Fluoride Action Network


Background: Fluoride is present in environment in various forms and ingested by man from solid foods, drinking water and inhaled from the air. Out of these, fluoride is present in large quantities in dissolved state in many sources of drinking water producing toxicity in man. Fluoride can cross the blood-brain barrier and it can cause adverse effects on the brain cell architecture, metabolism, enzymes and overall adverse effects on mental functions. Traces of fluoride are essential and beneficial to human being in minute concentrations in preventing dental carries and osteoporosis. However, intake in large quantities produces adverse and toxic effects on our body.

Objective: The present study was designed to investigate the toxic effects (evaluated as histopathological changes) of sodium fluoride on the brain (Cerebral cortex) in albino rabbit.

Materials and methods: Total 6 albino rabbits were used for this study, among them 2 rabbits were taken in the control group (Group A) and 2 rabbits each were taken in both group B and group C who were administered low and high dose of fluoride respectively. After 16 weeks, the brains of each group of the rabbits were studied in respect to their histological change.

Result: Histological changes in the brains (Cerebral cortex) of both Group B and Group C rabbits, following continuous daily exposure to sodium fluoride solutions in two different doses (0.5% solution for Group B and 3% solution for Group C) for 16 weeks of time were studied in detail and compared with those of the controls (Group A).

Conclusion: It is concluded that Sodium Fluoride solution in high doses for prolonged period has a definite adverse effect on the brain parenchyma.


From Table 1: Gross and brain cyto-architecture changes of experimental animals at the end of 16 weeks.

Changes in Brain Cytoarchitecture: The neurones lost their angular or pyramidal shape and acquired a plump, ovoid, rounded, or characteristic “ballooned” appearance (Figure 1). The nucleus was displaced to the periphery or axonal base and was shrunken, pyknotic, or absent. Reduction in the number of Purkinje neurones and in some areas even complete loss of neurones. Pyramidal neurones exhibited chromatolysis, Nissl substance was not detectable, and the perikaryon was filled with numerous small colorless vacuoles (Figure 2). Neuroglial cells showed chromatolysis, and in the neuroplasm of these cells, one or two spheroid bodies were present. The nucleus was located at the periphery of the cell (Figure 3).