Ginkgo biloba extract (EGb 761) mitigates methotrexate-induced testicular insult in rats: Targeting oxidative stress, energy deficit and spermatogenesis

Abstract

Methotrexate (MTX) is commonly used as a therapeutic agent in the treatment of malignancies and autoimmune disorders. Risk of subsequent infertility following MTX administration has been reported as a significant side effect due to testicular toxicity. The aim of the study was to evaluate the modulatory effects of Ginkgo biloba (standardized extract, EGb 761) on MTX-induced testicular oxidative stress, energy deficits and spermatogenic status in rats. All groups received intraperitoneal injection of MTX (0.5 mg/kg) twice weekly for four weeks except the control group that received the corresponding vehicles. Other groups received oral EGb761, at doses 25, 50 or 100 mg/kg/day, for four weeks, concurrently with MTX. Blood and semen sampling followed by testis dissection were performed 24 h after last EGb 761 treatment. Semen was examined for sperm progressive motility, percent of normal spermatozoa and sperm cell concentration as well as seminal plasma essential and non-essential amino acids. Serum LH, FSH and testosterone were detected as well as testicular MDA, GSH, GSSG, TNF-α, IL-1β, IL-6, NF-κB and the nuclear, cytoplasmic and mRNA expression levels of Nrf-2 besides the testicular cell energy; AMP, ADP and ATP. Histopathological studies of interstitial fibrosis and the severity of germ cell degeneration were also conducted. MTX induced significant decline in sperm quality along with decreased essential and non-essential amino acids in seminal plasma. MTX reduced serum FSH, LH and testosterone as well as testicular ATP, GSH and Nrf2, while increased levels of testicular ADP, AMP, MDA, GSSG and TNF-α. Results were confirmed by prominent interstitial fibrosis and severe germ cell degeneration in MTX group. Concurrent treatment with EGb 761 alleviated MTX-induced testicular insult evidenced by amelioration of oxidative stress biomarkers, energy functions, seminal sperms abnormalities and spermatogenesis status. The present study suggests a beneficial role of EGb 761 in MTX-induced testicular injury and subsequent distortion of spermatogenesis.