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Environmental Toxicology and... Aug 2022Aquatic organisms are concomitantly exposed to multiple noxious chemicals that can be discharged into water bodies. We aimed to investigate the single and simultaneous...
Neurotoxicity of singular and combined exposure of Oreochromis niloticus to methomyl and copper sulphate at environmentally relevant levels: Assessment of neurotransmitters, neural stress, oxidative injury and histopathological changes.
Aquatic organisms are concomitantly exposed to multiple noxious chemicals that can be discharged into water bodies. We aimed to investigate the single and simultaneous sub-acute exposure to copper and methomyl on juvenile Oreochromis niloticus. Compared to the controls, the outcomes revealed that brain of methomyl-exposed fish displayed significant declines in the activities of SOD, CAT, and GST in addition to higher MDA and lower GSH levels. Methomyl induced notable declines in levels of GABA and acetylcholine esterase in brain and muscle of exposed fish. Noteworthy downregulated gene expression levels of TNF-α, HSP-70 together with upregulated c-fos were evident in brain of fish expose to either of tested compounds. Marked apoptotic changes were observed in fish brain exposed to copper and methomyl indicated by augmented immune expression of caspase-3. Conclusively, the results indicated the possible interaction between both compounds with subsequent toxic effects that differ from their single exposure.
Topics: Animals; Cichlids; Copper; Copper Sulfate; Liver; Methomyl; Neurotransmitter Agents; Oxidative Stress; Water Pollutants, Chemical
PubMed: 35882308
DOI: 10.1016/j.etap.2022.103935 -
Zygote (Cambridge, England) Feb 2022Methomyl is a widely used carbamate insecticide and environmental oestrogen that has adverse effects on the reproductive system. However, there have been no reports on...
Methomyl is a widely used carbamate insecticide and environmental oestrogen that has adverse effects on the reproductive system. However, there have been no reports on the effect of methomyl on early embryos in mammals. In this study, we explored the effect of methomyl exposure on the quality of early embryonic development in mice and the possible mechanisms. During in vitro culture, different concentrations of methomyl (10, 20, 30 and 35 μM) were added to mouse zygote medium. The results showed that methomyl had an adverse effect on early embryonic development. Compared with the control group, the addition of 30 μM methomyl significantly reduced the rate of early embryo blastocyst formation. Methomyl exposure can increase oxidative stress and impair mitochondrial function, which may be the cause of blastocyst formation. In addition, we found that methomyl exposure promoted apoptosis and autophagy in mouse blastocysts. The toxic effect of methomyl on early embryos may be the result of oxidative stress induction. Taken together, our results indicate that methomyl can cause embryonic development defects in mice, thereby reducing the quality of early embryo development.
Topics: Animals; Blastocyst; Embryo Culture Techniques; Embryo, Mammalian; Embryonic Development; Female; Methomyl; Mice; Oxidative Stress; Pregnancy
PubMed: 33966682
DOI: 10.1017/S0967199421000277 -
Mutation Research. Genetic Toxicology... Dec 2019Exposure of pregnant women to pesticides in an occupational or incidental manner has been pointed out as a possible cause of health problems in newborns. Cypermethrin...
Genotoxic and mutagenic evaluation of the protective effect of exogenous melatonin in adult rats and their offspring exposed to the insecticides methomyl and cypermethrin during pregnancy.
Exposure of pregnant women to pesticides in an occupational or incidental manner has been pointed out as a possible cause of health problems in newborns. Cypermethrin and methomyl are insecticides whose active compounds and metabolites can cause harm to the health of pregnant women and their offspring. Both contribute to increases in the concentrations of oxidizing agents that damage DNA, causing mutations. Thus, the use of antioxidant substances, such as melatonin, could serve as protection against genetic damage, reducing the problems caused by insecticides. Here, we evaluated the protective effect of exogenous melatonin in adult rats and their offspring exposed to methomyl and cypermethrin during the gestational period. Thirty adult rats were divided into five groups from the first day of pregnancy: NC - negative control, Mth received 0.02 mg/kg/day of methomyl, Cyp received 0.05 mg/kg/day cypermethrin, MthMl received 0.02 mg/kg/day methomyl combined with 10 mg/kg/day melatonin, and CypMl received 0.05 mg/kg/day cypermethrin combined with 10 mg/kg/day melatonin. Blood and liver samples were collected from the dams; blood, liver, and brain samples were collected from the offspring. All tissues were used for comet assay; blood was used for micronucleus test. Our results demonstrate that cypermethrin and methomyl induce significant genetic damage in the tissues of dams and offspring. Treatment with melatonin significantly reduced cypermethrin-induced genetic damage in dams and pups; however, melatonin was not effective against the genetic damage caused by methomyl. Thus, melatonin may be considered a promising agent for the reduction of genotoxic effects induced by cypermethrin but appears to be inefficient against the genotoxic effects caused by methomyl, probably due to differences in the metabolism of each pesticide.
Topics: Animals; Female; Insecticides; Male; Maternal Exposure; Melatonin; Methomyl; Micronucleus Tests; Pregnancy; Pyrethrins; Rats
PubMed: 31708074
DOI: 10.1016/j.mrgentox.2019.503107 -
Pest Management Science Oct 2022The application of synthetic insecticides is the main strategy used to reduce the damage caused by the diamondback moth Plutella xylostella in commercial Brassica crops....
Lethal and sublethal effects of insecticides used in the management of Plutella xylostella (Lepidoptera: Plutellidae) on the predator Cycloneda sanguinea L. (Coleoptera: Coccinellidae).
BACKGROUND
The application of synthetic insecticides is the main strategy used to reduce the damage caused by the diamondback moth Plutella xylostella in commercial Brassica crops. However, incorrect insecticide use can cause biological and ecological disturbances in agroecosystems. Cycloneda sanguinea is a generalist voracious predator and is distributed widely in cultivated and noncultivated ecosystems. This study investigated the efficiency of four insecticides for the control of P. xylostella and the lethal and sublethal effects of these insecticides on C. sanguinea.
RESULTS
Spinosad (92% mortality) and chlorfenapyr (76% mortality) were highly toxic to P. xylostela. However, chlorantraniliprole (10% mortality) and methomyl (no mortality) were ineffective against this pest. Chlorantraniliprole was the only insecticide that was highly toxic to C. sanguinea by contact (90% mortality), however, it was nontoxic following the ingestion of chlorantraniliprole-contaminated aphids. Interestingly, ingestion of prey contaminated with methomyl and chlorfenapyr was highly toxic (100% mortality) to C. sanguinea. Spinosad was nontoxic to C. sanguinea via exposure to contaminated surfaces and following ingestion of contaminated prey. However, direct contact of the insects with both methomyl and spinosad significantly affected C. sanguinea flight activity (vertical flight and free-fall flight), whereas chlorfenapyr impacted vertical flight only.
CONCLUSION
These findings showed that chlorantraniliprole was not only ineffective for the control of P. xylostela, but was also highly toxic to C. sanguinea. The results indicated that spinosad was efficient against P. xylostela and was of low toxicity to C. sanguinea; however, the deleterious effects of this insecticide on flight behavior could result in reduced predatory efficiency. © 2022 Society of Chemical Industry.
Topics: Animals; Coleoptera; Ecosystem; Insecticide Resistance; Insecticides; Larva; Methomyl; Moths
PubMed: 35762333
DOI: 10.1002/ps.7060 -
Food Additives & Contaminants. Part B,... Dec 2021This study aimed to evaluate levels of pesticide residues commonly used on tomato crops in Western Algeria. It showed a significant use of pesticides, especially...
This study aimed to evaluate levels of pesticide residues commonly used on tomato crops in Western Algeria. It showed a significant use of pesticides, especially insecticides (47%) and fungicides (41%) among listed pesticides in crop fields. A total of 30 tomato samples were analysed using multi-residue analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after QuEChERS extraction. Five pesticides (difenoconazole, triadimenol, metalaxyl, chlorpyriphos and methomyl) were detected in 14 samples (47%). Among these five samples containing residues of two different types of pesticides. The levels ranged from 2.29 to 64.3 µg/kg. The methomyl residue in one sample was above the maximum limit (MRLs) set by the European Union. Our results indicate an excessive use of pesticides and undeniable non-compliance with good agricultural practices. Routine monitoring for pesticides is recommended to preserve consumer's health.
Topics: Algeria; Chromatography, Liquid; Food Contamination; Solanum lycopersicum; Pesticide Residues; Tandem Mass Spectrometry
PubMed: 34266368
DOI: 10.1080/19393210.2021.1953156 -
Toxicology Mar 2021The neurotoxicity and developmental effects of a widely applied insecticide (methomyl) was investigated by a multi-level approach (behavior and biometry, biochemical...
The neurotoxicity and developmental effects of a widely applied insecticide (methomyl) was investigated by a multi-level approach (behavior and biometry, biochemical alterations and neurodegeneration) in Caenorhabditis elegans upon a short-term exposure (1 h) and a post-exposure period (48 h). The 1-h exposure to sub-lethal concentrations of methomyl (lower than 0.320 g L; i.e. below the estimated LC) triggered significant changes on motor behavior and development impairment. The type of movement was significantly altered in methomyl-exposed worms, as well as biometric parameters (worms frequently idle and moving more backwards than controls; small body area, length and wavelength). These effects were followed by an increase of acetylcholine levels. Interestingly, after the 48-h recovery period, movement of previously exposed worms was similar to controls, and a concentration-dependent reversion of biometric endpoints was recorded, pointing out the transient action of the carbamate in line with an apparent absence of cholinergic neurons damage. This study provided new insight on the neurotoxicity of methomyl by showing that effects on movement and development were transient, and apparently did not result in neurodegeneration in cholinergic neurons. Moreover, these findings reinforced the advantages of using C. elegans in a multi-level approach for pesticide effects assessment.
Topics: Animals; Animals, Genetically Modified; Caenorhabditis elegans; Carbamates; Cholinergic Neurons; Dose-Response Relationship, Drug; Insecticides; Methomyl; Motor Activity; Nerve Degeneration
PubMed: 33508380
DOI: 10.1016/j.tox.2021.152684 -
Veterinary Medicine and Science Mar 2021Veterinary biocides used in animal husbandry have the potential to cause human health concerns. Biocidal products for veterinary use, which contain pesticides approved...
Veterinary biocides used in animal husbandry have the potential to cause human health concerns. Biocidal products for veterinary use, which contain pesticides approved in Korea, comprise 49 active ingredients within 234 products. Within 17 of these products there are 3 ingredients which are highly hazardous pesticides: coumaphos, dichlorvos and methomyl. In this study, the content of the active ingredients of 160 products sold domestically was investigated. Samples were collected for 119 biocidal products for veterinary use. These were analysed by high-performance liquid chromatography (HPLC) and gas chromatography (GC). Seventeen products were noncompliant (insufficient or excess quantity of active ingredients). The ingredients that were below the stated concentrations were amitraz, chlorpyrifos-methyl, cypermethrin, cyromazine, dichlorvos, fipronil, muscamone and trichlorfon. The ingredients that exceeded the stated concentrations were abamectin, fluvalinate and pyriproxyfen. The noncompliance rate in biocidal products for veterinary use was 9.19%. The results of this study show that three highly hazardous pesticides (coumaphos, dichlorvos and methomyl) and 10 active ingredients (abamectin, amitraz, chlorpyrifos-methyl, cypermethrin, cyromazine, fipronil, fluvalinate, muscamone, pyriproxyfen and trichlorfon) deviated from the stated concentrations. Thus, management plans should be established to ensure compliant veterinary drugs by post-distribution quality control, such as planning for regular inspection.
Topics: Chromatography, High Pressure Liquid; Pesticides; Republic of Korea; Veterinary Medicine
PubMed: 33107216
DOI: 10.1002/vms3.385 -
Pesticide Biochemistry and Physiology May 2020Thrips tabaci is a key pest of onions, especially in the Pacific Northwestern USA. Management of T. tabaci is dominated by the application of various insecticides....
Thrips tabaci is a key pest of onions, especially in the Pacific Northwestern USA. Management of T. tabaci is dominated by the application of various insecticides. However, T. tabaci is known to develop insecticide resistance which possibly leads to control failures, crop loss, and environmental concern. Here, we evaluated resistance status of T. tabaci populations from conventional and organic commercial onion fields to three widely used insecticides: oxamyl, methomyl, and abamectin with on-field concentration-mortality bioassays. The biochemistry and molecular mechanisms underlying resistance to these insecticides were also investigated by using enzymatic assays and detecting resistance-associated mutations. Field-evolved resistance to oxamyl, methomyl and abamectin were detected in most of the T. tabaci populations collected from conventional onion farms. At the labeled field rate, all the tested insecticides, particularly methomyl and oxamyl, had significantly reduced efficacy. Enzymatic assays of insecticide target and detoxification enzymes indicated that T. tabaci populations in Western USA onions harbor multiple mechanisms of resistance including enhanced activities of detoxification enzymes and target site insensitivity. Our results provide new information in understanding the dynamics of T. tabaci adaptation to multiple insecticides, which will help to design sustainable insecticide resistance management strategies for T. tabaci. Furthermore, this study provides the foundation for future research in identifying the biochemical and molecular markers associated with insecticide resistance in T. tabaci.
Topics: Animals; Insecticide Resistance; Insecticides; Methomyl; Onions; Thysanoptera
PubMed: 32359535
DOI: 10.1016/j.pestbp.2020.104553 -
Pest Management Science May 2022Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is released in extensive areas cultivated with cotton worldwide, but the use of synthetic insecticides...
BACKGROUND
Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) is released in extensive areas cultivated with cotton worldwide, but the use of synthetic insecticides threatens the establishment of augmented populations. Thus, an assessment of insecticides' effects on T. pretiosum is required to establish their compatibility with mass releases of the parasitoid. We studied in the laboratory the impact of insecticides administered through different exposure routes (direct-spraying, ingestion and residue contact) on T. pretiosum. Based on their toxicity, the insecticides were rated into four categories (harmless, slightly harmful, moderately harmful and harmful) as per the International Organization for Biological Control.
RESULTS
The survival, parasitism ability and emergence of the treated adults and offspring (F and F ), in addition to the persistence of the toxic effects in semi-field conditions, were assessed. Teflubenzuron did not reduce female survival and caused a lesser impact on T. pretiosum on both direct-spraying and ingestion bioassays. In the residue contact bioassay, teflubenzuron and flupyradifurone were rated as harmless and slightly harmful, respectively. The other active substances (chlorfenapyr, thiodicarb and methomyl) were harmful to the parasitoid by all exposure routes and were persistent (with toxicity duration surpassing 30 days).
CONCLUSION
From these findings, teflubenzuron is the insecticide most compatible with T. pretiosum releases and should be preferred over the other active substances. Further studies with the harmful insecticides (thiodicarb, chlorfenapyr and methomyl) are required to determine their toxicity under field conditions and confirm their incompatibility with T. pretiosum releases.
Topics: Animals; Female; Gossypium; Hymenoptera; Insecticides; Methomyl; Moths; Pest Control, Biological; Wasps
PubMed: 35064632
DOI: 10.1002/ps.6807 -
International Journal of Environmental... Sep 2021The present study was performed to fabricate a titanium dioxide (TiO) nanocatalyst with proper characteristics for the removal of some insecticides (dimethoate and...
The present study was performed to fabricate a titanium dioxide (TiO) nanocatalyst with proper characteristics for the removal of some insecticides (dimethoate and methomyl) from aqueous media. A TiO catalyst of regular (TiO-commercial-/HO/UV) or nano (TiO-synthesized-/HO/UV) size was employed as an advanced oxidation process by combining it with HO under light. Moreover, the total detoxification of insecticides after treatment with the most effective system (TiO(s)/HO/UV) was also investigated through exploring the biochemical alterations and histopathological changes in the liver and kidneys of the treated rats. Interestingly, the present study reported that degradation rates of the examined insecticides were faster using the TiO catalyst of nano size. Complete degradation of the tested insecticides (100%) was achieved under the TiO(s)/HO/UV system after 320 min of irradiation. The half-life values of the tested insecticides under HO/TiO(c)/UV were 43.86 and 36.28 for dimethoate and methomyl, respectively, whereas under the HO/TiO(c)/UV system, the half-life values were 27.72 and 19.52 min for dimethoate and methomyl, respectively. On the other hand, no significant changes were observed in the biochemical and histopathological parameters of rats administrated with water treated with TiO(s)/HO/UV compared to the control, indicating low toxicity of the TiO nanocatalyst-. Altogether, the advanced oxidation processes using TiO nanocatalyst can be considered as a promising and effective remediation technology for the complete detoxification of methomyl and dimethoate in water. However, further future research is needed to identify the possible breakdown products and to verify the safety of the used nanomaterials.
Topics: Animals; Catalysis; Hydrogen Peroxide; Insecticides; Oxidation-Reduction; Rats; Titanium; Ultraviolet Rays; Water; Water Pollutants, Chemical
PubMed: 34501865
DOI: 10.3390/ijerph18179278