RESUMO
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.
Assuntos
Dengue , Inseticidas , Praguicidas , Poecilia , Doenças Transmitidas por Vetores , Animais , Inseticidas/toxicidade , Mosquitos VetoresRESUMO
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.
Assuntos
Inseticidas , Poecilia , Infecção por Zika virus , Zika virus , Animais , Combinação de Medicamentos , Inseticidas/toxicidade , Leucócitos , Macrolídeos , Temefós/toxicidadeRESUMO
COVID-19 is a worldwide health emergency, therapy for this disease is based on antiviral drugs and immunomodulators, however, there is no treatment to effectively reduce the COVID-19 mortality rate. Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, antiviral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for the recovery of COVID-19. This work aimed to determine the effects of ex-vivo treatment with fucoidan on cytotoxicity, apoptosis, necrosis, and senescence, besides functional parameters of calcium flux and mitochondrial membrane potential (ΔΨm) on human peripheral blood mononuclear cells isolated from SARS-CoV-2 infected, recovered and healthy subjects. Data suggest that fucoidan does not exert cytotoxicity or senescence, however, it induces the increment of intracellular calcium flux. Additionally, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered females. Data suggest that fucoidan could ameliorate the immune response in COVID-19 patients.
Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Feminino , Humanos , Leucócitos Mononucleares , Cálcio , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêuticoRESUMO
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 (ß2) 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.
Assuntos
Ciclídeos/fisiologia , Inseticidas/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Sistema Colinérgico não Neuronal/efeitos dos fármacos , Compostos Organofosforados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Masculino , Baço/efeitos dos fármacos , Baço/fisiopatologiaRESUMO
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 Ca2+ 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 Ca2+ 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.
Assuntos
Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ciclídeos/imunologia , Inseticidas/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Compostos Organofosforados/toxicidade , Transdução de Sinais/efeitos dos fármacos , Animais , Diazinon/metabolismo , Inseticidas/metabolismo , MasculinoRESUMO
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 3.97â¯mg/L of DZN for 6 and 24â¯h. Our results indicated that phagocytic active cells decreased in fish exposed in vivo to 0.97 and 1.95â¯mg/L of DZN for 6 and 24â¯h. Regarding ROS production, H2O2 and O2- levels were higher on fish exposed to 1.95â¯mg/L for 6 and 24â¯h, while H2O2 production increased at 0.97â¯mg/L for 24â¯h. From this we can conclude that phagocytic parameters are sensitive to assess the effect of acute intoxication with organophosphorus pesticides on Nile tilapia.
Assuntos
Ciclídeos/fisiologia , Diazinon/efeitos adversos , Inseticidas/efeitos adversos , Leucócitos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória/efeitos dos fármacos , Animais , Biomarcadores/sangue , Ciclídeos/imunologia , Leucócitos/fisiologia , Masculino , Poluentes Químicos da Água/efeitos adversosRESUMO
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.
Assuntos
Apoptose/efeitos dos fármacos , Ciclídeos/fisiologia , Diazinon/efeitos adversos , Inseticidas/efeitos adversos , Leucócitos/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Poluentes Químicos da Água/efeitos adversos , Animais , Cálcio/metabolismo , Senescência Celular/efeitos dos fármacos , Leucócitos/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/fisiologiaRESUMO
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.
Assuntos
Ciclídeos/metabolismo , Diazinon/toxicidade , Brânquias/efeitos dos fármacos , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Proteínas de Peixes/metabolismo , Brânquias/metabolismo , Peróxidos Lipídicos/metabolismo , Fígado/metabolismo , Oxirredução/efeitos dos fármacos , Praguicidas/toxicidade , Carbonilação Proteica/efeitos dos fármacos , Fatores de Tempo , Poluentes Químicos da Água/toxicidadeRESUMO
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.
Assuntos
Crassostrea/metabolismo , Estuários , Estresse Oxidativo , Poluentes Químicos da Água/metabolismo , Poluição da Água/análise , Acetilcolinesterase/metabolismo , Animais , Catalase/metabolismo , Cobre/metabolismo , Cobre/toxicidade , Crassostrea/efeitos dos fármacos , Monitoramento Ambiental/métodos , Geografia , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glutationa Peroxidase/metabolismo , Ferro/metabolismo , Peróxidos Lipídicos/metabolismo , Manganês/metabolismo , Manganês/toxicidade , Metais/metabolismo , Metais/toxicidade , México , Naftalenos/metabolismo , Naftalenos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Estações do Ano , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidadeRESUMO
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.