RESUMEN
Dietary fiber can affect cadmium (Cd) absorption and toxicity, but the effect appears to depend on the type of dietary fiber. The aim of the present study was to compare the effect of dietary sources containing distinct amounts of soluble and insoluble fiber on Cd absorption, accumulation and toxicity in growing rats. The absorption of essential macrominerals (Ca, P and Mg) was also evaluated. Animals received a nutritionally balanced diet with cellulose (cel - control), wheat bran or flaxseed as the fiber source with 0 or 50 mg Cd kg(-1) diet, during 30 days. Cd exposure reduced body weight gain, feed efficiency ratio, epididymal fat relative weight and liver relative weight, and increased plasma alanine aminotransferase activity in all fiber groups. The apparent Cd absorption was similar among Cd-groups, but the flax-Cd group had a higher hepatic and renal Cd concentration. Cd decreased the absorption of Ca and P, and increased Mg absorption in the wheat bran and flaxseed groups, but not in the cel group. Although the different fiber sources investigated had no effect on Cd toxicity, the major soluble fiber source, flaxseed, increased Cd retention. Thus, caution should be taken in the intake of flaxseed by Cd-exposed populations.
Asunto(s)
Cloruro de Cadmio , Fibras de la Dieta/uso terapéutico , Contaminantes Ambientales , Lino/química , Preparaciones de Plantas/uso terapéutico , Semillas/química , Absorción , Animales , Peso Corporal/efectos de los fármacos , Cloruro de Cadmio/farmacocinética , Cloruro de Cadmio/envenenamiento , Intoxicación por Cadmio/dietoterapia , Intoxicación por Cadmio/metabolismo , Contaminantes Ambientales/farmacocinética , Contaminantes Ambientales/envenenamiento , Riñón/efectos de los fármacos , Riñón/metabolismo , Pruebas de Función Renal , Hígado/efectos de los fármacos , Hígado/metabolismo , Pruebas de Función Hepática , Masculino , Tamaño de los Órganos/efectos de los fármacos , Preparaciones de Plantas/química , Ratas , Ratas Wistar , SolubilidadRESUMEN
Strategies to diminish cadmium (Cd) absorption are highly desirable especially where Cd exposure due to environmental contamination is still inevitable. Cd toxicity may be influenced by dietary components, such as fiber and minerals. Multimixtures are low-cost cereal bran supplements used in Brazil and in other countries to counteract malnutrition in low-income populations. This study was aimed at evaluating whether multimixture would reduce Cd effects in young rats. Animals received a diet with or without the multimixture plus 0, 5, or 25 mg Cd/kg (control, Cd-5, and Cd-25 groups) during 30 days. The Cd-5 groups were similar to control groups in all parameters analyzed, except in the higher renal Cd concentration. However, the Cd-25 groups had lower biological growth parameters and renal delta-aminolevulinate dehydratase activity, besides higher renal Cd concentration and plasma alanine aminotransferase activity compared to the controls. The multimixture did not prevent Cd effects in the Cd-25 group, but caused a small reduction in renal Cd concentration in the Cd-5 group. Although this multimixture was ineffective to prevent Cd effects at the higher concentration, it seemed to reduce Cd accumulation at the lower Cd dietary concentration, which is similar to levels of human exposure in some polluted areas.