Constitutive nitric oxide synthase-like enzyme in two species involved in cutaneous and mucocutaneous leishmaniasis.

Leishmania is an obligate intracellular parasite that primarily inhabits macrophages. The destruction of the parasite in the host cell is a fundamental mechanism for infection control. In addition, inhibition of the leishmanicidal activity of macrophages seems to be related to the ability of some species to inhibit the production of nitric oxide (NO) by depleting arginine. Some species of Leishmania have the ability to produce NO from a constitutive nitric oxide synthase-like enzyme (cNOS-like). However, the localization of cNOS-like in Leishmania has not been described before. As such, this study was designed to locate cNOS-like enzyme and NO production in promastigotes of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis. NO production was initially quantified by flow cytometry, which indicated a significant difference in NO production between L. (L.) amazonensis (GMFC = 92.17 +/- 4.6) and L. (V.) braziliensis (GMFC = 18.89 +/- 2.29) (P < 0.05). Analysis of cNOS expression by immunoblotting showed more expression in L. (L.) amazonensis versus L. (V.) braziliensis. Subsequently, cNOS-like immunolabeling was observed in promastigotes in regions near vesicles, the flagellar pocket and mitochondria, and small clusters of particles appeared to be fusing with vesicles suggestive of glycosomes, peroxisome-like-organelles that compartmentalize the glycolytic pathway in trypanosomatid parasites. In addition, confocal microscopy analysis demonstrated colocalization of cNOS-like and GAPDH, a specific marker for glycosomes. Thus, L. (L.) amazonensis produces greater amounts of NO than L. (V.) braziliensis, and both species present the cNOS-like enzyme inside glycosomes.

Causes of mortality of seabirds stranded at the Northeastern coast of Brazil / Causas de mortalidade de aves marinhas encalhadas na costa do Nordeste do Brasil

The aim of this work was to determine the main species of stranded seabirds at the Northeastern coast of Brazil in addition to the most frequent causes of stranding and mortality. The study was conducted in a monitored area for three years (2012-2014), from the coastline of south Alagoas through north coast of Bahia encompassing 254km of coast. The seabirds found alive during the monitoring were sent to rehabilitation, clinically examined and the carcasses were removed, necropsied and histopathologically analyzed. A total of 1.347 seabirds were found stranded. Of these, 378 were found alive and sent to rehabilitation. From the 969 dead seabirds 806 were unsuitable for necropsy, being only 163 submitted to necropsy and histopathological analysis. Calonectris borealis, Puffinus gravis and Puffinus puffinus were the main seabirds stranded in the studied area. Most stranding occurred from March to June with an increase during April and May for the most species of seabirds. The main clinical signs of stranded seabirds consisted of inappetence, apathy, low body score, hypothermia, flying or movement difficulty and prolonged recumbency. Natural causes followed by infectious diseases and anthropogenic environmental factors were the main causes of death of seabirds stranded on the Northeastern coast of Brazil.(AU)

O objetivo deste trabalho foi determinar as principais espécies de aves marinhas encalhadas na costa do Nordeste do Brasil, bem como as mais frequentes causas de encalhe e mortalidade. O estudo foi desenvolvido em área monitorada durante três anos (2012-2014), entre o litoral sul de Alagoas e o litoral norte da Bahia, perfazendo um total de 254km de extensão da costa. As aves encontradas vivas foram encaminhadas para reabilitação e examinadas clinicamente; as carcaças foram removidas, necropsiadas e os órgãos foram analisados por meio da histopatologia. Um total de 1.347 aves foi encontrado, encalhadas. Dessas, 378 estavam vivas e foram encaminhadas para a reabilitação. Das 969 aves marinhas mortas, 806 estavam impróprias para realização de necropsia, sendo apenas 163 submetidas à necropsia e análise histopatológica. Calonectris borealis, Puffinus gravis e Puffinus puffinus foram as principais espécies encontradas na área estudada. A maioria dos encalhes para grande parte das aves marinhas ocorreram de março a junho, com um aumento durante abril e maio. Os principais sinais clínicos das aves marinhas consistiram em inapetência, apatia, baixo escore corporal, hipotermia, dificuldade de voo ou movimento e decúbito prolongado. Causas naturais, seguidas de doenças infecciosas e fatores antropogênicos, foram as principais causas de mortes de aves marinhas encalhadas na costa do Nordeste do Brasil.(AU)

Why are some cyano-based ionic liquids better glucose solvents than water?

Among different classes of ionic liquids (ILs), those with cyano-based anions have been of special interest due to their low viscosity and enhanced solvation ability for a large variety of compounds. Experimental results from this work reveal that the solubility of glucose in some of these ionic liquids may be higher than in water - a well-known solvent with enhanced capacity to dissolve mono- and disaccharides. This raises questions on the ability of cyano groups to establish strong hydrogen bonds with carbohydrates and on the optimal number of cyano groups at the IL anion that maximizes the solubility of glucose. In addition to experimental solubility data, these questions are addressed in this study using a combination of density functional theory (DFT) and molecular dynamics (MD) simulations. Through the calculation of the number of hydrogen bonds, coordination numbers, energies of interaction and radial and spatial distribution functions, it was possible to explain the experimental results and to show that the ability to favorably interact with glucose is driven by the polarity of each IL anion, with the optimal anion being dicyanamide.

Leishmanicidal Activity of (+)-Phyllanthidine and the Phytochemical Profile of Margaritaria nobilis (Phyllanthaceae).

The effects of the Securinega alkaloid (+)-phyllanthidine on Leishmania (L.) amazonensis and the first chemical investigation of Margaritaria nobilis L.f. (Phyllanthaceae) are described. Treating the parasites with this alkaloid caused a dose-dependent reduction in promastigote growth of 67.68% (IC50 82.37 µg/mL or 353 µM) and in amastigote growth of 83.96% (IC50 49.11 µg/mL or 210 µM), together with ultrastructural alterations in the promastigotes. No cytotoxic effect was detected in mammalian cells (CC50 1727.48 µg/mL or CC50 5268 µM). Classical chromatographic techniques and spectral methods led to the isolation and identification of betulinic acid, kaempferol, corilagin, gallic acid and its methyl ester, besides (+)-phyllanthidine from M. nobilis leaves and stems. Margaritaria nobilis is another source of the small group of Securinega alkaloids, together with other Phyllanthaceae (Euphorbiaceae s.l.) species. The low toxicity to macrophages and the effects against promastigotes and amastigotes are suggestive that (+)-phyllanthidine could be a promising antileishmanial agent for treating cutaneous leishmaniasis.

In vitro biological action of aqueous extract from roots of Physalis angulata against Leishmania (Leishmania) amazonensis.

BACKGROUND: Leishmaniasis is an infectious disease caused by various species of the protozoan parasites of the Leishmania genus and transmitted by phlebotomine sandflies. The protozoa multiply in phagocytic cells, mainly macrophages, which play an important role defending the organism from pathogens. The most effective treatment for leishmaniasis is the chemotherapy and besides the high cost, these drugs are toxic and require a long period of treatment. Currently, some herbal products are considered an important alternative source of a new leishmanicidal agent, which includes the plant Physalis angulata, . We evaluated effects of an aqueous extract from roots of Physalis angulata (AEPa) on Leishmania proliferation, morphology and also determined whether physalins were present in the extract contributing to the knowledge of its pharmacological efficacy. METHODS: Morphological alterations were determined by light microscopy, transmission and scanning electron microscopy. Host cell viability was evaluated by MTT, and propidium iodide. AEPa were submitted in full HRESITOF analysis. RESULTS: AEPa promoted a dose-dependent reduction on promastigotes (IC50 = 39.5 µg/mL ± 5.1) and amastigotes (IC50 = 43.4 µg/mL ± 10.1) growth. This growth inhibition was associated with several morphological alterations observed in promastigote forms. No cytotoxic effect in mammalian cells was detected (IC50 > 4000 µg/mL). Furthemore, the presence of physalins A, B, D, E, F, G and H were described, for the first time, in the P. angulata root. CONCLUSIONS: Results demonstrate that AEPa effectively promotes antileishmanial activity with several important morphological alterations and has no cytotoxic effects on host cells.