RESUMEN
Lichens are complex symbiotic organisms able to produce a vast array of compounds. The Algerian lichen diversity has only prompted little interest even given the 1085 species listed. Herein, the chemodiversity of four Algerian lichens including Cladonia rangiformis, Ramalina farinaceae, R. fastigiata, and Roccella phycopsis was investigated. A dereplication strategy, using ultra high performance liquid chromatography-high resolution-electrospray ionization-mass spectrometry (UHPLC-HRMS/MS), was carried out for a comprehensive characterization of their substances including phenolics, depsides, depsidones, depsones, dibenzofurans, and aliphatic acids. Some known compounds were identified for the first time in some species. Additionally, the lichenic extracts were evaluated for their antifungal and antimicrobial activities on human pathogenic strains (Candida albicans, C. glabrata, Aspergillus fumigatus, Staphylococcus aureus, and Escherichia coli). Cyclohexane extracts were found particularly active against human pathogenic fungi with MIC80 values ranging from 8 to 62.5 µg/mL, without cytotoxicity. This study highlights the therapeutic and prophylactic potential of lichenic extracts as antibacterial and antifungal agents.
Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Líquenes/química , Extractos Vegetales/farmacología , Argelia , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Aspergillus fumigatus/efectos de los fármacos , Candida/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-Actividad , Espectrometría de Masas en TándemRESUMEN
Here we engineered transgenic Leishmania infantum that express luciferase, the objectives being to more easily monitor in real time their establishment either in BALB/c mice--the liver and spleen being mainly studied-or in vitro. Whatever stationary phase L. infantum promastigotes population--wild type or engineered to express luciferase-the parasite burden was similar in the liver and the spleen at day 30 post the intravenous inoculation of BALB/c mice. Imaging of L. infantum hosting BALB/C mice provided sensitivity in the range of 20,000 to 40,000 amastigotes/mg tissue, two tissues-liver and spleen-being monitored. Once sampled and processed ex vivo for their luciferin-dependent bioluminescence the threshold sensitivity was shown to range from 1,000 to 6,000 amastigotes/mg tissue. This model further proved to be valuable for in vivo measurement of the efficiency of drugs such as miltefosine and may, therefore, additionally be used to evaluate vaccine-induced protection.