Redox status of equine seminal plasma reflects the pattern and magnitude of DNA damage in sperm cells

Antioxidant status of seminal plasma from 23 stallions was evaluated. We found a negative correlation between total antioxidant capacity (ABTS
• + decolorization assay) and thiol content of seminal plasma, and sperm DNA damage (8-oxoG immunostaining, TUNEL reaction, comet assay). Low seminal redox status was the strongest correlated with 8-oxoG level which may indicate that seminal total antioxidant capacity influences mainly the formation of single strand DNA breaks in sperm cells. Since inter-individual differences in seminal antioxidant status were reported, we postulated that the redox status of seminal plasma may be an additional important parameter, both with sperm quantitative and morphological analysis, for evaluation of equine semen quality.