Associations between Inflammatory Factors, Lipid Peroxidation and Antioxidant Capacity in Bovine Seminal Plasma

Oxidative stress and inflammation are cooperative events involved in male reproductive dysfunction. In the present study, we assessed the associations between the spermatozoa motility, inflammatory factors (C-reactive protein and Interleukin-6), total antioxidant status (TAS) and lipid peroxidation expressed as malondialdehyde (MDA) concentration in the seminal plasma of breeding bulls. 17 semen samples were included in the study. Computer-aided sperm analysis (CASA) system was used to assess the spermatozoa motion characteristics, and seminal plasma was collected for further analyses. Interleukin-6 (IL-6) was quantified using ELISA, while C-reactive protein (CRP) and markers of the oxidative balance were evaluated by UV/VIS spectrophotometry. The correlation analysis revealed significantly positive associations between the sperm motility and TAS (P<0.05), while both parameters were in significantly negative correlations with CRP (P<0.05), IL-6 (P<0.05) and MDA (P<0.01). At the same time, the samples were divided according to the motility characteristics into groups of Excellent (Ex) and Moderate (Mo) quality. CRP, IL-6 as well as MDA concentrations were significantly (P<0.05) higher in the Mo group, while the Ex group exhibited a significantly higher antioxidant capacity (P<0.05). The relationships between the oxidative balance and inflammatory markers detected in our study suggest their intricate involvement in the resulting semen quality.