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PloS One 2015The wheat aphids, Rhopalosiphum padi (Linnaeus) and Sitobion avenae (Fabricius), are key pests on wheat crops worldwide. Management practices rely primarily on...
The wheat aphids, Rhopalosiphum padi (Linnaeus) and Sitobion avenae (Fabricius), are key pests on wheat crops worldwide. Management practices rely primarily on insecticides. The pirimicarb (carbamate) is used extensively as an effective insecticide to control these two aphids. In addition to the mortality caused by pirimicarb, various sublethal effects may occur in aphids when exposed to low lethal or sublethal doses. Understanding the general effect of pirimicarb on aphids could help increasing rational use of this insecticide. Under laboratory conditions, we assessed the sublethal effects of a low lethal concentration of pirimicarb (LC25) on biological traits and acetylcholinesterase (AChE) activity of R. padi and S. avenae. Both direct and transgenerational effects, i.e. on parent and the F1 generations were assessed, respectively. We found that R. padi and S. avenae responded differentially to the LC25 of pirimicarb. The parent generation of R. padi showed a 39% decrease in fecundity and multiple transgenerational effects were observed in the F1 generation; overall juvenile development, reproductive period, adult longevity and lifespan were longer than those of the control group. By contrast, LC25 of pirimicarb showed almost no effects on S. avenae biological traits in both the parent and F1 generations; only the pre-reproductive duration was reduced in F1 generations. Demographic parameter estimates (e.g. rm) showed similar trend, i.e. significant negative effect on R. padi population growth and no effect on S. avenae. However, AChE activity decreased in both R. padi and S. avenae treated by the LC25 of pirimicarb. We demonstrated sublethal and transgenerational effects of pirimicarb in the two wheat aphid species; it hinted at the importance of considering sublethal effects (including hormesis) of pirimicarb for optimizing Integrated Pest Management (IPM) of wheat aphids.
Topics: Acetylcholinesterase; Animals; Aphids; Carbamates; Crosses, Genetic; Female; Fertility; Longevity; Male; Pyrimidines; Triticum
PubMed: 26121265
DOI: 10.1371/journal.pone.0128936 -
Toxicology in Vitro : An International... Aug 2015In vitro effects of the carbamates pirimicarb and zineb and their formulations Aficida® (50% pirimicarb) and Azzurro® (70% zineb), respectively, were evaluated in...
In vitro effects of the carbamates pirimicarb and zineb and their formulations Aficida® (50% pirimicarb) and Azzurro® (70% zineb), respectively, were evaluated in Chinese hamster ovary (CHO-K1) cells. Whereas the cytokinesis-blocked micronucleus cytome assay was employed to test for genotoxicity, MTT, neutral red (NR), and apoptosis evaluation were used as tests for estimating cell viability and succinic dehydrogenase activity, respectively. Concentrations tested were 10-300 μg/ml for pirimicarb and Aficida®, and 1-50 μg/ml for zineb and Azzurro®. All compounds were able to increase the frequency of micronuclei. A marked reduction in the nuclear division index was observed after treatment with 5 μg/ml of zineb and Azzurro® and 10 μg/ml of Azzurro®. Alterations in the cellular morphology not allowing the recognition of binucleated cells exposed to 300 μg/ml pirimicarb and Aficida® as well as 10-50 μg/ml zineb and Azzurro®. All four compounds induced inhibition of both cell viability and succinic dehydrogenase activity and trigger apoptosis in CHO-K1 cells, at least when exposed for 24 h. The data herein demonstrate the genotoxic and cytotoxic effects exerted by these carbamates and reveal the potential risk factor of these pesticides, still extensively used worldwide, for both human health and the environment.
Topics: Animals; Apoptosis; CHO Cells; Carbamates; Cell Survival; Cricetulus; Insecticides; Micronuclei, Chromosome-Defective; Micronucleus Tests; Mutagens; Pyrimidines; Zineb
PubMed: 25820133
DOI: 10.1016/j.tiv.2015.03.011 -
Environmental Toxicology and... Jan 2015It is necessary to explore the effect of confidence intervals on the combination index (CI) so that rationally evaluate the toxicological interaction (synergism or...
Application of the combination index integrated with confidence intervals to study the toxicological interactions of antibiotics and pesticides in Vibrio qinghaiensis sp.-Q67.
It is necessary to explore the effect of confidence intervals on the combination index (CI) so that rationally evaluate the toxicological interaction (synergism or antagonism) which is dependent on the concentration ratio, the mixture concentration and the exposure time. To effectively detect the toxicological interaction taking place in mixtures, we combined the CI with the observation-based confidence intervals (OCI) which can characterize the uncertainty in toxicity test and in data fitting. In time scale, the short-term (15min) and long-term (12h) toxicities of three chemicals (imidacloprid (IMI), pirimicarb (PIR) and streptomycin sulfate (STR)) and their binary mixtures on Vibrio qinghaiensis sp.-Q67 were determined by the microplate toxicity analysis (MTA). The mixtures of IMI, PIR and STR have additive actions all but four IMI-PIR rays (R2-R5) at the effect levels above about 30-40% whose long-term toxicological interaction are synergism.
Topics: Anti-Bacterial Agents; Carbamates; Drug Interactions; Imidazoles; Neonicotinoids; Nitro Compounds; Pesticides; Pyrimidines; Streptomycin; Vibrio
PubMed: 25589171
DOI: 10.1016/j.etap.2014.12.013 -
Bioinformation 2014Glutathione S-transferases (GSTs) are one of the major families of detoxifying enzymes that detoxifies different chemical compounds including insecticides in different...
Glutathione S-transferases (GSTs) are one of the major families of detoxifying enzymes that detoxifies different chemical compounds including insecticides in different insect species. Among the GST subclasses, sigma GSTs are found to be the most abundant and conserved among different insect orders. These GSTs are found to play an important role in lipid peroxidation as well as detoxification. Cotton aphid, Aphis gossypii is the most damaging sucking pest with a wide range of hosts and vector of more than 50 plant viruses. Resistance to insecticides in A. gossypii is reported in India and in other countries. Glutathione S transferases (GSTs), an oxidative enzyme is understood to have a role in insecticide resistance and plant resistance breakdown. In relation to this, we have focused on the sigma 1 (GenBank Accession No: JN989964.1) and sigma 2 (GenBank Accession No: JN989965.1) GSTs of A. gossypii and their interaction with plant natural compounds and insecticides. Molecular screening of different insecticides (Chlorphinamidine, Mevinphos, Nitenpyrum, Piperonyl butoxide, Tetrachlorovinphos, Pyrethrins, Resmetrin, Pirimicarb and Dinotefuran) and known plant derived natural compounds (Catechin, Gossypol, Myrcene, Kaempferol, P-coumaric acid, Quercetin, Tannins, α-mangostin, Capsaicin, Cinnamic acid, Citronellal, Curcumin, Dicumarol, Ellagic acid, Eugenol, Geriniol, Isoeugenol, Juglone, Menadione, Methyl jasmonate, Morin, Myricetin, Myristicin, Piperine, Plumbagin, Tangitinin C, Thymol, Vanillin, Alpha pipene, α-terpineol Apigenin and β-Caryophyllene) with sigma 1 and sigma 2 GST protein models was completed using Maestro 9.3 (Schrodinger, USA). This exercise showed the binding of piperonyl butoxide with sigma 1 GST and tannin with sigma 2 GST for further consideration.
PubMed: 25512683
DOI: 10.6026/97320630010679 -
Food Chemistry Apr 2015QuEChERS method was applied and validated for the multi-residue analysis of pesticides in eggs and egg products. The method includes extraction with buffered...
QuEChERS method was applied and validated for the multi-residue analysis of pesticides in eggs and egg products. The method includes extraction with buffered acetonitrile and clean-up with dispersive sorbents, followed by LC-MS/MS analysis. The validation parameters were used based on the guideline of SANCO/12495/2011. Recoveries were within the range of 71-108%, and the relative standard deviations were 2-13% at the 3 different concentrations evaluated for eggs and egg products. The limits of quantification for the target compounds ranged from 0.3 to 6 ng/g. Monitoring of 100 domestic eggs and 50 imported egg products were performed to verify the adaptability in real samples. No samples contained residues exceeding the maximum residue limit (MRL). Carbendazim, dimethoate, and pirimicarb were each found in egg yolks at the level of 2 ng/g, in the same sample, well below their MRLs of 50-100 ng/g.
Topics: Acetonitriles; Benzimidazoles; Carbamates; Chromatography, Liquid; Eggs; Food Analysis; Limit of Detection; Pesticide Residues; Pyrimidines; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 25466149
DOI: 10.1016/j.foodchem.2014.10.143 -
Parasitology Research Dec 2014Varroa 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...
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.
Topics: Acaricides; Acetylcholinesterase; Amino Acid Sequence; Animals; Base Sequence; Bees; Carbamates; Cholinesterase Inhibitors; Models, Molecular; Molecular Docking Simulation; Molecular Sequence Data; Pyrimidines; Sequence Alignment; Varroidae
PubMed: 25358237
DOI: 10.1007/s00436-014-4150-z -
Talanta Nov 2014A new HPLC column-switching method using large volume sample injection and fused-core columns for on-line solid phase extraction have been developed for the...
A new HPLC column-switching method using large volume sample injection and fused-core columns for on-line solid phase extraction have been developed for the determination of the following carbamates and pyrethroids: aldicarb, carbaryl, pirimicarb, carbofuran, kadethrin, flumethrin, fenpropathrin, fenoxycarb, tau-fluvalinate and fenvalerate, in surface water samples. Sudan I was used as internal standard. The proposed method was performed using 100 µl sample injection followed by an on-line solid phase extraction procedure and finally the compounds were identified and quantified by liquid chromatography with ultraviolet detection. The separation was carried out on C-18 reversed phase column based on fused-core particle technology. The influence of the injected sample volume, the variables affecting to SPE process and the conditions for the separation on an analytical column, were studied and optimized. The limits of detection ranged from 5.5 to 8.9 µg L(-1), and limits of quantification from 18.4 to 29.7 µg L(-1), while inter- and intra-day variability was under 15%. This new analytical procedure was satisfactorily applied for the determination of these organic pollutants in surface water samples located in Czech Republic. Concentration levels were found for some of these pollutants up to 26.11 µg L(-1) in the river Elbe and up to 34.53 µg L(-1) in the closed lakes samples.
Topics: Carbamates; Chromatography, High Pressure Liquid; Chromatography, Liquid; Czech Republic; Environmental Monitoring; Insecticides; Lakes; Online Systems; Organic Chemicals; Pyrethrins; Reproducibility of Results; Rivers; Solid Phase Extraction; Spectrophotometry, Ultraviolet; Water; Water Pollutants, Chemical
PubMed: 25127636
DOI: 10.1016/j.talanta.2014.06.037 -
Journal of Chromatography. A Aug 2014In this paper, graphene, a new sorbent material, was synthesized and used for solid-phase extraction (SPE) of the six carbamate pesticides (pirimicarb, baygon, carbaryl,...
Graphene based solid phase extraction combined with ultra high performance liquid chromatography-tandem mass spectrometry for carbamate pesticides analysis in environmental water samples.
In this paper, graphene, a new sorbent material, was synthesized and used for solid-phase extraction (SPE) of the six carbamate pesticides (pirimicarb, baygon, carbaryl, isoprocarb, baycarb and diethofencarb) in environmental water samples. The target analytes can be extracted on the graphene-packed SPE cartridge, and then eluted with acetone. The eluate was collected and dried by high purity nitrogen gas at room temperature. 1mL of 20% (v/v) acetonitrile aqueous solution was used to redissolve the residue. The final sample solution was analyzed by ultra performance liquid chromatography-tandem quadrupole mass spectrometry (UPLC-MS/MS) system. Under optimum conditions, good linearity was obtained for the carbamates with correlation coefficient in the range of 0.9992-0.9998. The limits of detection (S/N=3) for the six carbamate pesticides were in the range of 0.5-6.9ngL(-1). Relative standard deviations (RSD) for five replicate determinations were below 5.54%. RSD values for cartridge-to-cartridge precision (n=7) were in the range of 1.27-8.13%. After proper regeneration, the graphene-packed SPE cartridge could be re-used over 100 times for standard solution without significant loss of performance. The enrichment factors for the target analytes were in the range of 34.2-51.7. The established method has been successfully applied to the determination of carbamate pesticide residues in environmental water samples such as river water, well water and lake water.
Topics: Carbamates; Chromatography, High Pressure Liquid; Fresh Water; Graphite; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Pesticide Residues; Solid Phase Extraction; Tandem Mass Spectrometry; Water Pollutants, Chemical
PubMed: 24973804
DOI: 10.1016/j.chroma.2014.05.085 -
Food and Chemical Toxicology : An... Aug 2014Organophosphorus (OP) and carbamate (CM) pesticides are widely used in agriculture. These pesticides are highly toxic to humans and their residues in food pose potential...
Organophosphorus (OP) and carbamate (CM) pesticides are widely used in agriculture. These pesticides are highly toxic to humans and their residues in food pose potential threat to human health. In this study, we investigated the effect of subchronic low-level exposure of OPs (dichlorvos, DDVP; malathion, MAL), CM pirimicarb (PI), or their mixtures (DDVP+MAL, DDVP+PI) on mice liver. Metabonomic analysis based on (1)H nuclear magnetic resonance spectroscopy was carried out in combination with biochemical assays. Serum metabonomic analysis showed that levels of trimethylamine-N-oxide, lactate, acetone, very low- and low-density lipoprotein and 3-hydroxybutyrate changed after exposure to the pesticides. In the liver extracts, lactate, glucose, choline, glutathione, alanine, glutamine and isoleucine levels changed after the treatment by pesticides. Our results indicated that exposure to low dose DDVP, MAL and PI, either alone or in combination lead to alteration of liver glucose, fat and protein metabolism, energy metabolism and oxidative balance. This study also showed that metabonomics is of potential use in food toxicity study.
Topics: Animals; Carbamates; Cholinesterase Inhibitors; Dichlorvos; Liver; Magnetic Resonance Spectroscopy; Malathion; Male; Metabolomics; Mice; Mice, Inbred ICR; Oxidative Stress; Pesticides; Pyrimidines; Superoxide Dismutase; Toxicity Tests, Subchronic
PubMed: 24907623
DOI: 10.1016/j.fct.2014.05.027 -
Pest Management Science Apr 2015The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus...
BACKGROUD
The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus it is an effective target for organophosphate (OP) and carbamate (CB) insecticides.
RESULTS
The transcript levels of the four Ace genes were dramatically suppressed by injection of their respective dsRNA in Rhopalosiphum padi and Sitobion avenae. However, the AChE activity changes in the Ace1 knockdown aphids were consistent with the significant transcript level changes of Ace1 genes in these aphids, but not for Ace2. Bioassay results indicated that the suppression of RpAce1 increased its susceptibilities to pirimicarb and malathion, and SaAce1 silencing also increased susceptibility to pirimicarb in S. avenae, whereas the knockdowns of RpAce2 and SaAce2 had a slight effect on their susceptibilities. The knockdown of Ace1 genes also caused significant reductions in fecundity in the aphids of their parental generation.
CONCLUSIONS
These results suggest that AChE1 is a predominant cholinergic enzyme and is the target of anticholinesterase insecticides in both R. padi and S. avenae. It also plays a non-cholinergic role in fecundity of these aphids. AChE2 may also be important for the toxicological function, although its importance appeared to be lower than that of AChE1.
Topics: Acetylcholinesterase; Animals; Aphids; Carbamates; Cholinesterase Inhibitors; Gene Silencing; Insect Proteins; Insecticides; Malathion; Pyrimidines; Species Specificity
PubMed: 24729410
DOI: 10.1002/ps.3800