Kefir reduces nitrosative stress and upregulates Nrf2 in the kidney of diabetic rats

Abstract The aim was to analyse whether Kefir activates nuclear erythroid 2-related factor 2 (Nrf2) under hyperglycaemic conditions in the kidneys of diabetic rats (DM). DM received kefir for 8 weeks (DMK group). There was a significant reduction in water and chow intake, reduction in diuresis and glycaemia in DMK versus DM, the protein levels of catalase (CAT), superoxide dismutase-1 (SOD-1) and Nrf2 were significantly increased and 3-nitrotyrosine (3-NT) was significantly reduced. Glycaemia had a moderate correlation with NO or superoxide anion and a strong correlation with 3-NT. Kefir improved the metabolic profile, reducing blood glucose and increasing the concentration of Nrf2, modulating CAT and SOD-1 in the renal cortex of diabetic animals, thus contributing to reduced oxidative/nitrosative stress in these animals. These data suggest that kefir could be used as an additional therapy to improve glycaemic control and restore antioxidant defence in the progression of diabetic nephropathy.