Examinando por Autor "Gómez Rangel, Sergio-Yebrail"
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- PublicaciónAcceso abiertoAntiviral effect of compounds derived from the seeds of Mammea americana and Tabernaemontana cymosa on Dengue and Chikungunya virus infections(2017-01-18) Gómez Calderón, Cecilia; Mesa Castro, Carol; Robledo, Sara; Gómez Rangel, Sergio-Yebrail; Bolivar Avila, Santiago; Diaz Castillo, Fredyc; Martínez Gutiérrez, MarlenBackground The transmission of Dengue virus (DENV) and Chikungunya virus (CHIKV) has increased worldwide, due in part to the lack of a specific antiviral treatment. For this reason, the search for compounds with antiviral potential, either as licensed drugs or in natural products, is a research priority. The objective of this study was to identify some of the compounds that are present in Mammea americana (M. americana) and Tabernaemontana cymosa (T. cymosa) plants and, subsequently, to evaluate their cytotoxicity in VERO cells and their potential antiviral effects on DENV and CHIKV infections in those same cells. Methods Dry ethanolic extracts of M. americana and T. cymosa seeds were subjected to open column chromatographic fractionation, leading to the identification of four compounds: two coumarins, derived from M. americana; and lupeol acetate and voacangine derived from T. cymosa.. The cytotoxicity of each compound was subsequently assessed by the MTT method (at concentrations from 400 to 6.25 μg/mL). Pre- and post-treatment antiviral assays were performed at non-toxic concentrations; the resulting DENV inhibition was evaluated by Real-Time PCR, and the CHIKV inhibition was tested by the plating method. The results were analyzed by means of statistical analysis. Results The compounds showed low toxicity at concentrations ≤ 200 μg/mL. The compounds coumarin A and coumarin B, which are derived from the M. americana plant, significantly inhibited infection with both viruses during the implementation of the two experimental strategies employed here (post-treatment with inhibition percentages greater than 50%, p < 0.01; and pre-treatment with percentages of inhibition greater than 40%, p < 0.01). However, the lupeol acetate and voacangine compounds, which were derived from the T. cymosa plant, only significantly inhibited the DENV infection during the post-treatment strategy (at inhibition percentages greater than 70%, p < 0.01). Conclusion In vitro, the coumarins are capable of inhibiting infection by DENV and CHIKV (with inhibition percentages above 50% in different experimental strategies), which could indicate that these two compounds are potential antivirals for treating Dengue and Chikungunya fever. Additionally, lupeol acetate and voacangine efficiently inhibit infection with DENV, also turning them into promising antivirals for Dengue fever.
- PublicaciónAcceso abiertoCo-circulation and simultaneous co-infection of dengue, chikungunya, and zika viruses in patients with febrile syndrome at the Colombian-Venezuelan border(2018-01-30) Carrillo Hernández, Marlen Yelitza; Gómez Rangel, Sergio-Yebrail; Ruiz Saenz, Julian; Jaimes Villamizar, Lucy; Martínez Gutiérrez, MarlenBackground: In Colombia, the dengue virus (DENV) has been endemic for decades, and with the recent entry of the chikungunya virus (CHIKV) (2014) and the Zika virus (ZIKV) (2015), health systems are overloaded because the diagnosis of these three diseases is based on clinical symptoms, and the three diseases share a symptomatology of febrile syndrome. Thus, the objective of this study was to use molecular methods to identify their co-circulation as well as the prevalence of co-infections, in a cohort of patients at the Colombian-Venezuelan border. Methods: A total of 157 serum samples from patients with febrile syndrome consistent with DENV were collected after informed consent and processed for the identification of DENV (conventional PCR and real-time PCR), CHIKV (conventional PCR), and ZIKV (real-time PCR). DENV-positive samples were serotyped, and some of those positive for DENV and CHIKV were sequenced. Results: Eighty-two patients were positive for one or more viruses: 33 (21.02%) for DENV, 47 (29.94%) for CHIKV, and 29 (18.47%) for ZIKV. The mean age range of the infected population was statistically higher in the patients infected with ZIKV (29.72 years) than in those infected with DENV or CHIKV (21.09 years). Both co-circulation and coinfection of these three viruses was found. The prevalence of DENV/CHIKV, DENV/ZIKV, and CHIKV/ZIKV co-infection was 7.64%, 6.37%, and 5.10%, with attack rates of 14.90, 12.42, and 9.93 cases per 100,000 inhabitants, respectively. Furthermore, three patients were found to be co-infected with all three viruses (prevalence of 1.91%), with an attack rate of 4.96 cases per 100,000 inhabitants. Conclusion: Our results demonstrate the simultaneous co-circulation of DENV, CHIKV, ZIKV and their co-infections at the Colombian-Venezuelan border. Moreover, it is necessary to improve the differential diagnosis in patients with acute febrile syndrome and to study the possible consequences of this epidemiological overview of the clinical outcomes of these diseases in endemic regions.
- PublicaciónAcceso abiertoEvaluación de la actividad antifúngica y antibacteriana de dos moléculas aisladas de calea prunifolia.(Bucaramanga : Universidad de Santander, 2018, 2018-11-13) Montoya Díaz, Lisseth D.; Torres Meza, Karen T.; Zambrano Arguello, Angie D.; Gómez Rangel, Sergio-Yebrail; Trejos Suárez, JuanitaEl estudio de moléculas aisladas de material vegetal, es de gran importancia para obtener nuevos compuestos con potencial bioactivo y corroborar información de conocimiento popular que se atribuyen a algunas plantas como propiedades farmacológicas. En el presente trabajo se evaluó la actividad inhibitoria de dos moléculas extraídas de Calea plunifloria sobre bacterias y hongos de interés clínico, y su efecto citotóxico en células de mamífero y glóbulos rojos humanos.Las moléculas mostraron mayor actividad contra Candida albicans y Candida glabrata con una Concentración Mínima Inhibitoria (CMI) de 1.56 ug/ml. Sin embargo, al estudiar la inhibición contra bacterias solo se encontró actividad contra Streptococcus pneumoniae con CMI de 12.5 ug/ml. Además del potencial inhibitorio, se encontró bajo potencial tóxico líneas celulares epiteliales Vero con Concentraciones Citotóxicas 50% (CC50) de 228.9 ug/ml y 241.4 ug/ml para la molécula 1 y 2 respectivamente; teniendo en cuenta estos valores y la CMI reportada, se puede inferir un índice de selectividad de 146.7 y 154.7 para cada molécula. En ensayos de Glóbulos rojos humanos no se evidenció toxicidad asociada a hemólisis en ninguna de las concentraciones estudiadas. Los resultados sugieren una actividad promisoria antibacteriana y antimicótica en cepas de Streptococcus pneumoniae (ATCC 49619), Candida albicans (ATCC 22972) y Candida glabatra (ATCC 90030) demostrando el potencial bioactivo de las moléculas. Así mismo, se proponen trabajos complementarios para definir el mecanismo de acción en modelos in vivo y continuar con la búsqueda de otras moléculas con potencial antimicrobiano a partir de plantas del género Calea spp.
- PublicaciónAcceso abiertoEvaluación de la actividad antiparasitaria de moléculas obtenidas de Calea prunifolia contra Trypanosoma cruzi(Bucaramanga : Universidad de Santander, 2018, 2018-12-13) Quijano Sarmiento, Leonardo A.; Pabón Méndez, Mario I.; Gómez Rangel, Sergio-Yebrail; Trejos Suárez, JuanitaAmerican trypanosomiasis is a systemic parasitic disease caused by the flagellated protozoan, Trypanosoma cruzi. It is one of the most important neglected tropical diseases in the world and one of the most serious public health problems in Latin America. At present, Nifortimox and Benznidazole are the only drugs approved by the WHO for the treatment of the disease and in most cases produce secondary reactions to its consumption; therefore it is necessary to study new therapeutic alternatives for this pathology and to improve the quality of life of those who suffer from it. The present study seeks to determine the trypanocidal activity, through the IC50, of molecules obtained from Calea prunifolia; derivatives of p-hydroxyacetophenone, 1- (2-hydroxy-5- (1-methoxyethyl) phenyl) -3-methylbut-2-en-1-one (Molecule 1) and 1- (2-hydroxy-5-methoxyphenyl) ) -3-methylbut-2-en-1-one (Molecule 2). Initially, a growth curve was made to establish the optimal phase of logarithmic multiplication of T. cruzi epimastigotes. Growth rates of 1x105 and 1x106 parasites/mL were handled, taking the latter for the parasitic inhibition test. For this experiment, epimastigotes were cultured in 96-well plates and subjected to concentrations of 6.25 μg/mL to 400 μg/mL of both molecules under study. The results allowed to determine an IC50 of 166.4 μg/mL and 279.8 μg/mL for molecules 1 and 2 respectively. Thus reaching the conclusion of the existence of a trypanocidal potential of both molecules extracted from Calea prunifolia but with better results for molecule 1 that does not surpass the CC50 evaluated in other studies.
- PublicaciónAcceso abiertoEvaluación in vitro de la actividad antimicrobiana de un péptido sintético en patotipos y comensales de Escherichia coli(Bucaramanga : Universidad de Santander, 2018, 2018-12-13) Méndez Jaimes, Karen D.; Mendoza Espinel, Stephany Y.; Moreno Amézquita, July A.; Gómez Rangel, Sergio-Yebrail; Farfán García, Ana ElviraEn los últimos años las bacterias han ido desarrollando diversos mecanismos de resistencia frente a los antibióticos, lo que ha generado un gran problema de salud pública. Los péptidos antimicrobianos (PAM) han surgido como una estrategia prometedora en la generación de nuevos agentes antimicrobianos debido a sus múltiples mecanismos de acción, los cuales incluyen interacciones con la membrana celular, inhibición de la síntesis proteica y de ácidos nucleicos, funciones inmunomoduladoras y quimiotácticas, amplio espectro de actividad y la baja probabilidad en el desarrollo de resistencia. En este trabajo se evaluó la actividad antimicrobiana del péptido sintético Ib derivado de la planta Impatiens balsamina en cepas comensales y patotipos de Escherichia coli. El potencial inhibitorio se llevó a cabo mediante la determinación de la Concentración Mínima Inhibitoria (CMI) y la Concentración Bactericida Mínima (CBM). El péptido demostró tener un buen potencial inhibitorio al presentar concentraciones de CMI entre 0,7 y 12,5 μM. Particularmente, la actividad es diferente en cada cepa, y no se asocia directamente al patotipo. Dentro del estudio se incluyeron cepas comensales, las cuales presentaron valores de CMI más bajos que los patotipos, esto se puede relacionar con la deficiencia de mecanismos de patogenicidad en estas cepas. Adicionalmente los péptidos demostraron tener actividad bactericida en la mayoría de cepas, mediante la determinación de la CBM. Estos datos contribuyen al aporte que tienen estas sustancias como potencial para contrarrestar la farmacorresistencia.
- PublicaciónAcceso abiertoIb-M6 Antimicrobial Peptide(Basilea : MDPI, 2020, 2020-02-12) Flórez Castillo, Johanna-Marcela; Rondón Villarreal, Paola; Ropero Vega, José Luis; Mendoza Espinel, Stephany Y.; Moreno Amézquita, July A.; Méndez Jaimes, Karen D.; Farfán García, Ana Elvira; Gómez Rangel, Sergio-Yebrail; Gómez-Duarte, Oscar G.; Universidad de SantanderEl péptido Ib-M6 tiene actividad antibacteriana contra la cepa K-12 de Escherichia coli no patógena . La primera parte de este estudio determina la actividad antibacteriana de Ib-M6 contra catorce cepas patógenas de E. coli O157: H7. El ensayo de susceptibilidad mostró que Ib-M6 tenía valores de Concentración Inhibitoria Mínima (MIC) más bajos que la estreptomicina, usada como antibiótico de referencia. Además, para predecir la posible interacción entre Ib-M6 y los componentes de la membrana externa de E. coli, utilizamos simulaciones de acoplamiento molecular donde la proteína FhuA y su complejo con Lipopolisacárido (LPS-FhuA) se utilizaron como objetivos del péptido. Los complejos FhuA / Ib-M6 tenían valores de energía entre -39,5 y -40,5 unidades de energía Rosetta (REU) y solo un enlace de hidrógeno. En contraste, los complejos entre LPS-FhuA e Ib-M6 mostraron valores de energía entre -25,6 y -40,6 REU, y la presencia de cinco posibles enlaces de hidrógeno. Por tanto, la actividad antimicrobiana del péptido Ib-M6 mostrada en los ensayos experimentales podría deberse a su interacción con la membrana externa de E. coli .
- PublicaciónAcceso abiertoIb-M6 antimicrobial peptide: Antibacterial activity against clinical isolates of Escherichia coli and molecular docking(2020-03-12) Flórez Castillo, Johanna-Marcela; Rondón Villarreal, Paola; Ropero Vega, José Luis; Mendoza Espinel, Stephany Y.; Moreno Amézquita, July A.; Méndez Jaimes, Karen D.; Farfán García, Ana Elvira; Gómez Rangel, Sergio-Yebrail; Gómez Duarte, Oscar Gilberto; CLINIUDES; CIBASThe Ib-M6 peptide has antibacterial activity against non-pathogenic Escherichia coli K-12 strain. The first part of this study determines the antibacterial activity of Ib-M6 against fourteen pathogenic strains of E. coli O157:H7. Susceptibility assay showed that Ib-M6 had values of Minimum Inhibitory Concentration (MIC) lower than streptomycin, used as a reference antibiotic. Moreover, to predict the possible interaction between Ib-M6 and outer membrane components of E. coli, we used molecular docking simulations where FhuA protein and its complex with Lipopolysaccharide (LPS–FhuA) were used as targets of the peptide. FhuA/Ib-M6 complexes had energy values between −39.5 and −40.5 Rosetta Energy Units (REU) and only one hydrogen bond. In contrast, complexes between LPS–FhuA and Ib-M6 displayed energy values between −25.6 and −40.6 REU, and the presence of five possible hydrogen bonds. Hence, the antimicrobial activity of Ib-M6 peptide shown in the experimental assays could be caused by its interaction with the outer membrane of E. coli. View Full-Text