RESUMO

BACKGROUND: Hepatorenal syndrome (HRS) is the most prevalent form of acute kidney injury in cirrhotic patients. It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic patients with advanced disease. Previous research has indicated that antioxidants can delay the onset of a hyperdynamic circulatory state in cirrhosis and improve renal function in HRS patients. Regular omega-3 supplementation has significantly reduced the risk of liver disease. This supplementation could represent an additional therapy for individuals with HRS. AIM: To evaluated the antioxidant effect of omega-3 polyunsaturated fatty acid supplementation on the kidneys of cirrhotic rats. METHODS: Secondary biliary cirrhosis was induced in rats by biliary duct ligation (BDL) for 28 d. We used 24 male Wistar rats divided into the following groups: I (control); II (treated with omega-3, 1 g/kg of body weight); III (BDL treated with omega-3, 1 g/kg of body weight); and IV (BDL without treatment). The animals were killed by overdose of anesthetic; the kidneys were dissected, removed, frozen in liquid nitrogen, and stored in a freezer at -80℃ for later analysis. We evaluated oxidative stress, nitric oxide (NO) metabolites, DNA damage by the comet assay, cell viability test, and apoptosis in the kidneys. Data were analyzed by one-way analysis of variance, and means were compared using the Tukey test, with P ≤ 0.05. RESULTS: Omega-3 significantly decreased the production of reactive oxygen species (P < 0.001) and lipoperoxidation in the kidneys of cirrhotic rats treated with omega-3 (P < 0.001). The activity of the antioxidant enzymes superoxide dismutase and catalase increased in the BDL+omega-3 group compared to the BDL group (P < 0.01). NO production, DNA damage, and caspase-9 cleavage decreased significantly in the omega-3-treated BDL group. There was an increase in mitochondrial electrochemical potential (P < 0.001) in BDL treated with omega-3 compared to BDL. No changes in the cell survival index in HRS with omega-3 compared to the control group (P > 0.05) were observed. CONCLUSION: The study demonstrates that omega-3 can protect cellular integrity and function by increasing antioxidant enzymes, inhibiting the formation of free radicals, and reducing apoptosis.