Protective effect of nanoencapsulated curcumin against boldenone-induced testicular toxicity and oxidative stress in male albino rats

Background
Boldenone (BOL) (Equigan) is a synthetic anabolic steroid used mainly by veterinarians to treat and promote horses’ growth. Recently, body builders have started to use it to enhance their physical performance and muscle growth. Equigan is known to induce testicular injury and reduce fertility in males. Current treatments for reduced fertility are very costly. As alternatives, people are investigating naturally occurring bioactive compounds in plants such as curcumin.
Objective
This study was conducted to evaluate the prophylactic antioxidant effects of nanoencapsulated curcumin (NEC) on BOL-induced testicular toxicity and oxidative stress in male albino rats.
Materials and methods
NEC was prepared using a novel freeze-drying method. For their characterization, ultraviolet–visible spectrophotometry, transmission electron microscopy, and dynamic light scattering were used. Four groups of male rats were used: the first group served as control, the second group received NEC (100 mg/kg orally, once daily), the third group received BOL (5 mg/kg intramascular, once weekly) for 60 days, and BOL and NEC were concurrently administered in the fourth group. Blood was withdrawn from the rats’ retro-orbital veins 24 h after treatment. Animals were euthanized immediately; the epididymal sperm reserve was separated. Then, one testis from each rat was kept at −80°C for determination of oxidative stress indices, and the other was fixed in 10% formalin solution for histopathological investigation.
Results and conclusion
Treatment with BOL resulted in significant reproductive damage caused by increased levels of malondialdehyde and nitric oxide and decreased levels of superoxide dismutase and reduced glutathione. Downregulation of the levels of serum testosterone and reduction in semen quantity, sperm count, and motility were also detected in the BOL group. Histopathological examinations showed severe degenerative changes in the testes. Immunohistochemical examination indicated severe reduction in the proliferating cell nuclear antigen-positive spermatogonia in the BOL-treated group as compared with the control. Coadministration of NEC with BOL effectively reduces BOL-induced testicular damage and oxidative stress in male albino rats.