Tempol, a superoxide dismutase-mimetic drug, prevents chronic ischemic renal injury in two-kidney, one-clip hypertensive rats.

Tempol, a superoxide dismutase-mimetic drug, has been shown to attenuate radical-induced damage, exerting beneficial effects in the animal models of oxidative stress and hypertension. This study evaluated the effect of Tempol on renal structural and functional alterations in two-Kidney, one-Clip hypertensive rats. In this study, young male Wistar rats had the left kidney clipped (2K1C), and sham-operated animals (Sham) were used as controls. Animals received Tempol (1mmol/L in drinking water) or vehicle for 5 weeks. Systolic blood pressure was evaluated once a week. At the end of the experimental protocol, the animals were placed in metabolic cages to collect urine (24h) and then anesthetized with thiopental (70mg/kg i.p.) to collect blood by puncturing the descending aorta for biochemical analysis, and the clipped kidney for morphological and immunohistochemical analyses. The vasodilator effect of Tempol was evaluated in mesenteric arterial bed (MAB) isolated from adult Wistar rats. The chronic treatment with Tempol prevented the development of hypertension and the increased plasma levels of urea, creatinine, and 8-isoprostane in 2K1C animals. Tempol also improved both glomeruli number and kidney volume to normal levels in the 2K1C+Tempol group. In addition, the treatment prevented the increased collagen deposition and immunostaining for renin, caspase-3, and 8-isoprostane in the stenotic kidney of 2K1C animals. Moreover, Tempol induced a dose-dependent vasodilator response in MAB from Wistar rats. These results suggest that Tempol protects the stenotic kidney against chronic ischemic renal injury and prevents renal dysfunction in the 2K1C model, probably through its antioxidant, vasodilator and antihypertensive actions.

Euterpe oleracea Mart.-Derived Polyphenols Protect Mice from Diet-Induced Obesity and Fatty Liver by Regulating Hepatic Lipogenesis and Cholesterol Excretion.

The aim of this study was to investigate the effect of a polyphenol-rich Açaí seed extract (ASE, 300 mg/kg-1d-1) on adiposity and hepatic steatosis in mice that were fed a high-fat (HF) diet and its underlying mechanisms based on hepatic lipid metabolism and oxidative stress. Four groups were studied: C57BL/6 mice that were fed with standard diet (10% fat, Control), 10% fat + ASE (ASE), 60% fat (HF), and 60% fat + ASE (HF + ASE) for 12 weeks. We evaluated the food intake, body weight gain, serum glucose and lipid profile, hepatic cholesterol and triacyglycerol (TG), hepatic expression of pAMPK, lipogenic proteins (SREBP-1c, pACC, ACC, HMG-CoA reductase) and cholesterol excretion transporters, ABCG5 and ABCG8. We also evaluated the steatosis in liver sections and oxidative stress. ASE reduced body weight gain, food intake, glucose levels, accumulation of cholesterol and TG in the liver, which was associated with a reduction of hepatic steatosis. The increased expressions of SREBP-1c and HMG-CoA reductase and reduced expressions of pAMPK and pACC/ACC in HF group were antagonized by ASE. The ABCG5 and ABCG8 transporters expressions were increased by the extract. The antioxidant effect of ASE was demonstrated in liver of HF mice by restoration of SOD, CAT and GPx activities and reduction of the increased levels of malondialdehyde and protein carbonylation. In conclusion, ASE substantially reduced the obesity and hepatic steatosis induced by HF diet by reducing lipogenesis, increasing cholesterol excretion and improving oxidative stress in the liver, providing a nutritional resource for prevention of obesity-related adiposity and hepatic steatosis.