Association of liposome-encapsulated trivalent antimonial with ascorbic acid: an effective and safe strategy in the treatment of experimental visceral leishmaniasis.

BACKGROUND: Visceral leishmaniasis (VL) is a chronic debilitating disease endemic in tropical and subtropical areas, caused by protozoan parasites of the genus Leishmania. Annually, it is estimated the occurrence of 0.2 to 0.4 million new cases of the disease worldwide. Considering the lack of an effective vaccine the afflicted population must rely on both, an accurate diagnosis and successful treatment to combat the disease. Here we propose to evaluate the efficacy of trivalent antimonial encapsulated in conventional liposomes, in association with ascorbic acid, by monitoring its toxicity and efficacy in BALB/c mice infected with Leishmania infantum. METHODOLOGY/PRINCIPAL FINDINGS: Infected mice were subjected to single-dose treatments consisting in the administration of either free or liposome-encapsulated trivalent antimony (SbIII), in association or not with ascorbic acid. Parasite burden was assessed in the liver, spleen and bone marrow using the serial limiting dilution technique. After treatment, tissue alterations were examined by histopathology of liver, heart and kidney and confirmed by serum levels of classic biomarkers. The phenotypic profile of splenocytes was also investigated by flow cytometry. Treatment with liposome-encapsulated SbIII significantly reduced the parasite burden in the liver, spleen and bone marrow. Co-administration of ascorbic acid, with either free SbIII or its liposomal form, did not interfere with its leishmanicidal activity and promoted reduced toxicity particularly to the kidney and liver tissues. CONCLUSIONS/SIGNIFICANCE: Among the evaluated posological regimens treatment of L. infantum-infected mice with liposomal SbIII, in association with ascorbic acid, represented the best alternative as judged by its high leishmanicidal activity and absence of detectable toxic effects. Of particular importance, reduction of parasite burden in the bone marrow attested to the ability of SbIII-carrying liposomes to efficiently reach this body compartment.

Association of water extract of green propolis and liposomal meglumine antimoniate in the treatment of experimental visceral leishmaniasis.

This work investigated the use of water extract of green propolis (WEP) and its association with free or liposomal meglumine antimoniate (MA) for the treatment of murine visceral leishmaniasis. Mice infected with Leishmania infantum were treated with oral doses of WEP associated or not with a single dose of liposomal MA by intraperitoneal route. Parasite burden was assessed in the liver and spleen by limiting dilution assay, and alterations in the spleen cellular phenotype were evaluated by flow cytometry. Tissue damage was assessed by determination of biochemical markers of the liver, heart, and kidney function and histopathological analysis of the liver and spleen. Our data showed that treatment with WEP was able to reduce parasite load in the liver but not in the spleen. On the other hand, liposomal MA reduced parasite load in both organs. Unexpectedly, there was no synergism with the combination of WEP and liposomal MA in reducing the parasite load. The histopathological analysis showed that administration of WEP, liposomal MA, or their association was able to protect the liver and spleen from lesions caused by infection. No alteration in the profile of spleen cells by flow cytometry or in the liver, heart, and kidney functions by biochemical markers due to any of the treatments was observed. These results demonstrate that although WEP was able to significantly reduce the liver parasite load, its association with liposomal MA did not lead to significant improvement in reducing parasite load. On the other hand, treatment with WEP and/or liposomal MA protected the liver and spleen from lesions caused by the infection.

Levantamento etnobotânico de plantas medicinais na comunidade quilombola Carreiros, Mercês ­ Minas Gerais / Ethnobotanical survey of medicinal plants in maroon community Carreiros, Mercês - Minas Gerais

O objetivo do trabalho foi identificar as espécies medicinais utilizadas pela comunidade quilombola Carreiros, bem como traçar o perfil social das famílias desta comunidade. Para tanto, foram realizadas entrevistas semiestruturadas da comunidade, sendo um representante de cada família. Para fins de registro foram coletados dois exemplares de cada espécie medicinal identificada, os quais foram conservados na forma de exsicatas e mantidos no Laboratório de Ecologia do IF Sudeste MG ­ Campus Rio Pomba. As mulheres aparentemente desempenham importante papel social e estão bastante envolvidas no conhecimento das plantas medicinais. Nota-se, que o conhecimento existente foi adquirido de forma empírica e é evidente entre as famílias a preocupação em repassar os conhecimentos tradicionais sobre o uso das plantas medicinais aos jovens. Dentre as principais espécies utilizadas pela comunidade estão: Citrus Sinensis L., Psidium guajava L., Leonurus sibiricus L., Citrus Limonia (Osbeck), Carica sp., Vernonia condensata Backer, Sechuium edule (Jacq.) Sw, Sansevieria trifasciata Prain, Malpighia glabra L., e Saccharum zofficinarum L..