ABSTRACT Aspidosperma macrocarpon Mart. (Apocynaceae) is used in popular medicine to treat malaria and dengue. The aim of the present study was to morphoanatomically, histochemistry and phytochemically characterize A. macrocarpon young branches and leaves, seeking to indicate secondary compounds presenting medicinal potential to treat these diseases. Aspidosperma macrocarpon young branches and leaves were collected in private properties located in municipality of Alta Floresta, Mato Grosso State, Brazil. Sectional and paradermic sections were set freehand using a steelblade, were doubly stained and assembled on histological slides. The fresh material was subjected to histochemical and phytochemical tests for detection of saponins, tannins, alkaloids, flavonoids, cardiotonic glycosides, anthraquinone, steroids and terpenes. Aspidosperma macrocarpon presented glandular trichomes, cavities and secretory cells. We detected the presence of tannins, flavonoid, phenolic compounds, cardiotonic glycosides and alkaloids, which may confer antiplasmodic activity and antiviral properties to the species. As far as it is known, the present study was the first to identify aspects of the histochemical and phytochemical composition of young branches and leaves A. macrocarpon which may be associated with the popular use of this plant to treat malaria and dengue in a transition region between the Cerrado and Amazon biomes, where malaria and dengue occur endemically.

RESUMEN Aspidosperma macrocarpon Mart. (Apocynaceae) es empleada en la medicina popular para el tratamiento de la malaria y el dengue. El objetivo de este trabajo fue caracterizar morfoanatómicamente, histoquímicamente y fitoquímicamente el tronco y la lámina foliar de A. macrocarpon, buscando identificar compuestos secundarios con potencial farmacológico para el tratamiento de ambas enfermedades. Muestras de tallos verdes y hojas de A. macrocarpon fueron recolectados en propiedades particulares en el municipio de Alta Floresta, Mato Grosso, Brasil. Las secciones transversales y paradérmicas en los órganos fueron obtenidas a mano libre, con ayuda de lámina de acero, doblemente coloreadas y montadas en láminas histológicas. El material fresco fue sometido a pruebas histoquímicas y fitoquímicas para detección de saponinas, taninos, alcaloides, flavonoides, glucósidos cardiotónicos, antraquinonas, esteroides y terpenos. A. macrocarpon presenta tricomas glandulares, células secretoras y cavidades. Detectamos la presencia de taninos, flavonoides, compuestos fenólicos, glucósidos cardiotónicos y alcaloides, que pueden conferir a esta especie actividad antiplasmódica y propiedades antivirales. El presente estudio fue el primero en identificar aspectos de la composición histoquímica y fitoquímica de ramas jóvenes y hojas de A. macrocarpon que pueden estar asociados al uso popular de esa planta para el tratamiento de la malaria y del dengue en una región de transición entre los biomas Cerrado y Amazonia, donde la malaria y el dengue ocurren endémicamente.

ABSTRACT Studies on native medicinal plants strengthen initiatives to preserve the environments where those species naturally occur, many of them already strongly menaced even before their potential to humankind is known. Root and stem barks, leaves, and pericarps samples of Solanum agrarium Sendtn., S. lycocarpum A. St.-Hil., S. palinacanthum Dunal, S. paniculatum L., and S. stipulaceum Roem. & Schult., species that occur in the Cerrado (Brazililan savanna) were processed according to common light microscopy techniques for structural analysis, and histochemical tests were performed to locate and identify classes of chemical compounds. The distinctive features identified were low concentration of crystal sand in the root and stem, presence of terpene resin in the root, and absence of hypodermis in the leaf, in S. agrarium; bright spots (group of sclereids) in the root, isobilateral mesophyll, thickened cell walls with hemicelluloses and strong aroma in the fruit, in S. lycocarpum; high concentration of crystal sand in the root and stem, oval-shaped limb, presence of isolated crystals in the exocarp, in S. palinacanthum; strong sclerification and rays with great height in the root and stem, in S. paniculatum; and accumulation of soluble protein in the root and stem, presence of conspicuous membranaceous stipules, absence of spiniform trichomes, in S. stipulaceum. This work identifies distinctive structural features, its ecological importance, and determines the distribution of secondary compounds associated with the medicinal properties reported for these species and contributes to the conservation of the natural environments where they occur.

Tontelea micrantha (Mart. Ex. Schult.) A. C. Sm. é uma espécie nativa do Cerrado brasileiro cuja casca do caule subterrâneo é utilizada como medicinal no tratamento de doenças renais. As estruturas dos caules subterrâneo e aéreo foram estudadas e suas cascas avaliadas para a presença de classes de metabólitos secundários. Fragmentos das cascas foram processados de acordo com metodologias usuais em anatomia vegetal e submetidos às análises fitoquímicas colorimétricas, cromatografia em camada delgada e identificação química por cromatografia líquida de alta eficiência. O caule subterrâneo é um sóbole e apresenta atividade cambial não usual. Laticíferos que secretam terpenóides estavam presentes no córtex e floema de ambos os órgãos e podem contribuir para a identificação da espécie no campo. Drusas estão presentes em ambas as cascas, mas mono-cristais são observados apenas no sóbole. Taninos, flavonóides, alcalóides e terpenóides ocorrem em ambas as cascas, mas carotenóides são detectados apenas no sóbole. As semelhanças entre estes dois órgãos indicam que a casca do caule aéreo tem potencial para uso medicinal, representando uma alternativa plausível para o uso do sóbole, o que pode contribuir para a preservação de populações naturais da espécie.

The bark of the underground stem of Tontelea micrantha (Mart. ex. Schult.) A. C. Sm., a native Brazilian Cerrado species, is used in folk medicine for treating kidney ailments. The structures of the underground and the aerial stems were examined and their barks were analyzed for the presence of secondary metabolites. Bark fragments were processed according to conventional techniques in plant anatomy and their chemical compositions examined using histochemical and phytochemical tests, thin layer chromatography, and high-efficiency liquid chromatography. The underground stem is a sobol with unusual cambial activity. Laticifers that secrete terpenoids were present in the cortex and phloem of both organs and can contribute to the identification of the species in field. Druses were present in both barks, but mono-crystals were only observed in the sobol. Tannins, flavonoids, alkaloids, and terpenoids occurred in both types of bark, but carotenoids were only detected in the sobol. The similarities between these two organs indicate that the aerial stem bark has potential medicinal use and represents a plausible alternative to harvesting the sobol, which could contribute to the preservation of natural populations of this species.

Testes in vitro realizados com extratos ricos em taninos têm identificado muitas atividades biológicas dessa classe de substâncias. Nesse contexto, esse artigo propõe a avaliação da atividade antibacteriana de frações tânicas, obtidas de extratos de folhas de Anacardium humile A.St.-Hil. Extratos de A. humile em acetona 70% foram particionados com acetato de etila e butanol. Foram quantificados taninos totais das frações particionadas, do extrato bruto e dos resíduos aquosos, e foi realizado teste de atividade antibacteriana dos taninos contra Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 e Enterococcus faecalis ATCC 29212. Todos os extratos positivos foram submetidos ao isolamento de taninos, utilizando-se coluna de Sephadex LH-20. Os taninos isolados das amostras foram quantificados e testados sua concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os taninos do extrato bruto, partições e resíduos apresentaram inibição do crescimento de S.aureus com CIM =500 g mL-1. As frações tânicas apresentaram CIM contra todas as cepas e CBM, exceto contra E. faecalis. As frações tânicas de Anacardium humile possuem atividade antibacteriana contra Staphylococcus aureus, Pseudomononas aeruginosa e Enterococcus faecalis e, portanto, podem ser promissoras em sínteses futuras de novos agentes antimicrobianos.

In vitro tests conducted with extracts rich in tannins have identified several biological activities of this class of substance. Thus, this paper intends to evaluate the antibacterial activity of tannin-rich fraction obtained from leaf extracts of Anacardium humile A.St.-Hil. Extracts of A. humile leaves in 70% acetone were semi-purified with ethyl acetate and butanol. We quantified the total tannins of the semi-purified fractions, of the crude extract and of aqueous residues and then performed tests of the antibacterial activity of the tannins against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. All positive extracts underwent tannin isolation using a Sephadex LH-20 column. The tannins isolated from the samples were quantified and tested for the minimal inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). The tannins from crude extracts, semi-purifications and residues showed inhibition of S. aureus growth with MIC=500 g mL-1. All tannin fractions showed MIC against all strains and MBC, except against E. faecalis. The tannin fractions from Anacardium humile have antibacterial activity against Staphylococcus aureus, Pseudomononas aeruginosa and Enterococcus faecalis and, therefore, may be promising for future synthesis of new antibacterial agents.