In rivers, sediments act as sinks for retaining contaminants. This study evaluated the influence of sediment humic substances (HS) on the bioavailability of metals. The levels of metals in sediments and HS indicated that most are complexed with HS. Characterization of HS showed a high degree of humification. The complexation capacity of HS for metals established the affinity order:Pb2+<Cd2+<Co2+<Ni2+<Cu2+<Zn2+<Mn2+<Fe2+. Chemometric analysis demonstrated a correlation between the structural characteristics of HS and complexation capacity of metals.

Amapá amargo (Parahancornia fasciculata (Poir.) Benoist) produz um látex, que se presume ter propriedades medicinais, pois é usado no tratamento da malária, problemas pulmonares, gastrite, e como um agente de cura. Este estudo teve como objetivo analisar estrutural e histoquimicamente os locais de produção e/ou acumúlo de compostos biologicamente ativos, bem como realizar o doseamento de flavonóides presentes no limbo do amapá amargo. Para a análise estrutural e histoquímica foram utilizados protocolos padrão em anatomia vegetal. Considerando que, para o doseamento de flavonóides utilizou-se a espectrometria de absorção na região ultravioleta-visível. O sistema secretor das folhas de amapá amargo é constituído de idioblastos secretores e laticíferos ramificados. Os testes histoquímicos revelaram diferentes tipos de substâncias químicas nos protoplastos celulares de idioblastos e laticíferos. Propriedades farmacológicas do látex de amapa amargo podem ser atribuídas à dois compostos químicos (flavonoides e alcaloides) encontrados neste estudo, ambos estão presentes em idioblastos e laticíferos.

Bitter amapa (Parahancornia fasciculata (Poir.) Benoist) produces a latex, which is presumed to have medicinal properties, as it is used in the treatment of malaria, lung problems, gastritis, and as healing agent. This study aimed to analyze structural and histochemically the sites of production and/or accumulation of biologically active compounds, as well as to determine the kind of flavonoids present in the leaf blade of bitter amapa. For structural and histochemical analysis we used standard protocols in plant anatomy. Whereas to assay flavonoids we used absorption spectrometry in the ultraviolet-visible region. The secretory system of bitter amapa leaves is constituted of both secretory idioblasts and branched laticifers. Histochemical tests revealed different types of chemical substances in the cell protoplast of idioblasts and laticifers. Pharmacological properties of bitter amapa latex can be attributed to two chemical compounds (flavonoids and alkaloids) found in this study, both of them are present in idioblasts and laticifers.

Introduction: Montrichardia linifera extracts showed high toxicity to Artemia salina, which indicated high biological potential for antitumoral, antibacterial, antifungal activities, and action against Trypanossoma cruzi. Objective: to evaluate the antimalarial potential of the hexane extract from the Montrichardia linifera (Arruda) Schott leaves and to discover its phytochemical profile. Methods: the phytochemical prospection was conducted by the precipitation method whereas the antiplasmodial activity was evaluated in vitro using the W2 Plasmodium falciparum clone. Results: the phytochemical prospection just suggested the presence of steroids. Regarding the antiplasmodial activity after 24 hours at 100 µg/mL concentration, the parasite growth inhibition was 50.5 % but at other concentration ranges, significant inhibition was not observed. At 48 hours, the growth inhibition at 100 µg/mL concentrations was 34.7 %. After 72 hours, hemolysis was observed at 100 µg/mL and 50 µg/mL concentrations, so the percentage determination of the parasites was not possible. Conclusions: the hexane extract obtained from the M. linifera leaves presented with low antimalarial potential and proved to be positive for steroids.

Introducción: los extractos de M. linifera presentaron alta toxicidad para Artemia salina, lo cual sugiere un alto potencial biológico para actividad antitumoral, antibacteriana, antifúngica y actividad contra el Trypanosoma cruzi. Objetivo: evaluar el potencial antimalárico del extracto hexánico obtenido de hojas de Montrichardia linifera (Arruda) Schott y conocer su perfil fitoquímico. Métodos: la prospección fitoquímica se realizó por el método de precipitación y la actividad antiplasmódica fue evaluada in vitro utilizando el clon W2 de Plasmodium falciparum. Resultados: la prospección fitoquímica sugirió solamente la presencia de esteroides. En relación con la actividad antiplasmódica, después de 24 h en la concentración de 100 µg/mL la inhibición del crecimiento parasitario fue de 50,5 % y en las demás no fue observada una inhibición significativa. En 48 h, en la concentración de 100 µg/mL, la inhibición del crecimiento fue de 34,7 %. Después de 72 h las concentraciones de 100 y 50 µg/mL presentaron hemólisis, que imposibilitó la determinación porcentual parasitada. Conclusiones: el extracto hexánico obtenido de las hojas de M. linifera tiene un bajo potencial antimalárico y mostró positivamente esteroides.

Montrichardia linifera é uma planta aquática de amplo uso na medicina tradicional amazônica. Entretanto, muito pouco se conhece sobre a sua composição química, e sua atividade biológica ainda não foi comprovada. Na busca de substância(s) biologicamente ativa(s), este trabalho realizou um estudo fitoquímico biomonitorado no qual foram testados os extratos hexânico e etanólico obtidos do caule desta espécie, dos quais apenas o extrato etanólico foi selecionado para o fracionamento cromatográfico por ter apresentado toxicidade contra a Artemia salina e atividade contra o Plasmodium falciparum, parasita causador da malária. As atividades biológicas concentraram-se na fração diclorometânica que apresentou alta toxicidade contra A. salina (DL50<31μg mL-1) e alta atividade antiplasmódica (IC50<10 μg mL-1), mostrando promissora atividade antimalárica. Desta fração, o composto aromático p-hidroxibenzaldeído foi isolado pela primeira vez nesta planta.

Montrichardia linifera is an aquatic plant widely use in Amazon folkmedicine. However, very little is known about the chemical composition and biological activity. In search of biologically active (s) substance (s) phytochemical bioassay-guided study was conducted evaluating hexane extract and ethanol extract obtained from stems of this species. Since only the ethanol extract presented toxicity against Artemia salina and activity against Plasmodium falciparum, this extract was selected for chromatographic fractionation. The biological activities were concentred in dichloromethane fraction which showed high toxicity against A. saline (LD50< μg mL-1) and high antiplasmodial activity (IC50 <10 μg mL-1), showing promising antimalarial activity. Of this fraction, the aromatic compound p-hydroxybenzaldehyde was isolated for the first time in this plant.

Levels of Ca, Mg, Fe, Zn, Cu and Mn were determinated by FAAS in the tea and dry matter from senescent leaf from Montrichardia linifera, plant used in folk medicine Amazon. The content of these metals that are transferred of the leaf to the infusions have presented significant reductions, however, the Mn values in the infusion may exceed the tolerable daily intake (11 mg) if consumption of this tea is greater than 1.0 L per day. So the tea of senescent leaves of M. linifera may be considered as a toxic beverage and thus its use is not advised.

Montrichardia linifera (Araceae), conhecida popularmente como 'aninga', faz parte dos ecossistemas de várzea da Amazônia e da dieta natural de animais como peixe-boi, tartarugas, peixes, búfalo e gado. Com o objetivo de contribuir para o conhecimento químico e valor nutricional da mesma, folhas e frutos de M. linifera foram coletados às margens dos rios Guamá e Maratauíra, no Estado do Pará, Brasil. Em folhas e frutos foram realizadas análises de umidade, resíduo mineral fixo (cinzas), lipídios, proteínas, fibra bruta, concentração de carboidratos e valor calórico. A composição mineral (Ca, Mg, Cu, Fe, Zn e Mn) foi obtida por espectrometria de absorção atômica de chama. Observou-se que tanto as folhas quanto os frutos da aninga, apesar de calóricos (289,75 kcal e 355,12 kcal, respectivamente), possuem baixo valor protéico (0,44% e 0,24 %, respectivamente). As concentrações de manganês obtidas (folha = 3279,46 mg kg-1e fruto = 18151,53 mg kg-1) foram consideradas tóxicas, extrapolando o limite máximo tolerável para ruminantes (1000 mg kg-1). A M. linifera, tem capacidade de absorver e bioacumular grandes quantidades de Ca, Mg e Mn presentes no solo, o que torna inadequada a sua utilização exclusiva na alimentação de quelônios, bovinos e bubalinos, havendo necessidade de mais estudos para sua aplicação como parte da ração.

The aninga (Montrichardia linifera, Araceae) is often found in the floodplain ecosystems of the Amazon and is the natural diet of animals such as manatees, turtles, fish, buffalo and cattle. Aiming to contribute to the chemical knowledge and nutritional value of this plant, leaves and fruits of M. linifera were collected on the banks of the Guama and Maratauira rivers, Para State, Brazil. We determined the moisture content, ash mineral composition, lipids, protein, fiber, carbohydrate and caloric value of the fruits and leaves. The mineral composition (Ca, Mg, Cu, Fe, Zn and Mn) was obtained by flame atomic absorption spectrometry. The leaves and the fruits of M. linifera had caloric values of 289.75 kcal and 355.12 kcal, respectively; and a low protein concentration, 0.44% for leaves and 0.24% for fruits. Manganese concentrations were 3279.46 mg kg-1 for leaves and 18151.53 mg kg-1 for fruits. These Mn concentrations are considered toxic, as they exceed the maximum tolerable for the ruminants (1000 mg kg-1). The M. linifera has the capacity to absorb and bioaccumulate large amounts of Ca, Mg and Mn in the soil, which makes it inappropriate for exclusive use as food for turtles, cattle and buffaloes, requiring more studies for its application as part of the diet.