RESUMO
Sodium tungstate is an alternative to reduce hyperglycemia for the treatment of diabetes. In previous work, we showed that the administration of sodium tungstate increased the specific activity of salivary amylase in the parotid gland. Here, we investigated the effect of the administration of sodium tungstate on the lipid peroxidation and some antioxidant parameters in the submandibular (SM) and parotid (PA) salivary glands of streptozotocin (STZ)-induced diabetic rats. Thirty-two male Wistar rats were divided into four groups (n = 8, each): control (C), control treated with sodium tungstate (CT), diabetic (D), and diabetic treated with sodium tungstate (CT). Sodium tungstate (2 mg/ml) was administered to the STZ-induced diabetic rats for 15 days. Malondialdehyde (MDA), reduced (GSH) and oxidized (GSSG) glutathione, and blood glucose concentrations were quantified. In addition, superoxide dismutase (SOD) and catalase (CAT) activities were assessed. Results revealed that diabetes caused an increase in MDA concentration in both glands, a reduction in the SOD activity in SM, and an increase in catalase activity in PA glands. Administration of sodium tungstate reduced the blood glucose levels and normalized the SOD activity in the SM and MDA levels in both glands of the STZ-induced diabetic rats. Catalase activity was increased in PA glands of diabetic and tungstate-treated animals (p < 0.05). The GSH/GSSG ratio was increased in SM glands of tungstate-treated animals (p < 0.05). Overall, the reduction of hyperglycemia by sodium tungstate reduced lipid peroxidation and caused alterations in the antioxidant system in the salivary glands of STZ-induced diabetic rats.