(+)-Catechin and (-)-epigallocatechin gallate: are these promising antioxidant therapies for frozen goat semen?

The aim of this study was to evaluate the effects of different concentrations of (+)-catechin or (-)epigallocatechin gallate (EGCG) on goat semen freezability. Poolsof semen were processed (Experiment 1: 0, 15, 25, 50, 75, or 100 mu M (+)-catechin; Experiment 2: 0, 15, 25, 50, 75, or 100 mu M EGCG) and frozen. After thawing, the samples were evaluated for kinematics, plasma membrane (PMi) and acrosome integrity, morphology, and oxidative stress, at 0 and 1h. In Experiment 1, at 0h, VSL and VAP were greater (P<0.05) with 15 mu M than with 50 and 100; WOB was lower (P<0.05) with 100 mu M than with 0, 15, and 25; and BCF was higher (P<0.05) with 75 and 100 mu M than with 0. In turn, in Experiment 2, progressive motility was higher (P<0.05) with0 and 15 mu M than with50 and 75; LIN was lower (P<0.05) with75 and100 mu M than with0 and 15; WOB was higher (P<0.05) with0 and 15 mu M; and PMi was greater (P<0.05) with100 mu M than 0. Thus, (+)-catechin or EGCG at higher concentrations inhibits the kinematics of frozen goat sperm, in a transitory way, and 100 mu M of EGCG preserves the PMi.