51
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Dhakshinamoorthy V, Manickam V, Perumal E. Neurobehavioural Toxicity of Iron Oxide Nanoparticles in Mice. Neurotox Res 2017; 32:187-203. [PMID: 28321581 DOI: 10.1007/s12640-017-9721-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 01/24/2023]
Abstract
Iron oxide nanoparticles (Fe2O3-NPs) are widely used in various biomedical applications, extremely in neurotheranostics. Simultaneously, Fe2O3-NP usage is of alarming concern, as its exposure to living systems causes deleterious effects due to its redox potential. However, study on the neurobehavioural impacts of Fe2O3-NPs is very limited. In this regard, adult male mice were intraperitoneally administered with Fe2O3-NPs (25 and 50 mg/kg body weight) once a week for 4 weeks. A significant change in locomotor behaviour and spatial memory was observed in Fe2O3-NP-treated animals. Damages to blood-brain barrier permeability by Fe2O3-NPs and their accumulation in brain regions were evidenced by Evan's blue staining, iron estimation and Prussian blue staining. Elevated nitric oxide, acetylcholinesterase, lactate dehydrogenase leakage and demyelination were observed in the Fe2O3-NP-exposed brain tissues. Imbalanced levels of ROS generation and antioxidant defence mechanism (superoxide dismutase and catalase) cause damages to lipids, proteins and DNA. PARP and cleaved caspase 3 expression levels were found to be increased in the Fe2O3-NP-exposed brain regions which confirms DNA damage and apoptosis. Thus, repeated Fe2O3-NP exposure causes neurobehavioural impairments by nanoparticle accumulation, oxidative stress and apoptosis in the mouse brain.
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Affiliation(s)
- Vasanth Dhakshinamoorthy
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India
| | - Vijayprakash Manickam
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India
| | - Ekambaram Perumal
- Molecular Toxicology Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, 641 046, India.
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52
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Drummond J, Williamson SM, Fitchett AE, Wright GA, Judge SJ. Spontaneous honeybee behaviour is altered by persistent organic pollutants. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:141-150. [PMID: 27933553 PMCID: PMC5241328 DOI: 10.1007/s10646-016-1749-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 11/20/2016] [Indexed: 06/06/2023]
Abstract
The effect of environmental pollutants on honeybee behaviour has focused mainly on currently used pesticides. However, honeybees are also exposed to persistent organic pollutants (POPs). The aim of this laboratory based study was to determine if exposure to sublethal field-relevant concentrations of POPs altered the spontaneous behaviour of foraging-age worker honeybees. Honeybees (Apis mellifera) were orally exposed to either a sublethal concentration of the polychlorinated biphenyl (PCB) mixture Aroclor 1254 (100 ng/ml), the organochlorine insecticide lindane (2.91 ng/ml) or vehicle (0.01% DMSO, 0.00015% ethanol in 1M sucrose) for 1-4 days. The frequency of single event behaviours and the time engaged in one of four behavioural states (walking, flying, upside down and stationary) were monitored for 15 min after 1, 2, 3 and 4 days exposure. Exposure to Aroclor 1254 but not lindane increased the frequency and time engaged in honeybee motor activity behaviours in comparison to vehicle. The Aroclor 1254-induced hyperactivity was evident after 1 day of exposure and persisted with repeated daily exposure. In contrast, 1 day of exposure to lindane elicited abdominal spasms and increased the frequency of grooming behaviours in comparison to vehicle exposure. After 4 days of exposure, abdominal spasms and increased grooming behaviours were also evident in honeybees exposed to Aroclor 1254. These data demonstrate that POPs can induce distinct behavioural patterns, indicating different toxicokinetic and toxicodynamic properties. The changes in spontaneous behaviour, particularly the PCB-induced chronic hyperactivity and the associated energy demands, may have implications for colony health.
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Affiliation(s)
- Jade Drummond
- Medical Toxicology Centre, Newcastle University, Newcastle upon Tyne, NE2 4AA, UK
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Sally M Williamson
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ann E Fitchett
- Medical Toxicology Centre, Newcastle University, Newcastle upon Tyne, NE2 4AA, UK
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Geraldine A Wright
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Sarah J Judge
- Medical Toxicology Centre, Newcastle University, Newcastle upon Tyne, NE2 4AA, UK.
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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53
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Association of Long-Term Pesticide Exposure and Biologic Parameters in Female Farm Workers in Tanzania: A Cross Sectional Study. TOXICS 2016; 4:toxics4040025. [PMID: 29051428 PMCID: PMC5606649 DOI: 10.3390/toxics4040025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/16/2016] [Accepted: 09/20/2016] [Indexed: 12/24/2022]
Abstract
The study aimed to assess the association of long-term pesticide exposure (≥5 years) with hematological, serum biochemical parameters and acetylcholinesterase activity in farm workers. These pesticides included organophosphorus pesticides, carbamates, pyrethroids, dithiocarbamates, and other pesticides such as endosulfan. Applying a cross-sectional study design, 69 females from a pesticide-exposed farm population and 30 females from a district not using pesticides (reference group) were studied. The mean red cell corpuscular volume and hematocrit values were significantly lower (74.7 ± 9.1 fl; 95% CI 72.5-76.9 and 32.0% ± 4.6%; 95% CI 30.9-33.1, respectively) in the exposed compared to the reference group, whereas mean corpuscular hemoglobin concentration and platelets were significantly higher (37.4 ± 3.8 g/dL; 95% CI 36.5-38.3 and 374.1 ± 95.3/L; 95% CI 351.2-396.9, respectively) in the exposed compared to the reference group. Mean serum glutamic oxaloacetate transaminase (20.7 ± 8.9 U/L; 95% CI 18.5-22.9) and creatinine (83.9 ± 6.6 μmol/L; 95% CI 82.3-85.5) were significantly higher in the exposed compared to the reference group. A higher mean esterase activity (AChE 0.6 ± 0.2 mM/min/mg protein; 95% CI 0.56-0.7; BChE 0.9 ± 0.4 mM/min/mg protein; 95% CI 0.9-1.1) was noted in the exposed group. Regression models suggest that occupational exposure (p < 0.001) could be a predictor of esterase (AChE and BChE) activity and biochemical changes (β = 0.4, 95% CI: 0.3-0.5; β = 0.7, 95% CI: 0.6-0.9, respectively). Long-term pesticide exposure affects the hemato-biochemical and esterase responses, establishing the need for further studies.
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54
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Chaimanee V, Evans JD, Chen Y, Jackson C, Pettis JS. Sperm viability and gene expression in honey bee queens (Apis mellifera) following exposure to the neonicotinoid insecticide imidacloprid and the organophosphate acaricide coumaphos. JOURNAL OF INSECT PHYSIOLOGY 2016; 89:1-8. [PMID: 26979384 DOI: 10.1016/j.jinsphys.2016.03.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 03/09/2016] [Accepted: 03/11/2016] [Indexed: 05/21/2023]
Abstract
Honey bee population declines are of global concern. Numerous factors appear to cause these declines including parasites, pathogens, malnutrition and pesticides. Residues of the organophosphate acaricide coumaphos and the neonicotinoid insecticide imidacloprid, widely used to combat Varroa mites and for crop protection in agriculture, respectively, have been detected in wax, pollen and comb samples. Here, we assess the effects of these compounds at different doses on the viability of sperm stored in the honey bee queens' spermatheca. Our results demonstrate that sub-lethal doses of imidacloprid (0.02ppm) decreased sperm viability by 50%, 7days after treatment. Sperm viability was a downward trend (about 33%) in queens treated with high doses of coumaphos (100ppm), but there was not significant difference. The expression of genes that are involved in development, immune responses and detoxification in honey bee queens and workers exposed to chemicals was measured by qPCR analysis. The data showed that expression levels of specific genes were triggered 1day after treatment. The expression levels of P450 subfamily genes, CYP306A1, CYP4G11 and CYP6AS14 were decreased in honey bee queens treated with low doses of coumaphos (5ppm) and imidacloprid (0.02ppm). Moreover, these two compounds suppressed the expression of genes related to antioxidation, immunity and development in queens at day 1. Up-regulation of antioxidants by these compounds in worker bees was observed at day 1. Coumaphos also caused a repression of CYP306A1 and CYP4G11 in workers. Antioxidants appear to prevent chemical damage to honey bees. We also found that DWV replication increased in workers treated with imidacloprid. This research clearly demonstrates that chemical exposure can affect sperm viability in queen honey bees.
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Affiliation(s)
- Veeranan Chaimanee
- Department of Biotechnology, Maejo University Phrae Campus, Rong Kwang, Phrae 54140, Thailand.
| | - Jay D Evans
- Bee Research Laboratory, USDA-ARS, Beltsville, MD, United States
| | - Yanping Chen
- Bee Research Laboratory, USDA-ARS, Beltsville, MD, United States
| | - Caitlin Jackson
- Bee Research Laboratory, USDA-ARS, Beltsville, MD, United States
| | - Jeffery S Pettis
- Bee Research Laboratory, USDA-ARS, Beltsville, MD, United States
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55
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Lee S, Barron MG. A mechanism-based 3D-QSAR approach for classification and prediction of acetylcholinesterase inhibitory potency of organophosphate and carbamate analogs. J Comput Aided Mol Des 2016; 30:347-63. [PMID: 27055524 DOI: 10.1007/s10822-016-9910-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/30/2016] [Indexed: 12/20/2022]
Abstract
Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a serine residue in the enzyme active site, and their inhibitory potency depends largely on affinity for the enzyme and the reactivity of the ester. Despite this understanding, there has been no mechanism-based in silico approach for classification and prediction of the inhibitory potency of ether OPs or carbamates. This prompted us to develop a three dimensional prediction framework for OPs, carbamates, and their analogs. Inhibitory structures of a compound that can form the covalent bond were identified through analysis of docked conformations of the compound and its metabolites. Inhibitory potencies of the selected structures were then predicted using a previously developed three dimensional quantitative structure-active relationship. This approach was validated with a large number of structurally diverse OP and carbamate compounds encompassing widely used insecticides and structural analogs including OP flame retardants and thio- and dithiocarbamate pesticides. The modeling revealed that: (1) in addition to classical OP metabolic activation, the toxicity of carbamate compounds can be dependent on biotransformation, (2) OP and carbamate analogs such as OP flame retardants and thiocarbamate herbicides can act as AChEI, (3) hydrogen bonds at the oxyanion hole is critical for AChE inhibition through the covalent bond, and (4) π-π interaction with Trp86 is necessary for strong inhibition of AChE. Our combined computation approach provided detailed understanding of the mechanism of action of OP and carbamate compounds and may be useful for screening a diversity of chemical structures for AChE inhibitory potency.
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Affiliation(s)
- Sehan Lee
- Gulf Ecology Division, U.S. Environmental Protection Agency, Gulf Breeze, FL, 32561, USA.
| | - Mace G Barron
- Gulf Ecology Division, U.S. Environmental Protection Agency, Gulf Breeze, FL, 32561, USA
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56
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Urlacher E, Monchanin C, Rivière C, Richard FJ, Lombardi C, Michelsen-Heath S, Hageman KJ, Mercer AR. Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions. J Chem Ecol 2016; 42:127-38. [PMID: 26872472 DOI: 10.1007/s10886-016-0672-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/20/2015] [Accepted: 01/29/2016] [Indexed: 01/05/2023]
Abstract
Chlorpyrifos is an organophosphate pesticide used around the world to protect food crops against insects and mites. Despite guidelines for chlorpyrifos usage, including precautions to protect beneficial insects, such as honeybees from spray drift, this pesticide has been detected in bees in various countries, indicating that exposure still occurs. Here, we examined chlorpyrifos levels in bees collected from 17 locations in Otago, New Zealand, and compared doses of this pesticide that cause sub-lethal effects on learning performance under laboratory conditions with amounts of chlorpyrifos detected in the bees in the field. The pesticide was detected at 17 % of the sites sampled and in 12 % of the colonies examined. Amounts detected ranged from 35 to 286 pg.bee(-1), far below the LD50 of ~100 ng.bee(-1). We detected no adverse effect of chlorpyrifos on aversive learning, but the formation and retrieval of appetitive olfactory memories was severely affected. Chlorpyrifos fed to bees in amounts several orders of magnitude lower than the LD50, and also lower than levels detected in bees, was found to slow appetitive learning and reduce the specificity of memory recall. As learning and memory play a central role in the behavioral ecology and communication of foraging bees, chlorpyrifos, even in sublethal doses, may threaten the success and survival of this important insect pollinator.
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Affiliation(s)
- Elodie Urlacher
- University of Otago, Department of Zoology, 340 Great King Street PO Box 56, Dunedin, 9054, New Zealand.
| | - Coline Monchanin
- University of Otago, Department of Zoology, 340 Great King Street PO Box 56, Dunedin, 9054, New Zealand
| | - Coraline Rivière
- University of Otago, Department of Zoology, 340 Great King Street PO Box 56, Dunedin, 9054, New Zealand
| | - Freddie-Jeanne Richard
- Laboratoire Ecologie et Biologie des intéractions, UMR CNRS 7267, Team Ecologie Evolution Symbiose, University of Poitiers, 6, rue Michel Brunet, TSA 51106, F-86073, Poitiers Cedex 9, France
| | - Christie Lombardi
- Department of Chemistry, University of Otago, Union Street West, PO Box 56, Dunedin, 9054, New Zealand
| | - Sue Michelsen-Heath
- University of Otago, Department of Zoology, 340 Great King Street PO Box 56, Dunedin, 9054, New Zealand
| | - Kimberly J Hageman
- Department of Chemistry, University of Otago, Union Street West, PO Box 56, Dunedin, 9054, New Zealand
| | - Alison R Mercer
- University of Otago, Department of Zoology, 340 Great King Street PO Box 56, Dunedin, 9054, New Zealand
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57
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Stanley DA, Smith KE, Raine NE. Bumblebee learning and memory is impaired by chronic exposure to a neonicotinoid pesticide. Sci Rep 2015; 5:16508. [PMID: 26568480 PMCID: PMC4644970 DOI: 10.1038/srep16508] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 10/14/2015] [Indexed: 02/07/2023] Open
Abstract
Bumblebees are exposed to pesticides applied for crop protection while foraging on treated plants, with increasing evidence suggesting that this sublethal exposure has implications for pollinator declines. The challenges of navigating and learning to manipulate many different flowers underline the critical role learning plays for the foraging success and survival of bees. We assessed the impacts of both acute and chronic exposure to field-realistic levels of a widely applied neonicotinoid insecticide, thiamethoxam, on bumblebee odour learning and memory. Although bees exposed to acute doses showed conditioned responses less frequently than controls, we found no difference in the number of individuals able to learn at field-realistic exposure levels. However, following chronic pesticide exposure, bees exposed to field-realistic levels learnt more slowly and their short-term memory was significantly impaired following exposure to 2.4 ppb pesticide. These results indicate that field-realistic pesticide exposure can have appreciable impacts on learning and memory, with potential implications for essential individual behaviour and colony fitness.
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Affiliation(s)
- Dara A Stanley
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Karen E Smith
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Nigel E Raine
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK.,School of Environmental Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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58
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Milivojević T, Glavan G, Božič J, Sepčić K, Mesarič T, Drobne D. Neurotoxic potential of ingested ZnO nanomaterials on bees. CHEMOSPHERE 2015; 120:547-554. [PMID: 25305659 DOI: 10.1016/j.chemosphere.2014.07.054] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 07/17/2014] [Accepted: 07/18/2014] [Indexed: 06/04/2023]
Abstract
The honey bee is among most important pollinators threatened by environmental pollution, pest control and potentially, by products of nanotechnologies. The aim of the current study was an analysis of the neurotoxic potential of ingested zinc oxide nanomaterials (ZnO NMs) or zinc ions (Zn(2+)) on honey bees. We analysed a variety of biomarkers, including metabolic impairment, feeding rate, and survival, as well as the activities of a stress-related enzyme glutathione S-transferase, and the neurotoxicity biomarker acetylcholinesterase. Acetylcholinesterase activity was found to be elevated in bees exposed to either of the tested substances. In addition, we observed increased feeding rate in the group treated with Zn(2+) but not with ZnO NMs or control group. The observed effects we relate primarily to Zn(2+) ions. Here we provide evidence that zinc ions either originating from Zn salt or Zn-based NPs have a neurotoxic potential and thus might contribute to colony survival.
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Affiliation(s)
- Tamara Milivojević
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia
| | - Gordana Glavan
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia
| | - Janko Božič
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia
| | - Kristina Sepčić
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia
| | - Tina Mesarič
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia
| | - Damjana Drobne
- University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, Ljubljana SI-1000, Slovenia; Centre of Excellence in Advanced Materials and Technologies for the Future (CO NAMASTE), Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia; Centre of Excellence in Nanoscience and Nanotechnology (CO Nanocenter), Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
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59
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Abstract
Insecticides are chemicals used to kill insects, so it is unsurprising that many insecticides have the potential to harm honey bees (Apis mellifera). However, bees are exposed to a great variety of other potentially toxic chemicals, including flavonoids and alkaloids that are produced by plants; mycotoxins produced by fungi; antimicrobials and acaricides that are introduced by beekeepers; and fungicides, herbicides, and other environmental contaminants. Although often regarded as uniquely sensitive to toxic compounds, honey bees are adapted to tolerate and even thrive in the presence of toxic compounds that occur naturally in their environment. The harm caused by exposure to a particular concentration of a toxic compound may depend on the level of simultaneous exposure to other compounds, pathogen levels, nutritional status, and a host of other factors. This review takes a holistic view of bee toxicology by taking into account the spectrum of xenobiotics to which bees are exposed.
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Affiliation(s)
- Reed M Johnson
- Department of Entomology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster, Ohio 44691;
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60
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Su J, Yang M. Huperzine A production by Paecilomyces tenuis YS-13, an endophytic fungus isolated from Huperzia serrata. Nat Prod Res 2014; 29:1035-41. [PMID: 25427833 DOI: 10.1080/14786419.2014.980245] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Huperzine A (HupA), a naturally occurring alkaloid in the plant family Huperziaceae, has drawn great interest for its potential application in Alzheimer disease therapy. Our primary objective was to identify alkaloid- and HupA-producing fungi from the Chinese folk herb, Huperzia serrata. We established a rapid and efficient model for screening HupA-producing endophytic fungal strains. The presence of HupA in Paecilomyces tenuis YS-13 was analysed by thin-layer chromatography, high-performance liquid chromatography and mass spectrometry. The fermentation yield of HupA was 21.0 μg/L, and the IC50 of the crude extract of YS-13 fermentation broth was 1.27 ± 0.04 mg/mL. This is the first report of P. tenuis as a HupA-producing endophyte isolated from Huperziaceae.
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Affiliation(s)
- Jingqian Su
- a College of Life Science , Fujian Normal University , Fuzhou 350108 , P.R. China
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61
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Dulin F, Zatylny-Gaudin C, Ballandonne C, Guillet B, Bonafos R, Bureau R, Halm MP. Protecting honey bees: identification of a new varroacide by in silico, in vitro, and in vivo studies. Parasitol Res 2014; 113:4601-10. [PMID: 25358237 DOI: 10.1007/s00436-014-4150-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 09/23/2014] [Indexed: 11/28/2022]
Abstract
Varroa destructor is the main concern related to the gradual decline of honeybees. Nowadays, among the various acaricides used in the control of V. destructor, most presents increasing resistance. An interesting alternative could be the identification of existent molecules as new acaricides with no effect on honeybee health. We have previously constructed the first 3D model of AChE for honeybee. By analyzing data concerning amino acid mutations implicated in the resistance associated to pesticides, it appears that pirimicarb should be a good candidate for varroacide. To check this hypothesis, we characterized the AChE gene of V. destructor. In the same way, we proposed a 3D model for the AChE of V. destructor. Starting from the definition of these two 3D models of AChE in honeybee and varroa, a comparison between the gorges of the active site highlighted some major differences and particularly different shapes. Following this result, docking studies have shown that pirimicarb adopts two distinct positions with the strongest intermolecular interactions with VdAChE. This result was confirmed with in vitro and in vivo data for which a clear inhibition of VdAChE by pirimicarb at 10 μM (contrary to HbAChE) and a 100% mortality of varroa (dose corresponding to the LD50 (contact) for honeybee divided by a factor 100) were observed. These results demonstrate that primicarb could be a new varroacide candidate and reinforce the high relationships between in silico, in vitro, and in vivo data for the design of new selective pesticides.
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62
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Williamson SM, Willis SJ, Wright GA. Exposure to neonicotinoids influences the motor function of adult worker honeybees. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:1409-18. [PMID: 25011924 PMCID: PMC4165879 DOI: 10.1007/s10646-014-1283-x] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/27/2014] [Indexed: 05/07/2023]
Abstract
Systemic pesticides such as neonicotinoids are commonly used on flowering crops visited by pollinators, and their use has been implicated in the decline of insect pollinator populations in Europe and North America. Several studies show that neonicotinoids affect navigation and learning in bees but few studies have examined whether these substances influence their basic motor function. Here, we investigated how prolonged exposure to sublethal doses of four neonicotinoid pesticides (imidacloprid, thiamethoxam, clothianidin, dinotefuran) and the plant toxin, nicotine, affect basic motor function and postural control in foraging-age worker honeybees. We used doses of 10 nM for each neonicotinoid: field-relevant doses that we determined to be sublethal and willingly consumed by bees. The neonicotinoids were placed in food solutions given to bees for 24 h. After the exposure period, bees were more likely to lose postural control during the motor function assay and fail to right themselves if exposed to imidacloprid, thiamethoxam, clothianidin. Bees exposed to thiamethoxam and nicotine also spent more time grooming. Other behaviours (walking, sitting and flying) were not significantly affected. Expression of changes in motor function after exposure to imidacloprid was dose-dependent and affected all measured behaviours. Our data illustrate that 24 h exposure to sublethal doses of neonicotinoid pesticides has a subtle influence on bee behaviour that is likely to affect normal function in a field setting.
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Affiliation(s)
- Sally M. Williamson
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | - Sarah J. Willis
- School of Biology, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
| | - Geraldine A. Wright
- Faculty of Medical Sciences, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU UK
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63
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Hurst V, Stevenson PC, Wright GA. Toxins induce 'malaise' behaviour in the honeybee (Apis mellifera). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:881-90. [PMID: 25149875 PMCID: PMC4169619 DOI: 10.1007/s00359-014-0932-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 08/05/2014] [Accepted: 08/09/2014] [Indexed: 11/29/2022]
Abstract
To avoid poisoning and death when toxins are ingested, the body responds with a suite of physiological detoxification mechanisms accompanied by behaviours that in mammals often include vomiting, nausea, and lethargy. Few studies have characterised whether insects exhibit characteristic 'malaise-like' behaviours in response to intoxication. Here, we used the honeybee to investigate how intoxication produced by injection or ingestion with three toxins with different pharmacological modes of action quinine, amygdalin, and lithium chloride affected behaviour. We found that toxin-induced changes in behaviour were best characterised by more time spent grooming. Bees also had difficulty performing the righting reflex and exhibited specific toxin-induced behaviours such as abdomen dragging and curling up. The expression of these behaviours also depended on whether a toxin had been injected or ingested. When toxins were ingested, they were least 10 times less concentrated in the haemolymph than in the ingested food, suggesting that their absorption through the gut is strongly regulated. Our data show that bees exhibit changes in behaviour that are characteristic of 'malaise' and suggest that physiological signalling of toxicosis is accomplished by multiple post-ingestive pathways in animals.
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Affiliation(s)
- Victoria Hurst
- Centre for Behaviour and Evolution, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
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64
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Gill RJ, Raine NE. Chronic impairment of bumblebee natural foraging behaviour induced by sublethal pesticide exposure. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12292] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Richard J. Gill
- School of Biological Sciences; Royal Holloway University of London; Egham Surrey TW20 0EX UK
| | - Nigel E. Raine
- School of Biological Sciences; Royal Holloway University of London; Egham Surrey TW20 0EX UK
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Doublet V, Labarussias M, de Miranda JR, Moritz RFA, Paxton RJ. Bees under stress: sublethal doses of a neonicotinoid pesticide and pathogens interact to elevate honey bee mortality across the life cycle. Environ Microbiol 2014; 17:969-83. [DOI: 10.1111/1462-2920.12426] [Citation(s) in RCA: 248] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/24/2014] [Accepted: 01/31/2014] [Indexed: 01/24/2023]
Affiliation(s)
- Vincent Doublet
- Institut für Biologie; Martin-Luther-Universität Halle-Wittenberg; Halle (Saale) Germany
| | - Maureen Labarussias
- Institut für Biologie; Martin-Luther-Universität Halle-Wittenberg; Halle (Saale) Germany
| | | | - Robin F. A. Moritz
- Institut für Biologie; Martin-Luther-Universität Halle-Wittenberg; Halle (Saale) Germany
- German Center for Integrative Biodiversity Research (iDiv); Halle-Jena-Leipzig; Leipzig Germany
| | - Robert J. Paxton
- Institut für Biologie; Martin-Luther-Universität Halle-Wittenberg; Halle (Saale) Germany
- German Center for Integrative Biodiversity Research (iDiv); Halle-Jena-Leipzig; Leipzig Germany
- School of Biological Sciences; Queen's University Belfast; Belfast UK
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