Kefir administration reduced progression of renal injury in STZ-diabetic rats by lowering oxidative stress

Abstract

This study aimed at assessing the effects of Kefir, a probiotic fermented milk, on oxidative stress in diabetic animals. The induction of diabetes was achieved in adult male Wistar rats using streptozotocin (STZ). The animals were distributed into four groups as follows: control (CTL); control Kefir (CTLK); diabetic (DM) and diabetic Kefir (DMK). Starting on the 5th day of diabetes, Kefir was administered by daily gavage at a dose of 1.8 mL/day for 8 weeks. Before and after Kefir treatment, the rats were placed in individual metabolic cages to obtain blood and urine samples to evaluate urea, creatinine, proteinuria, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and C-reactive protein (CRP). After sacrificing the animals, the renal cortex was removed for histology, oxidative stress and NOS evaluation. When compared to CTL rats, DM rats showed increased levels of glycemia, plasmatic urea, proteinuria, renal NO, superoxide anion, TBARS, and plasmatic CRP; also demonstrated a reduction in urinary urea, creatinine, and NO. However, DMK rats showed a significant improvement in most of these parameters. Despite the lack of differences observed in the expression of endothelial NO synthase (eNOS), the expression of inducible NO synthase (iNOS) was significantly lower in the DMK group when compared to DM rats, as assessed by Western blot analysis. Moreover, the DMK group presented a significant reduction of glycogen accumulation within the renal tubules when compared to the DM group. These results indicate that Kefir treatment may contribute to better control of glycemia and oxidative stress, which is associated with the amelioration of renal function, suggesting its use as a non-pharmacological adjuvant to delay the progression of diabetic complications.

Mechanisms of Action of Kefir in Chronic Cardiovascular and Metabolic Diseases

“…These results were recently confirmed in an experimental model of MS [116]. In agreement with this study's results, Punaro et al [117] also demonstrated antioxidative and renoprotective effects after kefir supplementation using STZ-diabetic rats. Ostadrahimi et al [118] showed that kefir reduces glycemia and HbA1c in type 2 diabetes patients, suggesting that this symbiotic therapy may be an interesting adjuvant in the treatment of diabetes.…”

“…Ostadrahimi et al [118] showed that kefir reduces glycemia and HbA1c in type 2 diabetes patients, suggesting that this symbiotic therapy may be an interesting adjuvant in the treatment of diabetes. Other authors have shown that kefir was able to reduce ROS intracellular levels in insulinresponsive muscle cells [117] and in STZinduced diabetes mellitus in rats [118]. In addition, proteinuria and azotemia observed in rats with type I diabetes mellitus were reduced by treatment with kefir, an effect apparently related to its antioxidant capacity [115].…”

Microorganisms with Claimed Probiotic Properties: An Overview of Recent Literature

“…Also, several animal studies have observed positive effects of probiotic administration [101,102,103,104] which can have a consequential positive effect on public health of humans by lowering antibiotic consumption for animals used in food production. This will consequently lower the presence of drugs and multi-resistant organisms in the environment (including drinking water).…”

Coadjuvants in the Diabetic Complications: Nutraceuticals and Drugs with Pleiotropic Effects

“…In STZ-induced DM, it has been shown that daily administration of kefir caused an improvement in the increased levels of glycemia and glucose tolerance compared to conventional fermented milk [168,178,179]. Interestingly, kefiran, which is an exopolysaccharide isolated from kefir grains, has been shown to decrease blood pressure and blood glucose in animal models of hypertension [180] and an animal model of intolerance to glucose overload [181].…”