Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-33488744

RESUMO

The need for new therapeutic approaches to improve the response in acute leukemia (AL), either by directing therapy or with new therapeutic alternatives, has been a research and clinical interest topic. We evaluated whether blasts from AL patients were sensitive ex vivo to the induction chemotherapy and whether the extracts of Petiveria alliacea (Anamu SC) and Caesalpinia spinosa (P2Et) modulated the sensitivity of leukemic cells to death. Bone marrow samples were taken from 26 patients with de novo AL and 6 in relapse, and the cytotoxicity of the extracts alone or in combination with the chemotherapeutic was evaluated by XTT. Patients were classified as good (GR) and bad responders (BR) according to the ex vivo test. 70.5% of the GR patients to the ex vivo test achieved postinduction remission to induction chemotherapy with a median overall survival of 12.50 months versus 7.23 months in the two groups. Furthermore, it was found that the ex vivo response to extracts and chemotherapeutics is heterogeneous and shows an exclusive pattern between the extracts, Anamu being the more effective in inducing cell death. The combination of extracts with chemotherapeutic agents showed synergistic or antagonistic effects in the patients' blasts. These results show that the ex vivo evaluation of the sensitivity to induction drugs using primary blasts from patients exhibits a correlation with the response to induction chemotherapy in patients. These analyses would allow establishing a system to predict response to treatment and determine ex vivo susceptibility to new therapies under development, among which is phytotherapeutics.

2.
Phytomedicine ; 50: 109-117, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30466969

RESUMO

BACKGROUND: Eucalyptus tereticornis Sm (Myrtaceae) is a plant used in traditional medicine to control obesity, insulin resistance and diabetes. Chronic adipose tissue inflammation is involved in generating insulin resistance, the greatest risk factor in developing type 2 diabetes mellitus and cardiovascular disease. In the present study, a mixture of triterpenes, as obtained from the starting plant material, was evaluated in inflamed adipose tissue cells models. AIM: Our goal is to advance into the understanding, at the cellular level, of the immunometabolic effects of the triterpene mixes from Eucalyptus tereticornis in in vitro models of mouse and human adipose tissues. METHODS: Triterpene mixes were obtained from Eucalyptus tereticornis leaves by organic extraction. The major compounds of these mixes were identified by 1H NMR and 13C NMR in addition to HPLC using primary and secondary standards of ursolic acid, oleanolic acid and ursolic acid lactone. To provide an approach for evaluating the cellular and molecular mechanisms through which triterpene mixes act to modify the metabolic processes associated with obesity, mouse macrophage and adipocyte cell lines, human macrophage cell line and primary culture of human adipocytes were used as models. RESULTS: Adipocytes treated with the two natural chemically characterized triterpene mixes partially reduce lipogenesis and leptin expression. Additionally, an increase in the transcriptional expression of PPARγ, and C/EBPα is observed. In macrophages, these triterpene mixes, decrease the transcriptional and translational expression of pro-inflammatory cytokines, such as interleukin-6 (IL-6), interleukin 1ß (IL-1ß) and tumoral necrosis factor α (TNFα). Conditioned medium of 3T3-L1 adipocytes treated with the triterpene mix shows a stronger anti-inflammatory response on activated J774A.1 macrophages. CONCLUSION: The mixtures of the three triterpenes in the proportions obtained from the plant material may act on different components of the cell, generating a different response, which, in some cases, is more powerful than that seen when exposure to only two triterpenes. It makes this three triterpenes mix a good phytotherapeutic prototype for pathologies as complex as those associated with obesity.


Assuntos
Adipócitos/efeitos dos fármacos , Eucalyptus/química , Triterpenos/farmacologia , Células 3T3 , Adipócitos/metabolismo , Adipocinas/metabolismo , Tecido Adiposo/citologia , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Citocinas/metabolismo , Diabetes Mellitus Tipo 2 , Humanos , Inflamação/metabolismo , Resistência à Insulina , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Obesidade , Folhas de Planta/química , Células U937
3.
Rev. lasallista investig ; 14(2): 212-219, jul.-dic. 2017.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1093956

RESUMO

Resumen Diversos autores han presentado a la agroecología como una ciencia que se funda en principios. No obstante, no existe un consenso alrededor de cuáles son y algunos de los que son formulados no se corresponden con lo que es un principio científico, mientras otros no están redactados de manera adecuada impidiendo determinar de manera clara cuáles son los presupuestos básicos a partir de los cuales se estructura toda la teoría agroecología. Por este motivo, se realizó una revisión crítica de los diversos principios que se han planteado en la teoría y se formularon siete principios generales que pueden operar como un centro firme que permita avanzar en la consolidación de la agroecología.


Palabras clave: Sostenibilidad agraria, biomímesis, principios agroecológicos, biodiversidad


Abstract Several authors have presented agroecology as a science based on principles. However, there is not agreement on what are the basic principles of agroecology. Also, some of the principles have been formulated in a way that does not correspond to what a scientific principle is. For this reason, a critical review of theoretical literature was conducted in order to establish the basic principles of agroecology. Seven principles that can work as hard core of theory of agroecology.


Resumo Vários autores apresentaram agroecologia como uma ciência baseada em princípios. No entanto, não há consenso em torno do que são e alguns dos que são formulados não correspondem ao que é um princípio científico, enquanto outros não são elaborados de forma adequada, evitando a determinação clara dos orçamentos básicos com base em que é estruturada toda a teoria da agroecologia. Por esta razão, foi feita uma revisão crítica dos vários princípios que foram levantados na teoria e foram formulados sete princípios gerais que podem funcionar como um centro firme que permite o progresso na consolidação da agroecologia.

4.
Chem Biodivers ; 14(1)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27546067

RESUMO

Nine eremophilane sesquiterpenes 1 - 9, two flavonoids 11 and 12, and two known pirrolizidine alkaloids 13 and 14, were isolated from Senecio adenotrichius DC. Their structures were elucidated on the basis of spectroscopic data and by comparison with previously reported spectroscopic data of similar compounds. Compounds 5, 7, and 9 have not been previously reported as natural products. The antifeedant activity of these compounds was tested against Spodoptera litoralis and Myzus persicae. Eremophilanes 1, 3, and 8 were strong antifeedants to M. persicae, and 1 and 8 to Spodoptera littoralis. Their ixodicidal activity was tested against the tick Hyalomma lusitanicum, with eremophilanes 1, 3, and 8, being strong ixodicidal agents.


Assuntos
Inseticidas/química , Senécio/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Animais , Afídeos/efeitos dos fármacos , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Inseticidas/isolamento & purificação , Inseticidas/farmacologia , Extratos Vegetais/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Spodoptera/efeitos dos fármacos , Relação Estrutura-Atividade
5.
Adv Pharmacol Sci ; 2015: 418673, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26366171

RESUMO

Eucalyptus tereticornis is a plant used in traditional medicine to control diabetes, but this effect has not been proved scientifically. Here, we demonstrated through in vitro assays that E. tereticornis extracts increase glucose uptake and inhibit their production in insulin-resistant C2C12 and HepG2 cells, respectively. Furthermore, in a nutritional model using diabetic mice, the administration of ethyl acetate extract of E. tereticornis reduced fasting glycaemia, improved tolerance to glucose, and reduced resistance to insulin. Likewise, this extract had anti-inflammatory effects in adipose tissue when compared to control diabetic mice. Via bioguided assays and sequential purification of the crude extract, a triterpenoid-rich fraction from ethyl acetate extracts was shown to be responsible for the biological activity. Similarly, we identified the main compound responsible for the antihyperglycemic activity in this extract. This study shows that triterpenes found in E. tereticornis extracts act as hypoglycemic/antidiabetic compounds and contribute to the understanding of their use in traditional medicine.

6.
Toxicon ; 95: 38-45, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25553593

RESUMO

The use of ecotoxicological techniques for the evaluation of the quality of limnetic waters allows the early detection of toxic agents that pose risks to human health. In this study Moina micrura (two clones), Daphnia laevis (two clones) and Daphnia similis, a temperate species, were used to evaluate the toxicity of six Microcystis extracts from two Colombian reservoirs. Toxin was detected and quantified by HPLC. Microcystin-LR was found in all extracts with the highest concentrations in one sample from each reservoir (434 µg g(-1) and 538 µg g(-1)). The extracts that had the highest toxin concentration also had the highest toxicities to cladocerans. Measurement of 48-h LC50 showed consistent differences between cladoceran species but not clones, Also, reproduction data in two species were consistent with the MC-LR content of one sample tested, with decreased reproduction and disruption of egg production. However, only some growth results of neonates exposed to extracts were consistent with the acute response. In conclusion, Daphnia species are a good model for monitoring cyanotoxins as they respond in a sensitive way to natural phytoplankton samples containing microcystin-LR.


Assuntos
Cladóceros/efeitos dos fármacos , Microcistinas/toxicidade , Fitoplâncton/química , Animais , Cromatografia Líquida de Alta Pressão , Cladóceros/crescimento & desenvolvimento , Cladóceros/microbiologia , Cianobactérias/química , Daphnia/efeitos dos fármacos , Dose Letal Mediana , Toxinas Marinhas/toxicidade , Reprodução/efeitos dos fármacos , Espectrometria de Massas em Tandem , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica
7.
Toxicon ; 87: 26-31, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24880137

RESUMO

Bioaccumulation of microcystins (MC) in zooplankton has been shown in several studies, mainly in field samples. A few studies, however, have demonstrated MC bioaccumulation in laboratory experiments. Although ingestion of cell-bound MC is considered the main route of MC accumulation, another important source is the MC from the dissolved fraction (DMC). This study reports the accumulation of DMC from aqueous extracts of natural bloom samples in three cladoceran species: Moina micrura, Daphnia laevis and Daphnia similis. Animals were exposed for 96 h to aqueous extracts of lyophilized matter from two bloom samples from Colombian reservoirs in different concentrations (25-1000 mg DW L(-1)). Analysis by HPLC-MS detected MC-LR in these samples at concentrations of 434-538 µg g(-1). For the analysis of MC in animal tissues the samples were homogenized and sonicated in methanol:water (75%) and analyzed by ELISA. Results showed that the animals uptake of MC increased with increasing exposure concentrations of aqueous extracts, with M. micrura and D. laevis clones presenting the highest MC concentrations in their tissues (up to 1170-1260 µg g(-1)) while D. similis the lowest (184 µg g(-1)). This study shows, for the first time, that MC uptake from dissolved fraction by zooplankton is possible, not only from the ingestion of seston or cell-bound MC as previously demonstrated.


Assuntos
Carcinógenos/metabolismo , Cladóceros/metabolismo , Microcistinas/metabolismo , Animais , Colômbia , Daphnia/metabolismo , Microcistinas/toxicidade , Zooplâncton/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...