Avaliação do efeito da quercetina sobre o fígado e rim de ratos Wistar com síndrome metabólica induzida

Abstract

Metabolic syndrome (MS) is characterized by increased visceral fat, hypertriglyceridemia and hypertension. Epidemiological and clinical studies have confirmed that MS is associated with increased morbidity and mortality due to its association with inflammation and diseases such as cardiovascular disease , diabetes mellitus, dyslipidemia, chronic kidney disease and hepatic steatosis. Based on the diversity of factors causing or contributing to MS the ideal pharmacological treatment is not well defined. Due to quercetin antioxidant, anti-inflammatory and vasodilatory properties, it could be an alternative for treatment of MS comorbidities. This study aimed to evaluate the effect of quercetin in the liver and kidney of rats with MS dietinduced. Male Wistar rats were divided into three groups (n = 10): C-standard diet; MShigh-fat diet and MSQ-high-fat diet + 10mg/kg / day of quercetin solution orally administered in two months old rats. Water and food was received ad libitum. Body weight and tail blood pressure was assessed weekly. At the end of the experiment, at six months, tests were performed to evaluate oral glucose tolerance. The animals were anesthetized (xylazine: ketamine and 10mg/kg: 90mg/kg, ip) for direct measurement of blood pressure. Then, they were exsanguinated and euthanized by cervical dislocation, kidney, liver, epididymal and retroperitoneal fat left were removed and weighed. Serum glucose, triglycerides, cholesterol , AST, ALT and γ-GT; urinary creatinine was measured; Clearance and morphometry of the area and volume glomerular hematoxylin- Cromotrope stain. The presence of renal fibrosis was evaluated by picrosirius stain under polarized light. For immunohistochemical analyzes were quantified the expression of pro-fibrotic factor (TGF-β1) and myofibroblasts (α-SMA) makers in kidney tissue cells. The procedures were approved by CEUA-UFJF (Protocol No.010/2011). We observed that high fat diet promoted MS, characterized by central fat accumulation, hypertension, hyperglycemia and hypertriglyceridemia. In addition an increase in the levels of AST as well as the expression of TGF-β1 and percentage of fibrosis by picrosirius was observed. Chronic daily administration of quercetin in an experimental model of SM induced by high fat diet did not reduce blood pressure, did not affect the nutritional and metabolic and histomorphological profile of the animals, despite of attenuate the expression of markers of fibrosis.