Sixty young adult inbred Swiss strain male albino mice (Mus musculus) were randomly divided into six equal groups. Groups I and II served as control and antidote groups, respectively. Groups III and IV were orally administered 0.2 and 0.4 mg sodium fluoride (NaF) in 0.2 mL of deionized water/animal/day (= 6 mg and 12 mg NaF/kg bw/day, respectively) for 30 days and served as low dose (LD) and high dose (HD) groups, respectively. Groups V and VI were administered NaF as in groups III and IV but were also given 2% black tea extract (BTE) infusion instead of drinking water for 30 days. The mice in each group were weighed individually, and mean weights and percent gain in body weight were recorded. An average of 33.9% weight gain was found in Groups I and II, whereas the gain was only 6.24% in Groups III and IV, which was clearly and significantly lower than in the two control groups. BTE with NaF in Groups V ad VI showed a 29.49% average weight gain that was not only significantly higher than that of the NaF-treated Groups III and IV but also close to that of the two control groups. After 30 days of treatment, brains of control and treated groups of animals were quickly isolated. Cerebral hemisphere (CH), cerebellum (CB), and medulla oblongata (MO) regions of brain were separated carefully, weighed to the nearest mg and studied for their histopathology. NaF treatment (Groups III and IV) caused significant dose-dependent reduction in absolute organ weight whereas BTE together with NaF (Groups V and VI) resulted in
amelioration of weight loss of CH, CB, and MO. Normal features of histology were observed in control group slides of CH, which consisted of outer folded cortex of gray matter covering the inner white matter. CB showed a well-developed molecular layer, Purkinje cell layer, granular layer, and core of white matter. Similarly, MO showed a well-developed molecular layer, Purkinje cell layer, granular layer, and blood vessel structure. NaF treatment induced degenerative changes, pycnotic
nuclei, fatty infiltration, and chromatolysis in CH, CB, and MO with a more severe effect with HD than LD. With BTE in combination with NaF treatment, normal histological features similar to control slides were observed.