Background : Sodium benzoate is used as a disinfectant agent against some microorganisms in food. The toxic effect of this chemical has been shown in some studies. The aim of this study was to evaluate the effects of sodium benzoate on testicular tissue, gonadotropins and thyroid hormones level in adult (Balb/C) mice.

Materials and Methods: In this experimental study, 18 adult male mice (Balb/C, 10-12 weeks) were divided into three equal groups. Two groups of mice were given sodium benzoate 140 mg/kg/day and 280 mg/kg/day for 60 days respectively. The control animals received tap water. Post-anesthetic blood sampling from left ventricle was used for hormonal measurements. After scarification, the testes were removed and fixed for morphologic studies. Data were analyzed by student t-test.

Results: No significant difference was evident concerning weight loss between the control and case groups. The testosterone level was significantly decreased in the case groups (P<0.0001). Also FSH, LH, T3 and T4 levels was significantly decreased in the high dose against the control group (P<0.0001 for FSH, LH & p<0.001 for T3, T4) however, TSH was considerably increased in the high dose and control groups (P<0.001). Ultrastructural study of testicular tissue showed the picnotic nature of germinal cells nuclei and plenty of distended vascular in cytoplasm.

Conclusion: Sodium benzoate decreases plasma level of the testosterone, gonadotrophins, T3 and T4. Thus, it is recommended to replace it with other preservatives in drugs and foods.