67 resultados para Maytenus


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Os objetivos do presente trabalho foram: a) determinar o número cromossômico de diferentes populações de M. ilicifolia ocorrentes no Rio Grande do Sul; b) estimar viabilidade do pólen e o índice meiótico; c) estudar o comportamento meiótico; d) caracterizar sementes desta espécie quanto ao peso e analisar a produção de sementes por fruto.

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Maytenus ilicifolia is an important plant with potential on cancer treatment and has been largely used in Brazil and other countries. We have evaluated the crude ethanolic extract of M. ilicifolia as a potential antioxidant source using an assay based on the bleaching of the radical monocation 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(center dot+)) and by HOCl scavenger capacity. Trolox and uric acid were used as positive controls. The results indicated M. ilicifolia root bark as a great source of antioxidants based on its potential as scavenger of radicals. (c) 2006 Elsevier B.V. All rights reserved.

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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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Essa nota registra a recoleta e a primeira informação sobre a distribuição de Maytenus comocladiaeformis Reissek. A espécie era conhecida por apenas duas coletas pouco informativas, a última delas de 1950, e era considerada extinta.

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Maytenus s. l. (including Gymnosporia) is a morphologically diverse genus of about 300 species that is widely distributed in the tropics and subtropics of both the Old and New Worlds. Its delimitation has been extensively debated and despite the segregation of Gymnosporia, Maytenus s. s. remains a heterogeneous, polyphyletic group. To delimit natural segregate genera we increased taxon sampling and generated sequences from two nuclear gene regions (ITS and 26S rDNA) and two plastid loci (matK and trnL-F) to analyze together with morphological characters. Both Moya and Tricerma were found to be nested within the New World Maytenus and are recognized as synonyms of Maytenus s. s.. In contrast, the three New World species of Gymnosporia are recognized as a new genus that is closely related to Gyminda. Haydenia is erected for these three species: H. gentryi, H. haberiana, and H. urbaniana. One or more previously proposed or novel genera are required to accommodate the systematically difficult African Maytenus. Putterlickia, and most likely Gloveria, are nested within Gymnosporia and should be synonymized with that genus. New binomials are required for four Chinese and one Rapan species of Gymnosporia that have been previously treated only as Maytenus: Gymnosporia austroyunnanensis, G. confertiflora, G. dongfangensis, G. guangxiensis, and G. pertinax. Austral-Pacific Maytenus are transferred to Denhamia, requiring eight new binomials: Denhamia bilocularis, D. cunninghamii, D. cupularis, D. disperma, D. fasciculiflora, D. ferdinandii, D. fournieri, and D. silvestris. Existing intrageneric classifications of Gymnosporia and Maytenus s. s. were not supported in their entirety. Gymnosporia is inferred to have had an African origin followed by dispersals to Madagascar, southeast Asia and the Austral-Pacific.

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Pristimerin has been shown to be cytotoxic to several cancer cell lines. In the present work, the cytotoxicity of pristimerin was evaluated in human tumor cell lines and in human peripheral blood mononuclear cells (PBMC). This work also examined the effects of pristimerin (0.4; 0.8 and 1.7 mu M) in HL-60 cells, after 6, 12 and 24 h of exposure. Pristimerin reduced the number of viable cells and increased number of non-viable cells in a concentration-dependent manner by tripan blue test showing morphological changes consistent with apoptosis. Nevertheless, pristimerin was not selective to cancer cells, since it inhibited PBMC proliferation with an IC50 of 0.88 PM. DNA synthesis inhibition assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation in HL-60 cells was 70% and 83% for the concentrations of 0.4 and 0.8 mu M, respectively. Pristimerin (10 and 20 mu M) was not able to inhibit topoisomerase 1. In AO/EB (acridine orange/ethidium bromide) staining, all tested concentrations reduced the number of HL-60 viable cells, with the occurrence of necrosis and apoptosis in a concentration-dependent manner, results in agreement with trypan blue exclusion findings. The analysis of membrane integrity and internucleosomal DNA fragmentation by flow cytometry in the presence of pristimerin indicated that treated cells underwent apoptosis. The present data point to the importance of pristimerin as representative of an emerging class of potential anticancer chemicals, exhibiting an antiproliferative effect by inhibiting DNA synthesis and triggering apoptosis. (c) 2008 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Aqueous infusions of Brazilian Maytenus leaves are used as beverages, foodstuffs, and phytomedicines. Previously, we isolated two new flavonoid tetrasaccharides from the infusion of Maytenus aquifolium leaves that showed antiulcer activity. In this investigation a new flavonoid tetrasaccharide, kaempferol-3-O-alpha -L-rhamnopyranosyl (1-6)-O-[alpha -L-arabinopyranosyl (1 -->3)-O-alpha -L-rhamnopyranosyl (1-2)]-O-beta -D-galactopyranoside (3), was isolated, together with kaempferol tri- and disaccharides and quercetin trisaccharides from the aqueous infusion of Maytenus ilicifolia leaves. All structures were elucidated by ES-MS and NMR spectroscopic methods. The quantitative analysis of the flavonoid glycosides from Maytenus ilicifolia and M. aquifolium has been performed by HPLC.

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Explants of Maytenus aquifolium were induced to form callus and, subsequently, suspension cultures. The isolation of natural products from callus led to the identification of the cytotoxic triterpene quinonemethides, maitenin (1) and 22 beta-hydroxymaitenin (2), A rapid, sensitive and reliable reversed-phase high-performance liquid chromatography method was developed using a Cls column and isocratic elution for the determination of 1 and 2, the elaborated method gave well-resolved peaks for these compounds with good detection response and linearity in the range of 0.08-72.0 mu g. The quantification of 1 and 2 was performed by an external standard method. (C) 1998 John Wiley & Sons, Ltd.

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Droplet countercurrent chromatography and high-performance liquid chromatography fractionation of the aqueous infusion from Maytenus aquifolium Martius leaves afforded two flavonoid tetrasaccharides: quercetin 3-O-alpha-L-rhamnopyranosyl(1-->6)-O-[beta-D-glucopyranosyl(1-->3)-O-alpha-L-rhamnopranosyl( 1-->2)-O-beta-D-galactopyranoside and kaempferol 3-O-alpha-L-rhamnopyranosyl(1-->6)-O-[beta-D-glucopyranosyl( 1-->3)-O-alpha-L-rhamnopyranosy(1-->2-2)-O-beta-D-galactopyranoside. All structures were elucidated by spectroscopic methods. Pharmacological essays of the infusion showed antiulcer activity in rats.