Naringenin ameliorates streptozotocin-induced diabetic rat renal impairment by downregulation of TGF-β1 and IL-1 via modulation of oxidative stress correlates with decreased apoptotic events

Abstract

Context: Naringenin, a flavonone and a nutritive antioxidant which is mostly obtained from grapefruit, orange or tomato skin, has been extensively studied due to its radical scavenging activity.Objective: The present study investigates the protective effect of naringenin on rat kidney after streptozotocin-induced diabetes.Materials and methods: Sixty male Wistar rats were divided into six groups. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg) in groups II, III and IV. Naringenin 5 mg/kg body weight was given to groups III and V, but 10 mg/kg was given to groups IV and VI, orally once a day for 10 weeks. After which all animals were sacrificed, and the biochemical, histopathological, immunohistochemical and apoptotic assays were conducted.Results: Naringenin treatment with 5 and 10 mg/kg significantly decreased (p < 0.05) the serum biochemical parameters, elevated tissue malondialdehyde levels and increased (p < 0.01) the reduced superoxide dismutase, catalase and reduced glutathione enzyme activities in the diabetic kidney. Diabetes-induced naringenin-treated groups showed an improved histology and revealed a significant reduction in apoptosis activity (7.2 ± 0.01 and 1.8 ± 0.05) and in expression of TGF-β1 (18.9 ± 3.4 and 10.2 ± 2.1) at a dose of 5 and 10 mg/kg, respectively. Similarly, in contrast to the diabetic group, a significant difference was observed in the IL-1 expression (15.68 ± 4.3) in 5 mg/kg and (9.85 ± 2.1) in 10 mg/kg naringenin-treated groups.Conclusion: Naringenin acts as a protective agent in diabetic renal impairment by altering oxidative stress, modulation of cytokines expression and apoptotic events.