Introduction: Stinging nettle (Urtica dioica L.) is the most important genus in the plant family Urticaceae. Urtica Dioica root Extract (UDE) is widely used for the treatment of prostate hyperplasia. Side effects of UDE were not studied on other organs such as testes (an important organ of the male reproductive system). Furthermore, antagonist effects of UDE on testosterone were considered. Therefore, the current study aimed at evaluating the effects of UDE, alone or in combination with testosterone, on testicular structure.
Methods: Twenty-five male Wistar rats were divided randomly into 5 groups: the control group; 10 mg/kg/day testosterone receiving group, 50 mg/kg/day UDE receiving group, 10 mg/kg/day testosterone plus 50 mg/kg/day UDE receiving group, and 10 mg/kg/day almond oil (testosterone solvent) receiving group. After 42 days, blood and testicle tissue samples were collected. Weight and volume of the testes were recorded. Samples were fixed in 10% buffered formalin following the standard histological procedure. The 5-6-μm thickness sections were stained with Hematoxylin & Eosin (H&E).
Results: The relative weight of testes in the UDE group showed a significant increase, compared with that of the control group (P<0.05). Exposure of testis tissue to UDE caused to degenerative changes in seminiferous tubules, compared with the control group. Spermatogenesis Index (SI) showed a significant decrease in the group receiving U. dioica root extract, compared with that of the control group (P<0.05). Serum testosterone showed an insignificant increase in the UDE group, compared with that of the control group.
Conclusion: In summary, results of the current study showed reduced spermatogenesis and spermiogenesis following the consumption of U. dioica root extract.