Resveratrol and antifreeze protein type I show no synergistic benefits in cryopreserved ram sperm

This study investigated the effect of resveratrol (RV) after thawing of ram sperm cryopreserved with or without the addition of antifreeze protein I (AFPI) on sperm quality during the 3 h incubation period. Each ram ejaculate was split into two aliquots, diluted in a TRIS egg yolk (TEY) extender supplemented with 0 (control) or 0.1 mu g/mL AFPI, and then cooled and frozen. Thawed samples of both treatments were subdivided and incubated in Talp-Hepes medium with 0 (TEY and AFPI group) or 50 mu M of RV (TEY + RV group and AFPI + RV group) for 3 h at 38 degrees C. The sperm kinetics, capacitation status, plasma membrane integrity, mitochondrial activity, sperm-egg binding assay, and TBARS concentrations were evaluated at different intervals. Data were analyzed by mixed model, including the incubation time, AFP treatment, RV treatment, and their interactions as main effects, and the day of semen collection and the ram as random effects (P < 0.05; LS mean +/- pooled SEM). The AFPI, RV treatments, and their interaction did not affect the average total motility (similar to 17.1 +/- 2.4%), progressive motility (similar to 5.6 +/- 1.4%), mitochondrial activity (similar to 35.5 +/- 2.3 arbitrary unit), plasma membrane integrity (similar to 18.2 +/- 2.4%), sperm binding capacity (similar to 2.2 +/- 0.1 sperm per mm2), TBARS concentrations (similar to 1488.7 +/- 27.4 ng/mL) and rates of capacitated (similar to 27.5 +/- 1.6%), non-capacitated (similar to 20.9 +/- 1.6%) and acrosome-reacted (similar to 56.5 +/- 4.1%) sperm. It was concluded that adding 0.1 mu g/mL AFPI to the extender used for ram semen cryopreservation and/or further in vitro culture exposure to 50 mu M RV did not improve in vitro sperm quality.