Efeito do β-glucano no sistema antioxidante de tilápias do nilo (Oreochromis niloticus) submetidos ao Triclorfon
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2023-08-02
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Universidade Estadual Paulista (Unesp)
Resumo
A expansão da tilapicultura nas últimas décadas posicionou o Brasil como o quarto maior produtor global de tilápias (Oreochromis niloticus). O aumento das doenças infecciosas devido à intensificação aquícola despertou um interesse crescente na compreensão dos mecanismos de defesa desses organismos. O estudo do sistema imunológico em peixes é de grande importância global, pois permite a prevenção e tratamento dessas doenças, minimizando a mortalidade e as perdas econômicas associadas. Nesta pesquisa, o objetivo foi avaliar o potencial do β-glucano, um imunoestimulante amplamente utilizado e investigado em peixes, em relação ao sistema imunológico, particularmente quando administrado após uma dose sub-letal de triclorfon, um composto organofosforado usado para combater parasitas em aquicultura. O estudo avaliou o estresse oxidativo no tecido do fígado da tilápia-do-Nilo, medindo a expressão de genes como proteína de choque térmico (HSP70), catalase (CAT), superóxido dismutase (SOD), glutationa peroxidase (GPx), glutationa redutase (GR) e glutationa-S-transferase (GST-α), além de analisar às respostas antioxidantes enzimáticas de CAT, SOD e GPx, o desempenho de crescimento e parâmetros hematológicos. Os resultados mostraram que o consumo alimentar expressou diminuição nos animais que não foram expostos ao triclorfon aos 37 dias, enquanto a conversão alimentar foi maior nos animais que sofreram exposição ao triclorfon nesse período. Peixes alimentados com β-glucano por 37 dias, apresentaram aumento da SOD, indicando possível situação de estresse oxidativo. Já nos peixes alimentados com β-glucano por 22 dias e aqueles que foram expostos ao triclorfon apresentaram maior GR. Não houve diferença significativa na expressão do gene CAT e GSTα. A expressão relativa do gene GPx foi menor nos animais alimentados com β-glucano não expostos ao triclorfon. O gene HSP70 mostrou uma maior expressão relativa nos animais alimentados com β-glucano aos 22 dias, mas uma menor expressão nos animais alimentados com β-glucano e que não foram expostos ao triclofon. O uso do β-glucano induziu alterações significativas nas respostas antioxidantes no fígado, com a atividade hepática da CAT e do GPx sendo maior aos 37 dias nos animais alimentados com β-glucano, enquanto a atividade hepática do SOD foi maior aos 22 dias nesses animais. O uso do β-glucano elevou os níveis de leucócitos, trombócitos, linfócitos, eosinófilos, neutrófilos e monócitos. Esses resultados sugerem que o uso do β-glucano pode promover melhorias consideráveis nas respostas antioxidantes e no estresse oxidativo em tilápias-do-Nilo.
The expansion of tilapia farming in recent decades has positioned Brazil as the fourth largest global producer of tilapia (Oreochromis niloticus). The increase in infectious diseases due to aquaculture intensification has sparked a growing interest in understanding the defense mechanisms of these organisms. The study of the immune system in fish is of great global importance, as it allows the prevention and treatment of these diseases, minimizing mortality and associated economic losses. In this research, the objective was to evaluate the potential of β-glucan, a widely used immunostimulant investigated in fish, in relation to the immune system, particularly when administered after a sub-lethal dose of trichlorfon, an organophosphate compound used to combat parasites in aquaculture. The study evaluated oxidative stress in Nile tilapia liver tissue, measuring the expression of genes such as heat shock protein (HSP70), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST-α), in addition to analyzing the enzymatic antioxidant responses of CAT, SOD and GPx, growth performance and hematological parameters. The results showed that food consumption decreased in animals that were not exposed to trichlorfon at 37 days, while feed conversion was higher in animals that were exposed to trichlorfon during this period. Fish fed with β-glucan for 37 days showed an increase in SOD, indicating a possible situation of oxidative stress. Fish fed with β-glucan for 22 days and those exposed to trichlorfon showed higher GR. There was no significant difference in CAT and GSTα gene expression. The relative expression of the GPx gene was lower in animals fed with β-glucan not exposed to trichlorfon. The HSP70 gene showed a higher relative expression in animals fed with β-glucan at 22 days, but a lower expression in animals fed with β-glucan and that were not exposed to triclofon. The use of β-glucan induced significant changes in antioxidant responses in the liver, with hepatic CAT and GPx activity being greater at 37 days in animals fed with β-glucan, while hepatic SOD activity was greater at 22 days in these animals. The use of β-glucan increased the levels of leukocytes, thrombocytes, lymphocytes, eosinophils, neutrophils and monocytes. These results suggest that the use of β-glucan can promote considerable improvements in antioxidant responses and oxidative stress in Nile tilapia.
The expansion of tilapia farming in recent decades has positioned Brazil as the fourth largest global producer of tilapia (Oreochromis niloticus). The increase in infectious diseases due to aquaculture intensification has sparked a growing interest in understanding the defense mechanisms of these organisms. The study of the immune system in fish is of great global importance, as it allows the prevention and treatment of these diseases, minimizing mortality and associated economic losses. In this research, the objective was to evaluate the potential of β-glucan, a widely used immunostimulant investigated in fish, in relation to the immune system, particularly when administered after a sub-lethal dose of trichlorfon, an organophosphate compound used to combat parasites in aquaculture. The study evaluated oxidative stress in Nile tilapia liver tissue, measuring the expression of genes such as heat shock protein (HSP70), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST-α), in addition to analyzing the enzymatic antioxidant responses of CAT, SOD and GPx, growth performance and hematological parameters. The results showed that food consumption decreased in animals that were not exposed to trichlorfon at 37 days, while feed conversion was higher in animals that were exposed to trichlorfon during this period. Fish fed with β-glucan for 37 days showed an increase in SOD, indicating a possible situation of oxidative stress. Fish fed with β-glucan for 22 days and those exposed to trichlorfon showed higher GR. There was no significant difference in CAT and GSTα gene expression. The relative expression of the GPx gene was lower in animals fed with β-glucan not exposed to trichlorfon. The HSP70 gene showed a higher relative expression in animals fed with β-glucan at 22 days, but a lower expression in animals fed with β-glucan and that were not exposed to triclofon. The use of β-glucan induced significant changes in antioxidant responses in the liver, with hepatic CAT and GPx activity being greater at 37 days in animals fed with β-glucan, while hepatic SOD activity was greater at 22 days in these animals. The use of β-glucan increased the levels of leukocytes, thrombocytes, lymphocytes, eosinophils, neutrophils and monocytes. These results suggest that the use of β-glucan can promote considerable improvements in antioxidant responses and oxidative stress in Nile tilapia.
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Palavras-chave
Aquicultura, Compostos organofosforados, Estresse oxidativo, Aquaculture, Organophosphorus compounds, Oxidative stress
Como citar
MOROMIZATO, Basia Schlichting. Efeito do β-glucano no sistema antioxidante de tilápias do nilo (Oreochromis niloticus) submetidos ao Triclorfon. 2023. 100 f. Dissertação (Mestrado em Ciência e Tecnologia Animal) - Universidade Estadual Paulista (UNESP), Faculdade de Ciências Agrárias e Tecnológicas, Dracena, 2023.