Activation of the Keap1-Nrf2 pathway by specioside and the n-butanol extract from the inner bark of Tabebuia rosea (Bertol) DC.

Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H 2O 2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 µM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H 2O 2-induced oxidative stress in HepG2 cells.

Seroprevalencia de anticuerpos anti-Toxoplasma gondii en mujeres menores de 18 años de una localidad de Colombia / Seroprevalence of anti-Toxoplasma gondii antibodies in women under 18 years old from a locality of Colombia

Resumen OBJETIVO: Determinar la seroprevalencia de Toxoplasma gondii en mujeres menores de 18 años de dos instituciones educativas de un municipio de Colombia. MATERIALES Y MÉTODOS: Estudio de prevalencia, transversal, efectuado en 2016 en mujeres de dos colegios de Dosquebradas, Colombia, aprobado por los comités de ética de las instituciones participantes. Criterios de inclusión: ser menores de 18 años, firmar el consentimiento informado y responder las preguntas de una encuesta de datos demográficos. Criterios de exclusión: tener más de 18 años y haber tenido embarazos previos. Las muestras se analizaron contra anticuerpos IgM, IgG e IgG de avidez con antígenos recombinantes para Toxoplasma gondii altamente purificados con la prueba recomLine, con desarrollo de Western blot mikrogen Diagnostik. Para definir el momento infeccioso se determinó la avidez anti-IgG contra antígenos p30, MAG1, GRA1 y rSAG1 en muestras positivas para IgG total. La prueba se realizó e interpretó de acuerdo con las instrucciones del fabricante. RESULTADOS: Se estudiaron 80 pacientes con edad media de 15 años: 4 resultaron con IgM anti-Toxoplasma gondii, infección menor de 3 meses; 28 IgG anti-Toxoplasma gondii, con infección mayor a 3 meses y 17 IgG de avidez con infección superior a 6 meses. La prevalencia fue de 61.3%. CONCLUSIÓN: La seroprevalencia global de anticuerpos anti-toxoplasma encontrada fue de 61.3%, lo que pone de manifiesto que la toxoplasmosis es una enfermedad en la que debe pensarse para diagnosticarla y tratarla oportunamente.

Abstract OBJECTIVE: To determinate seroprevalence of Toxoplasma gondii in the female population of the municipality of Dosquebradas. MATERIALS AND METHODS: Cross-sectional prevalence study in reproductive age female of two school of the from a locality of Dosquebradas, Colombia, during 2016, was approved by the ethics committees of the participating institutions. The study volunteers signed the consent and completed the survey with demographic data, excluding women older than 18 years, and having had previous pregnancies. The samples were analyzed against IgM, IgG and avid IgG antibodies using highly purified recombinant antigens for Toxoplasma gondii using RecomLine test with development of Western blot mikrogen DIAGNOSTIK. To define the infectious moment, anti-IgG avidity against antigens p30, MAG1, GRA1 and rSAG1 were determined in samples positive for total IgG. The test was performed and interpreted according to the manufacturer's instructions. RESULTS: 80 patients were studied with average age of 15 years, 4 presented IgM anti-Toxoplasma gondii, infection less than 3 months; 28 IgG anti-Toxoplasma gondii, with infection greater than 3 months and 17 IgG of avidity with infection greater than 6 months, representing a prevalence of 61.3%. CONCLUSIONS: The global seroprevalence of anti-toxoplasma antibodies was 61.3%, which shows that toxoplasmosis is a disease in which it must be thought to diagnose and treat it in a timely manner.