Khadijeh Baranizadeh - Department of Clinical Biochemistry, Medicine School, Hamadan University of Medical Sciences, Hamadan, Iran.
Maryam Bahmanzadeh - Department of Anatomical Sciences, School of Medicine, Endometrium and Endometriosis Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
Heidar Tavilani - Department of Clinical Biochemistry, Medicine School, Hamadan University of Medical Sciences, Hamadan, Iran.
Tayebeh Ghiasvand - Department of Clinical Biochemistry, Medicine School, Hamadan University of Medical Sciences, Hamadan, Iran.
Iraj Amiri - Department of Anatomical Sciences, School of Medicine, Endometrium and Endometriosis Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
Mahnaz Yavangi - Department of Obstetrics and Gynecology, School of Medicine, Endometrium and Endometriosis Research Center, Fatemieh Hospital, Hamadan University of Medical Sciences, Hamadan, Iran.
Gholamreza Shafiee - Department of Clinical Biochemistry, Medicine School, Nutrition Health Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.

Background: Methylenetetrahydrofolate reductase enzyme (MTHFR) plays a key role in regulating folate balance, converting homocysteine to methionine, and producing s-adenosylmethionine (SAM) that plays a role in the methylation process. Objective: This study aimed to determine MTHFR activity and SAM level in men with normozoospermia and oligozoospermia. Materials and Methods: ۳۰ oligozoospermic and ۳۰ normozoospermic men as controls were enrolled in this case-control study. Semen analysis was conducted according to the world health organization criteria. All semen samples were collected after ۳-۵ days of sexual abstinence. The sperms were evaluated by sperm test video software. All subjects SAM level was measured by enzyme-linked immunosorbent assay kit, and MTHFR were measured manually. Results: ۲ groups had a significant difference in sperm morphology (p = ۰.۰۲), concentration (p = ۰.۰۲) and motility (p = ۰.۰۳). The MTHFR activity in normozoospermic and oligozoospermic groups had significantly differences (p = ۰.۰۱). The level of SAM in the semen of oligozoospermic men was statistically lower than normozoospermic men (p = ۰.۰۳). Also, there was a positive association between MTHFR enzyme activity and SAM level in the normozoospermia group (p = ۰.۰۲, β = ۰.۶۷) and oligozoospermia group (p = ۰.۰۳, β = ۰.۵۴). Conclusion: MTHFR activity and SAM concentration were statistically lower in oligozoospermia men. It seems they can affect sperm concentration, morphology, and motility.

Methylenetetrahydrofolate reductase, S-adenosylmethionine, Normozoospermia, Oligozoospermia, Folic acid., متیلن تتراهیدروفولات ردوکتاز, اس- آدنوزیل متیونین, نرمواسپرمی, الیگواسپرمی, اسید فولیک.