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Toxic plants containing monofluoroacetate (MFA) cause sudden death in livestock in Australia, South Africa and Brazil, causing economic losses to producers. The objective of this study was to determine the amount of MFA present in young leaves, mature leaves, senescent leaves, and seeds of Amorimia pubiflora harvested at different times of the year and to determine their toxic effect on sheep. Samples of Amorimia pubiflora were collected during April, August and December of 2015 and March of 2016, separated according to the vegetative stage (young leaves, seeds, mature leaves, and senescent leaves), dried in an oven, and administered in daily doses of 5 g/kg/body weight (bw) of fresh leaves to sheep through ruminal cannulae. The experiment was divided into four stages according to the time of collection of the plant so that each sheep received a different vegetative stage of the plant (young leaves, mature leaves, and senescent leaves). Only in the second stage of the experiment was it possible to collect A. pubiflora seeds, which were administered using the same method used for the administration of the leaves. The sheep were dosed with the plant until they showed clinical signs of toxicosis or until the plant was no longer available. Aliquots of leaves and seeds of A. pubiflora were analyzed for MFA concentration. The seeds and young leaves had higher concentrations of MFA than did the mature (harvested in August and December) and senescent (harvested in December) leaves. However, all vegetative stages of the plant were toxic and caused fatal poisoning. The results of our study showed that A. pubiflora is toxic to sheep even when MFA concentrations are low, demonstrating that the presence of this substance is a risk factor for the occurrence of poisoning. Knowing the toxic principle and its variations allow us to determine the conditions for the occurrence of plant toxicosis as well as possible treatment, control, and prophylaxis methods, contributing significantly to the reduction of economic losses on farms due to plant poisoning., (Copyright © 2018. Published by Elsevier Ltd.)

Senna occidentalis (S. occidentalis) is a toxic leguminous plant that contaminates crops and has been shown to be toxic to several animal species. All parts of the plant are toxic, but most of the plant's toxicity is due to its seeds. Despite its toxicity, S. occidentalis is widely used for therapeutic purposes in humans. The aim of the present work was to investigate, for the first time, the effects of the chronic administration of S. occidentalis seeds on hematopoietic organs, including the bone marrow and spleen. Fifty male Wistar rats were divided into five groups of 10 animals. Rats were treated with diets containing 0% (control), 0.5% (So0.5), 1% (So1), or 2% (So2) S. occidentalis seeds for a period of 90 days. Food and water were provided ad libitum, except to pair-fed (PF) group which received the same amount of ration to those of So2 group, however free of S. occidentalis seeds. It was verified that rats treated with 2% S. occidentalis seeds presented changes in hematological parameters. The blood evaluation also showed a significant decrease of the Myeloid/Erythroid (M/E) ratio. Chronic treatment with S. occidentalis promoted a reduction in the cellularity of both the bone marrow and spleen. Additionally, we observed changes in bone marrow smears, iron stores and spleen hemosiderin accumulation. Histological analyses of bone marrow revealed erythroid hyperplasia which was consistent with the increased reticulocyte count. These findings suggest that the long-term administration of S. occidentalis seeds can promote blood toxicity., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Plants of Crotalaria genus (Leguminosae) present large amounts of the pyrrolizidine alkaloid monocrotaline (MCT) and cause intoxication to animals and humans. Therefore, we investigated the MCT-induced cytotoxicity, morphological changes, and oxidative and genotoxic damages to glial cells, using the human glioblastoma cell line GL-15 as a model. The comet test showed that 24h exposure to 1-500microM MCT and 500microM dehydromonocrotaline (DHMC) caused significant increases in cell DNA damage index, which reached 42-64% and 53%, respectively. Cells exposed to 100-500microM MCT also featured a contracted cytoplasm presenting thin cellular processes and vimentin destabilisation. Conversely, exposure of GL-15 cells to low concentrations of MCT (1-10microM) clearly induced megalocytosis. Moreover, MCT also induced down regulation of MAPs, especially at the lower concentrations adopted (1-10microM). Apoptosis was also evidenced in cells treated with 100-500microM MCT, and a later cytotoxicity was only observed after 6 days of exposure to 500microM MCT. The data obtained provide support for heterogenic and multipotential effects of MCT on GL-15 cells, either interfering on cell growth and cytoskeletal protein expression, or inducing DNA damage and apoptosis and suggest that the response of glial cells to this alkaloid might be related to the neurological signs observed after Crotalaria intoxication.