Levels of 8-isoprostane and advanced oxidation protein products in relation to sperm count and motility

Background: Oxidative stress is implicated in male infertility, with reactive oxygen species contributing to sperm dysfunction. Among oxidative stress markers, 8-isoprostanes (8-isoP) and advanced oxidation protein products (AOPP) serve as indicators of lipid peroxidation and protein oxidation, respectively. However, their relationship with specific sperm abnormalities remains unclear. Aim: This study investigates the oxidative stress markers 8-isoprostane (8-isoP) and advanced oxidation protein products (AOPP) across different semen profiles and explores their correlation with sperm count and motility to evaluate their potential as diagnostic biomarkers in male infertility. Methods: A cross-sectional study was conducted on male partners of infertile couples between May 2024 and February 2025. Subjects were categorized into four groups based on semen analysis: normozoospermia (control), oligozoospermia, asthenozoospermia, and azoospermia. Seminal plasma levels of 8-isoP and AOPP were measured using sandwich ELISA kits, and results were compared among the groups. Results: Levels of 8-isoprostanes (8-isoP) and advanced oxidation protein products (AOPP) were significantly elevated in the asthenozoospermia group. In the azoospermia group, AOPP levels showed a significant increase, while 8-isoP exhibited a near-significant rise compared to the control. In contrast, the oligozoospermia group showed no significant increase in either marker. Conclusions: Although both markers increased in asthenozoospermia and azoospermia, AOPP showed greater sensitivity, highlighting protein oxidation’s role in severe sperm dysfunction. The oligospermic group showed no increase in both markers, indicating that isolated reduction in sperm count is unlikely to be caused by oxidative stress.