Eficácia do levamisol como modulador de respostas de estresse, do sistema imune inato e anti-helmíntico em tambaqui
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Data
2019-02-20
Autores
Feitoza-Silva, Allana
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Universidade Estadual Paulista (Unesp)
Resumo
A aquicultura é uma atividade que vem se intensificando nos últimos anos e, por conseguinte a produção mundial de pescado. Neste contexto, manejos inerentes da piscicultura intensiva afetam a homeostasia dos peixes, desencadeiam respostas de estresse, imunossupressão e suscetibilidade às infecções parasitárias e bacterianas. O presente estudo avaliou a ação do cloridrato de levamisol (CL) no estresse e imunidade inata do tambaqui (Colossoma macropomum), e também como anti-helmíntico, em dois experimentos. No Exp. 1, os peixes tinham 131,9 ± 42,58 g e 15,48 ± 1,37 cm, com alta infecção parasitária por Neoechornhynchus buttnerae (Acanthocephala). No Exp. 2, os peixes tinham 188,56 ± 70,92 g e 17,00 ± 2,07 cm e baixa infecção parasitária do mesmo parasito. Os peixes foram alimentados durante 15 e 30 dias com dietas suplementadas com 100 (T1), 300 (T2) e 500 (T3) mg kg-1 de CL e um grupo controle (T0) sem adição de CL. No Exp. 2, os peixes alimentados por 30 dias foram submetidos à exposição aérea. Os peixes de ambos experimentos foram eutanasiados com dose excessiva de anestésico após as amostragens de sangue e os intestinos removidos para análise parasitológica, no início e final do experimento, para determinação do grau de infecção. Foram determinados indicadores de estresse (cortisol e glicose plasmáticos) e do sistema imune inato (atividade hemolítica de proteínas do sistema complemento - via alternativa - ACH50 no soro). Observamos que os peixes do Exp. 1 estavam com carga parasitária maior. O CL não influenciou o perfil da concentração plasmática de glicose ao longo das amostragens em ambos os experimentos. Em relação ao cortisol, no Exp. 1, o CL, nas 3 concentrações testadas, reduziu os níveis do hormônio após 15 dias de administração. Já no Exp. 2, com peixes menos infectados, após 15 e 30 dias, não observamos efeito do CL nos níveis de cortisol circulante. Uma hora após a exposição aérea dos peixes, as concentrações de cortisol aumentaram, de modo geral, mas o aumento maior foi observado nos peixes que receberam 500 mg kg-1 de CL. O CL não interferiu na ACH50 do Exp. 1, no entanto, no Exp. 2, 24 horas após a exposição aérea dos peixes, todas as concentrações de CL foram eficientes para ativar a ACH50. Adicionalmente, a utilização de CL na dieta reduziu a intensidade da infecção pelo parasita, nos Exp. 1 e 2 (15 dias de alimentação com CL), mas não interferiu na prevalência do parasito. Após 30 dias de alimentação (Exp. 2), os peixes alimentados com 500 mg kg-1 de CL apresentaram redução da intensidade média de infecção. Concluindo, a administração oral de CL reduziu a resposta de estresse nos peixes com maior carga parasitária, ativou o sistema complemento após presença de um estressor, potenciou a resposta de estresse após exposição aérea dos peixes e como anti-helmíntico, promoveu redução na intensidade de infecção administrado por 15 dias para o tambaqui.
Aquaculture is an activity that has intensified in recent years and, consequently, the world fish production. In this context, the unavoidable management in fish farming threatens fish homeostasis, triggering stress responses, immunosupression and susceptibility to parasitic or bacterial infections. The present study evaluated the effect of levamisole hydrochloride (LHC) on the stress and innate immunity of tambaqui (Colossoma macropomum), as well as anthhelminthic, in two experiments. In experiment 1, the fishes presented 131.9 ± 42.58 g and 15.48 ± 1.37 cm, with a high parasitic rate by Neoechornhynchus buttnerae (Acanthocephala). The experiment 2, contained fish with 188.56 ± 70.92 g and 17.00 ± 2.07 cm and low parasite infection of the same parasite. The fish were fed for 15 and 30 days with diets supplemented with 100 (T1), 300 (T2) and 500 (T3) mg kg-1 of LHC and a control group T (0) without addition of LHC. In the second experiment, fish fed for 30 days were aerial exposed. Fish from both experiments were euthanized with excessive doses of anesthetics after blood samplings and intestines removed for parasitological analysis, at the beginning and end of the experiment to determine the degree of infestation. Indicators of stress (plasma cortisol and glucose) and of the innate immune system (serum hemolytic activity of proteins of the complement system - alternative pathway - ACH50) were determined. We observed that the fish in experiment 1 had a higher parasitic load. The LHC did not influence the plasma glucose concentration profile during the samplings in both experiments. Regarding cortisol, in the experiment 1, in which the fish had a higher parasitic load, he 3 concentrations of LHC reduced the levels of the hormone after 15 days of feeding. In experiment 2, with fish less infected, after 15 and 30 days, we did not observe effect of LHC on circulating cortisol levels. One hour after fish aerial exposure, cortisol concentrations increased overall but the higher increase was observed in fish that received 500 mg kg-1 of LHC. LHC did not interfere with the ACH50 of experiment 1, however, in experiment 2, 24 hours after fish aerial exposure, all LHC concentrations were efficient to activate the ACH50. In addition, the use of LHC in the dietary reduced the intensity of infection by the parasite in experiments 1 and 2 (15 days of LHC feeding) but did not interfere in the prevalence of the parasite. After 30 feeding days (experiment 2), the fish fed with 500 mg kg-1 of CL showed reduction of mean infection intensity. In conclusion, the oral administration of CL reduced the stress response in fish with higher parasite load, activated the complement system, potentiated the stress response after aerial fish exposition and promoted a reduction in the intensity of infection administered for 15 days to tambaqui.
Aquaculture is an activity that has intensified in recent years and, consequently, the world fish production. In this context, the unavoidable management in fish farming threatens fish homeostasis, triggering stress responses, immunosupression and susceptibility to parasitic or bacterial infections. The present study evaluated the effect of levamisole hydrochloride (LHC) on the stress and innate immunity of tambaqui (Colossoma macropomum), as well as anthhelminthic, in two experiments. In experiment 1, the fishes presented 131.9 ± 42.58 g and 15.48 ± 1.37 cm, with a high parasitic rate by Neoechornhynchus buttnerae (Acanthocephala). The experiment 2, contained fish with 188.56 ± 70.92 g and 17.00 ± 2.07 cm and low parasite infection of the same parasite. The fish were fed for 15 and 30 days with diets supplemented with 100 (T1), 300 (T2) and 500 (T3) mg kg-1 of LHC and a control group T (0) without addition of LHC. In the second experiment, fish fed for 30 days were aerial exposed. Fish from both experiments were euthanized with excessive doses of anesthetics after blood samplings and intestines removed for parasitological analysis, at the beginning and end of the experiment to determine the degree of infestation. Indicators of stress (plasma cortisol and glucose) and of the innate immune system (serum hemolytic activity of proteins of the complement system - alternative pathway - ACH50) were determined. We observed that the fish in experiment 1 had a higher parasitic load. The LHC did not influence the plasma glucose concentration profile during the samplings in both experiments. Regarding cortisol, in the experiment 1, in which the fish had a higher parasitic load, he 3 concentrations of LHC reduced the levels of the hormone after 15 days of feeding. In experiment 2, with fish less infected, after 15 and 30 days, we did not observe effect of LHC on circulating cortisol levels. One hour after fish aerial exposure, cortisol concentrations increased overall but the higher increase was observed in fish that received 500 mg kg-1 of LHC. LHC did not interfere with the ACH50 of experiment 1, however, in experiment 2, 24 hours after fish aerial exposure, all LHC concentrations were efficient to activate the ACH50. In addition, the use of LHC in the dietary reduced the intensity of infection by the parasite in experiments 1 and 2 (15 days of LHC feeding) but did not interfere in the prevalence of the parasite. After 30 feeding days (experiment 2), the fish fed with 500 mg kg-1 of CL showed reduction of mean infection intensity. In conclusion, the oral administration of CL reduced the stress response in fish with higher parasite load, activated the complement system, potentiated the stress response after aerial fish exposition and promoted a reduction in the intensity of infection administered for 15 days to tambaqui.
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Palavras-chave
Colossoma macropomum, Cloridrato de levamisol, Estressor, Imunoestimulante, Parasito