Effect of concurrent chronic exposure of fluoride and aluminum on rat brain.

The present in vivo study was designed to investigate the toxic potential of fluoride alone and in conjugation with aluminum on the rat brain. The region-specific response of both elements was studied in different regions of brain, namely the cerebrum, cerebellum, and medulla oblongata. Following fluoride exposure, oxidative stress increased significantly, estimated by increased lipid peroxidation and a decrease in the activity of the antioxidant enzyme, superoxide dismutase. The neurotransmitter (e.g., dopamine, norepinephrine, and serotonin) content was also altered. However, these aspects were more pronounced in animals given fluoride and aluminum together. Histological evidence showed deprivation of neuronal integrity with higher magnitude in concurrent fluoride and aluminum exposure, as compared to fluoride alone. Thus, it can be concluded that aluminum appears to enhance the neurotoxic hazards caused by fluoride.