136 resultados para Dehydropyrrolizidine alkaloids

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver megalocytosis in the donkeys ingesting 0.6 and 1g/kg/day. Two other donkeys that received daily doses of 3 and 5g seed/kg showed initial respiratory signs 70 and 40 days after the start of the administration, respectively. The donkeys were euthanized following severe respiratory signs and the main lung lesions were proliferation of Clara cells and interstitial fibrosis. Three donkeys ingested seeds of C. retusa containing 5.99% of monocrotaline at daily doses of 0.025, 0.05 and 0.1g/kg for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was moderate liver megalocytosis in each of the three donkeys. One donkey that received a single dose of 5g/kg of C. retusa seeds and another that received 1g/kg daily for 7 days both showed severe clinical signs and died with diffuse centrilobular liver necrosis. No lung lesions were observed. Another donkey that received a single dose of 2.5g/kg of C. retusa seeds showed no clinical signs. The hepatic and pneumotoxic effects observed are consistent with an etiology involving DHPAs. Furthermore, the occurrence of lung or liver lesions correlates with the type of DHPAs contained in the seeds. Similarly as has been reported for horses, the data herein suggest that in donkeys some DHPAs are metabolized in the liver causing liver disease, whereas others are metabolized in the lung by Clara cells causing lung disease. © 2013 Elsevier Ltd.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Two alkaloids, erysodine (1) and erysothrine (2) were isolated from the flowers of a Pakistani medicinal plant, Erythrina suberosa. These compounds were investigated for anxiolytic properties, and the results showed significant effect, in an acute oral treatment with 1-2, which were suspended in saline (NaCl 0.9%) plus DMSO 1%, and evaluated in 122 Swiss male mice exposed to two tests of anxiety - the elevated plus-maze (EPM) and the light/dark transition model (LDTM).

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In the present study, two alkaloids isolated from Pterogyne nitens, a plant native to Brazil, have been shown to induce apoptosis in human breast cancer cells. These compounds, pterogynine (PGN) and pterogynidine (PGD), were tested for their effect on a human infiltrating ductal carcinoma cell line (ZR-7531). The cell line was treated with each alkaloid at several concentrations. Time-dependence (with or without recuperation time) and concentration-dependence (in the range 0.25-10 mM) were investigated in cytotoxicity and apoptosis assays. The annexin assay indicated an apparently higher percentage of death by necrosis of malignant cells after 24 h exposure to both P. nitens extracts than the Hoechst assay. Thus, our results in the two tests demonstrated that the Hoechst assay can discriminate between late apoptotic cells and necrosis, whereas the flow cytometry-based annexin V assay cannot. We concluded that PGN and PGD have effective antineoplastic activity against human breast cancer cells in vitro, by inducing programmed cell death.

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Quinolizidine alkaloids (QAs) are secondary compounds found in seeds of many species of plants, possibly protecting them against pathogens and seed predators. QAs were isolated from Ormosia arborea seeds and bioassayed against red-rumped agoutis (Dasyprocta leporina, Rodentia: Caviomorpha) to verify if they inhibit seed predation and food hoarding (seed dispersal). Three treatments were used: (1) seeds of O. arborea, (2) palatable seeds of Mimusops coriacea (Sapotaceae) treated with MeOH, and (3) seeds of M. coriacea treated with QAs dissolved in MeOH in similar concentration to that present in O. arborea. Palatable seeds were significantly more preyed upon than seeds treated with QAs and Ormosia seeds, but QAs did not influence hoarding behavior. QAs in O. arborea may have a strong effect in avoiding seed predation by rodents, without reducing dispersal.

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