Modulator effect of watercress against cyclophosphamide-induced oxidative stress in mice

Watercress (Nasturtium officinale, Cruciferae; W. Aiton) is a vegetable widely consumed in our country, with nutritional and potentially chemopreventive properties. Previous reports from our laboratory demonstrated the protective effect of watercress juice against DNA damage induced by cyclophosphamide in vivo. In this study, we evaluated the in vivo effect of cress plant on the oxidative stress in mice. Animals were treated by gavage with different doses of watercress juice (0.5 and 1g/kg body weight) for 15 consecutive days before intraperitoneal injection of cyclophosphamide (100 mg/kg body weight). After 24 h, mice were killed by cervical dislocation. The effect of watercress was investigated by assessing the following oxidative stress biomarkers: catalase activity, superoxide dismutase activity, lipid peroxidation, and glutathione balance. Intake of watercress prior to cyclophosphamide administration enhanced superoxide dismutase activity in erythrocytes with no effect on catalase activity. In bone marrow and liver tissues, watercress juice counteracted the effect of cyclophosphamide. Glutathione balance rose by watercress supplementation and lipid oxidation diminished in all matrixes when compared to the respective control groups. Our results support the role of watercress as a diet component with promising properties to be used as health promoter or protective agent against oxidative damage.

El berro (Nasturtium officinale, crucíferas; W. Aiton) es una hortaliza ampliamente consumida en nuestro país, con valor nutricional y propiedades potencialmente quimiopreventivas. En trabajos previos demostramos que el jugo de berro tiene efecto protector in vivo contra el daño del ADN inducido por ciclofosfamida en tejidos del ratón. En el presente trabajo evaluamos, también in vivo, los efectos del jugo sobre el estrés oxidativo en diferentes tejidos del ratón. Los siguientes biomarcadores fueron investigados: actividad de superóxido dismutasa, actividad de catalasa, peroxidación lipídica y balance de glutatión. Los animales fueron tratados con diferentes dosis de jugo (0.5 y 1 g/kg de peso corporal) por alimentación forzada durante 15 días consecutivos antes de la inyección intraperitoneal con ciclofosfamida (100 mg/kg). La ingesta de berro antes de la administración de ciclofosfamida mejoró la actividad de superóxido dismutasa en los eritrocitos sin efecto sobre la actividad de la catalasa. En médula ósea e hígado, el jugo de berro contrarrestó el efecto deletéreo de la ciclofosfamida. En todas las matrices, el balance de glutatión fue mayor y la oxidación de lípidos menor que los valores encontrados en los grupos control. Nuestros resultados demuestran que el berro es un componente de la dieta con propiedades prometedoras como promotor de la salud o como agente protector contra el daño oxidativo.

Defensas antioxidantes en la insuficiencia renal crónica experimental / Antioxidant defenses in the experimental chronic renal failure

OBJETIVO: Evaluar el comportamiento de las defensas antioxidantes en relación con las modificaciones funcionales progresivas en la insuficiencia renal crónica experimental. MÉTODOS: Estudio experimental controlado en 40 ratas Wistar provocando insuficiencia renal por ablación de 5/6 de la masa renal. La muestra se dividió en 4 grupos de 10 animales, 1 grupo control y 3 experimentales (E) sometidos a extirpación del riñón derecho y ligadura de dos ramas de la arteria renal izquierda. El grupo experimental E-I evolucionó 2 sem después de la nefrectomía, el grupo E-II 4 sem y el grupo E-III durante 6 semanas. Se realizó aclaramiento plasmático de ácido paraminohipúrico (PAH) e inulina (I) para medir flujo plasmático renal efectivo (FPR) e intensidad de filtración glomerular (IFG) respectivamente. Los cambios de IFG y FPR permitieron constatar las modificaciones funcionales a medida que progresaba la insuficiencia renal. Los indicadores de defensa antioxidante incluyeron la actividad de la enzima superóxido dismutasa (SOD) y los niveles de glutatión reducido (GSH), medidos en homogenado de riñón. Se realizó análisis de regresión lineal para relacionar cambios funcionales y defensas antioxidantes. RESULTADOS: La función renal decreció progresivamente después de la nefrectomía. Se produjo disminución de la actividad de la SOD seguida de una superinducción a las 6 semanas y los niveles de GSH comenzaron a disminuir en la 4ta. sem posnefrectomía. CONCLUSIONES: Los cambios en los indicadores de defensa antioxidante a nivel renal sugieren que el estrés oxidativo aumenta en el órgano correlacionßndose con la pérdida progresiva de la función renal

OBJECTIVE: to evaluate the changes on antioxidant defenses in kidneys while function changes on remaining tissue during progression of renal failure after performing subtotal nephrectomy. METHODS: an experimental trial in 40 Wistar rats was done. The renal failure was induced by surgical ablation of 5/6 of the renal mass, removing the right kidney and tying two branches of the left renal artery to 30 rats; 3 study groups were formed and followed over a period of 2, 4, and 6 weeks. The remaining group of rats was used as control. Functional remainder state was evaluated by measurement of the Glomerular Filtration Rate (GFR) and effective Renal Plasmatic Flow (RPF), through renal plasmatic clearance methods. Measurement of reduced glutathione (GSH) and superoxide dismutase activity (SOD) in renal mass were used as markers of antioxidant defense. Lineal correlation was used to analyze correlations between progressive functional changes and oxidative status. RESULTS: Progressive decreasing of both GFR and RPF were noted. SOD activity diminished initially followed by a super induction at 6th week and GSH levels decreased markedly at 4th week after nephrectomy. CONCLUSION: The variations of antioxidant defenses markers on renal tissue suggest that oxidative stress increases in the remainder kidney correlated to the progressive reduction of the renal function

Bases metabólicas da suplementação de cisteína / Metabolic Basis of supplemental cysteine / Metabólicas Bases de cisteína suplementaria

A cisteína (Cys) é um aminoácido sulfurado produzido, endogenamente, a partir da transulfuração da homocisteína. É limitante da síntese da glutationa, principal antioxidante (peroxidase) solúvel no citosol e maior fonte sulfurada endógena. Adicionalmente, a Cys origina a taurina (Tau) com papel neurotransmissor, inativador de ácidos biliares, osmolito intracelular e agente antioxidante intrafagocitário. Apenas o fígado, pãncreas e rins formam Cys a partir da metionina (Met). Nos demais tecidos, a principal fonte de Cys é a sua concentração plasmática ou as de GSH e GSSG (desde que a célula contenha y-glutamil transpeptidase e dipeptidase). A Cys (SH) é instável e se oxida facilmente a cistina (S-S), forma predominante no plasma. As células desprovidas de redutase, como os linfócitos, não convertem a Cis (S-S) a Cys (SH) e tornam-se dependentes da Cys gerada por outras células sanguíneas ou da Cys plasmática. A Cys ativa a proliferação celular e as funções de quimiotaxia, fagocitose e citoxicidade natural (de células malignas). A deficiência de Cys está associada não apenas aos menores níveis de GSH e menor defesa antioxidante, mas também à diminuição de glutamina e consequente deficiência imunitária. Não há recomendações específicas para a Cys.A RDA para Met+Cys é de 17 mg/g...

The cysteine (Cys) is a sulfur-containing amino acid produced endogenously from the transsulfuration of homocysteine. It is limiting the synthesis of glutathione, the main antioxidant (peroxidase) soluble in the cytosol and increased endogenous sulfur source. Additionally, Cys originates taurine (Tau) with paper neurotransmitter inactivation of bile acids, intracellular osmolyte and antioxidant agent intrafagocitário. Only liver, pancreas and kidneys form Cys from methionine (Met). In other tissues, the main source of Cys is its plasma concentration or GSH and GSSG (as long as the cell containing y-glutamyl transpeptidase and dipeptidase). The Cys (SH) is unstable and easily oxidized to cystine (SS), the predominant form in plasma. Cells devoid of reductase, such as lymphocytes, do not convert to Cys (SS) to Cys (SH) and become dependent on Cys generated by other blood cells or plasma Cys. The Cys active cell proliferation and functions of chemotaxis, phagocytosis, and natural cytotoxicity (malignant cells). Cys deficiency is associated not only with lower levels of GSH and lower antioxidant defense, but also to the decrease of glutamine and subsequent immune deficiency. There are no specific recommendations for Cys.A for Met + Cys RDA is 17 mg / g...