Antioxidant Effect of a Polyphenol-Rich Murtilla (Ugni molinae Turcz.)‎ Extract and Its Effect on the Regulation of Metabolism in Refrigerated Boar Sperm

Abstract EN

The production of reactive oxygen species (ROS) in boar spermatozoa increases in refrigeration; this can have an impact on sperm quality and fertilization capacity.

We evaluated the effect of polyphenol-rich aqueous extract of murtilla (Ugni molinae Turcz) on boar sperm stored at 17°C in order to reduce oxidative stress and improve sperm quality in the long term.

Five experiments were performed: first, characterization of the polyphenol content from five genotypes of murtilla; second, determination of the genotype with the best antioxidant effect (MT-Ex); third, the antioxidant capacity on O2- and lipid peroxidation; fourth, the influence of MT-Ex on motility, calcium movement, cAMP, and metabolic parameters; and fifth, analysis of long-term refrigeration.

The average phenolic content was 344 ppm; gallic acid, catechin, quercetin, myricetin, and kaempferol were detected.

All extracts evaluated presented a concentration-dependent antioxidant effect.

MT-Ex reduces intracellular O2-/peroxides but low lipid peroxidation.

MT-Ex in nonstimulated ROS conditions reduces sperm motility, mitochondrial membrane potential, cAMP, and ATP, but the succinate dehydrogenase activity remained normal; also, we observed a reduction in calcium movement in in vitro sperm capacitation.

The long-term analyses showed that MT-Ex improved sperm motility decay and reduced membrane damage and ROS at 168 h.

Based on this study, we propose MT-Ex as a supplement in semen extenders.