Detrimental effects of oxidative stress on sperm membrane and DNA integrity in normozoospermic infertile men

Oxidative stress (OS) indicates an imbalance between the generation of reactive oxygen species (ROS) and total antioxidant capacity (TAC). ROS and TAC levels, lipid peroxidation (LPO), acrosome reaction status and OS induced DNA damage were assessed in normozoospermic infertile men (Group I) and compared with proven fertile men (Group II; controls). Forty men with normal semen parameters were grouped into normozoospermic infertile men (n=30) and proven fertile men (n=10). ROS and TAC levels were measured by chemiluminescence assay. LPO, acrosome reaction and DNA fragmentation were assessed and compared with ROS generation. Differences between these groups was calculated using two tailed Students t-test and statistical significance assessed at P value<0.05. Significant increase in ROS and decrease in TAC levels were observed in Group I patients as compared to Group II. These results correlated well with LPO results. Further, TAC was found to be reduced in cases with high ROS levels. DNA fragmentation was found to be positively correlated with ROS. A sharp decline in the acrosomal integrity was observed in Group II. Decreased number of acrosome reacted spermatozoa and increased LPO play a significant role in the etiology of normozoospermic infertile men. In conclusion, ROS and TAC are expected to play an important role in male infertility and may have an impact on the failure of conception in women having male partners with normal semen parameters.