A critical step in the infectious cycle of Leishmania is the differentiation of parasites within the sand fly vector to the highly infective metacyclic promastigote stage. Here, we establish tetrahydrobiopterin (H4B) levels as an important factor controlling the extent of metacyclogenesis. H4B levels decline substantially during normal development, and genetic or nutritional manipulations showe...

Promastigotes of Leishmania braziliensis panamensis were subjected to a heat shock transformation yielding an amastigote-like stage. During the process of conversion, the heat-induced differentiating form displayed an increase in infectivity (as determined by lesion size) accompanied by a total protein composition unlike that of the promastigote and a morphology resembling that of the amastigot...

The antiprotozoal activity of newly synthesised compounds, all [1,2,4]triazolo [1,5a]pyrimidine derivatives, was tested against the protozoan parasites Trypanosoma cruzi, Leishmania donovani and Phytotmonas staheli. Six of these compounds significantly inhibited in vitro cell growth of the epimastigote forms of T. cruzi, and the promastigote forms of L. donovani and P. staheli. Some of the comp...

Materials and methods: Th e eff ects of HBO on Leishmania tropica promastigote and amastigote forms were studied at a pressure of 2.5 atmosphere absolute (ata). We examined the cytotoxic eff ect of HBO on promastigotes using the trypan blue exclusion test and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye-reduction assay. To investigate the eff ects of HBO treatment ...

The pathway of de novo pyrimidine biosynthesis in the amastigote and Promastigote forms of Leishmania tropica has been investigated.Both parasite forms contained all six enzyme activities. Carbamoyl phosphate synthase (CPSase) utilizes Lglutamine and not ammonia as the amine group donor. Dihydroorotate dehydrogenase (DHO-DHase) was found to be cytoplasmic, where as orotate phosphoribosyltransfe...

A series of seven limonene beta-amino alcohol derivatives has been regioselectively synthesised in moderate to good yields. Two of these compounds were found to be significantly effective against in vitro cultures of the Leishmania (Viannia) braziliensis promastigote form in the micromolar range. The activities found for 3b and 3f were about 100-fold more potent than the standard drug, Pentamid...

The in vitro activity of the crude hydroalcoholic extract of the aerial parts of Miconia langsdorffii Cogn. was evaluated against the promastigote forms of L. amazonensis, the causative agent of cutaneous leishmaniasis in humans. The bioassay-guided fractionation of this extract led to identification of the triterpenes ursolic acid and oleanolic acid as the major compounds in the fraction that ...

The diagnosis of visceral leishmaniasis (VL) in humans and animal reservoir hosts is difficult, particularly in rural areas where the disease is endemic and laboratory facilities are limited. This study aimed to develop a latex agglutination test (LAT) for the rapid detection of anti-Leishmania antibodies against the A2 antigen derived from the amastigote form as well as those against crude ant...

BACKGROUND Gene reporter-fluorescent cells have emerged as alternative method for drug screening. OBJECTIVE Achievement of constitutive expression of fluorescent protein GFP by Leishmania braziliensis as alternative method for drug screening. METHODS L. braziliensis-GFP was generated using Leishmania tarentolae pLEXSY-egfp for constitutive expression of GFP. Fluorescent cells were selected ...

The development of leishmanicidal quinolines and their in vitro (promastigote and amastigote) and, where applicable, in vivo activities are reviewed. This survey provides a direct comparison of bioactivity across different species(e.g. L. donovani, L. amazonensis, L. chagasi, L infantum), and in different animal models (e.g. L. donovani Balb/c mice and L. donovani infected hamsters). The progre...