Use of an enzymatic micromethod to quantify amastigote stage of Leishmania amazonensis in vitro

1997 ◽  
Vol 83 (4) ◽  
pp. 401-403 ◽  
Author(s):  
Denis Sereno ◽  
Jean-Loup Lemesre
Keyword(s):  
Leishmania Amazonensis ◽  
Amastigote Stage ◽  
Enzymatic Micromethod

scholarly journals Activity of Cuban Plants Extracts against Leishmania amazonensis

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Marley García ◽  
Lianet Monzote ◽  
Ramón Scull ◽  
Pedro Herrera
Keyword(s):  
Leishmania Amazonensis ◽  
Major Health Problem ◽  
Major Health ◽  
Amastigote Stage ◽  
Bambusa Vulgaris ◽  
Hura Crepitans ◽  
Simarouba Glauca ◽  
Drug Leads ◽  
Important Drug

Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a major health problem worldwide that affects millions of people especially in the developing nations. There is no immunoprophylaxis (vaccination) available for Leishmania infections, and conventional treatments are unsatisfactory; therefore, antileishmanial drugs are urgently needed. In this work, 48 alcoholic extracts from 46 Cuban plants were evaluated by an in vitro bioassay against Leishmania amazonensis. Furthermore, their toxicity was assayed against murine macrophage. The three most potent extracts against the amastigote stage of Leishmania amazonensis were from Hura crepitans, Bambusa vulgaris, and Simarouba glauca.

scholarly journals Leishmanicidal Activity of Betulin Derivatives in Leishmania amazonensis; Effect on Plasma and Mitochondrial Membrane Potential, and Macrophage Nitric Oxide and Superoxide Production

2021 ◽  
Vol 9 (2) ◽  
pp. 320
Author(s):  
Wilmer Alcazar ◽  
Sami Alakurtti ◽  
Maritza Padrón-Nieves ◽  
Maija Liisa Tuononen ◽  
Noris Rodríguez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Leishmania Amazonensis ◽  
Superoxide Production ◽  
In Vitro Susceptibility ◽  
Intracellular Parasites ◽  
Betulin Derivatives

Herein, we evaluated in vitro the anti-leishmanial activity of betulin derivatives in Venezuelan isolates of Leishmania amazonensis, isolated from patients with therapeutic failure. Methods: We analyzed promastigote in vitro susceptibility as well as the cytotoxicity and selectivity of the evaluated compounds. Additionally, the activity of selected compounds was determined in intracellular amastigotes. Finally, to gain hints on their potential mechanism of action, the effect of the most promising compounds on plasma and mitochondrial membrane potential, and nitric oxide and superoxide production by infected macrophages was determined. Results: From the tested 28 compounds, those numbered 18 and 22 were chosen for additional studies. Both 18 and 22 were active (GI50 ≤ 2 µM, cytotoxic CC50 > 45 µM, SI > 20) for the reference strain LTB0016 and for patient isolates. The results suggest that 18 significantly depolarized the plasma membrane potential (p < 0.05) and the mitochondrial membrane potential (p < 0.05) when compared to untreated cells. Although neither 18 nor 22 induced nitric oxide production in infected macrophages, 18 induced superoxide production in infected macrophages. Conclusion: Our results suggest that due to their efficacy and selectivity against intracellular parasites and the potential mechanisms underlying their leishmanicidal effect, the compounds 18 and 22 could be used as tools for designing new chemotherapies against leishmaniasis.

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 Episomal Expression of Specific Sense and Antisense mRNAs in Leishmania amazonensis: Modulation of gp63 Level in Promastigotes and Their Infection of Macrophages In Vitro

2000 ◽  
Vol 68 (1) ◽  
pp. 80-86 ◽  
Author(s):  
De-Qiao Chen ◽  
Bala Krishna Kolli ◽  
Nagendra Yadava ◽  
Hong Gang Lu ◽  
Alice Gilman-Sachs ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
Single Copy ◽  
Antisense Transcription ◽  
Leishmania Amazonensis ◽  
Surface Glycoprotein ◽  
Major Surface Glycoprotein ◽  
Wild Type Clone ◽  
Major Surface ◽  
Specific Sense

ABSTRACT The major surface glycoprotein (gp63) of Leishmania amazonensis is a metalloprotease implicated in the infection of mammalian macrophages. The expression of gp63 and its participation in this infection were further examined by modulating the level of this molecule in a virulent gp63-abundant wild-type clone. Promastigotes were transfected with gp63 genes cloned into aLeishmania-specific vector in two different orientations, leading to the expression of gp63 sense and antisense RNAs. With increasing selective pressure, cell surface gp63 was increasingly augmented in the transfectants with sense transcripts and suppressed to a very low level in those with antisense transcripts. Thus, the expression of gp63 from chromosomal, repetitive genes is not stringently regulated at the protein level and can be substantially reduced by episomal antisense transcription of a single copy. The transfectants differed significantly only in the level of gp63, thereby allowing specific evaluation of this molecule in leishmanial infection of macrophages in vitro. Kinetic studies of infection in vitro indicate that gp63 plays a role not only in the binding of this parasite to these macrophages but also in its intramacrophage survival and replication.

scholarly journals In vitro activity evaluation of seven Brazilian Asteraceae against cancer cells and Leishmania amazonensis

2019 ◽  
Vol 121 ◽  
pp. 267-273 ◽  
Author(s):  
Ana Cláudia Nogueira da Silva ◽  
Renato Malveira Carreiro do Nascimento ◽  
Débora Caroline do Nascimento Rodrigues ◽  
Paulo Michel Pinheiro Ferreira ◽  
Cláudia Pessoa ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Leishmania Amazonensis ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Activity Evaluation

scholarly journals The toxic effect of Vu-Defr, a defensin from Vigna unguiculata seeds, on Leishmania amazonensis is associated with reactive oxygen species production, mitochondrial dysfunction, and plasma membrane perturbation

2018 ◽  
Vol 64 (7) ◽  
pp. 455-464 ◽  
Author(s):  
Géssika Silva Souza ◽  
Lais Pessanha de Carvalho ◽  
Edésio José Tenório de Melo ◽  
Valdirene Moreira Gomes ◽  
André de Oliveira Carvalho
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Membrane ◽  
Biological Activities ◽  
Reactive Oxygen ◽  
Leishmania Amazonensis ◽  
New Drugs ◽  
Oxygen Species ◽  
Membrane Perturbation ◽  
Plant Defensins

Plant defensins are plant antimicrobial peptides that present diverse biological activities in vitro, including the elimination of Leishmania amazonensis. Plant defensins are considered promising candidates for the development of new drugs. This protozoan genus has great epidemiological importance and the mechanism behind the protozoan death by defensins is unknown, thus, we chose L. amazonensis for this study. The aim of the work was to analyze the possible toxic mechanisms of Vu-Defr against L. amazonensis. For analyses, the antimicrobial assay was repeated as previously described, and after 24 h, an aliquot of the culture was tested for viability, membrane perturbation, mitochondrial membrane potential, reactive oxygen species (ROS) and nitric oxide (NO) inductions. The results of these analyses indicated that after interaction with L. amazonensis, the Vu-Defr causes elimination of promastigotes from culture, membrane perturbation, mitochondrial membrane collapse, and ROS induction. Our analysis demonstrated that NO is not produced after Vu-Defr and L. amazonensis interaction. In conclusion, our work strives to help to fill the gap relating to effects caused by plant defensins on protozoan and thus better understand the mechanism of action of this peptide against L. amazonensis.

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