182 resultados para Acute Toxicity Tests
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Anacardium occidentale L. (Anacardiaceae), popularly known as cajueiro is a native plant to Brazil, and largely used in popular medicine to treat ulcers, hypertension and diarrhea. In the present study, acute, 30-day subacute toxicity and genotoxicity assays were carried out. The crude extract did not produce toxic symptoms in rats in doses up to 2000 mg/kg. Based on biochemical analyses of renal and hepato-biliary functions, such as the level of urea, creatinine, transaminases and alkaline phosphatase, we determined that the extract is generally tolerated by rats. This was also confirmed by hematological and histopathological exams. Genotoxicity was accessed by the Ames test in Salmonella typhimurium strains TA97, TA98, TA 100, TA 102 and by the bone marrow micronucleus test in mice. The extract was shown to induce frameshift, base pair substitution and damage to the chromosomes. However, this effect was less deleterious than the clastogenic effect of ciclophosphamide. (c) 2006 Elsevier B.V.. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Screening the toxicity and biodegradability of petroleum hydrocarbons by a rapid colorimetric method
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The aim of this study was to determine the toxicity of the aqueous extract of neem leaves, a product extensively used in fish-farms as alternative for the control of fish parasites and fish fry predators, for the neotropical fish Prochilodus lineatus. The 24 It LC(50) of neem leaf extract for juveniles P lineatus was estimated as 4.8 g L(-1); the fish were then exposed for 24 h to 2.5, 5.0 and 7.5 g L(-1) or only clean water (control). Plasma glucose levels were higher in fish exposed to 2.5 g L(-1) and 5.0 g L(-1) neem extract, relative to control, indicating a typical stress response. Neem extract did not interfere with the osmoregulating capacity of the fish, as their plasma sodium, chloride, total protein and osmolarity did not change. The presence of the biopesticide interfered with the antioxidant defense system of P. lineatus, as there was a decrease in liver catalase activity at all neem concentrations and the detoxifying enzyme glutathione-S-transferase was activated in fish exposed to 5.0 g L(-1). Fish exposed to all neem extract concentrations exhibited damaged gill and kidney tissue. These results indicate that although neem extract is less toxic to P. lineatus than other synthetic insecticides used in fish-farming it does cause functional and morphological changes in this fish species. (c) 2006 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The acute toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D), a herbicide, was studied in chicks dosed with 100, 300, 500, or 600 mg 2,4-D/kg BW, by the oral route. Clinical, laboratory, and histopathological methods were used as indicators of toxicity. After acute exposure, the herbicide decreased motor activity and induced muscular weakness and motor incoordination; decreased weight gain; increased serum creatine kinase (CK) and alkaline phosphatase (AP) activities and serum uric acid (UA), creatinine (CR), and total proteins (TP) levels; and did not change serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) activities. These changes were time-and dose-dependent and reversible. The LD50 (lethal dose 50%) calculated for oral 2,4-D in chicks was 420 mg/kg BW (385 to 483). Chromatographic analysis of the serum of the intoxicated chicks showed the presence of the herbicide; the amount found was dose-and time-dependent, increasing from 2 to 8 h after exposure and decreasing afterwards. Histopathological post-mortem studies conducted on intoxicated chicks showed hepatic (vacuolar degeneration of the hepatocytes), renal (tubular nephrosis), and intestinal (hemorragic) lesions. Taken together, the observed alterations mainly reflected kidney and muscle tissue damage, although hepatic toxicity may also have occurred after acute 2,4-D intoxication.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Maytenus aquifolium (Celastraceae), Sorocea bomplandii (Moraceae) and Zolernia ilicifolia (Fabaceae) are native plants from the Tropical Atlantic Forest (Mata Atlantica, Brazil) known a 'espinheira-santa'. These plants are traditionally used as analgesic and antiulcerogenic medicine, with the same traditional uses of the true 'espinheira-santa' (Maytenus ilicifolia, Celastraceae), an efficient antiulcerogenic agent. Pharmacological and toxicological studies with these plants have not been carried out. The purpose in this study was to evaluate the efficacy (analgesic and antiulcerogenic activities), safety (acute toxicity) and quality (phytochemical profile) of these three plants. The analgesic effect was analyzed by writhing and tail flick tests, while anti Ulcerogenic effect was performed through ulcer induction by ethanol and indomethacin/bethanecol assays. LD., and acute toxic effects, as well as phytochemical profiles of all plants also were carried. Surprisingly, the three plants showed analgesic and antiulcerogenic effects at dose of 1000 mg/kg, v.o. Maytenus aquifolium lowering all ulcerogenic parameters (ethanol test), but increased the ulcerogenic effects in the indoniethacin/bethanecol test. Sorocea bomplandii produced antiulcerogenic effects in both experimental models used, while Zolernia ilicifolia showed significant effects only in indomethacin/bethanecol-induced gastric lesions. Pre-treatment with Zolernia ilicifolia induced someone toxic effects, A phytochemical profile for each plant species was determined and its main chemical classes of compounds were described. (C) 2001 Elsevier B.V. Ireland Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)