caused stronger oxidative stress on zebrafish embryo than (1S,3S)-tefluthrin. The molecular docking results revealed that there were stereospecific binding affinities between tefluthrin enantimers and sodium channel protein (Nav1.6), which may lead to acute toxicity differences. Transcriptome analysis showed that the two tefluthrin enantiomers markedly disturbed differential embryonic genes expression, thereby potentially causing the chronic enantioselective toxicity. The findings of the study reveal the toxicity differences and potential mechanism of tefluthrin enantiomers on zebrafish. These results also provides a foundation for a systematic evaluation of tefluthrin at enantiomer level.
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Affiliation(s)
- Hongjie Wang
- Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, School of Eco-Environment, Hebei University, Baoding 071002, China; Institute of Xiong'an New Area, Hebei university, Baoding 071002, China; College of Life Science, Hebei University, Baoding 071002, China
| | - Weiye Xu
- Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, School of Eco-Environment, Hebei University, Baoding 071002, China
| | - Lianshan Li
- Hebei Key Laboratory of Close-to-Nature Restoration Technology of Wetlands, School of Eco-Environment, Hebei University, Baoding 071002, China; Institute of Xiong'an New Area, Hebei university, Baoding 071002, China.
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Wang X, Li H, Wang S, Martínez MA, Ares I, Martínez M, Martínez-Larrañaga MR, Wang X, Anadón A, Maximiliano JE. Tefluthrin: metabolism, food residues, toxicity, and mechanisms of action. Crit Rev Toxicol 2022; 52:664-680. [PMID: 36625435 DOI: 10.1080/10408444.2022.2143320] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Tefluthrin is a Type I pyrethroid insecticide widely used all over the world. Residues of tefluthrin in various agricultural and animal-derived products may be related to potential human health risks. Tefluthrin metabolism in mammals involves hydrolysis of the ester bond to form cyclopropane acid and 4-methylbenzyl alcohol moieties, followed by oxidation. In this review manuscript, we provide crucial information regarding the toxicity of pyrethroids and propose natural antioxidants for amelioration poisoning in humans and animals. We call for the rational use of tefluthrin as an agrochemical product and for greater attention to the residual toxicity caused by tefluthrin in primary and succeeding crops. This greater attention is required given the global use of tefluthrin.
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Affiliation(s)
- Xiaohui Wang
- National Reference Laboratory of Veterinary Drug Residues, MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University (HZAU), Wuhan, PR China
| | - Houpeng Li
- National Reference Laboratory of Veterinary Drug Residues, MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University (HZAU), Wuhan, PR China
| | - Simeng Wang
- National Reference Laboratory of Veterinary Drug Residues, MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University (HZAU), Wuhan, PR China
| | - María-Aránzazu Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
| | - Irma Ares
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
| | - Marta Martínez
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
| | - María-Rosa Martínez-Larrañaga
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues, MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University (HZAU), Wuhan, PR China.,Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain.,MAO Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, PR China.,Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan, PR China
| | - Arturo Anadón
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
| | - Jorge-Enrique Maximiliano
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid (UCM), Research Institute Hospital 12 de Octubre (i + 12), Madrid, Spain
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Wu G, Li Q, Liu X, Li-Byarlay H, He B. Differential state-dependent effects of deltamethrin and tefluthrin on sodium channels in central neurons of Helicoverpa armigera. Pestic Biochem Physiol 2021; 175:104836. [PMID: 33993961 DOI: 10.1016/j.pestbp.2021.104836] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
The cotton bollworm, Helicoverpa armigera is one of the worldwide pests. Electrophysiological properties of voltage-gated sodium channels in central neurons of sensitive and pyrethroid resistant H. armigera were investigated using whole-cell patch clamp technique. The modification effects of pyrethroid insecticides deltamethrin and tefluthrin on sodium channels were also compared. The V0.5 of voltage dependence of activation of resistant H. armigera sodium channels (resistant channels) exhibited an obvious depolarizing shift by 13.52 mV compared to that of sensitive H. armigera sodium channels (sensitive channels). In contrast, the V0.5 of the voltage dependence of steady-state inactivation of the resistant channels showed a significant hyperpolarizing shift by 7.59 mV in comparison with that of the sensitive channels. The time course of recovery from inactivation for the resistant channels was prolonged significantly, by 0.17 ms, compared with that for the sensitive channels. We also assessed the use-dependent effects of deltamethrin and tefluthrin on sensitive sodium channels. Repetitive depolarization remarkably increased the extent of the sensitive channel modification by 10 μM deltamethrin by ~4.61-fold but had no effect on the extent of sensitive channel modifications by 10 μM tefluthrin. These results provide more direct evidence for the presence of nerve insensitivity in resistant H. armigera strains in North of China. The sodium channels of the resistant H. armigera differ from those of the sensitive H. armigera in the fundamental electrophysiological properties, and correspondingly, have a different response to the modification of pyrethroids. Both deltamethrin and tefluthrin have effects on the closed state of the sensitive sodium channels, but deltamethrin has higher affinity to the open state of these channels.
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Affiliation(s)
- Guangyan Wu
- Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Qingya Li
- Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiao Liu
- Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hongmei Li-Byarlay
- Agricultural Research and Development Program, Central State University, 1400 Brush Row Road, Wilberforce, OH, USA
| | - Bingjun He
- Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
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Wen Y, Zhou L, Li D, Lai Q, Shi H, Wang M. Ecotoxicological effects of the pyrethroid insecticide tefluthrin to the earthworm Eisenia fetida: A chiral view. Environ Res 2020; 190:109991. [PMID: 32768725 DOI: 10.1016/j.envres.2020.109991] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/14/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Tefluthrin was the first pyrethroid developed for soil treatment. There was no report about the toxicity to terrestrial invertebrates at the enantiomer level. The main objective of the present study was to investigate the enantiomer-specific acute toxicity to the earthworm Eisenia fetida and potential mechanism via multilevel response. The filter paper contact and the artificial soil method were used to detect the acute toxicity of tefluthrin enantiomers to earthworms. Histopathological examination (H&E), biochemical criterion, and comet assay were used to identify the effects and potential mechanism of toxicity. The order of acute toxicity was Z-cis-(1S,3S)-(-)-tefluthrin < Rac-tefluthrin < Z-cis-(1R,3R)-(+)-tefluthrin. H&E stained images showed that intestinal cells were suffered seriously damaged after exposed to Rac-tefluthrin, and the Z-cis-(1R,3R)-(+)-isomer. Tefluthrin and enantiomers also enantioselectively disturbed reactive oxygen species (ROS) level and enzymatic activity. Additionally, Z-cis-(1R,3R)-(+)-tefluthrin significantly increased the olive tail moment (OTM) and Trail DNA% compared with the control and other treatment groups at the concentration of 0.1 mg/kg was observed. It can be concluded that intestinal damage, body weight changes, DNA damage caused by oxidative stress that might be the primary mechanisms of tefluthrin toxicity to earthworms. The results indicated the rational use of chiral compounds in agriculture to avoid damage to the soil ecosystem.
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Affiliation(s)
- Yong Wen
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China
| | - Liangliang Zhou
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China
| | - Da Li
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China
| | - Qi Lai
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China
| | - Haiyan Shi
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China
| | - Minghua Wang
- Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, 210095, China.
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So EC, Wu SN, Lo YC, Su K. Differential regulation of tefluthrin and telmisartan on the gating charges of I Na activation and inactivation as well as on resurgent and persistent I Na in a pituitary cell line (GH 3). Toxicol Lett 2018; 285:104-112. [PMID: 29306026 DOI: 10.1016/j.toxlet.2018.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/23/2017] [Accepted: 01/02/2018] [Indexed: 12/19/2022]
Abstract
Voltage-gated Na+ currents (INa), known to contain many components (e.g., transient, resurgent and persistent INa) with unique gating properties, are involved in the generation and propagation of action potentials in excitable cells. In this study, how tefluthrin (Tef), a synthetic pyrethoid, and telmisartan (TEL), blocker of angiotensin II receptors can perturb those components of INa was investigated. The presence of either Tef or TEL increased the values of the gating charges of INa involved in the activation (za) and inactivation (zi). Tef also increased the amplitude of resurgent INa (INa(R)) or persistent INa (INa(P)) in a pituitary cell line (GH3), while TEL produced minimal effects on them. Subsequent addition of either ranolazine (a blocker of late INa) or d-limonene (a monoterpene), could reverse the changes by TEL or Tef on za or zi. In SCN5A-expressing HEK293T cells, addition of Tef or TEL also increased the peak amplitude and the inactivation time constant of INa which was accompanied by the increased za value of INa. Taken together, the results indicated that Tef- or TEL-mediated changes in the gating kinetics of INa are linked to their actions on functional activity of neurons, neuroendocrine or endocrine cells.
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Affiliation(s)
- Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, 70965, Tainan City, Taiwan; Department of Anesthesia, China Medical University, 40447 Taichung City, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, 70101 Tainan City, Taiwan.
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, 80756 Kaohsiung City, Taiwan.
| | - Kevin Su
- Department of Medicine, Shanghai Medical College, Fudan University, Shanghai City, China.
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Huff Hartz KE, Edwards TM, Lydy MJ. Fate and transport of furrow-applied granular tefluthrin and seed-coated clothianidin insecticides: Comparison of field-scale observations and model estimates. Ecotoxicology 2017; 26:876-888. [PMID: 28560497 DOI: 10.1007/s10646-017-1818-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/17/2017] [Indexed: 06/07/2023]
Abstract
The transport of agricultural insecticides to water bodies may create risk of exposure to non-target organisms. Similarly, widespread use of furrow-applied and seed-coated insecticides may increase risk of exposure, yet accessible exposure models are not easily adapted for furrow application, and only a few examples of model validation of furrow-applied insecticides exist using actual field data. The goal of the current project was to apply an exposure model, the Pesticide in Water Calculator (PWC), to estimate the concentrations of two in-furrow insecticides applied to maize: the granular pyrethroid, tefluthrin, and the seed-coated neonicotinoid, clothianidin. The concentrations of tefluthrin and clothianidin in surface runoff water, sampled from a field in central Illinois (USA), were compared to the PWC modeled pesticide concentrations in surface runoff. The tefluthrin concentrations were used to optimize the application method in the PWC, and the addition of particulate matter and guttation droplets improved the models prediction of clothianidin concentrations. Next, the tefluthrin and clothianidin concentrations were calculated for a standard farm pond using both the optimized application method and the application methods provided in PWC. Estimated concentrations in a standard farm pond varied by a factor of 100 for tefluthrin and 50 for clothianidin depending on the application method used. The addition of guttation droplets and particulate matter to the model increased the annual clothianidin concentration in a standard farm pond by a factor of 1.5, which suggested that these transport routes should also be considered when assessing neonicotinoid exposure.
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Affiliation(s)
- Kara E Huff Hartz
- Center for Fisheries, Aquaculture, and Aquatic Sciences, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Tracye M Edwards
- Center for Fisheries, Aquaculture, and Aquatic Sciences, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Michael J Lydy
- Center for Fisheries, Aquaculture, and Aquatic Sciences, Southern Illinois University Carbondale, Carbondale, IL, USA.
- Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL, USA.
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Soderlund DM, Tan J, He B. Functional reconstitution of rat Na v1.6 sodium channels in vitro for studies of pyrethroid action. Neurotoxicology 2017; 60:142-149. [PMID: 27013268 PMCID: PMC5031521 DOI: 10.1016/j.neuro.2016.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/17/2016] [Accepted: 03/17/2016] [Indexed: 01/14/2023]
Abstract
The ability to reconstitute sodium channel function and pharmacology in vitro using cloned subunits of known structure has greatly enhanced our understanding of the action of pyrethroid insecticides at this target and the structural determinants of resistance and interspecies selectivity. However, the use of reconstituted channels raises three critical questions: (1) Which subunits and subunit combinations should be used? (2) Which heterologous expression system is preferred? (3) Which combination of subunits and expression system best represents the function of native neuronal channels in the organism of interest? This review considers these questions from the perspective of recent research in this laboratory on the action of pyrethroid insecticides on rat Nav1.6 sodium channels by comparing the effects of heteroligomeric complex composition on channel function and insecticide response when channels are expressed in either Xenopus oocytes or stably-transformed HEK293 cells. These comparisons provide new insight into the influence of cellular context on the functional and pharmacological properties of expressed channels, the modulatory effects of sodium channel auxiliary subunits on the action of pyrethroids, and the relative fidelity of the Xenopus oocyte and HEK293 cell expression systems as model systems for studying of channel function and pyrethroid action.
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Affiliation(s)
- David M Soderlund
- Department of Entomology, Cornell University, Geneva, NY 14456, USA.
| | | | - Bingjun He
- College of Life Sciences, Nankai University, Tianjin 300071, China
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Whiting SA, Lydy MJ. A site-specific ecological risk assessment for corn-associated insecticides. Integr Environ Assess Manag 2015; 11:445-458. [PMID: 25557061 DOI: 10.1002/ieam.1613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/08/2014] [Accepted: 11/20/2014] [Indexed: 06/04/2023]
Abstract
A site-specific ecological risk assessment (ERA) was conducted to examine the simultaneous use of genetically modified corn (Bt corn) with a neonicotinoid seed coating, clothianidin, and use of a granular insecticide, tefluthrin, to protect crops from pest damage. A field study was conducted on site, and exposure data from the literature were summarized to determine the matrices and exposure concentrations that nontarget species could typically experience within an agricultural ecosystem. To determine ecological effects on nontarget species, acute toxicity bioassays were conducted on earthworms (Eisenia fetida), amphipods (Hyalella azteca), and Elmid riffle beetle larvae (Ancyronyx spp.) in which the test species were exposed to single insecticides as well as the mixture of the 3 insecticides. In the risk characterization section of the ERA, stressor-response profiles for each species tested were compared with field distributions of the insecticides, and a margin of safety at the 10th percentile (MOS10) was calculated to estimate risk. No acute toxicity was observed in any of the 3 nontarget species after exposure to senescent Bt corn leaf tissue. Large MOS10 values were calculated for clothianidin to the nontarget species. When bioassays were compared with tefluthrin field distributions, very low MOS10 values were calculated for earthworms (0.06) and H. azteca (0.08) because the environmental concentrations often exceeded the stressor-response profile. No increased toxicity was observed when nontarget species were exposed to a mixture of the 3 insecticides. In summary, the genetically modified corn insecticidal proteins and clothianidin were not found at environmental concentrations exceeding benchmark values for ecological effects, but tefluthrin was consistently detected in the environment at levels that could be causing toxicity to nontarget species, especially if this pyrethroid is able to travel off site.
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Affiliation(s)
- Sara A Whiting
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois, USA
| | - Michael J Lydy
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois, USA
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Whiting SA, Strain KE, Campbell LA, Young BG, Lydy MJ. A multi-year field study to evaluate the environmental fate and agronomic effects of insecticide mixtures. Sci Total Environ 2014; 497-498:534-542. [PMID: 25163650 DOI: 10.1016/j.scitotenv.2014.07.115] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/29/2014] [Accepted: 07/29/2014] [Indexed: 06/03/2023]
Abstract
A mixture of insecticides used in corn production was monitored over a three-year period in a field study to determine how long each persists in the environment, where each insecticide travels within the corn field, and the efficacy of using soil-applied insecticides with genetically modified corn. The genetically modified corn contained the insecticidal Cry1Ab and Cry3Bb1 proteins (Bt corn) and the Cry1Ab protein was found to persist only during the corn growing season in soil, runoff water, and runoff sediment with highest concentrations measured during pollination. Very low concentrations of Cry1Ab proteins were measured in soil collected in the non-Bt corn field, and no Cry1Ab proteins were detected in shallow groundwater or soil pore water. Clothianidin, a neonicotinoid insecticide used as a seed coating, was detected in all matrices and remained persistent throughout the year in soil pore water. Tefluthrin, a pyrethroid insecticide applied at planting to control corn rootworm larvae (Diabrotica spp., Coleoptera: Chrysomelidae) populations, was consistently detected in soil, runoff water, and runoff sediment during the corn growing season, but was not detected in groundwater or soil pore water. Tefluthrin did not have an effect on root damage from corn rootworm larvae feeding to Bt corn, but did prevent damage to non-Bt corn. A slight reduction in grain yield was observed in the non-Bt, no tefluthrin treatment when compared to all other treatments, but no significant difference in grain yield was observed among Bt corn treatments regardless of soil insecticide application. In the current study, the use of tefluthrin on Bt corn did not significantly affect crop damage or yield, and tefluthrin may travel off-site in runoff water and sediment.
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Affiliation(s)
- Sara A Whiting
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, 1125 Lincoln Dr., Southern Illinois University, Carbondale, IL 62901, USA.
| | - Katherine E Strain
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, 1125 Lincoln Dr., Southern Illinois University, Carbondale, IL 62901, USA.
| | - Laura A Campbell
- Plant, Soil, and Agricultural Systems Department, 1205 Lincoln Dr., Southern Illinois University, Carbondale, IL 62901, USA.
| | - Bryan G Young
- Plant, Soil, and Agricultural Systems Department, 1205 Lincoln Dr., Southern Illinois University, Carbondale, IL 62901, USA.
| | - Michael J Lydy
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, 1125 Lincoln Dr., Southern Illinois University, Carbondale, IL 62901, USA.
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Schumann M, Patel A, Vemmer M, Vidal S. The role of carbon dioxide as an orientation cue for western corn rootworm larvae within the maize root system: implications for an attract-and-kill approach. Pest Manag Sci 2014; 70:642-650. [PMID: 23821604 DOI: 10.1002/ps.3602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/31/2013] [Accepted: 07/02/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Western corn rootworm larvae use CO2 to locate maize roots. However, the importance of CO2 as a specific orientation cue close to maize roots has not been investigated unequivocally. This study aimed at elucidating the effect of CO2 -emitting capsules in combination with a soil insecticide (Tefluthrin = attract and kill) within the root system. We hypothesized that the capsules would result in aggregation of the larvae at the soil insecticide, thus increasing its efficacy. A nondestructive observation device was used to study larval distribution and behaviour. RESULTS Spatial analysis of distance indices (SADIE) revealed aggregation of the larvae around the capsules in an attract-and-kill treatment after 4 h, which was not found with the conventional treatment without the capsules. However, larval mortality did not differ between treatments. CONCLUSION CO2 is a weak attractant for western corn rootworm larvae within the root system. Consequently, an attract-and-kill strategy based on a CO2 product will not contribute to better control compared with conventional Tefluthrin applications. Host-specific compounds, combined with a CO2 source, should be used to target more larvae, making attract and kill a feasible management option against this pest.
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Affiliation(s)
- Mario Schumann
- Georg-August University, Department of Crop Science, Agricultural Entomology, Göttingen, Germany
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