Navegando por Assunto "Toxicidade aguda"

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Acesso aberto (Open Access)
Acute toxicity and histopathology in ornamental fish amazon bluespotted corydora (Corydoras melanistius) exposed to formalin
(2012-12) SANTOS, Rudã Fernandes Brandão; DIAS, Henrique Malta; FUJIMOTO, Rodrigo Yudi
The objective of this work was to evaluate the acute toxicity of formalin and histopathological effects on the Amazon ornamental fish, bluespotted coridora (Corydoras melanistius). A randomized design was used, with ten concentrations of formalin (40%) (0, 3, 6, 12, 25, 50, 100, 150, 200 and 250mg.L-1) with four replicates and five fish per container (3L) in static system for 96 hours. The moribund fish were killed and fixed in 10% formalin to proceed the histopathological analysis of gill, liver and kidney. At the end of this experiment the following mortality rates (%) were obtained in increasing order of exposure: 0, 0, 0, 0, 0, 65, 85, 100, 100 and 100%. The lethal concentration 50% (LC50-96h (I)) estimated was 50.76 mg.L-1 with regression of y = 0.51x, and r² = 0.80. Further, in higher concentrations morphological changes as gill hyperplasia, with filling of interlamellar spaces, disorganization of liver arrangement, and necrosis in kidney were observed. In this study, the formalin can be considered slightly toxic to bluespotted corydora, and cause morphological changes when exposed to high concentrations. The use of formalin to treat of ornamental fish in the inner river of capture with wrong concentration can provoke negative environmental and biological effects.
Acesso aberto (Open Access)
Avaliação toxicológica do óleo essencial de Piper aduncum L.
(2008-06) SOUSA, Pergentino José da Cunha; BARROS, Carlos Augusto Lima; ROCHA, José Carlos da Silva; LIRA, Denisléia Sertão; MONTEIRO, Gisele Muniz; MAIA, José Guilherme Soares
The aim of this work was the acute and subacute toxicological evaluation of the essential oil of Piper aduncum with the determination of the LD50 in mice and the analysis of their hematological and biochemical parameters in rats. The plant is used in the Amazon folk medicine for several diseases and the phenylpropanoid dilapiolle is the main constituent of its essential oil, possessing insecticidal, fungicidal, bactericidal, larvicidal and molluscicidal properties. The LD50 was 2.400 ± 191.7 mg/kg. The essential oil did not change the hematological and biochemical parameters in a significant manner when compared with the control in the subacute treatment, excepting the reduction of creatinine. The LD50 and the hematological and biochemical results have suggested that the essential oil presents low toxicity.
Acesso aberto (Open Access)
Estudo preliminar da atividade antiinflamatória de Bryophillum calycinum Salisb
(2005-03) SOUSA, Pergentino José da Cunha; ROCHA, José Carlos da Silva; PESSÔA, Alexandre Mendes; ALVES, Luiz Artur Dias; CARVALHO, José Carlos Tavares
The acute toxicity (LD50) and the anti-inflammatory effect of the crude freeze-dried aqueous extract of the leaves of Bryophillumcalycinum Salisb. (EBALBc) was evaluated, on the rat paw edema induced by carrageenin and dextran. The dose of 500 mg/kg (p.o) inhibited the paw edema induced by dextran in a significative manner (p < 0.05, ANOVA, Student Newman-Keuls test) 60 and 90 minutes, after stimulus while only the oral dose of 1 g/kg of EBALBc inhibited the paw edema induced by carrageenin. The results indicated an anti-edematogenic effect of the extract when tested on the paw edema induced by dextran and carrageenin, suggesting larger specificity of action on the edema induced by dextran. The EBALBc administered orally, in the doses of the 0.1 to 8 g/kg, it did not cause death, making impossible to determine the LD50.