Leishmania (Viannia) lainsoni: occurrence of intracellular promastigote forms in vivo and in vitro

Submitted by Sandra Infurna ([email protected]) on 2020-01-03T13:32:01Z No. of bitstreams: 1 JoseRCorrea_MaurilioSoares_IOC_2006.pdf: 1793231 bytes, checksum: 1d7a8de5d7a30a9971fdb3c56ece9a39 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-01-03T13:42:27Z (GMT) No. of bitstreams: 1 JoseRCorrea_MaurilioSoares_IOC_2006.pdf: 1793231 bytes, checksum: 1d7a8de5d7a30a9971fdb3c56ece9a39 (MD5)Made available in DSpace on 2020-01-03T13:42:27Z (GMT). No. of bitstreams: 1 JoseRCorrea_MaurilioSoares_IOC_2006.pdf: 1793231 bytes, checksum: 1d7a8de5d7a30a9971fdb3c56ece9a39 (MD5) Previous issue date: 2006Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Ultra-estrutura e Biologia Celular. Laboratório de Biologia Celular de Microrganismos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Ultra-estrutura e Biologia Celular. Laboratório de Biologia Celular de Microrganismos. Rio de Janeiro, RJ, Brasil.Experimental chronic (45-day-old) skin lesion in hamster hind foot induced by Leishmania (Viannia) lainsoni infection showed the presence of promastigote forms in the tissue, inside parasitophorous vacuoles, as assessed by transmission electron microscopy. Experimental in vitro interaction (24 and 48 h) between Leishmania (V.) lainsoni and J774-G8 macrophage cells also demonstrated the same profile. This morphological aspect is unusual, since in this parasite genus only amastigote forms have been described as the resistant and obligate intracellular forms

Combination of the essential oil constituents citral, eugenol and thymol enhance their inhibitory effect on Crithidia fasciculata and Trypanosoma cruzi growth

We analyzed the effect of the combination of citral, eugenol and thymol, respectively the main constituents of essential oils of Cympobogon citratus (DC) Stapf, Poaceae (lemon grass), Syzygium aromaticum(L.) Merr. & L.M. Perry, Myrtaceae (clove) and Thymus vulgarisL., Lamiaceae (thyme), on the proliferation of the trypanosomatids Crithidia fasciculataand Trypanosoma cruzi.The constituents were initially added individually at different concentrations to C. fasciculatacultures to estimate the IC50/24h. Concentrations in a triple combination were about 2 times and 16.5 times lower against C. fasciculata and T. cruzi, respectively, as compared to isolated compounds. Incubation of C. fasciculatawith the trypanocydal agent benznidazole did not affect parasite growth at concentrations up to 500 µg/ml, but the IC50 of this drug against T. cruziwas 15.8 µg/ml, a value about 2-5 times higher than that of constituents in the triple combination. Analysis of treated C. fasciculata by scanning electron microscopy showed rounding of the cell body. Our data show that combination of essential oil constituents resulted in increased inhibitory activity on growth of both non-pathogenic and pathogenic trypanosomatid species and indicate that the non-patogenic C. fasciculata may represent a resistant model for drug screening in trypanosomatids