Objective: The in vivo nephroprotective effect of quercetin against sodium fluoride (NaF)-induced damage was studied. Methods: Renal injury was induced by daily administration of NaF (600 ppm) through drinking water for 1 week. The levels of reduced glutathione (GSH), lipid peroxidation as well as superoxide dismutase and catalase activity of kidney homogenates were determined. The serum markers of glomerular damage, including creatinine, serum urea, and blood urea nitrogen levels, were also assessed. Results: The study revealed that administration of fluoride resulted in a significant downregulation of antioxidant defenses coupled with an increased serum level of glomerular damage markers. The administration of quercetin prior to fluoride reversed the antioxidant–oxidant balance to control (fluoride-untreated) level. The level of protection obtained for the 20 mg/kg quercetin treatment was equivalent to the positive control, ascorbic acid (10 mg/kg). The therapeutic implication of antioxidants in fluoride-induced nephrotoxicity is discussed. Conclusions: This study showed that NaF intoxication caused renal damage by increasing oxidative stress, and quercetin and vitamin C administration gave protection against fluoride-induced oxidative stress to some degree.
