Metabolic enzyme gene polymorphisms predict the effects of antioxidant treatment on idiopathic male infertility

To explore the relationship between genetic polymorphisms of metabolic enzymes such as CYP1A1, CYP2D6, GSTM1, GSTT1, and GSTP1 and idiopathic male infertility. By observing the efficacy of antioxidants in the treatment of idiopathic male infertility, the effect of metabolic enzyme gene polymorphisms on antioxidant therapy in patients with idiopathic male infertility was prospectively studied. This case–control study included 310 men with idiopathic infertility and 170 healthy controls. The cytochrome P450 1A1 (CYP1A1), cytochrome P450 2D6 (CYP2D6), glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and glutathione S-transferase P1 (GSTP1) genotypes in peripheral blood samples were analyzed by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). The idiopathic male infertility group was treated with vitamin C, vitamin E, and coenzyme Q10 for 3 months and followed up for 6 months. GSTM1(−), GSTT1(−), and GSTM1/T1(−/−) in the idiopathic male infertility groups were more common than those in the control group. The sperm concentration, motility, viability, mitochondrial membrane potential (MMP), and seminal plasma total antioxidant capacity (T-AOC) level in patients with GSTM1(−), GSTT1(−), and GSTM1/T1(−/−) were lower than those in wild-type carriers, and the sperm DNA fragmentation index (DFI), 8-hydroxy-2'-deoxyguanosine (8-OH-dG), and malondialdehyde (MDA) and nitric oxide (NO) levels were higher. Therefore, oxidative damage may play an important role in the occurrence and development of idiopathic male infertility, but antioxidant therapy is not effective in male infertility patients with GSTM1 and GSTT1 gene deletions.