Fluoride induced testicular toxicities in adult Wistar rats

Fluoride is essential for the development of teeth and bone but its excessive exposure causes reprotoxic effects. We have studied the graded effects of different doses of sodium fluoride (NaF) on 24 adult Wistar rats which were randomly divided into four groups (n = 6). All the rats were given normal diet prepared in our laboratory. Control (group I) rats were received vehicle only and treated rats (group II, III, and IV) were administered NaF orally at 10, 15, and 20 mg/kg/d doses, respectively, for 30 consecutive days. Gravimetric index of testis was decreased significantly in group III and IV rats but such changes were not observed in the accessory reproductive organs. Marked alterations in number, motility, viability, and plasma membrane functional integrity of caudal spermatozoa were noted in most of the treated groups. Noticeable alterations in testicular histoarchitecture were observed in group III and IV rats. Graded Changes of testicular redox homeostasis were noted by assessment of enzymatic (superoxide dismutase [SOD], catalase, glutathione s-transferase [GST], and glutathione peroxidase [GPx]) and nonenzymatic (malondialdehyde [MDA] and protein carbonyl [PC]) markers. Changes of testicular functional markers (acid phosphatase [ACP], alkaline phosphatase [ALP], and lactate dehydrogenase (LDH) activity) were noted in group III and IV rats. DNA fragmentation assay proved the possibility of DNA damage caused by oxidative stress, as evidenced by prominent trailing pattern of fragmented testicular genomic DNA from group III and IV rats. The study concludes that fluoride-mediated oxidative stress not only impedes the structural and functional facets of testis but also results in testicular DNA damage.