Effect of sodium fluoride on neuroimmunological parameters, oxidative stress and antioxidative defenses

Aims: This study was designed to evaluate the effect of sodium fluoride (NaF) in inducing neuroimmunological, oxidative and antioxidative damage. Methods: Twenty-four male Wistar rats broadly grouped into four groups containing six rats in each were fed with drinking water containing 20 ppm, 60 ppm, 100 ppm and 0.8 ppm (control) NaF. After 90 days, rats were sacrificed to assess the level of fluoride content and various neurotransmitters in brain. The levels of CD4, natural killer (NK) cells and IgG1 were assessed in blood and spleen. In addition, lipid peroxidation coupled with the levels of various antioxidative enzymes was also recorded. Results: Increase in the NaF concentration resulted in increased fluoride deposition in brain tissue. This increased fluoride content led to increased levels of certain neurotransmitters such as epinephrine, histamine, serotonin and glutamate and decreased levels of norepinephrine, acetylcholine and dopamine in a dose-dependent manner. NaF exposure led to the decrease in the levels of CD4, NK cells and IgG1 coupled with marked increase in lipid peroxidation and impairment of the antioxidative defense system. Conclusion: The result of the study emphasizes the toxic role of high NaF doses on the neurological and immunological functions.