RESUMO
Reactive oxygen species are implicated as mediators of tissue damage in the acute renal failure induced by inorganic mercury. Astaxanthin (ASX), a carotenoid with potent antioxidant properties, exists naturally in various plants, algae, and seafoods. This paper evaluated the ability of ASX to prevent HgCl(2) nephrotoxicity. Rats were injected with HgCl(2) (0 or 5 mg/kg b.w., sc) 6h after ASX had been administered (0, 10, 25, or 50mg/kg, by gavage) and were killed 12h after HgCl(2) exposure. Although ASX prevented the increase of lipid and protein oxidation and attenuated histopathological changes caused by HgCl(2) in kidney, it did not prevent creatinine increase in plasma and delta-aminolevulinic acid dehydratase inhibition induced by HgCl(2). Glutathione peroxidase and catalase activities were enhanced, while superoxide dismutase activity was depressed in HgCl(2)-treated rats when compared to control and these effects were prevented by ASX. Our results indicate that ASX could have a beneficial role against HgCl(2) toxicity by preventing lipid and protein oxidation, changes in the activity of antioxidant enzymes and histopathological changes.
Assuntos
Antioxidantes/farmacologia , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Cloreto de Mercúrio/antagonistas & inibidores , Cloreto de Mercúrio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Biomarcadores , Glutationa Transferase/metabolismo , Rim/efeitos dos fármacos , Rim/enzimologia , Testes de Função Renal , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Necrose/induzido quimicamente , Necrose/patologia , Sintase do Porfobilinogênio/metabolismo , Carbonilação Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Xantofilas/farmacologiaRESUMO
The lead and calcium content of calcium supplements available in Brazil were determined by graphite furnace and flame atomic absorption spectrometry, respectively. Samples were microwave-digested in concentrated HNO(3). Citric acid was used as a chemical modifier in the lead analysis. Supplements were classified into six categories: oyster industrialized (OI, n=4), oyster prepared in pharmacy (OP, n=3), refined industrialized (RI, n=6), refined prepared in pharmacy (RP, n=3), bone meal (B, n=3), and dolomite (D, n=4). Lead levels (microg g(-1) of measured calcium) were higher in D products (2.33), followed by OI, RP, OP, and RI products (1.46, 1.32, 1.29, 0.75), while B products had levels lower than the limit of quantification (0.02 microg g(-1) unit weight). Daily lead intake of eight supplements exceeded the limit of California, USA (1.5 microg g(-1) calcium), but none exceeded the federal limit of USA (7.5 microg g(-1) calcium) or the provisional tolerable lead intake by FAO/WHO (25 microg kg(-1) per week).