Antioxidant Activity of Glycyrrhiza glabra L. Extract and Protective Effect of its Leaf Extract on Ethanol-Induced Nephrotoxicity in Male Rats

Introduction: Acute alcohol consumption leads to induction of lipid peroxidation in renal tissues, but its chronic consumption has moderate effects on biochemical and histological characteristics of this organ. Antioxidants have protective effects against ethanol-induced oxidative stress and tissue injury. The aim of this study was to assess antioxidant activity of Glycyrrhiza glabra leaf and stem extracts and the protective effect of its leaf extract on ethanol-induced nephrotoxicity. Materials & methods: Total phenol and flavonoid contents of leaf and stem extracts of G. glabra were measured by Folin Ciocalteu and AlCl3 assays, respectively. Antioxidant activity of both extracts was assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. In addition, protective effect of the leaf extract was assessed using biochemical and histological analyses of renal tissues of male Wistar rats, which were divided into four groups including group 1 or control (received 1 ml distilled water daily), group 2 or ethanol group (received 1 ml of 50% ethanol daily), group 3 or ethanol + leaf extract group (received 1 ml of 50% ethanol + 500 mg/kg leaf extract daily), and group 4 (received 500 mg/kg of leaf extract daily). All treatments are performed through intragastric administration. Biochemical and histological analyses were used for the evaluation of nephrotoxicity. For histological study, the samples were stained with Hematoxylin-Eosin and examined by light microscopy. Finally, all the data were analyzed by SPSS (Ver. 20) and grouped by Duncan's Multiple Range Test at P