Avaliação dos efeitos do óleo de baru (Dipteryx alata Vog.) sobre a modulação da função renal e do perfil metabolômico em ratos diabéticos

Abstract

Hyperglycemia is the main initiator of deleterious molecular changes to organs, which have been associated with oxidative stress. Because these events, diabetic kidney disease affects around 40% of diabetics. Good glycemic control can reverse the initial stage of the disease, and it is important to search for complementary treatments that can help prevent the damage induced by DM2. The oil extracted from baru almonds is rich in monounsaturated fatty acids, capable of stimulating the release of insulin. This work aimed to evaluate the effects of ingesting baru oil on renal function and oxidative stress in the kidneys of normal and diabetic rats. Oil extraction was carried out by mechanical pressing of baru almonds using a hydraulic press. In this study we adopted a DM2 induction model. Male Wistar rats received a high-fat diet (30%) for 28 days and then an intraperitoneal injection of streptozotocin (35mg/kg). Healthy animals remained on the standard diet. After confirming diabetes (casual blood glucose >250mg/dl), treatments of healthy and diabetic animals were started with water and baru oil at doses of 0.75 g/kg; 1.5 g/kg and 3.0 g/kg, metformin (200 mg/kg) and gliclazide (10 mg/kg) alone and associated with baru oil (1.5 g/kg), for 90 days. In the final stage of treatment, the oral glucose tolerance test (OGTT) and the insulin tolerance test (ITT) were performed. Whole blood, urine and kidneys were collected to determine biochemical markers. The evaluation of the activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) as well as the analysis of malonaldehyde (MDA) were carried out in the serum and kidneys of the animals. Histological evaluation and determination of the metabolic profile were carried out in the kidney. Treatment with baru oil at doses of 1.5 g/kg and 3.0 g/kg reduced feed and water consumption, increased animal responsiveness in the OGTT and ITT, and decreased serum glucose and creatinine and albuminuria, in diabetic animals. The dose of 3.0 g/kg had a more significant effect on renal function markers. However, when evaluating oxidative stress in kidney tissue, it was observed that the diabetic group treated with 1.5 g/kg of the oil was able to attenuate the reduction in the activities of the enzymes SOD, CAT and GPx about the other treatments. with baru oil and reduce MDA levels. All treatments showed beneficial effects in reducing renal histological damage and the levels of metabolites of the Krebs cycle and adenosines of energy metabolism. The association of metformin with baru oil showed better ability to control glycemic and renal function, as it reduced serum glucose, fructosamine, creatinine and albuminuria levels. Furthermore, this treatment demonstrated the ability to modulate oxidative metabolism, restoring the activities of antioxidant enzymes.