Abstract Obesity is a major risk factor for type 2 diabetes mellitus development and is characterized by an abnormal expansion of adipose tissue and low-grade chronic inflammation that contribute to insulin resistance. Although there are multiple treatments, most therapies can produce undesirable side effects and therefore, new and effective treatments with fewer side effects are necessary. Previously, we demonstrated that a natural extract from the leaves of Eucalyptus tereticornis (OBE100) has anti-inflammatory, hypoglycemic and hypolipidemic activities. The major compounds identified in OBE100 were three pentacyclic triterpenoids, ursolic acid, oleanolic acid, and ursolic acid lactone. Triterpenoids have shown multiples biological activities. This current study compared the biological effect produced by OBE100 with five different reconstituted mixtures of these triterpenoids. Different cell lines were used to evaluate cytotoxicity, reactive oxygen species production, inflammatory cytokine expression, glucose uptake induction, leptin and adiponectin expression, and lipid accumulation. OBE100 treatment was the most efficacious and none of the formulated triterpenoid mixtures significantly improved on this. Moreover, OBE100 was less toxic and reduced reactive oxygen species production. Our study showed that the proven beneficial properties of triterpenoids may be enhanced due to the interaction with minor secondary metabolites present in the natural extract improving their anti-inflammatory properties.

Bis-alkylquinolines 1-6 were synthetized via Williamson reaction between 8-hydroxyquinaldine with different É, ù-dihaloalkanes. Structures of all the products were elucidated by spectroscopic analysis. Cytotoxic and antileishmanial activities of synthesized compounds were determinated on U-937 cells and L. (V) panamensis amastigotes, respectively. Compound 5, 1,9-bis[(2-methylquinolin-8-yl)oxy]nonane, was the most selective against axenic and intracellular amastigotes (EC50 = 11.3 and 22.6, ìg/mL), with selectivity indices greater than 17.7 and 8.8, respectively; which makes this compound promising for the developing of new leishmanicidal drugs.

INTRODUCTION: the use of our flora allows a approach to search of new substances with a high level of bioactivity characteristic of the Annonaceae family where it is reported a series of secondary metabolites very promissory to attack these pathogens. OBJECTIVE: to assess the leishmanicidal activity on intracellular amastigotes of Leishmania (V) panamensis and the toxic activity on human macrophages and Artemia salina. METHODS: it was applied the column chromatography and the preparative layer chromatography for extraction and isolation of alkaloids present in the stem bark of Annona cherimolioides Triana & Planch. Alkaloid extracts and fractions were assessed to determine the leishmanicidal activity by flow cytometry as well as cytotoxic activity on the U937 cellular line and on the peritoneal macrophages of hamster. The in vivo cytotoxic activity was assessed on Artemia salina. RESULTS: a purifying compound was obtained in which the presence of an aporphine nucleus was determined by 1-H nuclear magnetic resonance and spectrophotometry. There wasn't activity against the Leishmania parasites. The crude extract showed the highest toxicity on Artemia salina whereas the purifying compound showed a moderate toxicity on the U937 cell line. DISCUSSION: there was a selective cytotoxic activity against tumoral cells (U397 cell line) compared to toxicity seen in the primary culture (non-tumoral). Due to the cytotoxicity showed on the above cell line, it was impossible to determine the effective concentration of extracts against intracellular amastigotes, thus it is necessary to continue the assessments of in vitro systems using non-tumoral cells.

INTRODUCCIÓN: la utilización de nuestra flora permite un acercamiento en la búsqueda de nuevas sustancias con alto nivel de bioactividad característico de la familia Annonaceae, en donde se reportan una serie de metabolitos secundarios muy promisorios para combatir estos patógenos. OBJETIVO: evaluar la actividad leishmanicida sobre amastigotes intracelulares de Leishmania (V.) panamensis y la actividad tóxica en macrófagos humanos y Artemia salina. MÉTODOS: se aplicó cromatografía de columna y cromatografía en capa preparativa para la extracción y el aislamiento de los alcaloides presentes en la corteza de tallo de Annona cherimolioides Triana & Planch. Extractos y fracciones alcaloidales se evaluaron para determinar la actividad leishmanicida por medio de citometría de flujo, además de la actividad citotóxica sobre la línea celular U937 y sobre macrófagos peritoneales de hámster. La actividad citotóxica in vivo fue evaluada sobre Artemia salina. RESULTADOS: se obtuvo un compuesto depurado, en el cual se determinó la presencia de un núcleo aporfínico según resonancia magnética nuclear 1-H y espectrofotometría. No se encontró actividad contra los parásitos de Leishmania. El extracto crudo mostró mayor toxicidad sobre Artemia salina, mientras que el compuesto depurado mostró una citotoxicidad moderada sobre la línea celular U937. CONCLUSIONES: se encontró una actividad citotóxica selectiva contra las células tumorales (línea celular U937), en comparación con la toxicidad observada en células en cultivo primario (no tumorales). Debido a la citotoxicidad mostrada sobre la línea celular U937, no se pudo determinar la concentración efectiva de los extractos contra amastigotes intracelulares, por lo que se hace necesario continuar las evaluaciones en los sistemas in vitro utilizando células no tumorales.

Introducción: Los sistemas in vitro son útiles en la evaluación de compuestos con actividad biológica, permitiendo por ejemplo, determinar el potencial citotóxico y leishmanicida de un compuesto. Objetivo: Identificar el tipo de célula mamífera que permita una óptima infección in vitro por Leishmania y que constituya el sistema adecuado para el tamizaje in vitro de compuestos con actividad anti-Leishmania. Métodos: La susceptibilidad de las células a infección por L. panamensis se evalúo según la Concentración Infectiva 50 determinada por microscopía de luz y citometría de flujo; la supervivencia intracelular de los amastigotes se evaluó por microscopía de fluorescencia y la sensibilidad de las células a anfotericina B y antimoniato de meglumina se evalúo por espectrofotometría. Resultados: Los cultivos primarios son más susceptibles a la infección por L. panamensis in vitro. Sin embargo, la supervivencia intracelular del parásito fue mejor en U-937. Por su parte, la sensibilidad de las células a anfotericina B y antimoniato de meglumina vario según el tipo de célula. Conclusión: Las células U-937 son las adecuadas para la infección por Leishmania porque: a) presentan crecimiento ilimitado y se les puede inducir transformación a macrófagos. b) la susceptibilidad a la infección por Leishmania es similar a la observada en cultivos primarios de macrófagos y c) permiten mayor supervivencia de los amastigotes luego de la infección. Adicionalmente, las células U-937 son menos sensibles a la acción de los fármacos comúnmente utilizados como control en la detección de compuestos con actividad leishmanicida. Salud UIS 2010; 42: 200-211

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

Actualmente la quimioterapia de la leishmaniasis es promisoria, sin embargo aun no se dispone de un medicamento adecuado. Varias quinolinas sustituidas han presentado actividad in vitro contra agentes causales de leishmaniasis cutánea, leishmaniasis visceral, tripanosomiasis africana y enfermedad de Chagas. En este trabajo se sintetizan seis 2-arilquinolinas derivadas de la galipeina mediante condensación de Perkin a partir de quinaldina y aldehídos aromáticos. La actividad leishmanicida se evalúa en amastigotes axénicos y la actividad citotóxica en células U-937. Todos los compuestos muestran ser activos contra leishmania panamensis pero también contra células mamíferas. Los compuestos estirilquinolinas 2-[(E)-2-(2,5-dimetoxifenil)etenil]quinolina (1), 2-[(E)-2-(2,3-dimetoxifenil)etenil]quinolina (2) y N-{4-[(E)-2-quinolin-2-iletenil]fenil}acetamida (3) son mas activos sobre amastigotes axénicos (CE50 = 3,7; 4,5 y 19,1μg/mL) e intracelulares (CE50 = 1,4; 1,8 y 1,7μg/mL), en comparación con los derivados hidrogenados 2-[2-(2,5-dimetoxifenil)etil]quinolina (1a), 2-[2-(2,3-dimetoxifenil)etil]quinolina (2a) y N-[4-(2-quinolin-2-iletil)fenil]acetamida (3a) (CE50= 31,1; 23,6 y 59,3μg/mL). Todos los compuestos muestran también actividad contra células U-937 con CE50 de 3,7; 6,2 y 4,5μg/mL para las estirilquinolinas 1, 2 y 3, respectivamente y CE50 de 16,0; 12,9 y 20,2μg/mL para los derivados hidrogenados 1a, 2a y 3a, respectivamente. Aunque el proceso de hidrogenación produjo una disminución tanto de la actividad leishmanicida como de la actividad citotóxica, la actividad leishmanicida mostrada por los compuestos de tipo 2-estirilquinolinas les confiere un potencial como moléculas candidatas para el desarrollo de compuestos anti-leishmania.

The search of new treatments for leishmaniasis is an active task nowadays, since there is a lack of non-toxic, cheap and non-resistant medication. In the literature several quinolines have shown in vitro activity against agents of cutaneous leishmaniasis, visceral leishmaniasis, African trypanosomiasis and Chagas diseases. Six 2-styrylquinolines derived from galipeine were synthesized by Perkin condensation of quinaldine with aromatic aldehydes. Leishmanicidal activity was estimated for leishmania panamensis at the amastigote form and cytotoxic activity against U-937 cells. All compounds showed activity against both L. panamensis and U-937 cells. (E)-2-(2,5-dimethoxyphenyl)ethenyl)quinoline (1), (E)-2-(2,3-dimethoxyphenyl)ethenyl)quinoline (2) and (E)-N-[4-(2-quinolin-2-yl-ethenyl)phenyl]acetamide (3) were more active against axenic (EC50= 3.7, 4.5 and 19.1μg/mL) and intracellular amastigotes (EC50= 1.4, 1.8 and 1.7μg/ml, respectively), in comparison with hydrogenated derivatives 2-[2-(2,5-dimethoxyphenyl)ethyl]quinoline (1a), 2-[2-(2,3-dimethoxyphenyl)ethyl]quinoline (2a) and N-[4-(2-quinolin-2-ylethyl)phenyl]acetamide (3a) (CE50= 31.1, 23.6 and 59.3μg/mL, respectively). All compounds were also active against the U-937 cells. Styrylquinolines 1, 2 and 3 showed a LC50 of 3.7, 6.2 and 4.5μg/mL, respectively and the hydrogenated derivatives 1a, 2a and 3a showed a LC50 of 16.0. 12.9 and 20.2μg/mL, respectively. Although hydrogenation reduced the leishmanicidal and cytotoxic activities, the activity showed against leishmania parasites suggests this compound series has potential as drug candidates for the treatment of leishmaniasis.

En este trabajo se describe la síntesis de hidrazonas derivadas de cromano, tiocromano, alquil y aril hidrazonas, su actividad leishmanicida y su efecto sobre proteasas de cisteína de L. (V) panamensis. Se sintetizan feniltiocromanos y bencil y naftil derivados; solamente las fenilhidrazonas muestran alguna actividad sobre amastigotes de Leishmnia (V) panamensis. No se observa ningún efecto sobre una proteasa de cisteína del parásito lo que sugiere un mecanismo de acción diferente a la inhibición de esta enzima.

In this paper, the synthesis of hydrazones derived from cromano, thiocroman, alkyl and aril hydrazones is described, as well as their leishmanicidal activity and their effect on cysteine proteases from L. (V) panamensis. A series of novel phenylthiochromane and benzyl and naphtyl derivatives are synthesized and evaluated for their cytotoxic and antileishmanial activities. Their effect on parasite cysteine protease is also evaluated. Only phenylthiochromane derivatives display some activity against Leishmania (V) panamensis but all compounds are inactive against parasitic cystein protease. These results may suggest a different mechanism of action for these compounds.