Ecotoxicological strategies employing biochemical markers and organisms to monitor the efficacy of malathion photolysis treatment.

The objective of this study was to assess the photolysis-mediated degradation of malathion in standard and commercial formulations, and to determine the toxicity of these degraded formulations. Degradation tests were carried out with 500 µg L-1 of malathion and repeated three times. The initial and residual toxicity was assessed by using Lactuca sativa seeds for phytotoxicity, Stegomyia aegypti larvae for acute toxicity, and Stegomyia aegypti mosquitoes (cultivated from the larval stage until emergence as mosquitoes) to evaluate the biochemical markers of sublethal concentrations. For the standard formulations the photolytic process efficiently reduced the initial concentration of malathion to levels below the regulatory limits however, the formation of byproducts was revealed by chromatography, which allowed for a more complete proposal of photolytic-mediated malathion degradation route. The degraded formulations inhibited the growth of L. sativa seeds, while only the untreated formulations showed larvicidal activity and mortality. Both formulations slightly inhibited acetylcholinesterase activity in S. aegypti mosquitoes, while the standard formulation decreased and the commercial formulation increased glutathione S-transferase activity. However, there were no significant differences for superoxide dismutase, esterase-α, esterase-ß and lipid peroxidation. These findings indicate that in the absence of the target compound, the presence of byproducts can alter the enzymatic activity. In general, photolysis effectively degrade malathion lower than the legislation values; however, longer treatment times must be evaluated for the commercial formulation.

In vitro comparison of the acetylcholinesterase inhibition caused by V- and A-series nerve agents' surrogates.

Nerve agents (NA) pose as a great risk in the modern world. NA from the V-series, such as VX, are currently recognized as the most toxic among those compounds. However, the emergence of new classes of toxicants recently included in the Chemical Weapons Convention (CWC), such as the A-series NA, a class of organophosphorus compounds related to phosphoramidates, pose a new source of concern due to the lack of information. In order advance in the investigation on the toxicity of such toxic chemicals, we performed in vitro studies to compare representatives of the V- and A-series using affordable surrogates. Results suggest a similar inhibition potency between both agents.

Organophosphate esters in inert landfill soil: A case study.

Organophosphate esters (OPEs) used as flame retardants and plasticizers are additives in building and construction materials, decorations, furniture, electronic equipment, among other applications. The presence of materials containing these substances in construction and demolition waste (CDW) from weak waste management practices can result in environmental contamination. In this study, OPEs' presence in soil samples collected from a CDW landfill in Brazil was evaluated. Soil samples were collected in areas adjacent to CDW from an inert landfill, and the samples were analysed by gas chromatography coupled to mass spectrometry. The OPEs were detected in all soil samples at quantifiable concentrations ranging from 21 to 251 ng g-1, and detected compounds were tris(phenyl) phosphate, tris(2-butoxyethyl) phosphate, tris(1,3-dichloroisopropyl) phosphate, tris(2-chloroisopropyl) phosphate and 2-ethylhexyl diphenyl phosphate. The presence of these compounds in a CDW landfill is probably due to the lack of control of the materials sent to and deposited in the landfill, which, results in part from the lack of sampling and screening systems that can help identify the presence of contaminants in the CDW waste stream. This is partially due to OPEs not being considered controlled compounds under current regulations, thus screening or separation for handling of OPEs at construction and demolition work sites is rare to non-existent. The data generated in this study reveals the need for improving CDW management to minimize, if not eliminate, environmental contamination by OPEs.

Cu2+-dependent hydrolysis of O-hexyl 2,5-dichlorophenyl phosphoramidate by reptile sera.

This study shows the EDTA-resistant, Ca2+ and Cu2+-dependent hydrolysis of O-hexyl 2,5-dichlorophenyl phosphoramidate (HDCP) compound in reptiles sera determined by spectrophotometry UV/Vis and chiral chromatography. Samples of ten reptile species were incubated with aliquot of 100 or 400 µM HDCP in presence of 100 or 300 µM Cu2+, or 2.5 mM Ca2+ or 5 mM EDTA at 37 °C for 30-60 min. The results shown an activator effect of Cu2+ on HDCP hydrolysis in freshwater turtles sera (Trachemys scripta, Chelydra serpentina and Macrochelys temminckii) because the levels of 2,5-dichlorophenol (DCP; product hydrolysis) were similar (∼37 µM DCP) to chicken serum (positive control group). The marine turtles (Chelonia mydas and Eretmochelys imbricata) and crocodiles (Crocodylusacutus and Crocodylus moreletii) showed ∼50% less HDCPase activity (13-17 µM DCP) compared to the HDCPase activity of the freshwater turtle species. Terrestrial reptile species (snakes and lizards) showed around 25% of activity (7-13 µM DCP) with both copper concentrations. These Cu2+-dependent hydrolysis were stereospecific to R(+)-HDCP (p˂0.05) in the three freshwater turtle species that showed similar hydrolysis to the chicken serum. However, the Ca2+ did not show a significant activating effect on the HDCPase activity (1-8 µM DCP) in any reptile serum. Their hydrolysis levels were very similar to those of EDTA-resistant activity. The present study demonstrates a Cu2+-dependent A-esterase (HDCPase) activity in turtles and points serum albumin as the cuproprotein responsible for this activity, reinforcing its N-terminal sequence (DAEH) as a catalytic center.

A modified QuEChERS method for determination of organophosphate esters in milk by GC-MS.

Organophosphate esters (OPEs) are substances that have been detected in several matrices due to their use as flame retardants and plasticizers. Human exposure to OPEs can cause endocrine disruption, neurotoxicity, and reproductive disturbance. Ingestion of contaminated food can be a significant route of exposure to OPEs. Food can be contaminated by OPEs in the food chain, during cultivation, and by contact with plasticizers during the production chain of processed foods. In this study, a method for the determination of 10 OPEs in commercial bovine milk was developed. The procedure was based on QuEChERS extraction and gas chromatography coupled to mass spectrometry (GC-MS) analysis. QuEChERS modification included a freezing-out step after the extraction followed by the concentration of the entire acetonitrile phase before the clean-up step. Calibration linearity, matrix effects, recovery, and precision were evaluated. Significant matrix effects were observed, which were compensated by matrix-matched calibration curves. Recoveries ranged from 75 to 105%, with a relative standard deviation ranging from 3 to 38%. The method detection limits (MDLs) were in the range of 0.43-4.5 ng mL-1, while the method quantification limits (MQLs) were within the range from 0.98 to 15 ng mL-1. The proposed method was successfully validated and applied to determine the concentrations of OPEs in bovine milk. The 2-ethylhexyl diphenyl phosphate (EHDPHP) was detected in the analyzed milk samples but at levels below the MQL.

Organophosphate-Pesticide-Mediated Immune Response Modulation in Invertebrates and Vertebrates.

Organophosphate pesticides (OPs) have greatly facilitated food production worldwide, and their use is not limited to agriculture and the control of pests and disease vectors. However, these substances can directly affect the immune response of non-target organisms. In this sense, exposure to OPs can have negative effects on innate and adaptive immunity, promoting deregulation in humoral and cellular processes such as phagocytosis, cytokine expression, antibody production, cell proliferation, and differentiation, which are crucial mechanisms for host defense against external agents. This review focuses on the scientific evidence of exposure to OPs and their toxic effects on the immune system of non-target organisms (invertebrates and vertebrates) from a descriptive perspective of the immuno-toxic mechanisms associated with susceptibility to the development of bacterial, viral, and fungal infectious diseases. During the exhaustive review, we found that there is an important gap in the study of non-target organisms, examples of which are echinoderms and chondrichthyans. It is therefore important to increase the number of studies on other species directly or indirectly affected by Ops, to assess the degree of impact at the individual level and how this affects higher levels, such as populations and ecosystems.

Assessing the Therapeutic and Toxicological Profile of Novel Acetylcholinesterase Reactivators: Value of In Silico And In Vitro Data.

Organophosphorus compounds (OP) make up an important class of inhibitors, mostly employed as pesticides, even as chemical weapons. These toxic substances act through the inhibition of the acetylcholinesterase (AChE) enzyme, which results in elevated synaptic acetylcholine (ACh) levels, leading to serious adverse effects under the cholinergic syndrome. Many reactivators have been developed to combat the toxic effects of these AChE inhibitors. In this line, the oximes highlight because of their good reactivating power of cholinesterase enzymes. To date, no universal antidotes can reactivate AChE inhibited by any OP agent. This review summarizes the intoxication process by neurotoxic OP agents, along with the development of reactivators capable of reversing their effects, approaching aspects like the therapeutic and toxicological profile of these antidotes. Computational methods and conscious in vitro studies, capable of significantly predicting the toxicological profile of these drug candidates, might support the process of development of these reactivators before entering in vivo studies in animals, and then clinical trials. These approaches can assist in the design of safer and more effective molecules, reducing related cost and time for the process.

Novel fungal organophosphorus hydrolases in acidic media: an application to apples decontamination.

Organophosphorus pesticides bring significant improvements in agriculture, but their toxicity causes environmental and health negative impacts. The aim of this work was the development of robust biocatalysts to be applied in bioremediation. Four fungi were evaluated as hydrolase sources capable of degrading organophosphorus pesticides: Aspergillus niger, Fusarium sp., Penicillium chrysogenum, and Penicillium nalgiovense. The hydrolysis rates of methyl paraoxon obtained under acidic conditions were in the range of 10 to 21 mg L-1 d-1, which is remarkable since most similar biocatalysts are active under alkaline conditions. Penicillium chrysogenum activity was outstanding, and it was selected to prepare, characterize, and study the applications of its enzymatic extract. It was used to evaluate the bioremediation of apple surfaces at pH 2 in the presence of SDS, achieving complete methyl paraoxon degradation under proposed conditions. These results indicate that this biocatalyst could complement industrialized fruit washing processes for the elimination of organophosphorus pesticides.

Role of biotransformation in the diazinon-induced toxicity in HepG2 cells and antioxidant protection by tetrahydrocurcumin.

Diazinon (DZN) is an insecticide extensively used to control pests in crops and animals. However, its indicriminated use may lead to liver damage in animals and humans. This study aimed to evaluate the toxicity of DZN (25-150 µM) on human hepatoblastoma (HepG2) cells after 24 and 48 h of exposure and the role of its biotransformation on the toxicological potential. We also tested the protective effect of tetrahydrocurcumin (THC), an antioxidant agent, in the DZN-induced citotoxicity. DZN caused cytotoxicity in the HepG2 cells, inhibiting cell proliferation and reducing cell viability in a dose- and time-dependent manner. The pre-incubation of HepG2 cells with chemical inducers of cytochrome P450 monooxygenase 3-methylcholanthrene and phenobarbital resulted in a further decrease of cell viability associated with DZN exposure. In addition, the metabolite diazoxon was more toxic than DZN. Our results also revealed that THC alleviated DZN-induced cytotoxicity and reactive oxygen and nitrogen species (RONS) generation in HepG2 cells. In conclusion, our data provide novel insights into the involvement of biotransformation in the mechanisms of DZN-induced cytotoxicity and suggest that amelioration of RONS accumulation might be involved in the protective effect of THC on DZN-induced liver injury.

Structure-Reactivity Insights on the Alkaline Hydrolysis of Organophosphates: Non-Leaving and Leaving Group Effects in a Bilinear Brønsted-Like Relationship.

The high toxicity of organophosphates, along with its wide use as agrochemicals and chemical warfare, urges efficient degradation methods. Alkaline hydrolysis stands out, which is strongly structure-dependent. The alkaline hydrolysis of various organophosphates is described using a bilinear variation of the Brønsted equation, which evaluates concomitantly the effect of the leaving and non-leaving groups. Over 50 reactions were successfully correlated linearly and the contribution of the usually underestimated non-leaving group seems to be as important as the leaving group. The hetero atom effect (P=O and P=S) seems to vary the contribution of these groups. This concise understanding of the structure-reactivity relationship allows to predict optimal neutralization processes and is key for chemical security, saving time, resources and avoiding unnecessary manipulation of toxic chemicals.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L. system

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L. system / Análise integrativa na avaliação toxicológica do inseticida Malation no sistema Allium cepa L

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados ​​contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L system / Análise integrativa na avaliação toxicológica do inseticida Malation no sistema Allium cepa L

For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-¹ and 1.0 mg mL-¹ MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-¹). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-¹, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-¹ e 1,0 mg mL-¹ foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-¹ de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-¹, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L system / Análise integrativa na avaliação toxicológica do inseticida Malation no sistema Allium cepa L

For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-¹ and 1.0 mg mL-¹ MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-¹). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-¹, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.(AU)

Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-¹ e 1,0 mg mL-¹ foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-¹ de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-¹, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.(AU)

Agrochemical Residues in Fish and Bivalves from Sepetiba Bay and Parnaiba River Delta, Brazil.

Accumulation of pesticides has a harmful impact on the environment and human health. The main goal of this work was to develop a method to determine and quantify the residues of thirteen pesticides in edible fish and bivalves such as parati (Mugil curema), seabass (Centropomus ssp.), mullet (Mugil brasiliensis), clams (Anomalocardia brasiliana) and mussel (Mytilus galloprovincialis) collected from Sepetiba Bay and Parnaiba River Delta (Brazil) between 2019 and 2020. Matrix solid-phase dispersion (MSPD) was used for extraction and quantification through gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The method was validated (linearity, accuracy and precision) for fatty fish (Salmo salar), lean fish (Mugil curema) and bivalves (Mytilus edulis). The survey found linear correlation coefficients (r) equal to or greater than 0.9 for almost all analytes. The relative standard deviations (RSD) of five replicates were less than 20% for almost all analytes at different concentrations in lean fish, fatty fish and bivalves. Most analytes showed satisfactory accuracy. Alachlor herbicide was found in samples of seabass, mussels, clams and parati with levels ranging between 0.55 to 420.39 µg kg-1 dw. Ethion was found in parati (maximum 211.22 µg kg-1 dw), mussels (15.1 µg kg-1 dw) and clams (maximum 44.50 µg kg-1 dw). Alachlor was found in clams (maximum 93.1 µg kg-1 dw), and bifenthrin was found in parati (maximum 43.4 µg kg-1 dw) and clams (maximum 42.21 µg kg-1 dw). The validated method was satisfactory for the determination of eleven pesticides in the fatty fish matrix, and thirteen pesticides in the samples of lean fish and bivalves. The presence of alachlor, ethion and bifenthrin stands out.

Proteomic analysis of Burkholderia zhejiangensis CEIB S4-3 during the methyl parathion degradation process.

Methyl parathion is an organophosphorus pesticide widely employed worldwide to control pests in agricultural and domestic environments. However, due to its intensive use, high toxicity, and environmental persistence, methyl parathion is recognized as an important ecosystem and human health threat, causing severe environmental pollution events and numerous human poisoning and deaths each year. Therefore, identifying and characterizing microorganisms capable of fully degrading methyl parathion and its degradation metabolites is a crucial environmental task for the bioremediation of pesticide-polluted sites. Burkholderia zhejiangensis CEIB S4-3 is a bacterial strain isolated from agricultural soils capable of immediately hydrolyzing methyl parathion at a concentration of 50 mg/L and degrading the 100% of the released p-nitrophenol in a 12-hour lapse when cultured in minimal salt medium. In this study, a comparative proteomic analysis was conducted in the presence and absence of methyl parathion to evaluate the biological mechanisms implicated in the methyl parathion biodegradation and resistance by the strain B. zhejiangensis CEIB S4-3. In each treatment, the changes in the protein expression patterns were evaluated at three sampling times, zero, three, and nine hours through the use of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and the differentially expressed proteins were identified by mass spectrometry (MALDI-TOF). The proteomic analysis allowed the identification of 72 proteins with differential expression, 35 proteins in the absence of the pesticide, and 37 proteins in the experimental condition in the presence of methyl parathion. The identified proteins are involved in different metabolic processes such as the carbohydrate and amino acids metabolism, carbon metabolism and energy production, fatty acids ß-oxidation, and the aromatic compounds catabolism, including enzymes of the both p-nitrophenol degradation pathways (Hydroquinone dioxygenase and Hydroxyquinol 1,2 dioxygenase), as well as the overexpression of proteins implicated in cellular damage defense mechanisms such as the response and protection of the oxidative stress, reactive oxygen species defense, detoxification of xenobiotics, and DNA repair processes. According to these data, B. zhejiangensis CEIB S4-3 overexpress different proteins related to aromatic compounds catabolism and with the p-nitrophenol  degradation pathways, the higher expression levels observed in the two subunits of the enzyme Hydroquinone dioxygenase, suggest a preferential use of the Hydroquinone metabolic pathway in the p-nitrophenol degradation process. Moreover the overexpression of several proteins implicated in the oxidative stress response, xenobiotics detoxification, and DNA damage repair reveals the mechanisms employed by B. zhejiangensis CEIB S4-3 to counteract the adverse effects caused by the methyl parathion and p-nitrophenol exposure.

Organophosphorus Pesticides as Modulating Substances of Inflammation through the Cholinergic Pathway.

Organophosphorus pesticides (OPs) are widespread insecticides used for pest control in agricultural activities and the control of the vectors of human and animal diseases. However, OPs' neurotoxic mechanism involves cholinergic components, which, beyond being involved in the transmission of neuronal signals, also influence the activity of cytokines and other pro-inflammatory molecules; thus, acute and chronic exposure to OPs may be related to the development of chronic degenerative pathologies and other inflammatory diseases. The present article reviews and discusses the experimental evidence linking inflammatory process with OP-induced cholinergic dysregulation, emphasizing the molecular mechanisms related to the role of cytokines and cellular alterations in humans and other animal models, and possible therapeutic targets to inhibit inflammation.

Determination of organophosphorus compounds in water and food samples using a non-enzymatic electrochemical sensor based on silver nanoparticles and carbon nanotubes nanocomposite coupled with batch injection analysis.

This work presents, for the first time, a fast and highly sensitive electrochemical method for determination of three organophosphorus compounds (OPs), diazinon (DZN), malathion (MLT), and chlorpyrifos (CLPF), using a modified pyrolytic graphite electrode (PGE) coupled to batch injection analysis system with multiple pulse amperometric detection (BIA-MPA). The PGE was modified by a nanocomposite based on functionalized carbon nanotubes (CNTf) and silver nanoparticles (AgNPs). The OPs samples were directly analyzed on the modified working electrode surface by BIA-MPA system in Britton-Robinson (BR) buffer 0.15 mol L-1 at pH 6.0. The MPA detection of DZN, MLT and CLPF was performed using two potential pulses, which were sequentially applied on modified PGE at -1.3 V (100 ms) and +0.8 V (100 ms) for selective determination of these three OPs and working electrode cleaning, respectively. Under optimized conditions, the sensor presented a linear range of 0.1-20 µmol L-1 for DZN, 1.0-30 µmol L-1 for MLT and from 0.25 to 50 µmol L-1 for CLPF. The limits of detection (LOD) and quantification (LOQ) of 0.35 and 1.18 µmol L-1 for DZN, 0.89 and 2.98 µmol L-1 for MLT, and 0.53 and 1.78 µmol L-1 for CLPF were obtained. The proposed method exhibited high sensitivity of 0.068, 0.030 and 0.043 mA L µmol-1 for DZN, MLT and CLPF detection, respectively. Furthermore, the BIA-MPA system provided an analytical frequency of 71 determinations per hour for direct determination of these OPs in water and food samples. The modified PGE coupled to BIA-MPA system showed a high stability of electrochemical response for OPs detection with relative standard deviation (RSD) of 1.60% (n = 20). The addition-recovery studies of the proposed method were carried out in tap water, orange juice, and apple fruit real samples, which showed suitable recovery values between 77 and 124%. The analytical performance of the developed sensor provides an attractive alternative method for OPs determination with great potential for a fast and sensitive application in contaminated samples with these pesticides.

Theoretical and X-Ray Evidence of Electrostatic Phosphonium anti and gauche Effects.

Sulphur, not phosphorus, is the only known third-row element capable of experiencing an electrostatic gauche effect with fluorine. Some six-membered rings containing an endocyclic phosphorus atom and a ß-fluorine substituent that can interconvert to axial (gauche relative to phosphorus) and equatorial positions were then analysed. While phosphines do not establish an electrostatic attraction between fluorine and phosphorus, some oxidised forms exhibit surprising stability for the sterically disfavoured axial orientation. Because the nature of this behaviour was not obvious, since an intramolecular hydrogen bond can appear, a phosphonium derivative was further studied and its axial conformation was found to be highly stable. A preference for the gauche arrangement appears even for the acyclic and sterically hindered (2-fluoroethyl)triphenylphosphonium cation. On the other hand, (ethane-1,2-diyl)bis(phosphonium) cations are exclusively in anti conformation due to an (+/+)-electrostatic repulsion between the positively charged phosphonium groups.

Association of occupational exposure to pesticides with overweight and abdominal obesity in family farmers in southern Brazil.

The association of chronic exposure to pesticides with overweight and abdominal obesity in adult farmers was investigated. This cross-sectional study included a random sample of 122 farmers and their family members of both sexes (61% were male), living in the municipality of Farroupilha, southern Brazil. Pesticide groups and their individual compounds were self-reported and classified according to major functional and chemical classes (never used, 1-20 years, or > 20 years of use). Abdominal obesity and overweight were the outcomes of interest. A multivariate Poisson regression model was analyzed. After confounding factors were controlled, chronic use (>20 years) of insecticides (PR: 1.45; 95% CI: 1.00-2.10) and organophosphorus pesticides (PR: 1.48, 95% CI: 1.02-2.12) was associated with a higher prevalence of overweight but not abdominal obesity. Additional studies are needed to confirm our findings and clarify the specific mechanisms of these pollutants in the etiology of obesity.