Oxidative stress burden inhibits spermatogenesis in adult male rats: testosterone protective effect

Can J Physiol Pharmacol. 2018 Apr;96(4):372-381. doi: 10.1139/cjpp-2017-0459. Epub 2017 Nov 23.


In this study, we aimed to investigate the protective effects of androgens, using letrozole (LET; an aromatase inhibitor), grape seed extract (GSE; a naturally occurring aromatase inhibitor and antioxidant), and testosterone propionate (Tp), against methotrexate (MTX)-induced testicular toxicity in adult male rats. MTX has been shown to induce oxidative stress and exhibit antiproliferative effects in the testes. Adult male rats received oral saline gavage (control group with no treatment), the potential protective agents (LET, GSE, or Tp) alone, MTX alone, or a combination of one of the potential protective agents and MTX. The testicular levels of oxidative stress markers and cytokines (tumor necrosis factor-α and interleukin-1β) were measured. Spermatogenesis and sperm viability were microscopically evaluated. Administration of LET and GSE 7 days before MTX improved spermatogenesis and sperm viability, as well as reduced the levels of oxidative stress markers and cellular cytokines. Exogenous testosterone exhibited anti-inflammatory and antioxidant activities, similar to GSE and LET. We also showed that enhancing the endogenous androgenic activity by LET and GSE protected spermatogenesis against MTX-induced testicular toxicity via reduction of inflammation and oxidative stress in the testes. Our data suggest that testosterone protected spermatogenesis owing to its antioxidant and anti-inflammatory properties.

Keywords: aromatase inhibitor; estradiol; inhibiteur de l’aromatase; methotrexate; méthotrexate; oxidative stress; spermatogenesis; spermatogenèse; stress oxydatif; testes; testicule; testosterone; testostérone; œstradiol.

MeSH terms

  • Aging / metabolism*
  • Animals
  • Biomarkers / metabolism
  • Body Weight / drug effects
  • Estradiol / blood
  • Follicle Stimulating Hormone / blood
  • Grape Seed Extract / pharmacology
  • Inflammation / pathology
  • Letrozole
  • Male
  • Methotrexate / pharmacology
  • Nitriles / pharmacology
  • Organ Size / drug effects
  • Oxidative Stress / drug effects*
  • Protective Agents / pharmacology*
  • Rats, Sprague-Dawley
  • Seminiferous Tubules / drug effects
  • Seminiferous Tubules / pathology
  • Sperm Count
  • Sperm Motility / drug effects
  • Spermatogenesis / drug effects*
  • Testosterone / blood
  • Testosterone / pharmacology*
  • Triazoles / pharmacology


  • Biomarkers
  • Grape Seed Extract
  • Nitriles
  • Protective Agents
  • Triazoles
  • Testosterone
  • Estradiol
  • Letrozole
  • Follicle Stimulating Hormone
  • Methotrexate