scholarly journals Effect of DODAB Nano-Sized Cationic Bilayer Fragments against Leishmania amazonensis

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5741
Author(s):  
Thalita C. S. Ferreira ◽  
Ismael P. Sauter ◽  
Lina Borda-Samper ◽  
Enyd Bentivoglio ◽  
Jarina P. DaMata ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Control Strategies ◽  
Cationic Lipid ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Plasma Membrane Permeability ◽  
Life Cycle Stages ◽  
Bacteria And Fungi ◽  
Reported Data ◽  
Median Effective Concentration

The dioctadecyldimethylammonium bromide (DODAB) is a double-chained cationic lipid with potent bactericide and fungistatic activities; however, its toxicity on protozoan parasites is still unknown. Here, we show the antileishmanial activity of DODAB nano-sized cationic bilayer fragments on stationary-phase promastigotes and amastigotes of Leishmania amazonensis, the causative agent of cutaneous leishmaniasis. Upon treatment with DODAB, we analyzed the parasite surface zeta-potential, parasite viability, cellular structural modifications, and intracellular proliferation. The DODAB cytotoxic effect was dose-dependent, with a median effective concentration (EC50) of 25 µM for both life-cycle stages, comparable to the reported data for bacteria and fungi. The treatment with DODAB changed the membrane zeta-potential from negative to positive, compromised the parasite’s morphology, affected the cell size regulation, caused a loss of intracellular organelles, and probably dysregulated the plasma membrane permeability without membrane disruption. Moreover, the parasites that survived after treatment induced small parasitophorous vacuoles and failed to proliferate inside macrophages. In conclusion, DODAB displayed antileishmanial activity, and it remains to be elucidated how DODAB acts on the protozoan membrane. Understanding this mechanism can provide insights into the development of new parasite-control strategies.

Selective in vitro antileishmanial activity of Mimosa caesalpiniifolia stem barks and its main constituent betulinic acid against Leishmania amazonensis

2021 ◽  
Vol 140 ◽  
pp. 68-75
Author(s):  
Lucas Moreira Brito ◽  
Michel Muálem de Moraes Alves ◽  
Adriana Cunha Souza ◽  
Thaynara Parente de Carvalho ◽  
José Henrique Furtado Campos ◽  
...  
Keyword(s):  
Betulinic Acid ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Main Constituent

scholarly journals Antileishmanial activity and mechanism of action from a purified fraction of Zingiber officinalis Roscoe against Leishmania amazonensis

2016 ◽  
Vol 166 ◽  
pp. 21-28 ◽  
Author(s):  
Mariana C. Duarte ◽  
Grasiele S.V. Tavares ◽  
Diogo G. Valadares ◽  
Daniela P. Lage ◽  
Tatiana G. Ribeiro ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity

Quantitative Risk Assessment of Listeriosis-Associated Deaths Due to Listeria monocytogenes Contamination of Deli Meats Originating from Manufacture and Retail

2010 ◽  
Vol 73 (4) ◽  
pp. 620-630 ◽  
Author(s):  
ABANI K. PRADHAN ◽  
RENATA IVANEK ◽  
YRJÖ T. GRÖHN ◽  
ROBERT BUKOWSKI ◽  
IFIGENIA GEORNARAS ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Listeria Monocytogenes ◽  
Relative Risk ◽  
Storage Temperature ◽  
Control Strategies ◽  
Quantitative Risk Assessment ◽  
Sensitivity Analyses ◽  
Effective Control ◽  
Lag Phase ◽  
Reported Data

The objective of this study was to estimate the relative risk of listeriosis-associated deaths attributable to Listeria monocytogenes contamination in ham and turkey formulated without and with growth inhibitors (GIs). Two contamination scenarios were investigated: (i) prepackaged deli meats with contamination originating solely from manufacture at a frequency of 0.4% (based on reported data) and (ii) retail-sliced deli meats with contamination originating solely from retail at a frequency of 2.3% (based on reported data). Using a manufacture-to-consumption risk assessment with product-specific growth kinetic parameters (i.e., lag phase and exponential growth rate), reformulation with GIs was estimated to reduce human listeriosis deaths linked to ham and turkey by 2.8- and 9-fold, respectively, when contamination originated at manufacture and by 1.9- and 2.8-fold, respectively, for products contaminated at retail. Contamination originating at retail was estimated to account for 76 and 63% of listeriosis deaths caused by ham and turkey, respectively, when all products were formulated without GIs and for 83 and 84% of listeriosis deaths caused by ham and turkey, respectively, when all products were formulated with GIs. Sensitivity analyses indicated that storage temperature was the most important factor affecting the estimation of per annum relative risk. Scenario analyses suggested that reducing storage temperature in home refrigerators to consistently below 7°C would greatly reduce the risk of human listeriosis deaths, whereas reducing storage time appeared to be less effective. Overall, our data indicate a critical need for further development and implementation of effective control strategies to reduce L. monocytogenes contamination at the retail level.

scholarly journals In vitro antileishmanial activity of Anacardium othonianum and isolated compounds against Leishmania amazonensis

2021 ◽  
Vol 5 (1) ◽  
pp. 44
Author(s):  
Tavane Aparecida Alvarenga ◽  
Osvaine Júnior Alvarenga Alves ◽  
Mariana Cintra Pagotti ◽  
Wilson Roberto Cunha ◽  
Márcio Luís Andrade e Silva ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Anacardic Acid ◽  
Array Detector ◽  
Preparative Hplc ◽  
Moderate Activity ◽  
Phytochemical Study ◽  
Phenol Derivatives

This study analyzes the antileishmanial activity of the crude ethanol extract, fractions, and isolated compounds of A. othonianum nuts. Antileishmanial activity was evaluated against Leishmania amazonensis promastigotes in vitro. The phytochemical study was performed by high-performance liquid chromatography-high-resolution mass spectrometry-diode array detector (HPLC-HRMS-DAD) and by preparative HPLC. HPLC-HRMS-DAD analysis of the bioactive extract confirmed the presence of ten alkyl phenol derivatives that had previously been isolated from A. occidentale. Bioassay-guided isolation afforded cardanol triene, cardanol diene, cardanol monoene, cardol triene, anacardic acid triene, anacardic acid diene, and anacardic acid monoene. Cardol triene gave an IC50 of 80.66 µM. The obtained data suggest that the evaluated extract, fractions, and cardol triene had moderate activity against L. amazonensis promastigotes. This is the first description of alkyl phenols in A. othonianum.

Antileishmanial activity of verbascoside: Selective arginase inhibition of intracellular amastigotes of Leishmania (Leishmania) amazonensis with resistance induced by LPS plus IFN-γ

2017 ◽  
Vol 127 ◽  
pp. 28-33 ◽  
Author(s):  
Claudia do Carmo Maquiaveli ◽  
Arina Lázaro Rochetti ◽  
Heidge Fukumasu ◽  
Paulo Cezar Vieira ◽  
Edson Roberto da Silva
Keyword(s):  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Intracellular Amastigotes ◽  
Ifn Γ

scholarly journals Antileishmanial activity of Melampodium divaricatum and Casearia sylvestris essential oils on Leishmania amazonensis

2019 ◽  
Vol 61 ◽  
Author(s):  
Raquel Regina Duarte Moreira ◽  
André Gonzaga dos Santos ◽  
Flavio Alexandre Carvalho ◽  
Caio Humberto Perego ◽  
Eduardo José Crevelin ◽  
...  
Keyword(s):  
Essential Oils ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Casearia Sylvestris

scholarly journals Multi-center screening of the Pathogen Box collection for schistosomiasis drug discovery

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Martina Maccesi ◽  
Pedro H. N. Aguiar ◽  
Valérian Pasche ◽  
Melody Padilla ◽  
Brian M. Suzuki ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Control Strategies ◽  
Current Treatment ◽  
New Drugs ◽  
Core Set ◽  
The Usa ◽  
Reported Data ◽  
Differential Ability ◽  
The University ◽  
And Control

Abstract Background Over the past five years, as a public service to encourage and accelerate drug discovery for diseases of poverty, the Medicines for Malaria Venture (MMV) has released box sets of 400 compounds named the Malaria, Pathogen and Stasis Boxes. Here, we screened the Pathogen Box against the post-infective larvae (schistosomula) of Schistosoma mansoni using assays particular to the three contributing institutions, namely, the University of California San Diego (UCSD) in the USA, the Swiss Tropical and Public Health Institute (Swiss TPH) in Switzerland, and the Fundação Oswaldo Cruz (FIOCRUZ) in Brazil. With the same set of compounds, the goal was to determine the degree of inter-assay variability and identify a core set of active compounds common to all three assays. New drugs for schistosomiasis would be welcome given that current treatment and control strategies rely on chemotherapy with just one drug, praziquantel. Methods Both the UCSD and Swiss TPH assays utilize daily observational scoring methodologies over 72 h, whereas the FIOCRUZ assay employs XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide) at 72 h to measure viability as a function of NAD+/NADH redox state. Raw and transformed data arising from each assay were assembled for comparative analysis. Results For the UCSD and Swiss TPH assays, there was strong concordance of at least 87% in identifying active and inactive compounds on one or more of the three days. When all three assays were compared at 72 h, concordance remained a robust 74%. Further, robust Pearsonʼs correlations (0.48–0.68) were measured between the assays. Of those actives at 72 h, the UCSD, Swiss TPH and FIOCRUZ assays identified 86, 103 and 66 compounds, respectively, of which 35 were common. Assay idiosyncrasies included the identification of unique compounds, the differential ability to identify known antischistosomal compounds and the concept that compounds of interest might include those that increase metabolic activity above baseline. Conclusions The inter-assay data generated were in good agreement, including with previously reported data. A common set of antischistosomal molecules for further exploration has been identified.

scholarly journals Acyclic Sesquiterpenes from the Fruit Pericarp of Sapindus saponaria Induce Ultrastructural Alterations and Cell Death in Leishmania amazonensis

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Amanda Louzano Moreira ◽  
Débora Botura Scariot ◽  
Bruna Luíza Pelegrini ◽  
Greisiele Lorena Pessini ◽  
Tânia Ueda-Nakamura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Flow Cytometry ◽  
Hemolytic Activity ◽  
Solid Phase ◽  
Reversed Phase ◽  
Leishmania Amazonensis ◽  
Antileishmanial Activity ◽  
Ultrastructural Changes ◽  
Phosphatidylserine Exposure ◽  
Sapindus Saponaria

Previous studies reported antiprotozoal activities of Sapindus saponaria L. The aim of this work was the evaluation of antileishmanial activity and mechanism of action of extract and fractions of S. saponaria L. Hydroethanolic extract (EHA) obtained from fruit pericarps was fractionated using solid-phase extraction in a reversed phase, resulting in fractions enriched with saponins (SAP fraction) and acyclic sesquiterpene oligoglycosides (OGSA fraction). The activities of EHA, SAP, and OGSA were evaluated by antiproliferative assays with promastigote and intracellular amastigote forms. Cytotoxicity on macrophages and hemolytic activity were also analyzed. Morphological and ultrastructural changes in Leishmania amazonensis promastigotes were evaluated by electron microscopy. Flow cytometry was used to investigate mitochondrial dysfunction and phosphatidylserine exposure. OGSA was more selective for parasites than mammalian J774A1 macrophage cells, with selectivity indices of 3.79 and 7.35, respectively. Our results showed that only the OGSA fraction did not present hemolytic activity at its IC50 for promastigote growth. Electron microscopy revealed changes in parasite flagellum, cell body shape, and organelle size, mainly mitochondria. Flow cytometry analysis indicated mitochondrial membrane and cell membrane dysfunction. OGSA showed antileishmanial activity, resulting in several changes to protozoa cells, including mitochondrial depolarization and early phosphatidylserine exposure, suggesting a possible apoptotic induction.

scholarly journals Laboratory Measurements of Zeta Potential in Fractured Lewisian Gneiss: Implications for the Characterization of Flow in Fractured Crystalline Bedrock

2021 ◽  
Vol 12 (1) ◽  
pp. 180
Author(s):  
Jan Vinogradov ◽  
Miftah Hidayat ◽  
Yogendra Kumar ◽  
David Healy ◽  
Jean-Christophe Comte
Keyword(s):  
Zeta Potential ◽  
Fracture Aperture ◽  
X Ray Diffraction ◽  
Crystalline Bedrock ◽  
Confining Pressures ◽  
Basement Aquifers ◽  
Complex Solutions ◽  
Reported Data ◽  
The Impact

Despite the broad range of interest and possible applications, the controls on the electric surface charge and the zeta potential of gneiss at conditions relevant to naturally fractured systems remain unreported. There are no published zeta potential measurements conducted in such systems at equilibrium, hence, the effects of composition, concentration and pressure remain unknown. This study reports zeta potential values for the first time measured in a fractured Lewisian gneiss sample saturated with NaCl solutions of various concentrations, artificial seawater and artificial groundwater solutions under equilibrium conditions at confining pressures of 4 MPa and 7 MPa. The constituent minerals of the sample were identified using X-ray diffraction and linked to the concentration and composition dependence of the zeta potential. The results reported in this study demonstrate that the zeta potential remained negative for all tested solutions and concentrations. However, the values of the zeta potential of our Lewisian gneiss sample were found to be unique and dissimilar to pure minerals such as quartz, calcite, mica or feldspar. Moreover, the measured zeta potentials were smaller in magnitude in the experiments with artificial complex solutions compared with those measured with NaCl, thus suggesting that divalent ions (Ca2+, Mg2+ and SO42−) acted as potential determining ions. The zeta potential was also found to be independent of salinity in the NaCl experiments, which is unusual for most reported data. We also investigated the impact of fracture aperture on the electrokinetic response and found that surface electrical conductivity remained negligibly small across the range of the tested confining pressures. Our novel results are an essential first step for interpreting field self-potential (SP) signals and facilitate a way forward for characterization of water flow through fractured basement aquifers.

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