Levels of DNA, Protein, Lipid Oxidation and Apoptosis Biomarkers in Semen of Men with Hyperviscous Semen: A Cross-Sectional Study

BACKGROUND: Semen hyperviscosity is a threatening cause of abnormal spermatozoa and infertility in men. We aimed to evaluate oxidative stress, antioxidants depletion and sperm apoptosis as main reasons for poor quality of spermatozoa in men with hyperviscous semen. MATERIALS AND METHODS: In this cross-sectional study, ejaculate specimens were collected from fertile (n=102) and infertile men with hyperviscous semen (n=123) and without semen hyperviscosity (n=143). Total antioxidant capacity (TAC), glutathione (GSH), malondialdehyde (MDA), protein carbonyl (PC), 8-hydroxydeoxyguanosine (8-OHdG), and were measured in semen samples to estimate oxidative stress status. Gene expression pattern of BAX, CASPASE-9, CASPASE-3, and BCL2 was assessed to estimate sperm apoptosis. RESULTS: The average of sperm count, normal morphology, normal motility, and sperm vitality in men with hyperviscous semen was significantly lower than infertile subjects without hyperviscous semen (P<0.01). Men with hyperviscous semen exhibited higher levels of PC (8.34 ± 1.03 nmol/mg vs. 6.01 ± 0.93 nmol/mg, P=0.008), MDA (1.14 ± 0.27 nmol/ ml vs. 0.89 ± 0.22 nmol/ml, P=0.031), 8-OHdG (259.71 ± 24.59 ng/ml vs. 197.13 ± 18.47 ng/ml, P=0.009), but lower TAC contents (1250.44 ± 66.23 μM/L vs. 1784.31 ± 89.87 μM/L, P=0.018) and GSH (3.82 ± 1.05 μM vs. 5.89 ± 0.87 μM, P=0.021) than men with non-viscous semen. The expression of BAX, CASPASE-3 and CASPASE-9 genes in men with hyperviscous semen was significantly increased by 1.39-fold (P=0.041), 1.47-fold (P=0.046), 1.29-fold (P=0.048), respectively, as compared with the infertile subjects without hyperviscous semen. However, BCL2 expression in infertile men without hyperviscous semen was higher compared to those with hyperviscous semen (1.36-fold, P=0.044). CONCLUSION: Hyperviscous semen is markedly associated with depletion of seminal plasma antioxidants, sperm membrane lipid peroxidation, DNA and protein oxidation, and sperm apoptosis. Antioxidant therapy might be considered as a valuable strategy to protect sperm cells against oxidative damage in cases with seminal fluid hyperviscosity.