Effects of reactive oxygen species from activated leucocytes on human sperm motility, viability and morphology

Abstract

The accumulated data suggest that inflammation can increase the level of reactive oxygen species (ROS), which contribute to impaired sperm function and male infertility. Therefore, we propose that inflammation-mediated production of ROS in male and female reproductive tracts hinder sperm fertilisation. To test this hypothesis, phorbol myristate acetate (PMA) with polymorphonuclear leucocytes (PMNs) was applied to generate endogenous ROS. We evaluated the time-dependent effects of ROS on human sperm motility, viability and mitochondrial membrane potential (MMP). The results showed that after treatment with PMA and PMNs, the motility of human spermatozoa significantly decreased to 50% on Day 1 and 15% on Day 4 compared with that of the, respectively, negative controls (P = 0.012). The viability of human spermatozoa decreased on Day 4 of PMA + PMNs treatment (P = 0.028). The MMP of human spermatozoa significantly decreased from Day 2 to Day 4 in the PMA + PMN group compared with that of the controls (P = 0.019). Taken together, the 4-day cultivation approach provided an accurate evaluation of sperm quality, especially sperm motility and MMP. Our findings indicated that endogenous inflammation increased ROS levels, which might induce sperm oxidative damage. Additionally, sperm motility might be one of the earliest and most sensitive indicators of this damage.