RESUMO
The aim of this study was to evaluate in vitro the efficacy of cordycepin and pentostatin (alone or combined) against Trypanosoma cruzi, as well as the therapeutic efficiency of protocols of cordycepin and pentostatin combinations in mice experimentally infected with T. cruzi. In vitro, the cordycepin (3'-deoxyadenosine) and pentostatin (deoxycoformycin) exerted potent trypanocidal effect against T. cruzi (Colombian strain), similarly to benznidazole, which is the reference drug. For epimastigotes, the lethal dose of cordycepin capable of killing 50% (LD50) and 20% (LD20) of the parasites was 0.072 and 0.031â¯mg/mL, respectively and for trypomastigotes was 0.047 and 0.015â¯mg/mL, respectively. The combined use of cordycepin and pentostatin resulted in a LD50 and LD20 for epimastigotes of 0.068 and 0.027â¯mg/mL, respectively, as well as 0.056 and 0.018â¯mg/mL for trypomastigotes, respectively. In vivo, the combined use of cordycepin and pentostatin did not show the expected curative effect, however it was able to control the parasitema in the peak period. In summary, the combination of cordycepin and pentostatin showed no curative effect in mice infected by T. cruzi, despite the in vitro reduction of epimastigotes and trypomastigotes.
Assuntos
Antiprotozoários/farmacologia , Doença de Chagas/tratamento farmacológico , Desoxiadenosinas/farmacologia , Pentostatina/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Análise de Variância , Animais , Antiprotozoários/efeitos adversos , Antiprotozoários/uso terapêutico , Doença de Chagas/parasitologia , Desoxiadenosinas/uso terapêutico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Coração/efeitos dos fármacos , Dose Letal Mediana , Camundongos , Miocárdio/patologia , Doenças Negligenciadas/tratamento farmacológico , Doenças Negligenciadas/parasitologia , Nifurtimox/efeitos adversos , Nifurtimox/uso terapêutico , Nitroimidazóis/efeitos adversos , Nitroimidazóis/uso terapêutico , Dinâmica não Linear , Parasitemia/prevenção & controle , Pentostatina/uso terapêutico , Distribuição Aleatória , Análise de RegressãoRESUMO
The aim of this study was to evaluate the therapeutic efficacy of specific avian polyclonal antibodies (IgY) against Trypanosoma cruzi and their interaction with ecto-enzymes of the purinergic system (NTPDase and adenosine deaminase (ADA) activities) in splenic lymphocytes. For this, mice were divided into six groups: three non-infected (A, B, and C) and three infected (D, E, and F). The groups A and D were composed by negative and positive controls, respectively; while the groups B and E were treated prophylactically with IgY (50 mg/kg), and the groups C and F were treated therapeutically with IgY (50 mg/kg). Treatment with IgY reduced parasitemia on day 6 post-infection (PI) compared to the infected control group, but it was similar on day 8 PI. Moreover, infected and treated animals (the groups E and F) did not show neither amastigotes in the cardiac tissue nor cardiac lesions when compared to the positive control group (the group D). The E-NTPDase (ATP and ADP as substrate) and ADA activities in splenic lymphocytes increased significantly in the positive control group (the group D) compared to the negative control group (the group A). The therapeutic treatment of IgY (the group F) was able to prevent the increase of E-NTPDase and E-ADA activities compared to the positive control group (the group D), but this finding was not observed in animals that received the prophylactic treatment (the group E). The therapeutic treatment of IgY may be considered an interesting approach to improve the immune response of mice experimentally infected by T. cruzi.
Assuntos
Adenosina Desaminase , Anticorpos Antiprotozoários/farmacologia , Proteínas Aviárias/farmacologia , Doença de Chagas , Imunoglobulinas/farmacologia , Proteínas de Protozoários , Baço , Trypanosoma cruzi , Adenosina Desaminase/imunologia , Adenosina Desaminase/metabolismo , Animais , Doença de Chagas/tratamento farmacológico , Doença de Chagas/enzimologia , Doença de Chagas/imunologia , Galinhas , Feminino , Linfócitos/enzimologia , Linfócitos/imunologia , Linfócitos/patologia , Camundongos , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/metabolismo , Baço/enzimologia , Baço/imunologia , Baço/parasitologia , Baço/fisiologia , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/imunologiaRESUMO
The aim of this study was to evaluate whether Trypanosma cruzi infections cause alterations in the levels of seric purines, which could contribute to host immunomodulation. Twelve mice were divided into two groups identified as control (uninfected) and infected (T. cruzi) groups. The influence of the disease on seric purine levels was verified on day 20 post-infection (PI) by HPLC. Infected mice had circulating trypomastigotes during the experiment, as well as amastigote forms in the heart associated with inflammatory infiltrates. Increases on adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine (ADO), inosine (INO), and uric acid (URIC) levels were observed in the infected animals, while the adenosine monophosphate (AMP) and xanthine (XAN) levels were reduced compared with mice of the control group, indicating a possible impairment on the purinergic system, and consequently, on the immune system during the clinical course of the disease. In summary, the T. cruzi infection alters the seric purine levels, and consequently, modulates the immune system.
Assuntos
Cardiomiopatia Chagásica/imunologia , Imunomodulação , Nucleosídeos de Purina/imunologia , Nucleotídeos de Purina/imunologia , Trypanosoma cruzi/imunologia , Animais , Cardiomiopatia Chagásica/parasitologia , Cardiomiopatia Chagásica/patologia , Modelos Animais de Doenças , Feminino , CamundongosRESUMO
Chagas disease is an acute or chronic illness that causes severe inflammatory response, and consequently, it may activate the inflammatory cholinergic pathway, which is regulated by cholinesterases, including the acetylcholinesterase. This enzyme is responsible for the regulation of acetylcholine levels, an anti-inflammatory molecule linked to the inflammatory response during parasitic diseases. Thus, the aim of this study was to investigate whether Trypanosoma cruzi infection can alter the activity of acetylcholinesterase and acetylcholine levels in mice, and whether these alterations are linked to the inflammatory cholinergic signaling pathway. Twenty-four mice were divided into two groups: uninfected (control group, n = 12) and infected by T. cruzi, Y strain (n = 12). The animals developed acute disease with a peak of parasitemia on day 7 post-infection (PI). Blood, lymphocytes, and brain were analyzed on days 6 and 12 post-infection. In the brain, acetylcholine and nitric oxide levels, myeloperoxidase activity, and histopathology were analyzed. In total blood and brain, acetylcholinesterase activity decreased at both times. On the other hand, acetylcholinesterase activity in lymphocytes increased on day 6 PI compared with the control group. Infection by T. cruzi increased acetylcholine and nitric oxide levels and histopathological damage in the brain of mice associated to increased myeloperoxidase activity. Therefore, an intense inflammatory response in mice with acute Chagas disease in the central nervous system caused an anti-inflammatory response by the activation of the cholinergic inflammatory pathway.
Assuntos
Acetilcolina/sangue , Acetilcolinesterase/sangue , Encéfalo/metabolismo , Cardiomiopatia Chagásica/sangue , Linfócitos/metabolismo , Trypanosoma cruzi , Animais , Encéfalo/patologia , Cardiomiopatia Chagásica/patologia , Linfócitos/patologia , Camundongos , Óxido Nítrico/sangue , Peroxidase/sangueRESUMO
The aim of this study was to evaluate the efficacy of 3'-deoxyadenosine and deoxycoformycin combination in the treatment of mice infected by T. cruzi, as well as to verify the influence of the treatment on purinergic enzymes. Heart and serum samples were collected from 60 mice (30 infected and 30 uninfected) at day 12 post-infection. To verify treatment efficacy, parasitemia was monitored, and the treatment with 3'-deoxy adenosine and deoxycoformycin combination was able to reduce it, but had no curative effect on mice. Seric activities of NTPDase (ATP and ADP substrate) and ADA were increased significantly in untreated mice infected by T. cruzi compared to the negative control, as well as mice treated with 3'-deoxyadenosine and deoxycoformycin (alone or combined) modulated the activity of NTPDase (ATP and ADP substrate), preventing them from increasing in infected animals (activity similar to healthy animals). Treatment with deoxycoformycin alone and associated with 3'-deoxyadenosine modulated the activity of ADA preventing them from increasing in infected animals. However, seric activities of ADA in mice treated with 3'-deoxyadenosine (cordycepin) alone does not modify the ADA activity compared with infected and non-treated mice. However, the 5'-nucleotidase activity decreased significantly in infected untreated animals and the same occurred in infected and treated animals with deoxycoformycin and 3'-deoxyadenosine. However, treatment with deoxycoformycin associated with 3'-deoxyadenosine preventing them from decreasing the 5'-nucleotidase activity. Therefore, we conclude that the treatments did not have curative success for mice infected by T. cruzi. However, the treatments were able to modulate the purinergic enzymes during the infection by T. cruzi, which may contribute to reduce the inflammatory damage in heart.
Assuntos
Antiprotozoários/uso terapêutico , Doença de Chagas/tratamento farmacológico , Desoxiadenosinas/uso terapêutico , Parasitemia/tratamento farmacológico , Pentostatina/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Adenosina Desaminase/metabolismo , Animais , Doença de Chagas/parasitologia , Quimioterapia Combinada , Feminino , Camundongos , Parasitemia/parasitologia , Pirofosfatases/metabolismoRESUMO
Coagulation disorders have been described in Chagas disease with thrombocytopenia as an important event. Several mechanisms may be related to this pathogenesis, such as enzymes of the purinergic system, purine, and receptors involved in the regulation and modulation of physiological events related to hemostasis. Therefore, the aim of this study was to evaluate the activities of E-NTPDase, E-5'nucleotidase, and ecto-adenosine deaminase (E-ADA) in platelets of mice experimentally infected by Trypanosoma cruzi. Twelve female mice were used, divided into two groups (n = 6): uninfected and infected. Mice of infected group were intraperitoneally inoculated with 104 trypomastigotes of T. cruzi (strain Y). On day 12 post-infection (PI), blood samples were collected for quantitation and separation of platelets. A significant reduction in the number of platelets of infected mice (P < 0.05) was observed. The activities of E-NTPDase (ATP and ADP substrates), E-5'nucleotidase, and E-ADA in platelets increased significantly (P < 0.05) in mice infected by T. cruzi compared with uninfected animals. A negative correlation (P < 0.01)was observed between the number of platelets and ATP hydrolysis (r = -0.64), and ADP hydrolysis (r = -0.69) by E-NTPDase. Therefore, there is a response from the purinergic system activating ecto-enzymes in platelets of mice T. cruzi infected, as a compensatory effect of thrombocytopenia.
Assuntos
Adenosina Desaminase/metabolismo , Plaquetas/metabolismo , Doença de Chagas/enzimologia , Proteínas de Protozoários/metabolismo , Trombocitopenia/enzimologia , Trypanosoma cruzi/enzimologia , Trifosfato de Adenosina/metabolismo , Animais , Plaquetas/patologia , Feminino , Camundongos , Trombocitopenia/parasitologia , Trombocitopenia/patologiaRESUMO
The aim of this study was to evaluate the activity of purinergic enzymes in lymphocytes and cardiac tissue of mice experimentally infected by Trypanosoma cruzi. Twelve female mice were used, divided into two groups (n = 6): uninfected and infected. On day 12 post-infection (PI), the animals were anesthetized and after euthanized, and samples were collected for analyses. Infected mice showed reduction in erythrocyte counts, hematocrit and hemoglobin concentration, as well as reduced number of total leukocytes in consequence of neutrophilia (P < 0.01). The number of monocytes increased in infected mice (P < 0.001), however the number of lymphocytes and eosinophils did not differ between groups (P > 0.05). The E-NTPDase (ATP and ADP substrate) and E-ADA activities in lymphocytes increased significantly in mice infected by T. cruzi (P < 0.01). In the heart, multiple pseudocysts containing amastigotes within cardiomyocytes were observed, as well as focally extensive severe necrosis associated with diffuse moderate to severe inflammatory infiltrate of lymphocytes. Although, the NTPDase activity (ATP and ADP substrate) in the cardiac homogenate did not differ between groups, a reduction on 5'-nucleotidase activity (P < 0.001) and an increase in the ADA activity in infected animals (P < 0.05) were observed. Thus, animals infected by T. cruzi experienced the disease, i.e., showed anemia, leucopenia, and heart lesions. Associated with this, purinergic enzymes showed altered activities, which might be related to the modulation of the inflammatory response.
Assuntos
Doença de Chagas/enzimologia , Linfócitos/enzimologia , Miócitos Cardíacos/enzimologia , Purinas/metabolismo , 5'-Nucleotidase/metabolismo , Adenosina/metabolismo , Difosfato de Adenosina/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antígenos CD/metabolismo , Apirase/metabolismo , Doença de Chagas/patologia , Modelos Animais de Doenças , Feminino , Coração/parasitologia , Testes Hematológicos , Hidrólise , Camundongos , Miocárdio/patologia , Parasitemia/parasitologia , Trypanosoma cruzi/fisiologiaRESUMO
The aim of this study was to analyses nitric oxide, antioxidant status, and oxidative profile in the liver of laying hens naturally infected by Salmonella enterica subsp enterica serovar Gallinarum (S. Gallinarum). The nitrite/nitrate (NOx), reactive oxygen species (ROS), thiobarbituric acid-reactive substances (TBARS), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities were measured in liver samples, as well the biomarkers of hepatic function (alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), total protein and albumin levels measured in serum. NOx levels and CAT activity were reduced in hepatic tissue of infected hens. On the other hand, TBARS and ROS levels, GR, GPx and GST activities were higher in infected animals. On biomarkers of tissue damage, ALT, AST, GGT and total protein levels were higher in serum of infected hens, and showed decreased albumin levels. In summary, ROS and TBARS production lead to damage on the membrane lipids that alter activities of antioxidant enzymes CAT, GR, GPx and GSH, an adaptive response against S. Gallinarum infection, contributing to the pathophysiology and clinical signs of the disease.
Assuntos
Galinhas , Fígado/microbiologia , Fígado/patologia , Estresse Oxidativo , Doenças das Aves Domésticas/metabolismo , Salmonelose Animal/metabolismo , Salmonella enterica , Animais , Catalase/metabolismo , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Fígado/metabolismo , Óxido Nítrico , Oxirredução , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Espécies Reativas de Oxigênio , Salmonelose Animal/microbiologia , Salmonelose Animal/patologiaRESUMO
The aim of this study was to evaluate the role of butyrylcholinesterase (BChE) as a marker of inflammation and liver injury in the acute and subclinical phases of canine ehrlichiosis. Forty-two serum samples of dogs naturally infected with Ehrlichia canis were used, of which 24 were from animals with the acute phase of the disease and 18 with subclinical disease. In addition, sera from 17 healthy dogs were used as negative controls. The hematocrit, BChE activity, hepatic injury (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), nitric oxide, and cytokines levels were evaluated. The BChE activity was significantly elevated (P<0.05) in dogs with the acute phase of the disease when compared to healthy animals. However, there was a reduction on BChE activity on dogs with subclinical disease compared to the other two groups. AST and ALT levels were significantly higher (P<0.05) in the acute phase, as well as the inflammatory mediators (NOx, TNF-α, INF-γ, IL-4, IL-6) when compared to the control group. On the other hand, IL-10 levels were lower in the acute phase. Based on these results, we are able to conclude that the acute infection caused by E. canis in dogs leads to an increase on seric BChE activity and some inflammatory mediators. Therefore, this enzyme might be used as a marker of acute inflammatory response in dogs naturally infected by this bacterium.
Assuntos
Biomarcadores/sangue , Butirilcolinesterase/sangue , Doenças do Cão/enzimologia , Doenças do Cão/imunologia , Ehrlichia canis , Ehrlichiose/veterinária , Doença Aguda , Animais , Infecções Assintomáticas , Citocinas/sangue , Cães , Ehrlichiose/imunologia , Ehrlichiose/microbiologia , Ehrlichiose/fisiopatologia , Inflamação/enzimologia , Fígado/fisiopatologiaRESUMO
Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with titers of 1:64 (Group B), 20 samples of horses with titers of 1:256 (Group C), and five samples from horses with titers of 1:1024 (Group D). Positive animals (Groups B, C, and D) had higher levels of immunoglobulins (IgM and IgG), pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1, IL-4, and IL-6) and protein C-reactive protein, as well as lower levels of IL-10 (anti-inflammatory cytokine) when compared to seronegative horses (Group A). The nitric oxide levels were also elevated in seropositive horses. Therefore, we have found humoral and cellular immune responses in seropositive horses, and a correlation between high antibody levels and inflammatory mediators. Markers of cell injury by lipid peroxidation (TBARS) and protein oxidation (AOPP) were elevated in animals seropositives for T. gondii when compared to seronegatives. Therefore, seropositive horses to T. gondii can keep active immune responses against the parasite. As a consequence with chronicity of disease, they show cellular lesions that may lead to tissue damage with the appearance of clinical disease.