RESUMO
Hemodialysis patients face an elevated risk of cancer, arteriosclerosis, and other diseases, ascribed in part to increased oxidative stress. Red fruit juice with high anthocyanin/polyphenol content had been shown to reduce oxidative damage in healthy probands. To test its preventive potential in hemodialysis patients, 21 subjects in a pilot intervention study consumed 200 mL/day of red fruit juice (3-week run-in; 4-week juice uptake; 3-week wash-out). Weekly blood sampling was done to monitor DNA damage (comet assay +/- formamidopyrimidine-DNA glycosylase enzyme), glutathione, malondialdehyde, protein carbonyls, trolox equivalent antioxidant capacity, triglycerides, and DNA binding capacity of the transcription factor nuclear factor-kappaB. Results show a significant decrease of DNA oxidation damage (P < 0.0001), protein and lipid peroxidation (P < 0.0001 and P < 0.001, respectively), and nuclear factor-kappaB binding activity (P < 0.01), and an increase of glutathione level and status (both P < 0.0001) during juice uptake. We attribute this reduction in oxidative (cell) damage in hemodialysis patients to the especially high anthocyanin/polyphenol content of the juice. This provides promising perspectives into the prevention of chronic diseases such as cancer and cardiovascular disease in population subgroups exposed to enhanced oxidative stress like hemodialysis patients.
Assuntos
Antocianinas/metabolismo , Antioxidantes/metabolismo , Bebidas , Flavonoides/metabolismo , Frutas/química , Oxirredução/efeitos dos fármacos , Fenóis/metabolismo , Diálise Renal , Adulto , Idoso , Análise de Variância , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Feminino , Glutationa/sangue , Humanos , Hidrazonas/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , NF-kappa B/sangue , Projetos Piloto , Polifenóis , Estatísticas não Paramétricas , Triglicerídeos/sangueRESUMO
Acrylamide (AA) is a carcinogen as demonstrated in animal experiments, but the relevance for the human situation is still unclear. AA and its metabolite glycidamide (GA) react with nucleophilic regions in biomolecules. However, whereas AA and GA react with proteins, DNA adducts are exclusively formed by GA under conditions simulating in vivo situations. For risk assessment it is of particular interest to elucidate whether AA or GA within the plasma concentration range resulting from food intake are "quenched" by preferential reaction with non-critical blood constituents or whether DNA in lymphocytes is damaged concomitantly under such conditions. To address this question dose- and time-dependent induction of hemoglobin (Hb) adducts as well as genotoxic and mutagenic effects by AA or GA were studied in human blood as a model system.