Effects of fluoride on oxidative stress and apoptosis in primary rat hippocampal neurons

Objective To investigate the oxidative stress and apoptosis induced by fluoride in primary rat hippocampal neurons, and to explore the involved role of reactive oxygen species (ROS) on apoptosis. Methods The survival ratio of cells, intracellular ROS, malondialdehyde (MDA) content, and percentage of apoptosis were measured after the rat hippocampal neurons were incubated with 20,40,80 mg/L sodium fluoride for 24 hours in vitro. Results The rate of cellular survivors in the fluoride-treated groups, being 9.1%, 12.2%, 25.0% respectively, was lower that that of the control group, but the difference was not statistically significant (F = 106.8, P 0.05). Compared with the control group, the MDA contents in the fluoride-treated groups were remarkably higher(F = 7.151, P 0.05) and elevated in a dose-response dependent manner in fluoride-treated groups . The levels of ROS and percentages of apoptosis in moderate and high dose fluoride-treated groups were significantly higher than that in low dose fluoride-treated group. The positive correlation between percentage of apoptosis and ROS level was also demonstrated (r = 0.913, P 0.05). Conclusions Fluoride can induce oxidative stress and apoptosis in rat hippocampal neurons. ROS may play an important role in the apoptosis induced by fluoride.