Effects of sodium fluoride on immune response in murine macrophages

In this study, an in vitro evaluation is made of fluoride immunotoxicity using the RAW 264.7 murine macrophage line over a broad range of concentrations (2.5-75 mg/L). The results show that the highest fluoride concentrations used (50-75 mg/L) reduce the macrophage population in part as a consequence of the generation of reactive oxygen and/or nitrogen species and consequent redox imbalance, which in turn is accompanied by lipid peroxidation. A decrease in the expression of the antiinflammatory cytokine Il10 is observed from the lowest concentrations (5 mg/L). High concentrations (50 mg/L) in turn produce a significant increase in the proinflammatory cytokines Il6 and Mip2 from 4 h of exposure. In addition, cell phagocytic capacity is seen to decrease at concentrations of ≥ 20 mg/L. These data indicate that fluoride, at high concentrations, may affect macrophages and thus immune system function - particularly with regard to the inflammation autoregulatory processes, in which macrophages play a key role.