High 15-F2t-Isoprostane Levels in Patients with a Previous History of Nonmelanoma Skin Cancer: The Effects of Supplementary Antioxidant Therapy.

BACKGROUND: Phase I of this study was aimed at comparing the profiles of oxidative stress biomarkers in patients with history of nonmelanoma skin cancer (NMSC), previously treated with surgery, to the healthy subjects. Phase II aimed to evaluate the effects of supplementary antioxidant therapy on the levels of biomarkers in the case group. MATERIALS AND METHODS: In Phase I, oxidative stress biomarkers were measured in blood samples obtained from 24 healthy subjects and 60 patients with history of NMSC previously treated with surgery. In Phase II, the 60 patients with history of NMSC were randomized into two subgroups, one receiving placebo (n = 34) and the other (n = 26) receiving vitamin C, vitamin E, and zinc supplementation for 8 weeks, followed by reevaluation of biomarkers. RESULTS: In Phase I, patients with history of NMSC showed increased plasma concentrations of all biomarkers, but only 15-F2t-isoprostane was significantly higher than in the healthy subjects. Risk of NMSC increased by 4% for each additional 1 pg/mL increase in 15-F2t-isoprostane. In Phase II, supplementation did not significantly reduce levels of oxidative stress biomarkers. CONCLUSION: Patients with history of NMSC had significantly high 15-F2t-isoprostane plasma levels; supplementation did not result in significant reduction of oxidative stress biomarkers. This trial was registered with ClinicalTrials.gov (ID NCT02248584).

Antioxidant capacity total in non-melanoma skin cancer and its relationship with food consumption of antioxidant nutrients.

The non-melanoma skin cancer is the most common cancer and accounts for more than half of the diagnoses of cancer, and basal cell carcinoma (BCC), the most frequent cutaneous neoplasm, corresponding to 70-80% of cutaneous tumors. Oxidative stress is an important trigger for skin carcinogenesis. Thus, it is important to evaluate oxidative stress, in order to discern effective therapeutic strategies able to stop it or attenuate it, thereby prevent the installation of non-melanoma skin cancer. Cross-sectional study with controls, involving 84 individuals of both sexes aged between 38-84 years, divided into two groups: control group of healthy people(n = 24) and the case group included individuals who presented non-melanoma skin and they have undergoing surgery (n = 60). The blood samples of the individuals were obtained for evaluation of biomarkers of oxidative stress (F2-isoprostane, nitrite, thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity). The usual dietary intake and nutritional status of the subjects were evaluated. The significance level for this study was 5%. Patients in the case group had higher serum concentrations of biomarkers of oxidative stress, F2-isoprostane concentrations were significantly higher compared to controls. The results showed high rates of overweight and obesity in the case and control groups. The dietary concentrations of antioxidant minerals zinc, copper and selenium in the case group were significantly lower compared to controls. The correlation between markers of oxidative stress and dietary concentrations of antioxidant nutrients showed the influence of food intake of vitamins A and E in reducing oxidative stress, since these nutrients behave as important antioxidants, acting as sweepers of RL, by removing of the body the negative effects on the redox balance of the skin. We emphasize the importance of adopting healthy eating habits that optimize the consumption of antioxidant nutrients as a strategy to prevent oxidative damage to the skin.

El cáncer de piel no melanoma es el cáncer más común y representa más de la mitad de los diagnósticos de cáncer, y el carcinoma de células basales (BCC), la neoplasia cutánea más frecuente, representando el 70-80% de los tumores cutáneos. El estrés oxidativo es un disparador importante en la carcinogénesis de la piel. Por lo tanto, es importante para evaluar el estrés oxidativo, con el fin de prever y estrategias terapéuticas eficaces capaces de detener o mitigar ella, para evitar de este modo la instalación de cáncer de piel no melanoma. Estudio transversal con los controles, con la participación de 84 sujetos de ambos sexos con edades comprendidas entre 38 a 84 años, divididos en dos grupos: grupo control de sujetos sanos (n = 24) personas y el grupo de casos incluyeron los individuos que presentaron para el cáncer de piel no melanoma tiene someterse a la cirugía (n = 60). Las muestras de sangre de los sujetos fueron obtenidos para la evaluación de los biomarcadores de estrés oxidativo (F2-isoprostano, nitritos, sustancias reactivas al ácido tiobarbitúrico (TBARS) y capacidad antioxidante total). Se evaluó la ingesta dietética habitual y el estado nutricional de los sujetos. El nivel de significación para este estudio fue de 5%. Los pacientes en el grupo de casos tenían mayores concentraciones séricas de biomarcadores de estrés oxidativo, las concentraciones de F2-isoprostano fueron significativamente mayor en comparación con los controles. Los resultados mostraron altas tasas de sobrepeso y obesidad en los grupos de casos y controles. Las concentraciones dietéticas de antioxidante minerales de zinc, cobre y selenio en el grupo de casos fueron significativamente más bajos en comparación con los controles. La correlación entre los marcadores de estrés oxidativo y las concentraciones dietéticas de nutrientes antioxidantes destacó la influencia de la ingesta de alimentos de vitaminas A y E en la reducción del estrés oxidativo, ya que estos nutrientes se comportan como antioxidantes importantes, actuando como barrenderos RL, el cuerpo se deshaga de estos efectos negativos sobre el equilibrio redox de la piel. Hacemos hincapié en la importancia de adoptar hábitos de alimentación saludables que optimizan el consumo de nutrientes antioxidantes como estrategia para prevenir el daño oxidativo de la piel.

Hypoalbuminemia and oxidative stress in patients on renal hemodialysis program.

INTRODUCTION: Albumin is considered an important extracellular antioxidant molecule. hypoalbuminemia is a strong and independent predictor of mortality in patients on hemodialysis. The present study evaluated the relation between hypoalbuminemia and oxidative stress by comparing superoxide dismutase activity, lipid peroxidation and antioxidant micronutrient consumption in chronic renal failure patients. METHODS: A case-control study was carried out with 64 patients of both sexes aged 18 to 59 years. The patients with hypoalbuminemia (ALB < 3,5 g/dL) were defined as case (n = 26) and control (n = 38) those with ALB ≥ 3.5 g/dL.Determinations of activity superoxide dismutase (SOD)and nitric oxide production by the contraction of nitrite in erythrocytes, concentration of malondialdehyde (MDA)in plasma, lipid profile and micronutrient antioxidants intake were performed. For comparisons between groups,the Student t test was used. Possible associations between variables were tested using the chi-square test and Pearson correlation test. RESULTS: Consumption of copper was significantly lower(p < 0.05) in the group with hypoalbuminemia. There was a positive correlation between the concentrations of albumin and intake copper (r = 0.280). Negative correlation was found between albumin and MDA concentrations. CONCLUSION: Hypoalbuminemia is associated with increased lipid peroxidation, and can contribute to oxidative stress in chronic renal failure patients. Additionally, patients with chronic renal disease undergoing hemodialysis evaluated in this study had reduced consumption of cooper.

Introducción: La albumina se considera una molecula antioxidante extracelular importante. La hipoalbuminemia es un predictor fuerte e independiente de mortalidad en pacientes en hemodialisis. El presente estudio evaluo la relacion entre hipoalbuminemia y el estres oxidativo mediante la comparacion de la actividad de la superoxido dismutasa, la peroxidacion lipidica y el consumo de micronutrientes antioxidantes en pacientes con insuficiencia renal cronica. Métodos: Este estudio de casos y controles se llevo a cabo con 64 pacientes de ambos sexos de 18 a 59 anos. Los pacientes con hipoalbuminemia (ALB < 3,5 g / dL) se definieron como los casos (n = 26) y el grupo control (n = 38) aquellos con ALB ≥ 3,5 g/dL. Fueran realizadas determinaciones de la actividad de la superoxido dismutasa en los eritrocitos, la produccion de oxido nitrico por la contraccion de nitrito e concentracion de malondialdehido (MDA) en plasma, el perfil de lipidos en plasma, la ingesta de proteinas y micronutrientes antioxidantes se realizaron. Para las comparaciones entre grupos, se utilizo la prueba t de Student. Posibles asociaciones entre variables se analizaron mediante el test de correlacion lineal y Pearson y en la prueba de chi-cuadrado. Resultados: El consumo de cobre fue significativamente menor (p < 0,05) para el grupo con hipoalbuminemia. Correlaciones entres las concentraciones de albumina y el uso de cobre (r = 0,280). Se encontro correlacion negativa entre las concentraciones de albumina y MDA. Conclusión: La hipoalbuminemia se asocia con aumento de la peroxidacion lipidica, y puede contribuir al estres oxidativo en pacientes con insuficiencia renal cronica. Ademas, los pacientes con enfermedad renal cronica sometidos a hemodialisis evaluados en este estudio habian reducido el consumo de cobre.