The possible protective role of chromium chloride against sodium fluoride-induced changes in the structure of the cerebellar cortex of the adult male albino rat

Abstract

Introduction Fluoride is a mineral that occurs naturally in many types of food and in water. Excessive amounts of fluoride may induce central nervous system degeneration. Chromium has generated interest among researchers for its possible antioxidant effect. Aim of the work This study was carried out to investigate the effect of sodium fluoride (NaF) on the structure of the cerebellar cortex of adult male albino rats. The possible protective effect of chromium chloride (CrCl) was also investigated. Materials and methods Twenty-five adult male albino rats were used in this study. They were divided randomly into four groups: group I (the control group); group II (the chromium group), which received CrCl (300 ìg/kg/day for 2 months); group III (the fluoride group), which received NaF orally (12 mg/kg/day) for 2 months; and group IV (the fluoride+chromium group), which received both NaF (12 mg/kg/day) and CrCl (300 ìg/kg/day) for 2 months. At the end of the experiment, the animals were sacrificed. Their cerebella were dissected out and processed for light microscopic studies, transmission electron microscopic studies, morphometric studies, and for statistical analysis. Results In the fluoride-treated group, Purkinje cells were the most affected. They showed degenerative changes and an irregular distribution. They had an irregular outline, ill-defined nuclei, and margination of Nissl's granules. Ultrastructurally, Purkinje cells showed hyperchromatic nuclei. Their cytoplasms showed autophagosomes, multivesicular bodies, and degenerated mitochondria. Moreover, an apparent increase in nerve cell processes containing neurofibrils was evident in the molecular layer. Significantly increased glial fibrillary acidic protein immunoreactivity in glial cell processes was also evident. Chromium produced only partial restoration of the normal histological architecture of the cerebellar cortex. Conclusion Administration of NaF in rats induces degenerative and ultrastructural changes in the cerebellar cortex. Coadministration of CrCl with NaF partially protects against NaF.