Renoprotective Effects of Gallic Acid Against Gentamicin Nephrotoxicity Through Amelioration of Oxidative Stress in Rats

Gallic acid (GA), as a strong antioxidant, was selected in this study to investigate its possible nephroprotective effects against gentamicin (GM)-induced nephrotoxicity. Twenty-four rats were separated into three groups (n=8): group 1 (control group) received saline (0.5 mL/day), group 2 (GM group) received GM (100 mg/kg/day), and group 3 (treated group) received GM (100 mg/kg/day) and GA (100mg/kg/day). All treatments were performed intraperitoneally for 12 days. After 12 days, the rats were euthanized, and kidneys were removed immediately. For serum preparation, blood samples were collected before killing. Kidney paraffin sections were prepared from one of the kidneys and stained by the periodic acid-Schiff process. GA significantly decreased GM-induced renal histopathological injuries, including tubular necrosis, tubular cast, and leucocyte infiltration compared with the GM group. Additionally, GA significantly improved proteinuria, serum levels of urea and creatinine, and serum activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) compared with nephrotoxic animals. Furthermore, GA caused a significant improvement in the levels of cholesterol (Chol), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and cardiac risk ratios 1 and 2 in comparison with nephrotoxic animals. GA administration was observed to significantly improve the levels of lipid peroxidation, nitric oxide (NO), and glutathione (GSH) compared with the GM group. Finally, the activities and gene expression levels of catalase (CAT) and glutathione peroxidase (GPX) significantly increased following GA administration compared with the GM group. Our results indicated that GA has potential protective effects against GM nephrotoxicity by reducing oxidative stress in rats.