Introduction: Dexamethasone is a widely use glucocorticoid with numerous side effects. N-acetilcysteine (NAC) as strong antioxidants is able to minimize oxidative stress. The aim was to investigate the effect of N-acetylcysteine on the undesired effects of dexamethasone on the spermatogenesis indexes and daily sperm production. Materials and Methods: Twenty four NMRI mice were divided into 4 groups: Control, Dexamethasone (7mg/kg), NAC (100 mg/kg), and dexamethasone + NAC and treated for 7 days. One day after the last injection, the left testis was weighed, fixed, stained and used for stereological evaluation and the right testis was used to calculate the mean daily sperm production (DSP). The Mean tubular differentiation (TD), spermiogenesis (SP), Meiosis (M) and Sertoli cell (SC) indexes, the mean number of spermatocyte, round and long spermatid, Spermatogonia, Leydig and Sertoli cells, sperm tail length (STL) and sperm motility were also measured. In addition, Serum and tissue malondialdehyde (MDA) and testosterone levels were also analyzed. Data was statistically analyzed using One-Way ANOVA and Tukey’s test and the means were considered significantly different at P<0.05. Results: A Significant reduction in the mean sperm motility, TDI, MI, SPI, and mean number of spermatocyte, round and long spermatid, Leydig , DSP and mean level of serum testosterone was found in the Dexamethasone group compared to the control group (p<0.05). the mean levels of Serum and tissue malondialdehyde significantly increased in the Dexamethasone group compared to the control group (p<0.05). The mentioned parameters were compensated to the control level in the Dexamethasone + NAC group . Conclusion: This study showed that Co-administration of NAC with Dexamethasone could prevent the adverse effects of Dexamethasone on the spermatogenesis indexes and daily sperm production. Therefore its application in therapeutic regimens including Dexamethasone is suggested.
