Induction and growth pattern of callus from Piper permucronatum leaves / Indução e padrão de crescimento de calos de folhas de Piper permucronatum

ABSTRACT Piper permucronatum is a perennial shrub, a medicinal plant native to the Amazon Rainforest. Traditionally, the tea of its leaves is used to combat menstrual and intestinal cramps, stomach pain, digestive problems, diarrhea, hemorrhage, and nausea. Its leaf’s essential oil is effective against Aedes aegypti larvae; its flavones and flavanones have a fungicidal effect against Clamidosporium cladosporioides and C. sphaerospermum; its hexanic extract is effective against Leishmania amazonensis. The objective of this study was to provide a protocol for callus induction from P. permucronatum leaves and an identification of the callus growth pattern, focusing on the deceleration phase, when the callus cells must be subcultured into liquid medium in order to produce a cell suspension cultures. Leaf explants were inoculated in a solid MS medium supplemented with factorial combinations of 2,4-D, BA, NAA and GA3. Callus formation was evaluated weekly until the 49th day. Subsequently, new explants were inoculated at the hormonal combination that resulted in the highest callus cell proliferation and, every seven days during a period of 70 days, samples were dried and weighed to determine the callus growth pattern. NAA and GA3 were not effective for callus induction. Combinations of 2,4-D and BA resulted in callus induction and proliferation. The highest percentage of callus induction was observed with the combination of 4.52 µM 2,4-D and 4.44 µM BA. The calluses thereby produced were friable and whitish. The callus growth pattern followed a sigmoid shape. The deceleration phase started on the 56th day of culture.

RESUMO Indução e padrão de crescimento de calos de folhas de Piper permucronatum. Piper permucronatum é um arbusto perene, uma planta medicinal native da Floresta Amazônica. Tradicionalmente, o chá de suas folhas é usado em casos de cólicas menstruais e intestinais, dores de estômago, problemas digestivos, diarreia, hemorragia e náusea. O óleo essencial das folhas é efetivo contra a larva de Aedes aegypti; suas flavonas e flavanonas têm efeito fungicida contra Clamidosporium cladosporioides e C. sphaerospermum; seu extrato hexânico é efetivo contra Leishmania amazonensis. O objetivo deste trabalho foi determinar um protocolo para indução de calos em folhas de P. permucronatum e identificar o padrão de crescimento dos calos, com foco na fase de desaceleração, quando as células de calo devem ser subcultivadas em meio líquido para produzir culturas de células em suspensão. Explantes foliares foram inoculados em meio MS sólido suplementado com combinações fatoriais de 2,4-D, BAP, ANA e GA3. A formação de calos foi avaliada semanalmente até o 49º dia. Posteriormente, novos explantes foram inoculados na combinação hormonal que resultou na maior proliferação de células de calo e, a cada sete dias durante 70 dias, amostras foram secas e pesadas para determinar o padrão de crescimento dos calos. ANA e GA3 não foram efetivas para a indução de calos. Combinações de 2,4-D e BAP resultaram em indução e proliferação de calos. A maior porcentagem de indução de calos foi observada com a combinação de 4,52 µM de 2,4-D e 4,44 µM de BAP. Os calos produzidos eram friáveis e esbranquiçados. O crescimento dos calos seguiu um padrão sigmoide. A fase de desaceleração iniciou no 56º dia de cultivo.

Efeito de diferentes meios nutritivos e fitorreguladores visando à otimização da calogênese de Annona mucosa (Jacq. ) / Effect of different culture media and plant growth regulators for the optimization of callus induction of Annona mucosa (Jacq. )

Annona mucosa é uma árvore frutífera da família Annonaceae, produtora de importantes metabólitos secundários de interesse medicinal, como lignanas, acetogeninas e alcaloides. A cultura in vitro de calos representa um importante recurso para a produção contínua de metabólitos, viabilizando a conservação da biodiversidade química e a obtenção controlada de material para estudos biológicos e fitoquímicos. O objetivo deste trabalho foi otimizar a produção de calos friáveis de A. mucosa, avaliando o efeito de diferentes meios nutritivos e fitorreguladores. Segmentos de folha e de hipocótilo de plântulas germinadas in vivo foram utilizados como explantes e inoculados nos meios de cultura MS, WPM e B5 suplementados com picloram (2 - 20µM) isolado ou combinado com as citocininas BAP, KIN ou TDZ (0,2 - 1µM). As culturas foram mantidas a 26±2ºC, no escuro, com subcultivos mensais. A produção de calos foi avaliada por aferição do peso dos calos, após 90 dias. Em todos os tratamentos na presença da auxina picloram, o cultivo de hipocótilos resultou em maior porcentagem de formação de calos, sobretudo no meio de cultura WPM. A associação com TDZ produziu massa calogênica friável altamente proliferativa e ausente de oxidação, alcançando valores superiores àqueles obtidos em trabalhos prévios com a espécie. Os resultados viabilizam o uso do material em suspensões celulares e posterior caracterização fitoquímica para a exploração da produção in vitro de metabólitos da espécie.

The Annona mucosa is a fruit tree of the Annonaceae family that produces a range of secondary metabolites of medicinal interest, such as lignans, acetogenins and alkaloids. The callus culture represents a renewable source of valuable medicinal compounds and controlled supply of material for biological and phytochemical studies. Therefore, this study was carried out to investigate the effects of three nutrient media, different concentrations of picloram and cytokinin types, in order to optimize the biomass yield and friability of calluses of A. mucosa. Leaf and hypocotyl segments from seedlings produced from in vivo seed germination were used as explants, which were inoculated in MS, WPM and B5 culture media supplemented with picloram (2-20µM) only or in addition to the cytokinins BAP, KIN or TDZ (0,2 - 1µM ). Cultures were maintained at 26±2ºC in the dark, with monthly subcultures. After 90 days, biomass production was evaluated. In all treatments, hypocotyl explants provided the highest percentage of callus formation, particularly in WPM. The association with TDZ produced highly proliferative friable callus, with no oxidation, reaching higher values than the previous works with this species. The results enable the use of the calluses produced in cell suspensions and the subsequent phytochemical characterization, in order to explore the in vitro production of metabolites of the species.

Publicaçôes biomédicas brasileiras na literatura científica internacional. Doenças endêmicas transmissíveis / Brazilian biomedical publications in the international scientific literature. Endemic communicable diseases

The number of Brazilian periodicals listed in the Index Medicus dropped from 70 in 1964 to 15 in 1983, or 78 per cent, while the total number of listed periodicals from other countries fell only 11 per cent. The total number of articles published in Brazil on Chagas' disease, schistosomiasis, leishmaniasis, leprosy, malaria, and filariasis, and listed in the Index Medicus did not change significantly between 1965 and 1982, because, with the exception of the journal O Hospital, the Brazilian periodicals that published 74 per cent of all articles on those diseases remained listed throughout the period considered. The predominant subjects in articles on endemic diseases were Chagas' disease and schistosomiasis, and in the later years there was a tendency to index more articles on basic than on applied research. The number of articles on Chagas' disease published by Brazilian authors directly in foreign journals increased considerably during the latter decade. Analysis of all the data together suggests that the developed countries select a specific portion of the Brazilian output of biomedical literature--which is kept listed in secondary and international publications or published directly in foreign journals--while another portion of the same output gradually loses visibility on the international scene (Au)

Análisis de la información científica publicada en el Brasil en cinco años sobre la enfermedad de Chagas, esquistosomiasis, malaria, leishmaniasis y filariasis / Analysis of scientific information published in Brazil in 5 years on Chagas disease, schistosomiasis, malaria, leishmaniasis and filariasis

This paper offers a quantitative evaluation of the scientific information produced in Brazil on several endemic diseases: Chagas' disease, schistosomiasis, leishmaniasis, leprosy, malaria and filariasis. The source of data was the Index Medicus Latino Americano (IMLA), and the published scientific information was analyzed in general and specifically, by type of disease and year of publication. The indexed production of articles on the material of the Latin American countries as a whole increased from 3,506 articles in 1978 to 5,528 in 1982 (for an increase of 52.7 per cent), whereas that of Brazil alone rose from 1,781 to 2,531 (an increase of 42.1 per cent) during the same period. The output of articles on endemic diseases totaled 703 papers (6.3 per cent of the total indexed production). Of this total, 441 (62.7 per cent) was on applied research and 262 (37.3 per cent) were on basic research, and these proportions held relatively constant. Chagas' disease and schistosomiasis accounted for 75.2 per cent of that total over the period considered. The production of papers on the diseases of interest grew 79.2 per cent, at the same rate as that of all biomedical information published in Brazil over the period. An equilibrium was reached between the numbers of basic and applied papers. The analysis also identified the core of Brazilian periodicals that most frequently publish information on those endemics. It was also found that a large proportion of articles by Brazilian authors are published in journals of international circulation, and the foreign journals that publish papers by researchers in Brazil were identified (Au)