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1.
Pan Afr Med J ; 39: 36, 2021.
Artigo em Francês | MEDLINE | ID: mdl-34422159

RESUMO

The evolution and contemporary challenges of health research (HR) in Madagascar are poorly documented. We aim to gain insights on the factors that shape Madagascar's National Health Research System (NHRS) to better understand their influence. We conducted a qualitative case study, which included a documentary review and semi-structured interviews with 38 key informants. We carried out a thematic analysis and used the WHO/AFRO NHRS Barometer to structure the presentation of the results. There is no legislative framework to support HR activities and institutions. There is, however, a policy document outlining national priorities for HS. Human resources for HR are insufficient, due to challenges in training and retaining researchers. International collaboration is almost the only source of HR funding. Collaborations contribute to developing human and institutional capacity, but they are not always aligned with research carried out locally and the country's priority health needs. Incomplete efforts to improve regulation and low public investment in research training and research implementation reflect an insufficient commitment to HR by the government. Negotiating equitable international partnerships, the availability of public funding, and aligning HR with national health priorities would constitute a solid basis for the development of the NHRS in Madagascar.


Assuntos
Pesquisa Biomédica/organização & administração , Política de Saúde , Prioridades em Saúde , Pesquisa Biomédica/economia , Pesquisa Biomédica/tendências , Humanos , Cooperação Internacional , Entrevistas como Assunto , Madagáscar , Apoio à Pesquisa como Assunto , Recursos Humanos/organização & administração
2.
Methods Mol Biol ; 2013: 307-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31267508

RESUMO

On the island of Madagascar, prior to the arrival of the Europeans, some pathologies including malaria, locally known as tazo (fever), were already described. As part of the Malagasy traditional knowledge, traditional medicine mainly based on the use of herbal remedies is part of the malaria treatment still today. Across the country, hundreds of plants are identified as antimalarial, and some compounds from plants show interesting in vitro activities against human Plasmodium. However, it has become clear that most of the antimalarial herbal remedies traditionally used are not efficient antimalarials. In order to identify authentic antimalarial herbal remedies, methodical approaches should range from plant selection to biological screening. In this paper, we share our point of view based on our experience on antimalarial plants in Madagascar.


Assuntos
Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Plantas Medicinais/química , Humanos , Madagáscar , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/patogenicidade
3.
Econ Bot ; 71(1): 75-82, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-29129935

RESUMO

Bioassay screening of plant extracts can identify unique lead compounds for drug development, but the "hit rate" from random screening is very low. Targeted screening of medicinal plants has been repeatedly reported to increase the percentage of samples displaying bioactivity. Contrarily, Maranz (2012) suggested that African antimalarial plants were unsuitable sources of antimalarial drugs because high prevalence of malaria would result in rapid evolution of resistance to active compounds that directly targeted the parasite. As malaria is highly prevalent in much of Madagascar, it was of interest to determine whether Malagasy antimalarial plants would outperform randomly selected plants in conventional antimalarial assays being conducted as part of a discovery program. Of 1294 plant samples screened for antimalarial activity, 39.6% had an IC50 <50 µg/ml and 21.1% had an IC50 <20 µg/ml (the minimum to qualify as a first-pass "hit"). Ethnobotanical uses were coded at both the generic and the species level, as neither samples nor use reports in literature were always identifiable to species level. The 526 samples belonging to genera having reported uses for malaria were slightly more likely than average to display activity (44.3% with IC50 <50 µg/ml, p < .01; 23.2% with IC50 <20 µg/ml). Of these, 67 samples from individual species with documented use were still more likely to be modestly active (49.3% with IC50 <50 µg/ml), yet less likely to be highly active (17.9% with IC50 <20 µg/ml). Thus, in this specific context, ethnobotanically directed screening would not have substantially improved screening efficiency, and would have missed most of the potential hits.

4.
Nat Prod Bioprospect ; 6(5): 261-265, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27655634

RESUMO

Melicope madagascariensis (Rutaceae) is an endemic plant species of Madagascar that was first classified as a member of the genus Euodia J. R. & G. Forst (Rutaceae) under the scientific name Euodia madagascariensis Baker. Based on morphological characteristics, Thomas Gordon Hartley taxonomically revised E. madagascariensis Baker to be M. madagascariensis (Baker) T.G. Hartley. Chemotaxonomical studies have long been used to help the identification and confirmation of taxonomical classification of plant species and botanicals. Aiming to find more evidences to support the taxonomical revision performed on E. madagascariensis, we carried out phytochemical investigation of two samples of the plant. Fractionation of the ethanol extracts prepared from two stem bark samples of M. madagascariensis (Baker) T.G. Hartley led to the isolation of seven known furoquinoline alkaloids 1-7 and two known methoxyflavones 8 and 9. The presence of furoquinoline alkaloids and methoxyflavones in the title species is in agreement with its taxonomic transfer from Euodia to Melicope. Antiprotozoal evaluation of the isolated compounds showed that 6-methoxy-7-hydroxydictamnine (heliparvifoline, 3) showed weak antimalarial activity (IC50 = 35 µM) against the chloroquine-resistant strain Dd2 of Plasmodium falciparum. Skimmianine (4) displayed moderate cytotoxicity with IC50 value of 1.5 µM against HT-29 colon cancer cell line whereas 3,5-dihydroxy-3',4',7-trimethoxyflavone (9) was weakly active in the same assay (IC50 = 13.9 µM).

5.
Tetrahedron Lett ; 56(23): 3630-3632, 2015 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-26034338

RESUMO

Bioassay-directed fractionation of an antiproliferative ethanol extract of the roots of Ocotea macrocarpa (Lauraceae) afforded the new butanolide macrocarpolide A (1), and the two new secobutanolides macrocarpolides B (2) and C (3), together with the known butanolides linderanolide B (4) and isolinderanolide (5). The structure elucidation of all compounds was carried out based on NMR and mass spectroscopic data analyses. The absolute configurations of all compounds isolated were determined by comparison of their optical rotation values with those found in literature. Compounds 1-5 showed good antiproliferative activities against the A2780 ovarian cell line, with IC50 values of 2.57 ± 0.12 (1), 1.98 ± 0.23 (2), 1.67 ± 0.05 (3), 2.43 ± 0.41 (4), and 1.65 ± 0.44 µM (5), respectively.

6.
Org Lett ; 16(10): 2626-9, 2014 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-24773558

RESUMO

The new triterpene turranoic acid (1) and the new N-containing nor-triterpene turraenine (2), along with triptocallic acid B (3) and esculentoic acid (4) were isolated from leaves of a Turraea sp. Compounds 1-3 showed weak to moderate in vitro antiplasmodial activity against the chloroquine-resistant Plasmodium falciparum strain FCM29. Compound 1 also displayed weak cytotoxic activity against the nonsmall lung cancer cell line H522-T1 with an IC50 value of 16.4 µM.


Assuntos
Antimaláricos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Meliaceae/química , Nitrogênio/química , Triterpenos/isolamento & purificação , Antimaláricos/química , Antimaláricos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Cloroquina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Folhas de Planta/química , Plasmodium falciparum/efeitos dos fármacos , Triterpenos/química , Triterpenos/farmacologia
7.
Chem Biodivers ; 10(2): 233-40, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23418170

RESUMO

Investigation of the endemic Madagascan plant Nematostylis anthophylla (Rubiaceae) for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of the known triterpene saponin randianin (1), and the two new bioactive triterpene saponins 2"-O-acetylrandianin (2) and 6"-O-acetylrandianin (3). The structures of the two new compounds were elucidated based on analysis of their 1D- and 2D-NMR spectra, and mass spectrometric data. The three isolated triterpene saponins displayed moderate but selective antiproliferative activities, with IC(50) values of 1.2, 1.7, and 2.2 µM, respectively, against the A2780 ovarian cancer, but only weak inhibitions of the proliferation of A2058 melanoma and the H522 lung cancer cell lines.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Rubiaceae/química , Saponinas/química , Saponinas/farmacologia , Triterpenos/química , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Madagáscar , Melanoma/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação
8.
Mol Phylogenet Evol ; 57(1): 258-65, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20601002

RESUMO

Ptaeroxylaceae is an Afro-Malagasy family containing three genera, Bottegoa, Cedrelopsis, and Ptaeroxylon. Although the family is morphologically well delimited, it is currently considered part of the subfamily Spathelioideae in a broadly circumscribed orange family (Rutaceae). The Malagasy Cedrelopsis has traditionally been associated with different families of the order Sapindales and its phylogenetic placement in Rutaceae sensu lato has yet to be tested with molecular data. The present molecular phylogenetic study reaffirms the monophyly of Ptaeroxylaceae and its placement in Spathelioideae. Therefore, molecules and morphology support close affinities between Bottegoa, Cedrelopsis, and Ptaeroxylon and also their current generic circumscriptions. We report a case of an evolutionary change from one-seeded to two-seeded carpels within the Harrisonia-Cneorum-Ptaeroxylaceae clade of Spathelioideae. Finally, the sister-group relationship between the African Bottegoa and the Afro-Malagasy Ptaeroxylon-Cedrelopsis clade suggests an African origin of Cedrelopsis.


Assuntos
Evolução Molecular , Filogenia , Rutaceae/classificação , Rutaceae/genética , DNA de Cloroplastos/genética , DNA de Plantas/genética , Geografia , Sementes , Análise de Sequência de DNA
9.
Bioorg Med Chem ; 17(7): 2871-6, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19282186

RESUMO

Bioassay-guided fractionation of an ethanol extract of a Madagascar collection of the bark of Scutia myrtina led to the isolation of three new anthrone-anthraquinones, scutianthraquinones A, B and C (1-3), one new bisanthrone-anthraquinone, scutianthraquinone D (4), and the known anthraquinone, aloesaponarin I (5). The structures of all compounds were determined using a combination of 1D and 2D NMR experiments, including COSY, TOCSY, HSQC, HMBC, and ROESY sequences, and mass spectrometry. All the isolated compounds were tested against the A2780 human ovarian cancer cell line for antiproliferative activities, and against the chloroquine-resistant Plasmodium falciparum strains Dd2 and FCM29 for antiplasmodial activities. Compounds 1, 2 and 4 showed weak antiproliferative activities against the A2780 ovarian cancer cell line, while compounds 1-4 exhibited moderate antiplasmodial activities against P. falciparum Dd2 and compounds 1, 2, and 4 exhibited moderate antiplasmodial activities against P. falciparum FCM29.


Assuntos
Antraquinonas/química , Antimaláricos/química , Antineoplásicos Fitogênicos/química , Rhamnaceae/química , Animais , Antraquinonas/isolamento & purificação , Antraquinonas/farmacologia , Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Humanos , Madagáscar , Casca de Planta/química , Extratos Vegetais/química , Plasmodium falciparum/efeitos dos fármacos
10.
Planta Med ; 72(15): 1438-40, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17091436

RESUMO

Bioassay-directed separation of the butanol-soluble portion of an extract of Sloanea rhodantha (Baker) Capuron var. Rhodantha (Elaeocarpaceae) active against the drug-sensitive HB3 strain of Plasmodium falciparum led to the isolation of seven phenolic compounds, gallic acid (1), 3,5-di-O-galloylquinic acid (2), 1,6-di-O-galloyl glucopyranoside (3), 3,4,5-tri-O-galloylquinic acid (4), 1-O-eudesmoylquinic acid (5), 1,2,3,6-tetra-O-galloyl glucopyranoside (6), and 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-b-D-glucopyranoside (7). The structure of the new compound 5 was established on the basis of interpretation of its 1D and 2D NMR spectroscopic data. Compounds 2, 3, 4, 6, and 7 showed weak inhibitory activity against the drug-sensitive HB3 and the drug-resistant FCM29 strains of P. falciparum, with IC (50) values ranging from 8.0 - 43.0 and 16.1 - 93.0 microg/mL, respectively.


Assuntos
Antimaláricos/farmacologia , Elaeocarpaceae , Fitoterapia , Extratos Vegetais/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Madagáscar , Medicina Tradicional , Testes de Sensibilidade Parasitária , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Árvores
11.
J Nat Prod ; 67(12): 2053-7, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15620250

RESUMO

Bioassay-guided fractionation of an EtOAc extract of the leaves of Melampodium camphoratum using an assay for inhibitors of the degradation of hemin resulted in the isolation of six new eudesmane sesquiterpenes (1-6) and the known 6-epi-beta-verbesinol coumarate (7). The structures of compounds 1-6 were established as 6alpha-(4'-O-methyl-7'E-coumaryloxy)eudesm-4(14)-ene (1), 6alpha-({4'-O-stearyl}-7'E-coumaryloxy)eudesm-4(14)-ene (2), 6alpha-({4'-O-palmityl}-7'E-coumaryloxy)eudesm-4(14)-ene (3), 6alpha-({4'-O-[9' 'Z-hexadecenoyl]}-7'E-coumaryloxy)eudesm-4(14)-ene (4), 6alpha-(7'Z-coumaryloxy)eudesm-4(14)-ene (5), and 6alpha-({4'-acetoxy}-7'Z-coumaryloxy)eudesm-4(14)-ene (6). Compounds 1-4 showed weak activity in the hemin degradation assay, while compounds 5-7 were inactive.


Assuntos
Antimaláricos/isolamento & purificação , Asteraceae/química , Hemina/metabolismo , Plantas Medicinais/química , Sesquiterpenos de Eudesmano/isolamento & purificação , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Concentração Inibidora 50 , Estrutura Molecular , Folhas de Planta/química , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos de Eudesmano/química , Sesquiterpenos de Eudesmano/farmacologia , Estereoisomerismo , Suriname
12.
Malar J ; 2: 25, 2003 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-12921540

RESUMO

BACKGROUND: Malaria is known as tazo or tazomoka in local terminology in Madagascar. Within the context of traditional practice, malaria (and/or malaria symptoms) is commonly treated by decoctions or infusions from bitter plants. One possible approach to the identification of new antimalarial drug candidates is to search for compounds that cure or prevent malaria in plants empirically used to treat malaria. Thus, it is worth documenting the ethnobotanical data, and testing the antiplasmodial activity of the extractive from plants. METHODS: We interviewed traditional healers, known locally as ombiasy, at Andasibe in the eastern, rainy part of Madagascar. We recorded details of the preparation and use of plants for medicinal purposes. We extracted five alkaloids from Z. tsihanimposa stem bark, and tested them in vitro against Plasmodium falciparum FCM29. RESULTS: We found that traditional healers treat malaria with herbal remedies consisting of one to eight different plants. We identified and listed the medicinal plants commonly used to treat malaria. The plants used included a large number of species from different families. Zanthoxylum sp (Rutaceae) was frequently cited, and plants from this genus are also used to treat malaria in other parts of Madagascar. From the plant list, Zanthoxylum tsihanimposa, bitter plant endemic to Madagascar, was selected and examined. Five alkaloids were isolates from the stem bark of this plant, and tested in vitro against malaria parasite. The geometric mean IC50 values ranged from 98.4 to 332.1 micromolar. The quinoline alkaloid gamma-fagarine exhibited the strongest antiplasmodial activity. CONCLUSIONS: The current use of plants for medicinal purposes reflects the attachment of the Malagasy people to their culture, and also a lack of access to modern medicine. The possible extrapolation of these in vitro findings, obtained with plant extracts, to the treatment of malaria and/or the signs evoking malaria is still unclear. If plants are to be used as sources of novel antimalarial compounds, we need to increase our knowledge of their empirical use to improve plant selection. In the hope of preserving useful resources, we should now gather and record ethnobotanical data in Madagascar, and should try to bridge the gaps between empirics and realism.


Assuntos
Antimaláricos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Fitoterapia/métodos , Preparações de Plantas/administração & dosagem , Preparações de Plantas/uso terapêutico , Plantas Medicinais , Animais , Antimaláricos/administração & dosagem , Prescrições de Medicamentos , Humanos , Concentração Inibidora 50 , Madagáscar , Plasmodium falciparum/efeitos dos fármacos
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