Efecto de una dieta hipocalórica en el estrés oxidativo en sujetos obesos sin prescripción de ejercicio y antioxidantes / Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants

Fundamento y objetivo: La obesidad se caracteriza por un aumento generalizado de tejido adiposo, alta producción de adipocitocinas y presencia de estrés oxidativo sistémico. El objetivo de este estudio fue evaluar los cambios generados en el estrés oxidativo y los parámetros antropométricos en sujetos obesos por la prescripción de una dieta hipocalórica en combinación con ejercicio aeróbico moderado y suplementación con antioxidantes. Pacientes y métodos: El daño oxidativo fue determinado en el plasma de 30 sujetos con normopeso y 30 sujetos obesos. Se consideraron 3 grupos de tratamiento: dieta hipocalórica (DH), DH más ejercicio aeróbico moderado (DHE), y DHE más antioxidantes (DHEA). Se determinaron biomarcadores de daño oxidativo (compuestos reactivos al ácido tiobarbitúrico [CRAT], grupos carbonilo, ditirosinas) y valores de parámetros antropométricos. Resultados: Se observaron valores incrementados en biomarcadores de daño oxidativo en sujetos obesos (13.74 ± 1.2 uM, carbonilos 0,89 ± 0,04 nmoles de osazonas/mg de proteína, ditirosinas 478,9 ± 27,4 URF/mg de proteína) en comparación con sujetos con normopeso (CRAT 7,08 ± 0,8 uM, carbonilos 0,65 ± 0,04 nmoles de osazonas/mg de proteína, ditirosinas 126,3 ± 12,6 URF/mg de proteína), demostrando la presencia de un daño oxidativo. La prescripción de DH disminuyó el daño oxidativo y los parámetros antropométricos en el sujeto obeso. No se observaron efectos benéficos adicionales en estas determinaciones con los tratamientos DHE o DHEA. Conclusiones: Demostramos que una DH reduce el daño oxidativo en sujetos obesos. El estrés oxidativo es un factor importante en el desarrollo de comorbilidades en obesidad. Por lo tanto, la prescripción de una DH podría ser un punto clave en el tratamiento de la enfermedad (AU)

Background and objective: Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants. Patients and methods: Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined. Results: Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 μM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 μM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments. Conclusions: We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease (AU)

[Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants]. / Efecto de una dieta hipocalórica en el estrés oxidativo en sujetos obesos sin prescripción de ejercicio y antioxidantes.

BACKGROUND AND OBJECTIVE: Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants. PATIENTS AND METHODS: Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined. RESULTS: Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 µM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 µM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments. CONCLUSIONS: We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease.

Arginase activity in patients with breast cancer: an analysis of plasma, tumors, and its relationship with the presence of the estrogen receptor.

BACKGROUND: Breast cancer is an important cause of cancerrelated death in women. In this pathological condition, arginase plays a role by providing ornithine as a substrate for the biosynthesis of polyamines which are important in tumor progression. The aim of this work was to determine the arginase activity in the plasma and tumors of patients with breast cancer; also, we investigated the relationship between this activity and the presence of the estrogen receptor. PATIENTS AND METHODS: We evaluated the plasma arginase activity levels in 80 women with breast cancer and 42 healthy control subjects. We also measured the arginase levels in 42 breast cancer biopsies and 42 control tissues. RESULTS: The mean activity of arginase in plasma was higher in breast cancer patients (0.78 nM/min/mg protein ± 0.04; p = 0.001) than in healthy volunteers (0.53 nM/ min/mg protein ± 0.04); however, this difference was indicative of patients in the advanced stages of the disease (n = 38, stage III; p < 0.0001). In addition, we did not find a relationship between the estrogen receptor and arginase activity. CONCLUSION: Our results show a higher arginase activity in the plasma of patients in the advanced stages of the disease, suggesting that arginase activity could serve as a possible biological marker of breast cancer progression.

Stimulatory effects of the flavanol (-)-epicatechin on cardiac angiogenesis: additive effects with exercise.

The consumption of moderate amounts of cocoa products has been associated with reductions in the incidence of cardiovascular diseases. In animal studies, the flavanol (-)-epicatechin (Epi) yields cardioprotection. The effects may be partly due to its capacity to stimulate endothelial nitric oxide synthase (eNOS). The sustained activation of eNOS, as observed with exercise, can serve as a trigger of muscle angiogenesis via the activation of vascular endothelial growth factor (VEGF)-related events. Experiments were pursued to examine the potential of Epi to stimulate myocardial angiogenesis and determine the effects that its combined use with exercise (Ex) may trigger. Hearts obtained from a previous study were used for this purpose. Animals received 1 mg/kg of Epi or water (vehicle) via oral gavage (twice daily). Epi and/or Ex (by treadmill) was provided for 15 days. Results indicate that Ex or Epi significantly stimulate myocardial angiogenesis by ~30% above control levels. The use of Epi-Ex lead to further significant increases (to ~50%). Effects were associated with increases in protein levels and/or activation of canonical angiogenesis pathway associated events (HIF1a, VEGF, VEGFR2, PI3K, PDK, AKT, eNOS, NO, cGMP, MMP-2/-9, Src-1, and CD31). Thus, the use of Epi may represent a safe and novel means to stimulate myocardial angiogenesis.