Histopathological and Immunohistochemical Evaluation of Methotrexate-Induced Gonadal Damage in Rats: Role of SCF, mTOR, and SIRT-1.

Objective: Methotrexate (MTX) is a highly effective chemotherapy for cancer. This drug has a gonadotoxic effect, mainly in the testes and ovaries. Our study used histopathological and immunohistochemical methods to assess the potential damage to testicular and ovarian tissue caused by MTX use.

Methods: Twenty-four Wistar albino rats, both male and female, were used in our study. Four sets of rats; control male, MTX male, control female, and MTX female were created. The male and female MTX-treated groups received a single intraperitoneal dose of 20 mg/kg MTX. The testes and ovaries of rats sacrificed under general anesthesia were extracted and histopathologically analyzed. In addition, the immunoreactivity intensities of stem cell factor (SCF), mechanistic target of rapamycin (mTOR), and SIRT-1 in both tissues were measured by immunohistochemistry.

Results: Johnsen's testicular biopsy score in the testicular seminiferous tubules was significantly lower in the MTX group than in the control group (p<0.001). The ovary showed substantial follicular degeneration (p<0.05), vascular congestion (p<0.01), and fibrosis (p<0.001). MTX reduced SCF immunoreactivity density in the testis and ovary (p<0.05). Furthermore, MTX reduced mTOR, a marker of autophagy, in the testis (p<0.05) and ovary (p<0.001) compared with the control. SIRT-1 intensity increased dramatically in the testis (p<0.001) and ovary (p<0.01) in the injured group, unlike the mTOR marker.

Conclusions: Our investigation revealed that the gonads incurred significant damage as a result of MTX. One vital option for reducing or eliminating this damage to the ovaries and testicles is the use of anti-oxidant-rich substances.