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Liu S, Pei H, Chen W, Zhu X, Wang Y, Li J, He Z, Du R. Evaluating the effect of ginsenoside Rg1 on CPF-induced brain injury in mice via PI3k/AKT pathway. J Biochem Mol Toxicol 2023; 37:e23319. [PMID: 36811218 DOI: 10.1002/jbt.23319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 12/13/2022] [Accepted: 02/02/2023] [Indexed: 02/24/2023]
Abstract
Organophosphorus pesticides (OPs) have long been used extensively on agricultural land and can lead to significant improvements in crop yields. Due to occupational exposure, humans are exposed to pesticides through dermal contact, inhalation, and ingestion. The effects of OPs on the organism are currently studied for their effects on livers, kidneys, hearts, blood indicators, neurotoxicity, and teratogenic, carcinogenic, and mutagenic effects, while studies in the direction of brain tissue damage have not been reported in detail. Previous reports have confirmed that ginsenoside Rg1 is a prominent and representative tetracyclic triterpenoid derivative rich in ginseng and has good neuroprotective activity. Considering that, the aim of this study was to establish a mouse model of brain tissue injury by using the OP-type pesticide chlorpyrifos (CPF) and to explore the therapeutic effects and possible molecular mechanisms of Rg1. Mice in the experimental group were pre-protected with Rg1 by gavage for 1 week, and brain tissue damage was induced using CPF (5 mg/kg for 1 week) to assess the effect of Rg1 (80 and 160 mg/kg for 3 weeks) in alleviating brain damage. Morris water maze and histopathological analysis were performed to assess cognitive function and pathological changes in the mouse brain, respectively. Protein expression levels of Bax, Bcl-2, Caspase-3, Cl-Cas-3, Caspase-9, Cl-Cas-9, phosphoinositide 3-kinase (PI3K), phosphorylated-PI3K, protein kinase B (AKT), and phosphorylated-AKT were quantified by protein blotting analysis. Rg1 obviously restored CPF-induced oxidative stress damage in mouse brain tissue, increased the levels of antioxidant parameters (total superoxide dismutase, total antioxidative capacity, and glutathione) in the brain, and significantly reduced the overexpression of apoptosis-related proteins induced by CPF. At the same time, Rg1 also markedly attenuated the histopathological changes in the brain induced by CPF exposure. Mechanistically, Rg1 could effectively activate the phosphorylation of PI3K/AKT. Furthermore, molecular docking studies revealed a stronger binding capacity between Rg1 and PI3K. Rg1 attenuated neurobehavioural alterations and reduced lipid peroxidation in the mouse brain to a great extent. Apart from that, Rg1 administration improved brain histopathology in CPF-induced rats. All results suggest that ginsenoside Rg1 has potential antioxidant effects on CPF-induced oxidative brain injury, and it is evident that Rg1 could be used as a promising therapeutic strategy for the study of brain injury from OP poisoning.
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Affiliation(s)
- Silu Liu
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Hongyan Pei
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Weijia Chen
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China.,Jilin Provincial Engineering Research Center for Efficient Breeding and Product Development of Sika Deer, Jilin Agricultural University, Changchun, Jilin, China
| | - Xiaoying Zhu
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Yu Wang
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Jianming Li
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Zhongmei He
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China
| | - Rui Du
- College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, Jilin, China.,Jilin Provincial Engineering Research Center for Efficient Breeding and Product Development of Sika Deer, Jilin Agricultural University, Changchun, Jilin, China.,Key Laboratory of Animal Production and Product Quality and Safety, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
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Boedeker W, Watts M, Clausing P, Marquez E. The global distribution of acute unintentional pesticide poisoning: estimations based on a systematic review. BMC Public Health 2020; 20:1875. [PMID: 33287770 PMCID: PMC7720593 DOI: 10.1186/s12889-020-09939-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Human poisoning by pesticides has long been seen as a severe public health problem. As early as 1990, a task force of the World Health Organization (WHO) estimated that about one million unintentional pesticide poisonings occur annually, leading to approximately 20,000 deaths. Thirty years on there is no up-to-date picture of global pesticide poisoning despite an increase in global pesticide use. Our aim was to systematically review the prevalence of unintentional, acute pesticide poisoning (UAPP), and to estimate the annual global number of UAPP. METHODS We carried out a systematic review of the scientific literature published between 2006 and 2018, supplemented by mortality data from WHO. We extracted data from 157 publications and the WHO cause-of-death database, then performed country-wise synopses, and arrived at annual numbers of national UAPP. World-wide UAPP was estimated based on national figures and population data for regions defined by the Food and Agriculture Organization (FAO). RESULTS In total 141 countries were covered, including 58 by the 157 articles and an additional 83 by data from the WHO Mortality Database. Approximately 740,000 annual cases of UAPP were reported by the extracted publications resulting from 7446 fatalities and 733,921 non-fatal cases. On this basis, we estimate that about 385 million cases of UAPP occur annually world-wide including around 11,000 fatalities. Based on a worldwide farming population of approximately 860 million this means that about 44% of farmers are poisoned by pesticides every year. The greatest estimated number of UAPP cases is in southern Asia, followed by south-eastern Asia and east Africa with regards to non-fatal UAPP. CONCLUSIONS Our study updates outdated figures on world-wide UAPP. Along with other estimates, robust evidence is presented that acute pesticide poisoning is an ongoing major global public health challenge. There is a need to recognize the high burden of non-fatal UAPP, particularly on farmers and farmworkers, and that the current focus solely on fatalities hampers international efforts in risk assessment and prevention of poisoning. Implementation of the international recommendations to phase out highly hazardous pesticides by the FAO Council could significantly reduce the burden of UAPP.
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Affiliation(s)
| | - Meriel Watts
- PAN Asia Pacific, P.O. Box 1170, 10850, Penang, Malaysia
| | | | - Emily Marquez
- PAN North America, 2029 University Ave., Suite 200, Berkeley, CA, 94704, USA
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Ramírez-Santana M, Zúñiga-Venegas L, Corral S, Roeleveld N, Groenewoud H, Van der Velden K, Scheepers PTJ, Pancetti F. Reduced neurobehavioral functioning in agricultural workers and rural inhabitants exposed to pesticides in northern Chile and its association with blood biomarkers inhibition. Environ Health 2020; 19:84. [PMID: 32698901 PMCID: PMC7374955 DOI: 10.1186/s12940-020-00634-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 07/03/2020] [Indexed: 05/16/2023]
Abstract
BACKGROUND Previous biomonitoring studies have shown that people in the rural population of Coquimbo, the major agricultural area in northern Chile are being occupationally and environmentally exposed to organophosphate/carbamate (OP/CB) pesticides. Given their harmful effects, this study had two aims; first, to evaluate the effect of cumulative or chronic exposure to OP/CB pesticides on the neurobehavioral performance of agricultural workers and rural inhabitants; second, to determine if changes in the neurobehavioral performance are associated to changes in blood biomarkers of OP/CB pesticides during the spray season, when exposure is higher. METHODS For the first aim, a cross sectional study of neurobehavioral performance in adult volunteers (men and women, 18-50 years-old, right-handed) was carried out in the pre-spray season. Sampling was done by convenience and a questionnaire was used to categorize participants depending on their level of chronic exposure, as either: occupationally exposed (OE, n = 87), environmentally exposed (EE, n = 81), or non-exposed controls or reference group (RG, n = 100). A neurobehavioral test battery consisting of 21 tests to measure cognitive, motor and emotional state was applied. For the second aim, neurobehavioral measures were taken a second time from EE and OE groups during the spray season, and their exposure corroborated by blood-based biomarker inhibition. RESULTS Lower neurobehavioral performance was observed in the pre-spray evaluation of EE and OE groups compared to the non-exposed, OE being the worst performing group. Seasonal exposure impaired performance in both exposure groups on all tests except those on attention and mood. Data modeling of the basal (pre-spray) measurements showed that the level of exposure was the best predictor of performance. During spraying, inhibition of BChE activity in the EE group was the best predictor of low performance in tests measuring logical, auditory and visual memory, inhibitory control of cognitive interference, constructional and planning abilities, executive functions, and motor speed and coordination. CONCLUSION Long-term occupational or environmental exposure to pesticides caused impairment in neurobehavioral functioning, which worsened during the spraying season, mainly in EE. BChE inhibition was the best predictor for seasonal neurobehavioral changes in EE.
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Affiliation(s)
- Muriel Ramírez-Santana
- Departemento de Salud Pública, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
- Radboud university medical center, Nijmegen, The Netherlands
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Liliana Zúñiga-Venegas
- Centro de Investigaciones y Estudios Avanzados de Maule (CIEAM), Universidad Católica del Maule, Talca, Chile
- Centro de Investigación en Neuropsicología y Neurociencias Cognitivas (CINPSI), Universidad Católica del Maule, Talca, Chile
- Laboratorio de Neurotoxicología Ambiental, Facultad de Medicina, Universidad Católica del Norte, Larrondo 1281, 1780000, Coquimbo, Chile
| | - Sebastián Corral
- Laboratorio de Neurotoxicología Ambiental, Facultad de Medicina, Universidad Católica del Norte, Larrondo 1281, 1780000, Coquimbo, Chile
- Laboratorio de Psiquiatría Translacional, Departamento de Psiquiatría y Salud Mental, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Escuela de Psicología, Facultad de Ciencias Sociales, Universidad Central de Chile, Santiago, Chile
| | - Nel Roeleveld
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Hans Groenewoud
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Koos Van der Velden
- Department of Primary and Community Care, Radboud university medical center, Nijmegen, The Netherlands
| | - Paul T J Scheepers
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Floria Pancetti
- Laboratorio de Neurotoxicología Ambiental, Facultad de Medicina, Universidad Católica del Norte, Larrondo 1281, 1780000, Coquimbo, Chile.
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Jiang C, Zhao P, Li W, Tang Y, Liu G. In silico prediction of chemical neurotoxicity using machine learning. Toxicol Res (Camb) 2020; 9:164-172. [PMID: 32670548 DOI: 10.1093/toxres/tfaa016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/01/2020] [Accepted: 03/18/2020] [Indexed: 12/29/2022] Open
Abstract
Neurotoxicity is one of the main causes of drug withdrawal, and the biological experimental methods of detecting neurotoxic toxicity are time-consuming and laborious. In addition, the existing computational prediction models of neurotoxicity still have some shortcomings. In response to these shortcomings, we collected a large number of data set of neurotoxicity and used PyBioMed molecular descriptors and eight machine learning algorithms to construct regression prediction models of chemical neurotoxicity. Through the cross-validation and test set validation of the models, it was found that the extra-trees regressor model had the best predictive effect on neurotoxicity ([Formula: see text] = 0.784). In addition, we get the applicability domain of the models by calculating the standard deviation distance and the lever distance of the training set. We also found that some molecular descriptors are closely related to neurotoxicity by calculating the contribution of the molecular descriptors to the models. Considering the accuracy of the regression models, we recommend using the extra-trees regressor model to predict the chemical autonomic neurotoxicity.
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Affiliation(s)
- Changsheng Jiang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd, Xuhui District, Shanghai 200237, China
| | - Piaopiao Zhao
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd, Xuhui District, Shanghai 200237, China
| | - Weihua Li
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd, Xuhui District, Shanghai 200237, China
| | - Yun Tang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd, Xuhui District, Shanghai 200237, China
| | - Guixia Liu
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Rd, Xuhui District, Shanghai 200237, China
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Neuropathological Mechanisms Associated with Pesticides in Alzheimer's Disease. TOXICS 2020; 8:toxics8020021. [PMID: 32218337 PMCID: PMC7355712 DOI: 10.3390/toxics8020021] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/14/2020] [Accepted: 03/22/2020] [Indexed: 12/12/2022]
Abstract
Environmental toxicants have been implicated in neurodegenerative diseases, and pesticide exposure is a suspected environmental risk factor for Alzheimer’s disease (AD). Several epidemiological analyses have affirmed a link between pesticides and incidence of sporadic AD. Meanwhile, in vitro and animal models of AD have shed light on potential neuropathological mechanisms. In this paper, a perspective on neuropathological mechanisms underlying pesticides’ induction of AD is provided. Proposed mechanisms range from generic oxidative stress induction in neurons to more AD-specific processes involving amyloid-beta (Aβ) and hyperphosphorylated tau (p-tau). Mechanisms that are more speculative or indirect in nature, including somatic mutation, epigenetic modulation, impairment of adult neurogenesis, and microbiota dysbiosis, are also discussed. Chronic toxicity mechanisms of environmental pesticide exposure crosstalks in complex ways and could potentially be mutually enhancing, thus making the deciphering of simplistic causal relationships difficult.
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Anger WK, Farahat FM, Lein PJ, Lasarev MR, Olson JR, Farahat TM, Rohlman DS. Magnitude of behavioral deficits varies with job-related chlorpyrifos exposure levels among Egyptian pesticide workers. Neurotoxicology 2020; 77:216-230. [PMID: 32006538 DOI: 10.1016/j.neuro.2020.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 01/17/2023]
Abstract
Chronic occupational exposure to organophosphorus pesticides (OPs) is consistently associated with deficits on behavioral tests when compared to unexposed comparison groups. However, a dose-response relationship has yet to be established, leading some to doubt an association between occupational OP exposure and behavioral deficits. Pesticide application teams in Egypt who are primarily exposed to one OP, chlorpyrifos (CPF), were recruited into a field assessment. Trail Making A and the more challenging Trail Making B tests were administered to 54 engineers (who supervise the pesticide application process, usually from the side of the field), 59 technicians (who guide the pesticide applicators in the field), 31 applicators (who mix and apply pesticides using knapsack sprayers), and 150 controls (who did not work in the fields) at two different times during the OP application season as well as immediately after applications had ended and 1.5 months later. All participants were males since only males work on pesticide application teams in Egypt. Urinary levels of 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of CPF, confirmed the pattern of lower to higher CPF exposures from engineers to technicians to applicators, and these were all greater than urinary metabolite levels in controls. A consistent relationship between job title and performance speed on the behavioral task was observed: Controls had the best (fastest) performance on Trail Making A and B tests throughout the application season, and applicators had significantly slower performance than engineers on Trail Making A (p = 0.015) and B (p = 0.003). However, individual urinary TCPy, blood acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) levels did not predict individual performance. This study identifies a dose-related effect based on job title, which serves as a surrogate for chronic exposure in that differing job titles exhibit varying group exposure levels. The results establish that chronic occupational exposure to chlorpyrifos is neurotoxic and suggest that the classic biomarkers of recent CPF exposure are not predictive of chronic exposure effects.
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Affiliation(s)
- W Kent Anger
- Oregon Health & Science University, Institute of Occupational Health Sciences, Portland, OR 97239, USA.
| | - Fayssal M Farahat
- Menoufia University, Department of Public Health and Community Medicine, Menoufia, Egypt; King AbdulAziz Medical City, King Saud bin AbdulAziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Pamela J Lein
- Oregon Health & Science University, Institute of Occupational Health Sciences, Portland, OR 97239, USA; Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA 95616, USA
| | - Michael R Lasarev
- Oregon Health & Science University, Institute of Occupational Health Sciences, Portland, OR 97239, USA
| | - James R Olson
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Taghreed M Farahat
- Menoufia University, Department of Public Health and Community Medicine, Menoufia, Egypt
| | - Diane S Rohlman
- Oregon Health & Science University, Institute of Occupational Health Sciences, Portland, OR 97239, USA; Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, USA
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Shaffo FC, Grodzki AC, Schelegle ES, Lein PJ. The Organophosphorus Pesticide Chlorpyrifos Induces Sex-Specific Airway Hyperreactivity in Adult Rats. Toxicol Sci 2019; 165:244-253. [PMID: 29939342 DOI: 10.1093/toxsci/kfy158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Occupational and environmental exposures to organophosphorus pesticides (OPs) are associated with increased incidence of asthma and other pulmonary diseases. Although the canonical mechanism of OP neurotoxicity is inhibition of acetylcholinesterase (AChE), it was previously reported that the OP chlorpyrifos (CPF) causes airway hyperreactivity (AHR) in guinea pigs at levels that do not inhibit lung or brain AChE. The guinea pig is considered to have inherently hyperresponsive airways, thus, cross-species validation is needed to confirm relevance to humans. Additionally, sex differences in asthma incidence have been demonstrated in the human population, but whether OP-induced AHR is sex-dependent has not been systematically studied in a preclinical model. In this study, 8-week old male and female Sprague Dawley rats were administered CPF at doses causing comparable AChE inhibition in whole lung homogenate (30 mg/kg in males, 7 mg/kg in females, sc) prior to assessing pulmonary mechanics in response to electrical stimulation of the vagus nerves at 24 h, 48 h, 72 h, 7 d or 14 d post-exposure in males, and 24 h or 7 d post-exposure in females. CPF significantly potentiated vagally induced airway resistance and tissue elastance at 7 d post-exposure in males, and at 24 h and 7 d post-exposure in females. These effects occurred independent of significant AChE inhibition in cerebellum, blood, trachealis, or isolated airway, suggesting that AChE independent OP-induced airway hyperreactivity is a cross-species phenomenon. These findings have significant implications for assessing the risk posed by CPF, and potentially other OPs, to human health and safety.
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Affiliation(s)
| | | | - Edward S Schelegle
- Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, California 95616
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Occupational-like organophosphate exposure disrupts microglia and accelerates deficits in a rat model of Alzheimer's disease. NPJ Aging Mech Dis 2019; 5:3. [PMID: 30701080 PMCID: PMC6342990 DOI: 10.1038/s41514-018-0033-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/19/2018] [Indexed: 12/13/2022] Open
Abstract
Occupational exposure to organophosphate pesticides, such as chlorpyrifos (CPF), increases the risk of Alzheimer's disease (AD), though the mechanism is unclear. To investigate this, we subjected 4-month-old male and female wild-type (WT) and TgF344-AD rats, a transgenic AD model, to an occupational CPF exposure paradigm that recapitulates biomarkers and behavioral impairments experienced by agricultural workers. Subsequent cognition and neuropathology were analyzed over the next 20 months. CPF exposure caused chronic microglial dysregulation and accelerated neurodegeneration in both males and females. The effect on neurodegeneration was more severe in males, and was also associated with accelerated cognitive impairment. Females did not exhibit accelerated cognitive impairment after CPF exposure, and amyloid deposition and tauopathy were unchanged in both males and females. Microglial dysregulation may mediate the increased risk of AD associated with occupational organophosphate exposure, and future therapies to preserve or restore normal microglia might help prevent AD in genetically vulnerable individuals exposed to CPF or other disease-accelerating environmental agents.
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Ramírez-Santana M, Farías-Gómez C, Zúñiga-Venegas L, Sandoval R, Roeleveld N, Van der Velden K, Scheepers PTJ, Pancetti F. Biomonitoring of blood cholinesterases and acylpeptide hydrolase activities in rural inhabitants exposed to pesticides in the Coquimbo Region of Chile. PLoS One 2018; 13:e0196084. [PMID: 29718943 PMCID: PMC5931667 DOI: 10.1371/journal.pone.0196084] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/05/2018] [Indexed: 11/18/2022] Open
Abstract
In Chile, agriculture is a relevant economic activity and is concomitant with the use of pesticides to improve the yields. Acute intoxications of agricultural workers occur with some frequency and they must be reported to the surveillance system of the Ministry of Health. However the impacts of chronic and environmental pesticide exposure have been less studied. Among pesticides frequently used in Chile for insects control are organophosphates (OP) and carbamates (CB). They are inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). In this study we determined the pattern of both biomarkers activity in three populations with different type of chronic exposure to OP/CB: environmentally exposed (EE), occupationally exposed (OE) and a reference group (RG) without exposure. Besides this, we also measured the activity of acylpeptide hydrolase (APEH), an enzyme involved in relevant functions in the central synapses that is also expressed in erythrocytes and previously reported to be highly inhibited by some OP. A baseline measurement was done in both exposure groups and then a second measurement was done during the spraying season. The RG was measured only once at any time of the year. Our results indicate that people under chronic OP/CB exposure showed an adaptive response through an increase of basal BChE activity. During the spray season only BChE activity was decreased in the EE and OE groups (p<0.05 and p<0.01, respectively) and the higher magnitude of BChE inhibition was observed in the EE group. The analysis of the frequencies of inhibition above 30% (biological tolerance limit declared by Chilean legislation) indicated that BChE was most frequently inhibited in the EE group (53% of the individuals displayed inhibition) and AChE in the OE group (55% of the individuals displayed AChE inhibition). APEH activity showed the highest frequency of inhibition in the EE group independent of its magnitude (64%). Our results demonstrate that the rural population living nearby agricultural settings displays high levels of environmental exposure. APEH activity seems to be a sensitive biomarker for acute low-level exposure and its usefulness as a routine biomarker must to be explored in future studies. Systematic biomonitoring and health outcomes studies are necessary as well as obtaining the baseline for BChE and AChE activity levels with the aim to improve environmental and occupational health policies in Chile.
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Affiliation(s)
- Muriel Ramírez-Santana
- Department of Public Health, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
- Department of Primary and Community Care, Radboud university medical center, Nijmegen, The Netherlands
| | - Cristián Farías-Gómez
- Laboratory of Environmental Neurotoxicology, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Liliana Zúñiga-Venegas
- Laboratory of Biomedical Research, Faculty of Medicine, Universidad Católica del Maule, Talca, Chile
| | - Rodrigo Sandoval
- Laboratory of Environmental Neurotoxicology, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
| | - Nel Roeleveld
- Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Koos Van der Velden
- Department of Primary and Community Care, Radboud university medical center, Nijmegen, The Netherlands
| | - Paul T. J. Scheepers
- Radboud Institute for Health Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Floria Pancetti
- Laboratory of Environmental Neurotoxicology, Faculty of Medicine, Universidad Católica del Norte, Coquimbo, Chile
- * E-mail:
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Neural mechanisms of functional impairment across the lifespan: The 15th Biennial Meeting of the International Neurotoxicology Association and 39th Annual Meeting of the Neurobehavioral Teratology Society. Neurotoxicology 2018; 59:131-132. [PMID: 28347437 DOI: 10.1016/j.neuro.2017.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Voorhees JR, Rohlman DS, Lein PJ, Pieper AA. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds. Front Neurosci 2017; 10:590. [PMID: 28149268 PMCID: PMC5241311 DOI: 10.3389/fnins.2016.00590] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/08/2016] [Indexed: 01/06/2023] Open
Abstract
Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally.
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Affiliation(s)
- Jaymie R. Voorhees
- Department of Psychiatry, University of Iowa Carver College of MedicineIowa City, IA, USA
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa Carver College of MedicineIowa City, IA, USA
| | - Diane S. Rohlman
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa Carver College of MedicineIowa City, IA, USA
- Department of Occupational and Environmental Health, University of Iowa College of Public HealthIowa City, IA, USA
| | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, DavisDavis, CA, USA
| | - Andrew A. Pieper
- Department of Psychiatry, University of Iowa Carver College of MedicineIowa City, IA, USA
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa Carver College of MedicineIowa City, IA, USA
- Department of Neurology, University of Iowa Carver College of MedicineIowa City, IA, USA
- Department of Free Radical and Radiation Biology Program, University of Iowa Carver College of MedicineIowa City, IA, USA
- Department of Radiation Oncology Holden Comprehensive Cancer Center, University of Iowa Carver College of MedicineIowa City, IA, USA
- Department of Veteran Affairs, University of Iowa Carver College of MedicineIowa City, IA, USA
- Weill Cornell Autism Research Program, Weill Cornell Medical CollegeNew York, NY, USA
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Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides. Toxicology 2016; 340:53-62. [PMID: 26775027 DOI: 10.1016/j.tox.2016.01.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 12/23/2015] [Accepted: 01/10/2016] [Indexed: 12/19/2022]
Abstract
Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at a level that inhibits hippocampal cholinesterase to less than 20% of control. An equally significant finding is that subchronic exposure to CPF at a level that produces more moderate inhibition of hippocampal cholinesterase (approximately 50% of control) does not produce a discernable change in gene expression.
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Meyer-Baron M, Knapp G, Schäper M, van Thriel C. Meta-analysis on occupational exposure to pesticides--neurobehavioral impact and dose-response relationships. ENVIRONMENTAL RESEARCH 2015; 136:234-45. [PMID: 25460642 DOI: 10.1016/j.envres.2014.09.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/01/2014] [Accepted: 09/16/2014] [Indexed: 05/22/2023]
Abstract
While the health impact of high exposures to pesticides is acknowledged, the impact of chronic exposures in the absence of acute poisonings is controversial. A systematic analysis of dose-response relationships is still missing. Its absence may provoke alternative explanations for altered performances. Consequently, opportunities for health prevention in the occupational and environmental field may be missed. Objectives were (1) quantification of the neurotoxic impact of pesticides by an analysis of functional alterations in workers measured by neuropsychological performance tests, (2) estimates of dose-response relationships on the basis of exposure duration, and (3) exploration of susceptible subgroups. The meta-analysis employed a random effects model to obtain overall effects for individual performance tests. Twenty-two studies with a total of 1758 exposed and 1260 reference individuals met the inclusion criteria. At least three independent outcomes were available for twenty-six performance variables. Significant performance effects were shown in adults and referred to both cognitive and motor performances. Effect sizes ranging from dRE=-0.14 to dRE=-0.67 showed consistent outcomes for memory and attention. Relationships between effect sizes and exposure duration were indicated for individual performance variables and the total of measured performances. Studies on adolescents had to be analyzed separately due to numerous outliers. The large variation among outcomes hampered the analysis of the susceptibility in this group, while data on female workers was too scant for the analysis. Relationships exist between the impact of pesticides on performances and exposure duration. A change in test paradigms would help to decipher the impact more specifically. The use of biomarkers appropriate for lower exposures would allow a better prevention of neurotoxic effects due to occupational and environmental exposure. Intervention studies in adolescents seem warranted to specify their risk.
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Affiliation(s)
- Monika Meyer-Baron
- IfADo - Leibniz Research Centre for Working Environment and Human Factors, Research Group: Neurotoxicology and Chemosensation, Ardeystr. 67, D-44139 Dortmund, Germany.
| | - Guido Knapp
- TU Dortmund University, Department of Statistics, Vogelpothsweg 87, D-44227 Dortmund, Germany
| | - Michael Schäper
- IfADo - Leibniz Research Centre for Working Environment and Human Factors, Research Group: Neurotoxicology and Chemosensation, Ardeystr. 67, D-44139 Dortmund, Germany
| | - Christoph van Thriel
- IfADo - Leibniz Research Centre for Working Environment and Human Factors, Research Group: Neurotoxicology and Chemosensation, Ardeystr. 67, D-44139 Dortmund, Germany
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Khokhar JY, Tyndale RF. Intracerebroventricularly and Systemically Delivered Inhibitor of Brain CYP2B (C8-Xanthate), Even Following Chlorpyrifos Exposure, Reduces Chlorpyrifos Activation and Toxicity in Male Rats. Toxicol Sci 2014; 140:49-60. [DOI: 10.1093/toxsci/kfu075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sapbamrer R, Nata S. Health symptoms related to pesticide exposure and agricultural tasks among rice farmers from Northern Thailand. Environ Health Prev Med 2014; 19:12-20. [PMID: 23835647 PMCID: PMC3890077 DOI: 10.1007/s12199-013-0349-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/18/2013] [Indexed: 10/26/2022] Open
Abstract
PURPOSE The objective of this cross-sectional study was to investigate health symptoms related to occupational pesticide exposure and agricultural tasks in rice farmers. METHODS Data on demographic variables and health symptoms associated with pesticide exposure were collected from 182 rice farmers (exposed subjects) and 122 non-farmers (controlled group) using interviews and measuring whole blood acetylcholinesterase (AChE) activity during August and October 2012. RESULTS Rice farmers had a significantly lower median AChE activity than the controls (9,594 vs. 10,530 U/L, respectively) and a significantly higher prevalence of difficulty in breathing and chest pain [odds ratio (OR) 2.8, P < 0.01 and OR 2.5, P < 0.05, respectively]. The prevalence of dry throat and cramp was associated with those farmers who sprayed and mixed pesticides (OR 2.5 and 2.6 for dry throat, OR 2.5 and 2.9 for cramp, respectively; P < 0.01). The prevalence of numbness and diarrhea was associated with those farmers who scattered seed (OR 2.2, P < 0.01 and OR 3.6, P < 0.05, respectively). The prevalence of numbness and increasing anxiety was also associated with those farmers who harvested crops (OR 3.6, P < 0.01 and OR 3.0, P < 0.05, respectively). CONCLUSIONS Our findings suggest that occupational pesticide exposure and agricultural tasks in the paddy field may be associated with the increasing prevalence of respiratory tract and muscle symptoms. This possibility warrants further investigation in more detail.
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Affiliation(s)
- Ratana Sapbamrer
- School of Medicine, University of Phayao, 19 Moo2, Mae Ka Subdistrict, Muang District, Phayao, 56000, Thailand,
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Muthaiah VPK, Venkitasamy L, Michael FM, Chandrasekar K, Venkatachalam S. Neuroprotective role of naringenin on carbaryl induced neurotoxicity in mouse neuroblastoma cells. J Pharmacol Pharmacother 2013; 4:192-7. [PMID: 23960424 PMCID: PMC3746302 DOI: 10.4103/0976-500x.114599] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Neuroprotective effect of naringenin against carbaryl toxicity was studied in mouse neuroblastoma cell line. MATERIALS AND METHODS Mouse neuroblastoma cells (Neuro 2A) obtained from National Center for Cell Sciences, Pune, India were either exposed to carbaryl or pre-treated with naringenin (a flavonoid prepared from grape fruit) before their exposure to carbaryl. Results were analyzed using MTT [3-4,5-Dimethylthiazol-2-yl)-2,5-diphenltetrazolium bromide] assay for cell viability, FACS (fluorescence assisted cell sorting) analysis for apoptotic and necrotic cell populations, DCFH-DA (2`,7`-dichlorofluorescin-diacetate) assay for Reactive Oxygen Species (ROS) visualization, JC-1 staining for determining mitochondrial membrane potential and real-time PCR for quantifying pro and anti-apoptotic gene expression. RESULTS Exposure to naringenin resulted in better survival of Neuro 2A cells which were subsequently subjected to carbaryl toxicity. Treatment with naringenin was found to reduce the oxidative stress by decreasing the ROS and was found to maintain the integrity of mitochondrial membrane potential. It was also found to downregulate pro-apoptotic genes (BAX and Caspase-3) while upregulating anti-apototic gene (Bcl2). CONCLUSION The results of this pilot study underline the potential of naringenin in treating carbaryl induced neurotoxicity and further studies are warranted to establish the effect of naringenin in vivo conditions.
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Krause KH, van Thriel C, De Sousa PA, Leist M, Hengstler JG. Monocrotophos in Gandaman village: India school lunch deaths and need for improved toxicity testing. Arch Toxicol 2013; 87:1877-81. [PMID: 23943209 DOI: 10.1007/s00204-013-1113-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 08/01/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Karl-Heinz Krause
- Department of Pathology and Immunology, Geneva Medical Faculty, Centre Medical Universitaire, University of Geneva (UNIGE), 1, rue Michel-Servet, 1211, Geneva 4, Switzerland,
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MacPhail RC, Grulke EA, Yokel RA. Assessing nanoparticle risk poses prodigious challenges. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2013; 5:374-87. [PMID: 23568806 DOI: 10.1002/wnan.1216] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Risk assessment is used both formally and informally to estimate the likelihood of an adverse event occurring, for example, as a consequence of exposure to a hazardous chemical, drug, or other agent. Formal risk assessments in government regulatory agencies have a long history of practice. The precision with which risk can be estimated is inevitably constrained, however, by uncertainties arising from the lack of pertinent data. Developing accurate risk assessments for nanoparticles and nanoparticle-containing products may present further challenges because of the unique properties of the particles, uncertainties about their composition and the populations exposed to them, and how these may change throughout the particle's life cycle. This review introduces the evolving practice of risk assessment followed by some of the uncertainties that need to be addressed to improve our understanding of nanoparticle risks. Given the clarion call for life-cycle assessments of nanoparticles, an unprecedented degree of national and international coordination between scientific organizations, regulatory agencies, and stakeholders will be required to achieve this goal.
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Affiliation(s)
- Robert C MacPhail
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
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Fenske RA, Farahat FM, Galvin K, Fenske EK, Olson JR. Contributions of inhalation and dermal exposure to chlorpyrifos dose in Egyptian cotton field workers. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2012; 18:198-209. [PMID: 23026005 DOI: 10.1179/1077352512z.00000000030] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Chlorpyrifos exposures were assessed in 12 Egyptian cotton field workers. METHODS 3,5,6-trichloro-2-pyridinol (TCPy) was measured in 24-hour urine samples to estimate absorbed dose. Workshift air samples were used to calculate chlorpyrifos inhalation dose. RESULTS Patches on legs had the highest chlorpyrifos loading rates among body regions sampled. Geometric mean chlorpyrifos air concentrations were 5·1, 8·2, and 45·0 μg/m(3) for engineers, technicians, and applicators, respectively; peak TCPy urinary concentrations were 75-129, 78-261, and 487-1659 μg/l, respectively; geometric mean doses were 5·2-5·4, 8·6-9·7, and 50-57 μg/kg, respectively, considering TCPy excretion half-life values of 27 and 41 hours. All worker doses exceeded the acceptable operator exposure level of 1·5 μg/kg/day. An estimated 94-96% of the dose was attributed to dermal exposure, calculated as the difference between total dose and inhalation dose. DISCUSSION Interventions to reduce dermal exposure are warranted in this population, particularly for the hands, feet, and legs.
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