Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion

Abstract

ABSTRACT Introduction: Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury. Objective: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress. Methods: Male Wistar rats were distributed into six groups (N=6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR) and maintained until animal sacrifice (48h after surgery). We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx. Results: Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx. Conclusion: Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

Keywords

• Isquemia
• Reperfusão
• Lesão renal aguda
• Estresse oxidativo
• Inflamação
• Castanha-do-brasil
• Ratos