Efeito da dieta hiperlipídica na bexiga de ratos e ação bioativa do óleo de castanha-do-Brasil

Abstract

High-fat diet-induced obesity is associated with metabolic disorders. The Brazil nut has bioactive substances and has been used to control the damage caused by obesity in several organs. The work intend to show the damage caused by high-fat diet in the bladder wall and if the Brazil nut oil added to the diet could ameliorate or reverse this effect. Sixty-day-old rats were divided into two groups: C (control, n=30) and HF (high-fat, n=30) diets. At 90 days, 10 animals of each group were sacrificed. The others were divided into 4 groups: C and HF (animals that maintained their previous diet, n=10 for each group) and C/Bno and HF/Bno (animals whose control or high-fat diet was supplemented by Brazil nut oil, n=10 for each group). At 120 days the animals were killed. The bladders were removed and fixed in 4% buffered formalin following the laboratory histological routine procedure for paraffin embedd. Morphometric data of epithelial height, collagen between muscle fiber, muscle fiber diameter and total collagen were obtained using Image J software and analyzed with GraphPad Prism software. Epithelial height increased by 22% in the HF group at 90 days and 120 days. In contrast, the C / Bno presented lower epithelial height in relation to the groups C (-23%, p <0.01), HF (-38%, p <0.0001) and HF / Bno (-28%, p <0.0001). The percentage of collagen between the fibers of the detrusor muscle was significantly higher in C / Bno (+ 17%, p <0.001), HF (+ 45%, p <0.001) and HF / Bno than in the control group. The HF group presented greater muscle fiber diameter at 90 days and was maintained up to 120 days. The HF group increased by 34%, p <0.001 the muscle fiber diameter in relation to the C group, while the C / Bno presented lower values than the HF and HF / Bno groups (-30%, p <0.001). There was no change in the percentage of total bladder collagen. HF diets induce damage to the bladder wall such as increased epithelial height, diameter in the muscle fiber, and collagen in the detrusor muscle. These changes in the rat bladder wall were partially reversed by Brazil nut oil.