Effect of Sodium Ascorbate or Alpha-Tocopherol on the Resin-Dentin Interface and Bond Strength after Endodontic Treatment and Bleaching / Efecto del Ascorbato de Sodio o Alfa-Tocoferol sobre la Interfaz Resina-Dentina y la Fuerza de Unión Después del Tratamiento de Endodoncia y Blanqueamiento

The objective of this in vitro study was to assess the effects of two antioxidants (sodium ascorbate [SA] and alpha-tocopherol [AT]) on the adhesive interface and dentin bond strength immediately after bleaching with 38 % hydrogen peroxide (38HP) in endodontically-treated teeth. Two stages of experimentation were carried out. Bovine incisors were allocated into four groups (n = 10/group for each experiment): NB, non-bleached restored crowns; 38HP, bleached and immediately restored crowns; 38HP-SA, bleached crowns and SA use; and 38HP-AT, bleached crowns and AT use. Hybrid layer length in dentin (μm) and bond strength (MPa) were assessed with confocal microscopy laser and micro-shear bond strength (μSBS) test, respectively. Failure mode was determined by stereomicroscope. Data analysis was performed with analysis of variance (ANOVA) and Kruskal-Wallis, Dunn, Tukey, and Fisher-exact tests (a = 0.05). Higher values of hybrid layer length were observed similarly in the NB and 38HP-SA groups. The highest μSBS mean values were observed in the NB group (18 .51 ? 1.33), whereas the SBS values for 38HP-AT (1.68 ? 0.32) were similar to the 38HP group (1.61 ? 0.51) (p > 0.05) and significantly lower than the 38HP-SA group (5.78 ? 0.71). Adhesive failures were predominant in the 38HP and 38HP-AT groups. Cohesive and mixed failures were mostly observed in the NB and 38HP-SA groups, respectively. In conclusion, AT has no immediate effect on the hybrid layer formation and μSBS of dentin. Although SA promotes an increase in hybrid layer formation, it was not reflected in the μSBS values.

El objetivo de este estudio in vitro fue evaluar los efectos de dos antioxidantes (ascorbato de sodio [AS] y alfa-tocoferol [AT]) sobre la interfaz adhesiva y la fuerza de unión de la dentina inmediatamente después del blanqueamiento con peróxido de hidrógeno al 38 % (38HP) en endodoncia. -Dientes tratados. Se llevaron a cabo dos etapas de experimentación. Los incisivos bovinos se dividieron en cuatro grupos (n = 10 / grupo para cada experimento): NB, coronas restauradas no blanqueadas; 38HP, coronas blanqueadas y restauradas inmediatamente; 38HP- AS, coronas blanqueadas y uso SA; y 38HP-AT, coronas blanqueadas y uso de AT. La longitud de la capa híbrida en dentina (μm) y la fuerza de unión (MPa) se evaluaron con láser de microscopía confocal y la prueba de fuerza de unión por micro-cizallamiento (μSBS), respectivamente. El modo de falla se determinó mediante estereomicroscopio. El análisis de los datos se realizó con análisis de varianza (ANOVA) y pruebas de Kruskal-Wallis, Dunn, Tukey y Fisher (α = 0,05). De manera similar, se observaron valores más altos de longitud de capa híbrida en los grupos NB y 38HP-AS. Los valores medios más altos de μSBS se observaron en el grupo NB (18,51 ? 1,33), mientras que los valores de SBS para 38HP-AT (1,68 ? 0,32) fueron similares a los del grupo 38HP (1,61 ? 0,51) (p> 0,05) y significativamente más bajos que el grupo 38HP-AS (5,78 ? 0,71). Las fallas adhesivas fueron predominantes en los grupos de 38HP y 38HP-AT. Las fallas cohesivas y mixtas se observaron principalmente en los grupos NB y 38HP-AS, respectivamente. En conclusión, la AT no tiene un efecto inmediato sobre la formación de la capa híbrida y el μSBS de dentina. Aunque AS promueve un aumento en la formación de capas híbridas, no se refleja en los valores de μSBS.

Evidencia científica sobre la aplicabilidad del ácido ascórbico en lesiones cutáneas / Scientific Evidence regarding the Applicability of Ascorbic Acid against Skin Lesions

Introducción: Las lesiones cutáneas se caracterizan por la ruptura de la continuidad del tegumento que resulta de varios factores. Así, la atención médica de las personas con lesiones cutáneas debe ser multidimensional e interdisciplinaria entre los profesionales de la salud. Una de las alternativas terapéuticas que viene ganando espacio en el tratamiento de pacientes con lesiones cutáneas es el uso de productos naturales, como el ácido ascórbico. Objetivo: Analizar la mejor evidencia científica sobre el uso del ácido ascórbico como método terapéutico en lesiones cutáneas. Métodos: Revisión sistemática, donde se buscaron estudios en las bases de datos Pubmed, Scopus, Cinahl, Web of Science y The Cochrane Data Base, con investigación dirigida a la aplicabilidad del ácido ascórbico en las lesiones de la piel. Los estudios se analizaron de forma pareada y se clasificaron con respecto a su mejor evidencia científica. Conclusión: Después de analizar los ensayos clínicos, que presentaron solidez científica, se notó que hay un fomento de la contribución del ácido ascórbico a la curación, ya que disminuye el proceso inflamatorio y conduce a la neovascularización, la concentración de macrófagos y la concentración de fibroblastos y fibras de colágeno. Entre los estudios analizados, se evidencia que el uso del ácido ascórbico tiene un efecto en el proceso terapéutico en pacientes con lesiones, pero requiere nuevos estudios para complementar esta tesis(AU)

Introduction: Skin lesions are characterized by break in the continuity of tissue resulting from several factors. Therefore, the medical care provided to people with skin lesions must be multidimensional and interdisciplinary. One of the therapeutic alternatives that is increasingly being used for the treatment of patients with skin lesions is the use of natural products, such as ascorbic acid. Objective: To analyze the best scientific evidence on the use of ascorbic acid as a therapeutic method against skin lesions. Methods: Systematic review consisting in search for studies in the databases Pubmed, Scopus, Cinahl, Web of Science and The Cochrane Data Base, with research directed to the applicability of ascorbic acid against skin lesions. The studies were paired and ranked according to their best scientific evidence. Conclusion: After analyzing the clinical trials, which presented scientific solidity, it was noted that there is some promotion of the contribution of ascorbic acid to healing, since it decreases the inflammatory process and leads to neovascularization, to concentration of macrophages, as well as of fibroblasts and collagen fibers. Among the studies analyzed, it is evidenced that the use of ascorbic acid has an effect on the therapeutic process of patients with injuries, but new studies are required to complement this thesis(AU)

Informe diário de evidências COVID-19: busca referente aos dias 1, 2 e 3 de agosto de 2020 / COVID-19 daily evidence report: search related to August 1, 2 and 3, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referentes ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 16 artigos.

Vitamin C for COVID-19: a living systematic review / Vitamina C para COVID-19: una revisión sistemática viva

OBJECTIVE: This living systematic review aims to provide a timely, rigorous, and continuously updated summary of the available evidence on the role of vitamin C in treating patients with COVID-19. DATA SOURCES: We conducted searches in PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), grey literature, and in a centralized repository in L·OVE (Living OVerview of Evidence). In response to the COVID-19 emergency, L·OVE was adapted to expand the range of evidence it comprises and has been customized to group all COVID-19 evidence in one place. All the searches covered the period until April 29, 2020 (one day before submission). STUDY SELECTION AND METHODS: We adapted an already published standard protocol for multiple parallel systematic reviews. We searched for randomized trials evaluating the effect, in patients with COVID-19, of vitamin C versus placebo or no treatment. Anticipating the lack of randomized trials directly addressing this question, we also searched for trials evaluating MERS-CoV and SARS-CoV, and non-randomized studies in COVID-19. Two reviewers independently screened each study for eligibility. A living, web-based version of this review will be openly available during the COVID-19 pandemic, and we will resubmit it to the journal whenever there are substantial updates. RESULTS: We screened 95 records, but no study was considered eligible. We identified 20 ongoing studies, including 13 randomized trials evaluating vitamin C in COVID-19. CONCLUSIONS: We did not find any studies that met our inclusion criteria, and hence there is no evidence to support or refute the use of vitamin C in the treatment of patients with COVID-19. A substantial number of ongoing studies should provide valuable evidence to inform researchers and decision-makers soon.

OBJETIVO: Esta revisión sistemática viva tiene como objetivo proporcionar un resumen oportuno, riguroso y continuamente actualizado de la evidencia disponible sobre el papel de la vitamina C en el tratamiento de pacientes con COVID-19. FUENTES DE DATOS: Realizamos búsquedas en PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), literatura gris y en un repositorio centralizado en L·OVE (Living OVerview of Evidence). En respuesta a la emergencia de COVID-19, L·OVE se adaptó para ampliar el rango de evidencia que cubre y se personalizó para agrupar toda la evidencia de COVID-19 en un solo lugar. Todas las búsquedas abarcaron el período hasta el 29 de abril de 2020 (un día antes de su envío). SELECCIÓN DE ESTUDIOS Y MÉTODOS: Adaptamos un protocolo común publicado para múltiples revisiones sistemáticas paralelas. Se buscaron ensayos aleatorios que evaluaran el efecto de la vitamina C versus placebo o ningún tratamiento en pacientes con COVID-19. Anticipando la falta de ensayos aleatorios que aborden directamente esta cuestión, también buscamos ensayos que evaluaran MERS-CoV y SARS-CoV, y estudios no aleatorios en COVID-19. Dos revisores seleccionaron de forma independiente cada estudio para determinar su elegibilidad. Una versión viva y basada en la web de esta revisión estará abiertamente disponible durante la pandemia de COVID-19, y se volverá a enviar a publicación cuando haya actualizaciones sustanciales. RESULTADOS: Se examinaron 95 registros, pero ningún estudio se consideró elegible. Se identificaron 20 estudios en curso, incluidos 13 ensayos aleatorios que evalúan la vitamina C en COVID-19. CONCLUSIONES: No se encontró ningún estudio que cumpliera con los criterios de inclusión, por lo que no hay evidencia para apoyar o refutar el uso de vitamina C en el tratamiento de pacientes con COVID-19. Un número sustancial de estudios en curso debería proporcionar evidencia valiosa para informar a los investigadores y los tomadores de decisiones en un futuro próximo.

Informe diário de evidências COVID-19: busca realizada em 28 de julho de 2020 / COVID-19 daily evidence report: search conducted on July 28, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referentes ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 18 artigos e 3 protocolos.

Informe diário de evidências COVID-19: busca realizada em 5 de junho de 2020 / COVID-19 daily evidence report: search conducted on June 5, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referente ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 11 artigos e 7 protocolos.

Informe diário de evidências COVID-19: busca realizada entre 9 e 11 de maio de 2020 / COVID-19 daily evidence report: search conducted between May 9 and 11, 2020

Essa é uma produção do Departamento de Ciência e Tecnologia (Decit) da Secretaria de Ciência, Tecnologia, Inovação e Insumos Estratégicos em Saúde (SCTIE) do Ministério da Saúde (Decit/SCTIE/MS), que tem como missão promover a ciência e tecnologia e o uso de evidências científicas para a tomada de decisão do SUS, tendo como principal atribuição o incentivo ao desenvolvimento de pesquisas em saúde no Brasil, de modo a direcionar os investimentos realizados em pesquisa pelo Governo Federal às necessidades de saúde pública. Informar sobre as principais evidências científicas descritas na literatura internacional sobre tratamento farmacológico para a COVID-19. Além de resumir cada estudo identificado, o informe apresenta também uma avaliação da qualidade metodológica e a quantidade de artigos publicados, de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, entre outros). Foram encontrados 16 artigos e 17 protocolos.

Escorbuto. Comunicación de un caso y revisión de la literatura / SCURVY - CASE REPORT AND LITERATURE REVIEW

El escorbuto es una enfermedad ocasionada por el déficit de vitamina C. La vitamina C, también llamada ácido ascórbico, actúa como cofactor de la propil-lisil hidroxilasa, enzima que interviene en la biosíntesis de colágeno; por ello es de vital importancia en la integridad estructural de piel, mucosas, anexos, vasos sanguíneos, huesos y dientes. Las manifestaciones clínicas incluyen síntomas constitucionales severos como debilidad y fatiga. Los hallazgos cutáneos iniciales son pápulas hiperqueratósicas foliculares y púrpura palpable perifolicular. Con el tiempo aparecen áreas extensas de equimosis, edema en miembros inferiores, hemorragias en astillas en uñas y alopecia difusa. Por lo general se describe esta enfermedad como asociada a tiempos pasados y extremadamente infrecuente en países desarrollados. Sin embargo, actualmente se ha detectado un aumento en el número de casos, asociados con malnutrición severa. Desórdenes psiquiátricos como la anorexia nerviosa, alcoholismo y deficiencias nutricionales por dietas excesivas y mal balanceadas o escasez de recursos económicos constituyen los principales factores de riesgo hoy en día. El tratamiento consiste en la corrección del déficit mediante la mediante suplementación con vitamina C vía oral. Presentamos una mujer de 24 años con escorbuto asociado a anorexia nerviosa y a dieta pobre en vegetales y fruta.

Scurvy is a disease caused by a deficit of vitamin C. Vitamin C, also called ascorbic acid, acts as a cofactor for propyl-lysyl hydroxylase, an enzyme that is involved in collagen biosynthesis, vitally important in the structural integrity of skin, mucous membranes, annexes, blood vessels, bones and teeth. Clinical manifestations include severe constitutional symptoms such as weakness and fatigue. The initial cutaneous findings are follicular hyperkeratotic papules and perifollicular palpable purpura. Over time, large areas of ecchymosis, edema of the lower limbs, splinter hemorrhages in nails and diffuse alopecia appear. Usually this disease is described as associated with past times and extremely uncommon in developed countries. However, the number of cases have been increasing, especially those associated with severe malnutrition. Psychiatric disorders such as anorexia nervosa, alcoholism and nutritional deficiencies due to excessive and poorly balanced diets or shortage of economic resources are the main risk factors nowadays. Correcting the deficit with oral vitamin C supplementation is the treatment of the disease. We present a 24-year-old woman with scurvy associated with anorexia nervosa and a diet low in vegetables and fruit.

Escorbuto en el siglo XXI / Scurvy in XXI century

El escorbuto es una enfermedad causada por la deficiencia de vitamina C o ácido ascórbico. Sus manifestaciones clínicas son variadas debido a que esa vitamina es un cofactor de enzimas que intervienen en numerosos procesos, como la síntesis de colágeno y la absorción de diferentes nutrientes. La expresión cutánea característica son las petequias foliculares con pelos en cuello de cisne y en tirabuzón. El compromiso mucoso se manifiesta como hipertrofia y hemorragia gingival, gingivitis y pérdida de piezas dentarias. El diagnóstico es clínico y puede confirmarse mediante la determinación de la vitamina C plasmática o leucocitaria. El tratamiento se basa en el aporte suplementario de esa vitamina. Se presenta el caso de un paciente de 32 años con escorbuto debido a una dieta casi exclusivamente a base de harinas y carente de frutas y verduras. (AU)

Scurvy is a disease caused by vitamin C deficiency (also called ascorbic acid). Its clinical manifestations are varied because this vitamin is a cofactor of enzymes that take part in numerous processes, such as the synthesis of collagen and the absorption of different nutrients. Cutaneous expression of scurvy is follicular petechiae with corkscrew hairs. Mucous involvement manifests as gingival hypertrophy and bleeding, gingivitis and loss of teeth. The diagnosis of this entity is clinical and can be confirmed by plasma or leukocyte vitamin C dosing. The treatment consists of vitamin C supplementation. We present a 32-year-old male patient with scurvy secondary to a diet based almost exclusively on flour and lacking in fruits and vegetables. (AU)

Selenium, vitamin c and n-acetylcysteine do not reduce the risk of acute kidney injury after off-pump cabg: a randomized clinical trial

Abstract Objective: The aim of this study was to investigate the impact of perioperative administration of N-acetylcysteine, selenium and vitamin C on the incidence and outcomes of acute kidney injury after off-pump coronary bypass graft surgery. Methods: 291 patients requiring elective off-pump coronary bypass graft surgery were randomized to receive either N-acetylcysteine, vitamin C and selenium 600 mg, 1500 mg, 0.5 mg, and nothing orally twice a day, respectively, from the day before to 2 days after surgery. They were assessed for the development of acute kidney injury using Acute Kidney Injury Network criteria, time of onset, its severity and duration, duration of mechanical ventilation, intensive care unit and hospital length of stay, and in-hospital mortality. Results: 272 patients completed the study. The total incidence of acute kidney injury was 22.1% (n=60) with 14 (20.9%), 15 (22.1%), 21 (31.8%), and 10 (14.1%) patients in the vitamin C, NAC, selenium, and control groups, respectively (P=0.096). We did not register significant differences in the incidence, the time of occurrence, the severity and the duration of acute kidney injury, as well as the duration of mechanical ventilation, the intensive care unit and hospital length of stay, and the in-hospital mortality among the four groups. Conclusion: We found that perioperative administration of N-acetylcysteine, vitamin C and selenium were not effective in preventing acute kidney injury and associated morbidity and mortality after off-pump coronary bypass graft surgery.

¿Cuál es el efecto del tratamiento con vitamina C en la duración y severidad del resfrío común? / What are the effects of vitamin C on the duration and severity of the common cold?

Resumen INTRODUCCIÓN: El resfrío común causa una gran morbilidad en todo el mundo y no se cuenta con agentes terapéuticos eficaces contra éste. Existe la creencia de que ingerir vitamina C durante un episodio de resfrío ayuda a disminuir la duración y severidad de los síntomas, sin embargo existe controversia respecto a esta afirmación. MÉTODOS: Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cuatro revisiones sistemáticas que en conjunto incluyeron ocho estudios primarios, de los cuales siete son ensayos aleatorizados. Concluimos que la vitamina C tiene un impacto mínimo o nulo en la duración del resfrío y en los días en casa o sin trabajar.

Abstract INTRODUCTION: The common cold causes great morbidity throughout the world and there are no effective therapeutic agents against it. There is a belief that consuming vitamin C during a cold episode would help reduce duration and severity of symptoms. However, there is controversy about this claim. METHODS: To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified four systematic reviews that included eight primary studies overall, of which seven were randomized trials. We concluded vitamin C has minimal or no impact on the duration of common cold or in the number of days at home or out of work.

Treatment with ascorbic acid and alpha-tocopherol modulates oxidative-stress markers in the spinal cord of rats with neuropathic pain

Vitamin E (vit. E) and vitamin C (vit. C) are antioxidants that inhibit nociception. The effect of these vitamins on oxidative-stress markers in the spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve is unknown. This study investigated the effect of intraperitoneal administration of vit. E (15 mg·kg-1·day-1) and vit. C (30 mg·kg-1·day-1), given alone or in combination, on spinal cord oxidative-stress markers in CCI rats. Adult male Wistar rats weighing 200-250 g were divided equally into the following groups: Naive (rats did not undergo surgical manipulation); Sham (rats in which all surgical procedures involved in CCI were used except the ligature), and CCI (rats in which four ligatures were tied loosely around the right common sciatic nerve), which received injections of vitamins or vehicle (saline containing 1% Tween 80) for 3 or 10 days (n=6/each group). The vitamins prevented the reduction in total thiol content and the increase in superoxide-anion generation that were found in vehicle-treated CCI rats. While nitric-oxide metabolites increased in vehicle-treated CCI rats 3 days after surgery, these metabolites did not show significant changes in vitamin-treated CCI rats. In all rats, total antioxidant capacity and hydrogen-peroxide levels did not change significantly. Lipid hydroperoxides increased 25% only in vehicle-treated CCI rats. These changes may contribute to vit. C- and vit. E-induced antinociception, because scavenging reactive oxygen species seems to help normalize the spinal cord oxidative status altered by pain.

Avoiding liver injury with papaverine and ascorbic acid due to infrarenal cross-clamping: an experimental study

Abstract Objective: Ischemia-reperfusion injury after acute ischemia treatment is a serious condition with high mortality and morbidity. Ischemia-reperfusion injury may result in organ failure particularly in kidney, lung, liver, and heart. In our study, we investigated the effects of papaverine and vitamin C on ischemia-reperfusion injury developed in the rat liver after occlusion-reperfusion of rat aorta. Methods: 32 Sprague-Dawley female rats were randomized into four groups (n=8). Ischemia was induced with infrarenal aortic cross-clamping for 60 minutes; then the clamp was removed and reperfusion was allowed for 120 minutes. While the control group and the ischemia-reperfusion group did not receive any supplementary agent, two other groups received vitamin C and papaverine hydrochloride (papaverine HCL). Liver tissues were evaluated under the light microscope. Histopathological examination was assessed by Suzuki's criteria and results were compared between groups. Results: In ischemia-reperfusion group, severe congestion, severe cytoplasmic vacuolization, and parenchymal necrosis over 60% (score 4) were observed. In vitamin C group, mild congestion, mild cytoplasmic vacuolization and parenchymal necrosis below 30% (score 2) were found. In papaverine group, moderate congestion, moderate cytoplasmic vacuolization and parenchymal necrosis below 60% (score 3) were observed. Conclusion: An ischemia of 60 minutes induced on lower extremities causes damaging effects on hepatic tissue. Vitamin C and papaverine are helpful in reducing liver injury after acute ischemia reperfusion and may partially avoid related negative conditions.

Evaluation of antioxidant therapy in experimental Chagas disease

Abstract INTRODUCTION: Stimulation of inflammatory mediators such as cytokines and chemokines may cause oxidative stress in Chagas disease. In this study, we evaluated the merit of vitamins C and E as antioxidant therapy to minimize the oxidative stress-induced damage in an experimental model of Chagas disease. METHODS: Ninety-six Swiss mice were infected with Trypanosoma cruzi QM2 and treated with vitamins C, E, or both (C/E) for 60 and 120 days, and their effects compared to placebo administration were evaluated in the acute and chronic disease phases. RESULTS: There was no difference in parasitemia among treatment groups. However, histological analysis showed more severe inflammation in the skeletal muscle in the vitamin supplementation groups at both the acute and chronic phases. Biochemical analyses during the acute phase showed increased ferric-reducing ability of plasma (FRAP) and glutathione (GSH) levels in the vitamin C and C/E groups. In the chronic phase, a decrease in GSH levels was observed in the vitamin E group and a decrease in thiobarbituric acid reactive substances (TBARS) was observed in the vitamin C/E group. Moreover, there was a decrease in TBARS in the cardiac tissues of the vitamin C and C/E groups compared to that of the placebo group, although this level was greater in the vitamin E group than in the vitamin C group. CONCLUSIONS: The antioxidant action of vitamins C and E reduced oxidative stress in both the acute and chronic phases of Chagas disease, with a marked effect from joint administration, indicating their inherent synergism.

Caracterización de la pulpa de Annona Muricata L. cultivada en el Norte del Departamento de Bolivar - Colombia / Characterization of the pulp of Annona Muricata L. grown in the north of Bolívar Department in Colombia

Introducción: la Annona muricata L. (guanábana) es una de las frutas con mayor contenido vitamínico, además posee minerales como sodio, calcio, magnesio, potasio, fósforo y hierro. En Colombia se comercializa en fresco constituyéndose en toda una industria que representa ganancia para los fruticultores, al ser considerada como una de las frutas tropicales más gustosas y promisorias. Objetivo: caracterizar la pulpa de A. muricata cultivada en norte del departamento de Bolívar-Colombia. Métodos: A. muricata fue recolectada en el municipio de Turbana, ubicado en el norte del departamento de Bolívar (10º 16' 22″ latitud norte y 75º 26' 38″ longitud oeste). La pulpa de la guanábana se obtuvo a partir del fruto; y le se determinó pH, Brix, acidez titulable, índice de madurez, contenido de vitamina C (ácido ascórbico), humedad, ceniza, grasa, proteínas, fibra cruda, carbohidratos y minerales (Ca2+, Mg2+, Na+ , Fe2+ y K+). Resultados: el rendimiento de la pulpa fue del 75 por ciento, los sólidos solubles totales 14,10°Brix, acidez 0,87 por ciento ácido málico, índice de maduración 16,21, pH 3,97, ceniza 0,70 por ciento, humedad 81,49 por ciento, proteína 1,49por ciento, grasa 0,2 por ciento, fibra cruda 1,64 por ciento, carbohidratos 16,12 por ciento y Vitamina C 27,44 mg ácido ascórbico. El mineral más abundante presente en la pulpa de la guanábana es el potasio con un valor de 45,2 mg. Conclusiones: la pulpa de A. muricata es considerado como promisorio para diseñar productos nutracéuticos por su elevado contenido de vitamina C(AU)

Introduction: Annona muricata L. (soursop) is one of the fruits with the highest content of vitamins, as well as minerals like sodium, calcium, magnesium, potassium, phosphorus and iron. In Colombia it is sold fresh, and constitutes a whole industry yielding profits for its growers, being as it is one of the tastiest and promising fruits. Objective: Characterize the pulp of A. muricata grown in the north of Bolívar Department in Colombia. Methods: A. muricata was collected from the municipality of Turbana, in the north of Bolívar Department (10º16?22?N 75º26?38?W). The soursop pulp was obtained from the fruit. Determination was made of pH, Brix, titratable acidity, maturation index, content of vitamin C (ascorbic acid), humidity, ash, fat, proteins, crude fiber, carbohydrates and minerals (Ca2+, Mg2+, Na+, Fe2+ and K+). Results: The following results were obtained: pulp yield 75 percent, total soluble solids 14, 10°Brix, acidity 0.87 percent malic acid, maturation index 16.21, pH 3.97, ash 0.70 percent, humidity 81.49 percent, protein 1.49 percent fat 0.2 percent, crude fiber 1.64 percent, carbohydrates 16.12 percent and vitamin C 27.44 mg ascorbic acid. The most abundant mineral in soursop pulp was potassium, with 45.2 mg. Conclusions: A. muricata pulp is considered to be promising for the design of nutraceutical products, due to its high vitamin C content(AU)

Ascorbic acid in the prevention and treatment of cancer / Ácido ascórbico na prevenção e no tratamento do câncer

Summary This review is aimed at the systematic mapping of ascorbic acid in the prevention and/or treatment of cancer in clinical and non-clinical studies from 2011 to 2015, in order to understand dose-response variations as well as its mechanisms of action as an antioxidant and antitumor agent. Seventy-eight articles were retrieved from the PubMed/Bireme database, of which only 30 included ascorbic acid in the prevention and/or treatment of cancer. However, there are controversies regarding doses and a lack of clinical studies featuring its mechanism of action more clearly. Other studies are needed to understand dose-response variations, as well as its targeting mechanisms of action, both as an antioxidant and antitumor agent, to assist treatment and prevention of cancer, aiming at better quality of life for both patients and the general population.

Resumo Este estudo de revisão teve como objetivo fazer o mapeamento sistemático do ácido ascórbico na prevenção e/ou no tratamento do câncer como antioxidante e/ou pró-oxidante em estudos clínicos e não clínicos, entre 2011 e 2015, para o entendimento das variações de dose-resposta, bem como dos seus mecanismos de ação como agente antioxidante e antitumoral. Nas bases de dados Pubmed e Bireme, foram identificados 78 artigos, dos quais apenas 30 apontavam o ácido ascórbico na prevenção e/ou no tratamento do câncer. Contudo, há controvérsias sobre as doses utilizadas e faltam estudos clínicos que caracterizem melhor o seu mecanismo de ação. Outros estudos devem ser realizados para o entendimento das variações de dose-resposta, bem como de seus mecanismos de ação, como agente antioxidante ou antitumoral, para auxiliar o tratamento e a prevenção do câncer, visando à melhor qualidade de vida dos pacientes e da população em geral.

Radioiodine-induced oxidative stress in patients with differentiated thyroid carcinoma and effect of supplementation with vitamins C and E and selenium (antioxidants)

ABSTRACT Objective The objective of this study, in addition to confirming that therapy with 131I causes oxidative stress, was to evaluate the effect of supplementation with vitamins C and E and selenium on this phenomenon by measuring plasma 8-epi-PGF2a, a marker of lipid peroxidation. Subjects and methods Forty patients with thyroid cancer submitted to thyroidectomy, who received 3.7 GBq 131I after levothyroxine withdrawal, were selected; 20 patients did not receive (control group) and 20 patients received (intervention group) daily supplementation consisting of 2000 mg vitamin C, 1000 mg vitamin E and 400 µg selenium for 21 days before 131I. Plasma 8-epi-PGF2a was measured immediately before and 2 and 7 days after 131I. Results A significant increase in plasma 8-epi-PGF2a after 131I was observed in the two groups. The concentrations of 8-epi-PGF2α were significantly higher in the control group before and 2 and 7 days after 131I. The percentage of patients with elevated 8-epi-PGF2α was also significantly higher in the control group before and after 131I. Furthermore, the increase (percent) in 8-epi-PGF2α was significantly greater in the control group (average of 112.3% versus 56.3%). Only two patients (10%) reported side effects during supplementation. Conclusions Ablation with 131I causes oxidative stress which can be minimized by the use of antioxidants.