Avaliação de múltiplos biomarcadores após exposição aos pesticidas glifosato e fipronil durante o desenvolvimento pré- eclosão de Podocnemis expansa (Testudines, Podocnemididae)
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Data
2021-11-04
Autores
Mendonça, Juliana dos Santos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Os agrotóxicos exercem importantes funções na produção agrícola garantindo formas mais econômicas de plantio e colheita com o aumento da produtividade, qualidade e redução de perdas. Apesar de resultar em benefícios para o produtor, seu uso irracional e aplicação exacerbada tornaram-no a principal fonte de contaminantes orgânicos, levando altas concentrações de resíduos de pesticidas para o meio ambiente. Dentre os agrotóxicos, destacam-se o glifosato e o fipronil, que são frequentemente utilizados conjuntamente no Brasil e são suscetíveis a causar efeitos indesejáveis, sobretudo em ecossistemas hídricos. Dentre os possíveis organismos não alvo, os répteis aquáticos, sobretudo os Testudines, representam uma das ordens de animais que estão indiretamente afetadas pela aplicação dos agrotóxicos. Nesse contexto, objetivou-se investigar os potenciais efeitos tóxicos de diferentes concentrações de glifosato e/ou fipronil em embriões e neonatos de Podocnemis expansa expostos a substrato contaminado durante incubação artificial. Após a exposição, foi realizada a avaliação de múltiplos biomarcadores por meio da análise de viabilidade de ovos, biomassa corpórea, malformações ósseas, bromatologia das cascas dos ovos, mutageneicidade, histopatologia hepática e cerebral de embriões ou neonatos de P. expansa. Para tal fim, ovos coletados no ambiente natural foram incubados artificialmente em areia umedecida com água contendo glifosato Atar 48 nas concentrações de 65μg/L ou 6500μg/L e fipronil Regent 800WG a 4μg/L ou 400μg/L, ou a associação de ambos os agrotóxicos. A exposição combinada se deu a partir de 65μg/L de glifosato e 4μg/L de fipronil e 6500μg/L de glifosato com 400μg/L de fipronil. Os resultados do presente estudo demonstram que a exposição aos agrotóxicos testados, isoladamente ou em combinação, interferem no crescimento embrionário de P. expansa, bem como induz malformações ósseas no anel ossicular escleral. Com relação a bromatologia, a exposição aos pesticidas ocasionou redução do teor de umidade e proteína bruta e aumento nos níveis de extrato etéreo da casca dos ovos. Alterações de micronúcleo, demais anormalidades nucleares eritrocitárias e histopatológicas de fígado e encéfalo evidenciaram danos mutagênicos, hepatóxicos e neurotóxicos em neonatos de P. expansa. Essas descobertas ressaltam o potencial risco ecotoxicológico das formulações comerciais de glifosato e fipronil sobre a biologia da espécie estudada, reforçando a importância da inclusão dos Testudines nos testes de risco ambiental causados por agrotóxicos.
Pesticides play important roles in agricultural production, ensuring more economical ways of planting and harvesting with productivity and quality increasing and reduced losses. Despite resulting in benefits for the producer, its irrational use and exacerbated application made it the main source of organic contaminants, taking high concentrations of pesticide residues into the environment. Among pesticides, glyphosate and fipronil stand out, which are often used together in Brazil and are susceptible to causing undesirable effects, especially in water ecosystems. Among the possible non-target organisms, aquatic reptiles, especially Testudines, represent one of the animals orders that are indirectly affected by the application of pesticides. In this context, the objective of this work was to investigate the potential toxic effects of different concentrations of glyphosate and/or fipronil on Podocnemis expansa embryos and neonates exposed to contaminated substrate during artificial incubation. After exposure, multiple biomarkers were evaluated by analyzing the viability of eggs, body biomass, bone malformations, egg shell bromatology, mutagenicity, hepatic and cerebral histopathology of P. expansa embryos or neonates. For this purpose, eggs collected in the natural environment were artificially incubated in sand moistened with water containing glyphosate Atar 48 at concentrations of 65μg/L or 6500μg/L and fipronil Regent 800WG at 4μg/L or 400μg /L, or the association of both pesticides. The combined exposure was from 65μg/L of glyphosate and 4μg/L of fipronil and 6500μg/L of glyphosate with 400μg/L of fipronil. The results of the present study demonstrated that exposure to the tested pesticides, alone or in combination, interfered with the embryonic growth of P. expansa, as well as inducing bone malformations in the scleral ossicular ring. Regarding bromatology, exposure to pesticides caused a reduction in the moisture and crude protein content and increased the levels of ether extract from the eggshells. Micronucleus alterations, other nuclear erythrocyte and histopathological abnormalities of the liver and brain showed mutagenic, hepatotoxic and neurotoxic damage in neonates of P. expansa. These findings highlighted the potential ecotoxicological risk of commercial formulations of glyphosate and fipronil on the biology of the studied specie, reinforcing the importance of including Testudines in tests for environmental risk caused by pesticides.
Pesticides play important roles in agricultural production, ensuring more economical ways of planting and harvesting with productivity and quality increasing and reduced losses. Despite resulting in benefits for the producer, its irrational use and exacerbated application made it the main source of organic contaminants, taking high concentrations of pesticide residues into the environment. Among pesticides, glyphosate and fipronil stand out, which are often used together in Brazil and are susceptible to causing undesirable effects, especially in water ecosystems. Among the possible non-target organisms, aquatic reptiles, especially Testudines, represent one of the animals orders that are indirectly affected by the application of pesticides. In this context, the objective of this work was to investigate the potential toxic effects of different concentrations of glyphosate and/or fipronil on Podocnemis expansa embryos and neonates exposed to contaminated substrate during artificial incubation. After exposure, multiple biomarkers were evaluated by analyzing the viability of eggs, body biomass, bone malformations, egg shell bromatology, mutagenicity, hepatic and cerebral histopathology of P. expansa embryos or neonates. For this purpose, eggs collected in the natural environment were artificially incubated in sand moistened with water containing glyphosate Atar 48 at concentrations of 65μg/L or 6500μg/L and fipronil Regent 800WG at 4μg/L or 400μg /L, or the association of both pesticides. The combined exposure was from 65μg/L of glyphosate and 4μg/L of fipronil and 6500μg/L of glyphosate with 400μg/L of fipronil. The results of the present study demonstrated that exposure to the tested pesticides, alone or in combination, interfered with the embryonic growth of P. expansa, as well as inducing bone malformations in the scleral ossicular ring. Regarding bromatology, exposure to pesticides caused a reduction in the moisture and crude protein content and increased the levels of ether extract from the eggshells. Micronucleus alterations, other nuclear erythrocyte and histopathological abnormalities of the liver and brain showed mutagenic, hepatotoxic and neurotoxic damage in neonates of P. expansa. These findings highlighted the potential ecotoxicological risk of commercial formulations of glyphosate and fipronil on the biology of the studied specie, reinforcing the importance of including Testudines in tests for environmental risk caused by pesticides.
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Palavras-chave
Anormalidades eritrocitárias, Bromatologia, Ecotoxicologia, Malformações, Histopatologia, Erythrocyte abnormalities, Bromatology, Ecotoxicology, Malformations, Histopathology