Fluoride Action Network

Abstract

To investigate the effects of fluoride exposure on the microglialmorphology and the expression of inflammatory cytokines in the cerebral cortex ofmice, thirty-six ICR male mice were randomly divided into groups and given differentdoses of sodium fluoride (0, 25, and 50 mg/L NaF). After 50 days, the microglialmorphology and the expression of interleukin-6 (IL-6), interleukin-1? (IL-1?),transforming growth factor-? (TGF-?), and tumor necrosis factor-? (TNF-?) weredetected using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay(ELISA). In our results, the degeneration of pyramidal cells and glial cells was one of themost obvious pathological changes in the fluoride-exposed brains. Compared to thecontrol group, the number of ramified, intermediate, and amoeboid microglia wassignificantly elevated in the NaF treatment groups. Additionally, the ELISA resultsshowed that 50 mg/L NaF dramatically increased the expression of IL-6, IL-1?, TGF-?,and TNF-? when compared to the control group. These findings suggest that NaF canpromote morphological changes of activated microglia and the release of inflammatoryfactors in the cortex, which may be one of the mechanisms of fluoride-induced nervedamage.