Thirteen aminoalcohols and eight diamines were obtained and tested against Trypanosoma cruzi epimastigotes strains MG, JEM and CL-B5 clone. Some of them were equal or more potent (1.0-6.6 times) than the reference compound nifurtimox. From them, three aminoalcohols and two diamines were selected for amastigotes assays. Compound 5 was as potent as the reference drug nifurtimox against amastigote...

Leishmania spp. must attach to mononuclear phagocyte surfaces before entering this host cell. We investigated the potential role of fibronectin in facilitating parasite attachment. Human plasma fibronectin bound to axenically cultured promastigotes, and promastigotes and amastigotes preferentially bound to fibronectin-coated cover slips. Promastigotes grown in the absence of fibronectin were st...

The in vitro susceptibilities of the reference strain Leishmania donovani MHOM/ET/67/L82 to sodium stibogluconate, amphotericin B, miltefosine, and the experimental compound PX-6518 were determined for extracellular log-phase promastigotes, established axenic amastigotes, fresh spleen-derived amastigotes, and intracellular amastigotes in primary mouse peritoneal macrophages. Susceptibility to a...

Leishmaniasis is initiated when sandflies inject the extracellular promastigote form of the parasite into the skin. Promastigotes are rapidly phagocytized, after which they transform into the intracellular amastigote form. The multiplication of the latter within macrophages leads to clinical disease. Treatment of leishmaniasis is primarily with pentavalent antimonials, parenteral and potentiall...

Amastigotes of the protozoan parasite Leishmania proliferate in phagolysosomes of macrophages. They abundantly express glycoinositol phospholipids (GIPLs), which are considered necessary for parasite survival by providing a shield at the surface against lysosomal hydrolases and by serving as receptors for the interaction with host cells. The structures of four GIPLs of L. mexicana amastigotes w...

Leishmaniases are diseases caused by protozoa of the genus Leishmania that affect more than 20 million people in the world. The initial phase of the infection is fundamental for either the progression or control of the disease. The Leishmania parasites are injected in the skin as promastigotes and then, after been phagocytized by the host macrophages, rapidly transform into amastigotes. In this...

This work aims at identifying an effective protocol to raise anti-Leishmania chagasi amastigote antibodies in different animal species. Protocols of immunization by subcutaneous injections of L. chagasi promastigote and amastigote lysates or by either intravenous or subcutaneous inoculation of live metacyclic promastigotes were assessed in mice, rabbits, and dogs. The immunization with live pro...

Leishmania parasites alternate in their life cycle between promastigote stages that develop in the gut of phlebotomine sand flies and amastigotes residing inside phagocytic cells of vertebrate hosts. For experimental infections of sand flies, promastigotes are frequently used as this way of infection is technically easier although ingestion of promastigotes by sand flies is unnatural. Here we a...

Protozoan parasites of Leishmania spp. invade macrophages as promastigotes and differentiate into replicative amastigotes within parasitophorous vacuoles. Infection of inbred strains of mice with Leishmania major is a well-studied model of the mammalian immune response to Leishmania species, but the ultrastructure and biochemical properties of the parasitophorous vacuole occupied by this parasi...

In many tropical areas, infections by Leishmania species are endemic and include visceral leishmaniasis (VL), which is often fatal if untreated. Outside India, VL treatment and control are based on long-term administration of highly toxic pentavalent antimonials. Previously, we described the synthesis and in vitro leishmanicidal activity of a series of nine benzophenone derivatives with low tox...