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Temephos and spinosad are pesticides used for control of vector-borne diseases such as dengue, chikungunya and zika. However, the inadequate use of these substances has affected the health of non-target organisms. The aim of this study was to evaluate and compare, the effects of temephos and spinosad on leukocyte viability and death, using guppy fish (Poecilia reticulate) as a model organism. Guppies were exposed to temephos (10 mg/L) and spinosad (0.5 mg/L) for 7, 14, and 21 days. Afterwards, they were placed in pesticide-free fish tanks (7, 35, and 70 days) for recovery. The results showed that exposure to temephos caused leukocyte death, even at 35 days of recovery. Contrarily, the exposure to spinosad did not cause leukocyte death. This research show, for the first time, that a single dose of temephos causes apoptosis up to 56 days post-exposition, indicating that this pesticide induces chronic effects on immune response cells. [ABSTRACT FROM AUTHOR]

Spinosad and temefos are widely used pesticides for chemical control of dengue vector-borne disease (Aedes aegypti). The aim of this study was to compare the effect of acute exposure (7 days) to spinosad (0.5 mg A.I. L−1) and temefos (10 mg A.I. L−1), concentrations used by the Mexican Ministry of Health, on phagocytic capacity (PC) of mononuclear cells of guppies fish (Poecilia reticulata), as well as to assess PC in fish, at 96 days after exposure to those pesticides. Obtained results indicated that spinosad did not alter PC, while an acute exposure to temefos significantly affected phagocytosis and this parameter was maintained downed even 96 days after the acute exposure, suggesting that the immunotoxic effects of temefos may be chronic. [ABSTRACT FROM AUTHOR]

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Naphthalene is one of the most abundant polycyclic aromatic hydrocarbons (PAH) in aquatic ecosystems, and it can cause alterations in the immune system of organisms that live there. The oyster Crassostrea corteziensis is a species native to the Eastern Tropical Pacific, with economic and ecological importance. In this study, we evaluated the effect of subacute exposure to sublethal concentrations of naphthalene on the parameters of the humoral immune response (lysozyme and phenoloxidase activity, and nitric oxide production) on the oyster C. corteziensis. The results indicated that naphthalene, under the conditions tested, significantly deregulated the parameters evaluated. This could increase susceptibility to infections and therefore affect oyster production. [ABSTRACT FROM AUTHOR]

Chlorpyrifos is an organophosphorous insecticide widely used in agriculture and domestic activities. However, little is known about the effect of this pesticide on the immune system of fish and other alterations of its physiological system. The aims of the present study were the evaluation of the LC50 (lethal concentration50) and the potential toxicity of this substance on Nile tilapia (Oreochromis nilotucus), as well as its effect on some hematological values and phagocytic functions of this fish. Results obtained showed that chlorpyrifos does not have any effect on the following parameters: number of red blood cells, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). However, the phagocytic index and the percentage of phagocytic active cells were significantly affected, which could indicate that phagocytic parameters from Nile tilapia are more sensitive than hematological ones to assess the effect of acute intoxication with chlorpyrifos. [ABSTRACT FROM AUTHOR]

Chlorpyrifos is an organophosphorous insecticide widely used in agriculture and domestic activities. However, little is known about the effect of this pesticide on the immune system of fish and other alterations of its physiological system. The aims of the present study were the evaluation of the LC50 (lethal concentration50) and the potential toxicity of this substance on Nile tilapia (Oreochromis nilotucus), as well as its effect on some hematological values and phagocytic functions of this fish. Results obtained showed that chlorpyrifos does not have any effect on the following parameters: number of red blood cells, hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). However, the phagocytic index and the percentage of phagocytic active cells were significantly affected, which could indicate that phagocytic parameters from Nile tilapia are more sensitive than hematological ones to assess the effect of acute intoxication with chlorpyrifos. [ABSTRACT FROM AUTHOR]

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Organophosphorus pesticides (OPs) are a broad-spectrum insecticides widely used in agricultural activities, representing 50% of the world's use of pesticides. Diazoxon, a metabolite of diazinon, has as its main mechanism of toxicity the inhibition of the Acetylconlinesterase (AChE) enzyme, causing immunotoxic effects that can alter humoral and cellular parameters of vertebrate organisms, including fishes. Within the cellular mechanisms of adaptive immunity in fish, subpopulations of T helper lymphocytes CD4+ (Th1, Th2 and Th17) have been characterized, involved in the production of cytokines and that jointly collaborate in different phases of the immune response. The polarization towards the different phenotypes of these subpopulations of T lymphocytes is regulated by the expression of gene transcription factors such as T-bet, GATA-3, Foxp3 and RORγt. Various pathological processes of immunological origin have been described due to problems in the expression of these transcription factors generally associated with inflammatory diseases. Therefore, the present project intends to evaluate the in vitro effect of Diazoxon on the expression of these master transcription factors in lymphocytes, using the Nile tilapia fish (Oreochromis niloticus) as a study model. [ABSTRACT FROM AUTHOR]

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Los neutrófilos son células del sistema inmune innato esenciales para la defensa de los organismos frente a patógenos y se caracterizan por ser la primera línea de defensa, para ello poseen diversos mecanismos microbicidas. Sin embargo, existen sustancias como diazinón (DZN), un plaguicida organofosforado, que se caracteriza por inhibir a la enzima acetilcolinesterasa, produciendo efectos inmunotóxicos y neurotóxicos en los organismos. Por lo que, el objetivo de este trabajo fue evaluar el efecto inmunotóxico de DZN sobre los diferentes tipos de muerte celular de neutrófilos de tilapia nilótica (Oreochromis niloticus). Para este propósito, los peces fueron expuestos in vivo a 3,91, 1,95 y 0,97 mg/L de DZN durante 6 y 24 h. La formación de trampas extracelulares de neutrófilos (NETs) se visualizó con microscopia de fluorescencia, mientras que la apoptosis y necrosis se analizaron mediante citometría de flujo. Los resultados mostraron que DZN no induce apoptosis, ni necrosis de neutrófilos; mientras que la formación de NETs se observó incrementada. Los resultados indican que DZN per se estimula a los neutrófilos, lo que puede tener repercusiones en procesos inflamatorios. [ABSTRACT FROM AUTHOR]

Copyright of Revista Biociências is the property of Revista Biociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

En la actualidad, la contaminación ambiental es un serio problema que afecta a todo el mundo. Dentro de los distintos compuestos contaminantes del ambiente podemos encontrar agentes químicos, como el BPA, y contaminantes biológicos como los huevos de distintos parásitos, tal es el caso de Toxocara canis. En el presente trabajo, se evaluó el efecto del BPA administrado durante la etapa perinatal en ratas, sobre la respuesta inmunitaria durante la vida adulta, y la susceptibilidad al parásito zoonótico T. canis. Se analizaron las cargas parasitarias, así como los porcentajes de las subpoblaciones celulares del sistema inmunitario, la expresión de citocinas, y los títulos de anticuerpos contra el parásito. Se observó un aumento en el número de parásitos a nivel hepático y pulmonar. No hubo cambios significativos en los porcentajes de las células de la respuesta inmunitaria analizadas, sin embargo, hubo un aumento en las citocinas Th1 (TNF-α e IFN-γ) y una disminución en las Th2 (Il-4, IL-5 e IL- 13), además de una reducción en los títulos de anticuerpos contra el parásito en las ratas expuestas perinatalmente al BPA. En conclusión, la administración perinatal de BPA, afecta el desarrollo de la respuesta inmunitaria durante la vida adulta, modificando la producción de citocinas y anticuerpos por parte de las células de la respuesta inmune, lo cual ocasiona un aumento en la susceptibilidad a la infección por T. canis. [ABSTRACT FROM AUTHOR]

Murine leprosy is a systemic infectious disease of mice caused by Mycobacterium lepraemurium (MLM) in which the central nervous system (CNS) is not infected; nevertheless, diseased animals show measurable cognitive alterations. For this reason, in this study, we explored the neurobehavioral changes in mice chronically infected with MLM. BALB/c mice were infected with MLM, and 120 days later, the alterations in mice were evaluated based on immunologic, histologic, endocrine, neurochemical, and behavioral traits. We found increases in the levels of IL-4 and IL-10 associated with high bacillary loads. We also found increase in the serum levels of corticosterone, epinephrine, and norepinephrine in the adrenal gland, suggesting neuroendocrine deregulation. Mice exhibited depression-like behavior in the tail suspension and forced swimming tests and anxiolytic behavior in the open field and elevated plus maze tests. The neurobehavioral alterations of mice were correlated with the histologic damage in the prefrontal cortex, ventral hippocampus, and amygdala, as well as with a blood-brain barrier disruption in the hippocampus. These results reveal an interrelated response of the neuroimmune--endocrinological axis in unresolved chronic infections that result in neurocognitive deterioration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 IBRO. Published by Elsevier Ltd. All rights reserved.)

Organophosphate pesticides as diazinon disrupt the neuroimmune communication, affecting the innate and adaptive immune response of the exposed organisms. Since the target molecule of diazinon is typically the acetylcholinesterase enzyme (AChE), the existence of a non-neuronal cholinergic system in leukocytes makes them susceptible to alterations by diazinon. Therefore, the aim of this work was to evaluate the activity of AChE, acetylcholine (ACh) concentration, and the expression of nicotinic ACh receptors (nAChR) and muscarinic ACh receptors (mAChR) in spleen mononuclear cells (SMNC) of Nile tilapia (O. niloticus) exposed in vitro to diazoxon, a diazinon metabolite. SMNC were exposed in-vitro to 1 nM, 1 μM, and 10 μM diazoxon for 24 h. The enzyme activity of AChE was then evaluated by spectrophotometry, followed by ACh quantification by ultra-performance liquid chromatography. Finally, mAChR and nAChR expression was evaluated by RT-qPCR. The results indicate that AChE levels are significantly inhibited at 1 and 10 μM diazoxon, while the relative expression of (M3, M4, and M5) mAChR and (β2) nAChR is reduced significantly as compared against SMNC not exposed to diazoxon. However, ACh levels show no significant difference with respect to the control group. The data indicate that diazoxon directly alters elements in the cholinergic system of SMNC by AChE inhibition or indirectly through the interaction with AChR, which is likely related to the immunotoxic properties of diazinon and its metabolites., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The immune response of teleosts (bonefish) is altered by diazinon (DZN), an organophosphate pesticide. It has been suggested that such alteration is due to the extraneuronal cholinergic system in fish leukocytes that renders these cells a target of pesticides. Diazoxon (DZO), the oxon metabolite of DZN, has been attributed immunotoxic effects. Still, to date there are no reports on the effects of DZO upon parameters involved in the signaling cascade of immune response cells. Therefore, this work evaluated the effect of DZO on key parameters of cell signaling (intracellular Ca 2+ flux, ERK 1/2 phosphorylation), cell proliferation, and antiproliferative processes (apoptosis, senescence, mitochondrial membrane potential) in spleen mononuclear cells of Nile tilapia fish. The results obtained show that DZO does not affect cell proliferation but causes a lack of response to stimulation with PMA and ionomycin to release intracellular calcium. In addition, it inhibits ERK 1/2 phosphorylation and causes loss of mitochondrial membrane potential, apoptosis, and senescence. These results suggest that the lack of cell response to release intracytoplasmic Ca 2+ inhibits ERK which disrupts the mitochondrial membrane potential, leading to cell apoptosis and senescence. These findings prove that DZO significantly affects key parameters involved in the survival of immune response cells., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Diazinon (DZN) is an organophosphate pesticide characterized by inhibiting the enzyme acetylcholinesterase (AChE) (E.C. 3.1.1.7), affecting the nervous system. There is currently enough evidence proving this pesticide also affects the immune response; however, the immunotoxicity mechanisms through which these substances exerts toxic effects remain unclear. For that reason, this work evaluated the effect of diazinon on the intracellular calcium flux, ERK1/2 phosphorylation (pERK1/2), apoptosis, senescence, and mitochondrial membrane potential (ΔΨm) in spleen mononuclear cells (SMNC) of Nile tilapia, a teleost fish of commercial and ecological relevance. The results obtained indicate that diazinon causes significant damage in all evaluated parameters, which play an essential role in intracytoplasmic signaling of immune cells, suggesting these signal pathways could be related with the immunotoxicity mechanism of these type of pesticides., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Nervous and immune systems maintain a bidirectional communication, expressing receptors for neurotransmitters and cytokines. Despite being well established in mammals, this has been poorly described in lower vertebrates as fishes. Experimental evidence shows that the neurotransmitter acetylcholine (ACh) regulates the immune response. In this research, we evaluated mRNA levels of muscarinic acetylcholine receptor (mAChR) in spleen mononuclear cells of Nile tilapia (Oreochromis niloticus) and compared the expression levels of immune cells with the brain. The mAChR subtypes (M2-M5A) were detected in both tissues, but mAChRs mRNA levels were higher in immune cells. This data have a potential use in biomedical and comparative immunology fields., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Organophosphorus pesticides (OPs) are broad-spectrum insecticides. One of the commonly used OPs is diazinon (DZN). The aim of this study was to evaluate the immunotoxic effect of DZN on phagocytic parameters of blood leukocytes using the teleost fish Oreochromis niloticus as a study model. For this purpose, fish were exposed in vivo to 0.97, 1.95 and 3.97 mg/L of DZN for 6 and 24 h. Our results indicated that phagocytic active cells decreased in fish exposed in vivo to 0.97 and 1.95 mg/L of DZN for 6 and 24 h. Regarding ROS production, H 2 O 2 and O 2 - levels were higher on fish exposed to 1.95 mg/L for 6 and 24 h, while H 2 O 2 production increased at 0.97 mg/L for 24 h. From this we can conclude that phagocytic parameters are sensitive to assess the effect of acute intoxication with organophosphorus pesticides on Nile tilapia., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Boca de Camichin Estuary is one of the main producers of Crassostrea corteziensis oysters in Mexico, but the presence of pollutants can affect oyster production. Molluscs produce reactive oxygen species (ROS) in response to changes in the environment and pollution. These ROS induce oxidative damage in biomolecules. The main objective of this study was to evaluate pollution in the estuary and the subsequent oxidative stress in C. corteziensis oysters during the 2010 production cycle. For this aim, we performed monthly samplings in the oyster farms from January to May. We took water samples to quantify polycyclic aromatic hydrocarbon (PAH) and metal content; also, we evaluated oxidative damage (lipoperoxidation, lipidic hydroperoxides, protein oxidation) and enzyme activity (CAT, SOD, GPx, GST and AChE) in oyster gills. The results show the presence of Cu, Fe, Mn, naphthalene, benz[a]anthracene, pyrene, benz[a]pyrene and benzo[k]fluoranthene. On the other hand, AChE activity was not inhibited, which suggests that organophosphorus pollutants or carbamates were absent. Regarding oxidative stress, oysters from the estuary had oxidative damage in lipids, not proteins, and altered antioxidant enzyme activity, when compared to control organisms. Interestingly, we did not observe any correlation between the pollutants and the oxidative stress parameters evaluated in this study. Thus, we cannot rule out that a synergistic effect between the environmental variables and the pollutants is causing the oxidative stress in these oysters., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The physiological system of molluscs, particularly pro-oxidant and antioxidant mechanisms, could be altered by pollutants and induce disturbance on health status and productive parameters of aquatic organisms, such as oyster. Therefore, the aim of this study was to evaluate the chemical contamination in water (total metals and polycyclic aromatic hydrocarbons) and oxidative stress parameters in oysters (Crassostrea corteziensis) in Camichin estuary, located in Mexican Tropical Pacific. The results obtained showed the presence of arsenic, lead and zinc, as well as naphthalene, pyrene and benzo[a]pyrene in concentrations relatively higher than criteria established by local and international guidelines. Regarding the biomarkers of oxidative stress response (H2O2 and O2 concentration, catalase activity, lipid peroxidation, and hydroperoxide concentration), differences between oyster from estuary and control group were significant. These results indicate that these pollutants could be related with oxidative stress detected in oyster., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Chlorpyrifos and methyl parathion are among the most widely used insecticides in the world. Human populations are constantly exposed to low doses of both due to their extensive use and presence in food and drinking water. Glutathione S-transferase (GST) catalyzes the conjugation of glutathione on electrophilic substrates and is an important line of defense in the protection of cellular components from reactive species. GST alpha1 (GSTA1) is the predominant isoform of GST expressed in the human liver; thus, determining the effect of insecticides on GSTA1 transcription is very important. In the present study, we analyzed the effects of methyl parathion and chlorpyrifos on GSTA1 gene expression in HepG2 cells using real time PCR, and activity and immunoreactive protein assays. The results demonstrated that exposure to methyl parathion and chlorpyrifos increased the level of GSTA1 mRNA, GSTA1 immunoreactive protein and GST activity relative to a control. These results demonstrated that these insecticides can increase the expression of GSTA1. In conclusion, HepG2 cell cultures treated with methyl parathion and chlorpyrifos could be a useful model for studying the function of GSTA1 and its role in the metabolism of xenobiotics in the liver., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Endosulfan is a hazardous organochlorine pesticide banned or restricted in several countries. However, it has been found in the environment and in animal samples. To study a potential way to bioremediate soils contaminated with this pesticide, two plant species of the genus Ocimum were studied: Ocimum basilicum L. and Ocimum minimum L., since they are economically feasible and well adapted to the climatic conditions of the Nayarit zone (Mexican pacific coast). Young plants were transplanted into soil experimentally polluted with endosulfan. Growth of both species was not affected by endosulfan, the plants grew, flourished, and produced seeds; 30 days later, endosulfan concentration was lower in the soil with O. basilicum than in the soil without plants. On day 90, no differences in endosulfan concentrations were found between soil with or without O. minimum. At day 1, plants in the polluted soil showed lipoperoxidation, as measured by thiobarbituric acid-reactive species (TBARS). Interestingly, a higher TBARS value was observed at day 3 in transplanted plants as compared to non-transplanted plants. In conclusion, both species can endure endosulfan pollution (as high as 1 g kg(-1)) in soils. O. basilicum seems to be an adequate candidate for bioremediation of soils polluted with endosulfan., (Copyright © 2011 Elsevier B.V. All rights reserved.)