Ameliorative effects of chitosan on fluoride-induced kidney injury in rats: a stereological and immunohistochemical study.

The present study aimed to investigate the possible protective effects of chitosan (CS) on fluoride-induced nephrotoxicity. 28 rats were divided into four groups (n = 7). The Control group received drinking water. Sodium fluoride (NaF) group received 100 mg/L NaF in drinking water. NaF + CS group received 100 mg/L NaF and 250 mg/kg/day CS by gastric gavage. CS group was given 250 mg/kg/day CS by gavage. The study period lasted 12 weeks. Total kidney volume, Bowman's capsule volume, Bowman's space volume, Tubular volume and Glomerulus volume were measured by stereological methods. Immunohistochemically, caspase-3 and TNF-alpha expressions were evaluated. Biochemically, levels of urea and creatinine were measured. In addition, a histopathological evaluation of the kidney was performed. According to the control group, an increase was observed in all stereological parameters except glomerulus volume in the NaF group. CS treatment inhibited the increase in stereological parameters. Fluoride increased expressions of caspase-3 and TNF-α in the kidney, and serum urea and creatine levels, but CS decreased these parameters. In addition, pathological changes in the kidney caused by fluoride such as tubular dilatation, enlargement of the Bowman's space, and deterioration in tubular epithelial cells were restored with CS treatment. The conclusions of the current study reveal that fluoride can cause nephrotoxicity and CS treatment can prevent fluoride-induced nephrotoxicity.