Green tea ameliorates renal oxidative damage induced by gentamicin in rats

Abstract

Recent studies indicate that free radicals are important mediators of renal damage induced by gentamicin (GM), an aminoglycoside antibiotic widely used in treating severe gram-negative infections. Green tea extract (GTE) was reported to have antioxidant and free radical scavenging activities. Therefore, the aim of this work was to investigate the possible protective effect of GTE against gentamicin-induced nephrotoxicity. For this purpose, rats were divided into four groups. Group-1 (control) received normal saline. Group-2 received GTE (300 mg/kg/d, orally). Group-3 received gentamicin (80 mg/kg/d, intraperitoneally). Group-4 was injected with GTE plus gentamicin simultaneously. Daily urinary total protein levels were estimated to assess kidney dysfunction. The rats were sacrificed on the seventh day and kidneys were collected for histopathological studies. Blood urea nitrogen (BUN) and creatinine levels were measured in the blood. Moreover, glutathione (GSH), lipid peroxide expressed as thiobarbituric acid reactive substance (TBARS) levels, superoxide dismutase (SOD) and catalase (CAT) activities were determined in renal tissues. GM produced elevation in urinary total protein, BUN, serum creatinine and TBARS levels. On the other hand, GM reduced the GSH level and SOD, CAT activities. The simultaneous administration of GTE plus gentamicin protected kidney tissues against nephrotoxic effect of gentamicin as evidenced from amelioration of histopathological alterations and normalization of kidney biochemical parameters.