Sorting procedures submit sperm cells to a set of stressful steps that can trigger an increase
of ROS production and consequently reduce sorted semen quality. This study evaluated
the effect of supplementation with different antioxidants (EGCG, Na pyruvate + catalase,
SOD) on acrosome and plasma membrane integrity, activation of caspases (as assayed by
FITC-VAD/PI staining) and immunolocalization of Hsp70 of boar spermatozoa after sperm
preparation (Hoechst 33342 staining) and sorting procedure. The effect of antioxidants,
with or without seminal plasma, on sorted spermatozoa stored for 24 h at 15 ◦C was also
evaluated.
Antioxidants did not exert any preventive action on sperm modification induced by staining
and sorting. After 24 h of storage at 15 ◦C, sorted samples supplemented with either
EGCG or SOD plus seminal plasma showed a significant (p < 0.05) increase of the percentage
of viable spermatozoa, while no positive effect on the other tested parameters was
observed; EGCG seems to exert an inhibition on caspase activation in that a decrease of the
number of dead cells FITC-VAD+/PI+ was recorded.
In conclusion, our results indicate that EGCG and SOD in association with seminal plasma
are effective in exerting some compensatory protection against the detrimental effects
of storage of sorted semen while their action is not evident during steps of the sorting
procedure.