Browsing by Autor "Sara M. Robledo"

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Antiprotozoal activities of Colombian plants
(Elsevier BV, 2001) Bernard Weniger; Sara M. Robledo; Gabriel Jaime Murillo Arango; Eric Deharo; Raúl Aragón; Victoria Muñoz; Jorgia Callapa; Annelise Lobstein; Robert Anton
Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae
(Elsevier BV, 2007) Edison Osorio; Gabriel Jaime Murillo Arango; Nora Jiménez; Fernando Álzate; Grace Ruiz; David Gutiérrez; Marco Antonio Paco; Alberto Giménez; Sara M. Robledo
In Vitro and In Vivo Cytotoxicities and Antileishmanial Activities of Thymol and Hemisynthetic Derivatives
(American Society for Microbiology, 2005) Sara M. Robledo; Edison Osorio; Diana L. Muñoz; Luz Jaramillo; Adriana Restrepo; Gabriel Jaime Murillo Arango; Iván Darío Vélez
The in vitro and in vivo antileishmanial and cytotoxic activities of thymol and structural derivatives in comparison to those of Glucantime were studied. The results showed here suggest that thymol and hemisynthetic derivatives have promising antileishmanial potential and could be considered as new lead structures in the search for novel antileishmanial drugs.
Influencia de las nanopartículas de Ag sobre las propiedades mecánicas y tribológicas y en el efecto citotóxico y bactericida de los recubrimientos de TaN(Ag)
(Spanish National Research Council, 2017) Aida M. Echavarría; Sara M. Robledo; Gilberto Bejarano Gaitán
En este trabajo se desarrolló el recubrimiento compuesto de TaN(Ag) con una variación del contenido de plata entre 2,26 y 28,51 %at, mediante la técnica de pulverización catódica asistida por campo magnético desbalanceado. Se eligió el recubrimiento que presentó el mejor balance entre propiedades mecánicas y tribológicas, y se sometió a un ciclo de tratamientos térmicos con temperaturas entre 175 °C y 275 °C para producir la nucleación, el crecimiento y difusión controlada de las nanopartículas de Ag hasta la superficie del recubrimiento. Se verificó el tamaño y densidad de distribución de las nanopartículas en la superficie del recubrimiento, y su influencia en las propiedades mecánicas y tribológicas. Posteriormente se estudió el efecto bactericida frente a la bacteria P. aeruginosa mediante las pruebas de inhibición al crecimiento y de adherencia, así como el comportamiento citotóxico del material frente a osteoblastos humanos utilizando el método MTT. El recubrimiento TaN(Ag)-3 tratado térmicamente a 200 °C durante 4 min, incrementó la microdureza del acero inoxidable AISI 316L de 2,6 GPa a 10,7 GPa, y disminuyó la tasa de desgaste de 1.11x10-3 mm3/N.m a 0.17x10-12 mm3/N.m.. Este recubrimiento presentó 100% de viabilidad celular de osteoblastos, y un excelente comportamiento a la inhibición del crecimiento y adherencia de la bacteria P. aeruginosa.
Leishmanicidal and cytotoxic activity of extracts and saponins from <i>Ilex laurina</i> (Aquifoliaceae)
(Pharmacotherapy Group, University of Benin, Benin City, 2016) Juan M. Pérez; Sara M. Robledo; Wilson Cardona; Fernando Álzate; Diana L. Muñoz; Angie Herrera
Purpose: To evaluate the leishmanicidal and cytotoxic activity of alcohol and non-alcohol extracts and saponins from Ilex laurina.Methods: Extracts were obtained by percolation with solvents of different polarities: hexane, dichloromethane, ethyl acetate and ethanol. The ethyl acetate extract was subjected to silica gel column chromatography eluting with a step gradient of dichloromethane-methanol. All products were evaluated in vitro for leishmanicidal activity against amastigotes of leishmania panamensis and cytotoxicity on U-937 cells.Results: Two saponins were isolated from the ethyl acetate extract. The ethyl acetate extract showed high leishmanicidal activity against intracellular amastigotes of L. panamensis (EC50, 7.5 ± 1.5 μg/mL) and low activity against axenic amastigotes (EC50, 52.8 ±1.6 μg/mL); this extract showed also high cytotoxicity (LC50, 57.7 ± 12.1 μg/mL). Saponin 2 exhibited high activity against intracellular amastigotes (EC50, 5.9 ± 0.5 μg/mL) but also showed high cytotoxicity on U-937 cells (EC50, 25.7 ± 6.1 μg/mL). This compound showed similar leishmanicidal activity and cytotoxicity to meglumine antimoniate and amphotericin B, respectively, drugs currently used for the treatment of leishmaniasis.Conclusions: Based on these results, Ilex laurina is a potential source of compounds that can lead to the development of new therapeutic alternatives against leishmaniasis.Keywords: Leishmaniasis, Antiprotozoal, Saponin, Ilex laurina, Aquifoliaceae
Susceptibilidad in vitro a infección por Leishmania y sensibilidad a medicamentos difiere según tipo de macrófagos
(2010) Carol V. Mesa; Diana L. Muñoz; Mónica Echeverry; Iván Darío Vélez; Sara M. Robledo
Introduction: In vitro systems are useful in the evaluation of compounds with biological activity determining the cytotoxic and leishmanicidal activity of the candidates. Objective: To identify the mammalian cell that allows the optimal in vitro infection by Leishmania and therefore, identify the suitable system for the in vitro evaluation of leishmanicidal activity of drugs. Methodology: The susceptibility to the infection by L. panamensis was evaluated according to the Infective Concentration 50 tested by light microscopy and flow citometry; the intracellular survival of amastigotes was determined by fluorescence microscopy and the sensitivity to amphotericine B and meglumine antimoniate was evaluated by spectrophotometry. Results: The primary culture cells were more susceptible to the in vitro infection by L. panamensis because they did require fewer parasites per cell ratio to achieve the 50% infection rate whereas the intracellular survival of parasites was better in the U-937 cells. All cells showed differential sensitivity to amphotericine B and meglumine antimoniate. Conclusion: The U-937 cells are the most suitable model for the in vitro infection by L. panamensis because: a) they are a cell line with unlimited growth where transformation into macrophages can be induced. b) The susceptibility to infection by L. panamensis is similar to that observed in primary cultures macrophages and, c) They allow the intracellular survival of amastigotes after the infection process. In addition the U-937 cells are less sensitive to the action of the commonly drugs used as a control in the screening of compounds with leishmanicidal activity.
The susceptibility to infection by Leishmania panamensis and the sensitivity to drugs differ according to the macrophage type
(2010) Carol V. Mesa; Diana L. Muñoz; Mónica Echeverry; Iván Darío Vélez; Sara M. Robledo
Introduction: In vitro systems are useful in the evaluation of compounds with biological activity determining the cytotoxic and leishmanicidal activity of the candidates. Objective: To identify the mammalian cell that allows the optimal in vitro infection by Leishmania and therefore, identify the suitable system for the in vitro evaluation of leishmanicidal activity of drugs. Methodology: The susceptibility to the infection by L. panamensis was evaluated according to the Infective Concentration 50 tested by light microscopy and flow citometry; the intracellular survival of amastigotes was determined by fluorescence microscopy and the sensitivity to amphotericine B and meglumine antimoniate was evaluated by spectrophotometry. Results: The primary culture cells were more susceptible to the in vitro infection by L. panamensis because they did require fewer parasites per cell ratio to achieve the 50% infection rate whereas the intracellular survival of parasites was better in the U-937 cells. All cells showed differential sensitivity to amphotericine B and meglumine antimoniate. Conclusion: The U-937 cells are the most suitable model for the in vitro infection by L. panamensis because: a) they are a cell line with unlimited growth where transformation into macrophages can be induced. b) The susceptibility to infection by L. panamensis is similar to that observed in primary cultures macrophages and, c) They allow the intracellular survival of amastigotes after the infection process. In addition the U-937 cells are less sensitive to the action of the commonly drugs used as a control in the screening of compounds with leishmanicidal activity. Salud UIS 2010; 42: 200-211