BACKGROUND/OBJECTIVES Human leishmaniases are parasitic diseases causing severe morbidity and mortality. No vaccine is available and numerous factors limit the use of current therapies. There is thus an urgent need for innovative initiatives to identify new chemotypes displaying selective activity against intracellular Leishmania amastigotes that develop and proliferate inside macrophages, ther...

The standard treatment of human visceral leishmaniasis involves the use of pentavalent antimony (Sb(V)). Its mechanism of action is unknown because of the limited information available about intracellular antimony metabolism and about the genes that regulate these processes. Herein, flow injection-inductively coupled plasma mass spectrometry (ICP-MS), flow injection hydride generation ICP-MS, a...

Formycin B is metabolized by cutaneous Leishmania amastigotes within cultured human macrophages to give formycin B 5'-monophosphate and formycin A 5'-mono-, di-, and triphosphates. Formycin A is also incorporated into RNA. The activity of formycin B against amastigotes was correlated with the levels of formycin A metabolites formed in the parasites. Uninfected macrophages also convert formycin ...

Leishmaniasis is one of the world's most neglected diseases, largely affecting the poorest of the poor, mainly in developing countries. Over 350 million people are considered at risk of contracting leishmaniasis, and approximately 2 million new cases occur yearly(1). Leishmania donovani is the causative agent for visceral leishmaniasis (VL), the most fatal form of the disease. The choice of dru...

The intracellular amastigote form of leishmania is responsible for the cell-to-cell spread of leishmania infection in the mammalian host. In this report, we identify a high-affinity, heparin-binding activity on the surface of the amastigote form of leishmania. Amastigotes of Leishmania amazonensis bound approximately 120,000 molecules of heparin per cell, with a Kd of 8.8 x 10(-8) M. This hepar...

the onset of infections by leishmania parasites mainly caused by amastigote growth inside the macrophages. one of the important properties of lesion-derived amastigote is thought to be the attachment of various host proteins including immunoglobulins on the surface of amastigote. in this study, the presence of immunoglobulins on the surface of lesion-derived amastigotes was detected by western ...

This study evaluated the anti-Leishmania amazonensis activity of a lipophilic extract from the brown alga Stypopodium zonale and atomaric acid, its major compound. Our initial results revealed high inhibitory activity for intracellular amastigotes in a dose-dependent manner and an IC50 of 0.27 μg/mL. Due to its high anti-Leishmania activity and low toxicity toward host cells, we fractionated th...

The cytotoxicity of 18 new 1,2,6-thiadiazin-3,5-dione 1,1-dioxides was evaluated. This group of products was previously assayed against epimastigotes of Trypanosoma cruzi and some of them showed a high antiprotozoal activity. Thereafter 13 compounds with a high anti-epimastigote activity and low cytotoxicity were selected to be assayed against amastigotes. Some of the products showed the same o...

The onset of infections by Leishmania parasites mainly caused by amastigote growth inside the macrophages. One of the important properties of lesion-derived amastigote is thought to be the attachment of various host proteins including immunoglobulins on the surface of amastigote. In this study, the presence of immunoglobulins on the surface of lesion-derived amastigotes was detected by Western ...