Thiamine attenuates methotrexate-induced reproductive toxicity in adult male mice

Chemotherapy agents impose harmful side effects beside their therapeutic properties. This study aimed to uncover the ameliorative effects of thiamine (VitB1) on sperm characteristics and in vitro fertilizing ability in methotrexate (MTX) exposed mice. For this purpose, 36 apparently healthy adult male mice were randomly divided into six groups (n = 6), including control (0.10 mL normal saline per day; intraperitoneally [IP]), sham (10.00 mg kg^-1 per week MTX; IP), positive control group (100 mg kg^-1 per day VitB1; IP), and three experimental groups (25.00, 50.00, and 100 mg kg^-1 per day; IP VitB1 plus MTX, respectively; IP). Then, sperm parameters and the in vitro fertilizing potentials were assessed. The sperm count, motility, and viability in the sham group showed a significant decrease in comparison with the VitB1-treated and control groups. In the VitB1 100 mg kg^-1 + MTX group, there was a significant increase in sperm count in comparison with the sham group. The sperms with DNA damages and immature sperms in the sham group significantly increased in comparison with the positive control and control groups. In vitro fertilization and embryonic development in the sham group were decreased in comparison with both the control and VitB1 groups. In VitB1 50.00 mg kg^-1 and 100 mg kg^-1 + MTX groups, there was an increase in the fertilization rate, along with embryonic development promotion. According to the results of this study, thiamine ameliorates toxic effects of MTX on sperm traits and in vitro fertilizing potentials by constraining oxidative stress.