RESUMO

O uso popular, e mesmo o tradicional, não são suficientes para validar as plantas medicinais como medicamentos eficazes e seguros. Para melhor entendimento, é necessário avaliar a relação risco/benefício de seu uso, por meio de estudos toxicológicos. O objetivo desta pesquisa foi estimar a toxicidade aguda do extrato etanólico das cascas secas de Pithecellobium cochliocarpum (Gomez) Macbr através da obtenção da dose letal (DL50) em roedores, e da Concentração letal (CL50) frente à Artemia salina Leach. Foram realizados experimentos por via oral e intraperitoneal utilizando camundongos fêmeas albinos Swiss (Mus musculus) (n=6). Por via oral foram administradas 3 doses (1.000, 3.000 e 5.000 mg Kg-1) e por via entraperitoneal, 5 doses (155, 160, 176, 345,6 e 414,72 Kg-1). Os sinais comportamentais foram avaliados durante uma hora após a administração do extrato, ficando em observação até 48 horas. O número de óbitos foi quantificado para posterior cálculo da DL50. A administração por via intraperitoneal foi realizada em intervalo de 5 minutos para cada animal. Nos ensaios de toxicidade por via oral a solução foi introduzida por via intragástrica através de cânula metálica acoplada a seringa (gavagem) no mesmo intervalo de tempo utilizado pela via intraperitoneal. Os animais do grupo de administração oral apresentaram algumas reações, porém não letais até a dose de 5.000 mg Kg-1. A DL50 para a via intraperitoneal foi 257, 49 mg Kg-1 (muito tóxico, grau 4) (Schuartsman, 1980). A CL50 (543,5 µg Kg-1) demonstrou ser tóxica frente à A. salina. Conclui-se que sob condições agudas de exposição, o extrato do Pithecellobium cochliocarpum é um agente tóxico, devendo ser considerado como tal, dependendo da dose administrada ou absorvida, do etempo e frequência de exposição e das vias de administração.

The popular use, and even the traditional one, is not enough to validate medicinal plants as effective and safe medicines. For a better understanding, it is necessary to assess the risk / benefit ratio of their use through toxicological studies. The aim of this work was to evaluate the acute toxicity of Pithecellobium cochliocarpum (Gomez) Macbr dried bark ethanolic extract through its lethal dose (LD50), in mice, and lethal concentration (LC50) in relation to Artemia salina Leach. Experiments were performed by oral and intraperitoneal route using female Swiss albino mice (Mus musculus) (n = 6). The first three doses were given orally (1,000, 3,000 and 5,000 mg kg-1) and the last five doses were given intraperitoneally (155, 160, 176, 345.6 and 414.72 Kg-1). The behavioral signs were evaluated one hour after administration of the extract, being observed up to 48 hours. The number of deaths was quantified for subsequent calculation of LD50. The intraperitoneal administration was carried out at an interval of 5 minutes for each animal. For the oral toxicity test, the solution was introduced in the digestive system of the animals through a metal cannula coupled to a syringe (gavage) at the same time interval used for the intraperitoneal route. The animals from the oral group presented some reactions, but they were not lethal up to the dose of 5.000 mg kg-1. The LD50 for the intraperitoneal group was 257.49 mg kg-1 (very toxic, grade 4) (Schuartsman, 1980). The LC50 (543.5 mg kg-1) was toxic to A. salina. We can conclude that, under acute conditions of exposure, the Pithecellobium cochliocarpum extract is a poisonous agent and should be considered as such depending on the administered or absorbed dose, the time and frequency of exposure, and the administration routes.

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This study investigated the level of morphometric and genetic variability among populations of Anastrepha pickeli Lima from several localities in Brazil, one locality in Bolivia and one in Paraguay. Traditional and geometric morphometric analyses were used, as well as sequencing of a fragment of the cytochrome oxidase gene (COI). Six variables were measured from the aculeus for traditional morphometric analysis and 14 landmarks from the right wing were used for geometric analysis, using 10 specimes/population. The aculeus tip length, aculeus width at the end of the cloaca opening, and the serrate part length contributed with 62.7 percent for grouping. According to the results from traditional morphometry, there was no significant difference, but the multivariate tests showed that the canonical variables were statistically significant, indicating a difference in the wing conformation among populations. Molecular phylogenetic analysis indicated that the populations clustered into three clades and revealed a high level of genetic variation within A. pickeli populations from various geographic regions. Anastrepha pickeli populations differed among them according to the methods used in this study, showing incongruence among the methods used.

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Centris aenea Lepeletier is a solitary bee that has raised interest in management to pollinate crops, such as acerola, Malpighia emarginata. This study investigated the level of morphometric variability among populations of C. aenea from Northeastern Brazil. Traditional and geometric morphometric analyses were used. Head length, leg length, wing length, and wing shape were measured in samples (5-10 females) from eight localities. We did not find statistically significant differences among the populations (P > 0.01). The partial wing warps were similar in the populations and indicated that the bees were not morphometrically different. Our results suggest that C. aenea shows low population morphometric variability and highlight the need for further investigations on population variation in this species, preferably including populations sampled at the extremes of their geographic distribution. Significant insight into the population variation of C. aenea will probably require the use of molecular markers to allow a comparative approach between morphometric variability and genetic variability.

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