Effect of a Novel Hydroxybenzoic Acid Based Mitochondria Directed Antioxidant Molecule on Bovine Sperm Function and Embryo Production

SIMPLE SUMMARY: Gametes are particularly susceptible to oxidative stress that impairs the reproductive function. This study was conducted to study the effect of a mitochondria-targeted dietary antioxidant (AntiOxBEN2) on bovine sperm function. Different doses of this antioxidant were tested during spermatozoa capacitation and/or fertilization processes. Spermatozoa mitochondrial function was improved when AntiOxBEN2 was supplemented to the capacitation medium. Supplementation of both capacitation and fertilization media with AntiOxBEN2 (lowest dose) improved the fertilization process and embryo production. Our results showed that AntiOxBEN2 can be used for the prevention of oxidative stress in bovine spermatozoa and may constitute a putative novel therapeutic strategy to improve the outcomes of assisted reproductive techniques. ABSTRACT: Sperm cells are particularly vulnerable to reactive oxygen species (ROS), impairing their fertilizing ability. Our objective was to study the effect of a novel mitochondrial-directed antioxidant, AntiOxBEN2, on bovine sperm function. This antioxidant was added to the semen capacitation medium (CAP), during the swim-up process, and to the fertilization medium (FERT) during the co-incubation of matured oocytes and capacitated spermatozoa, in concentrations of 0 (control), 1, and 10 µM. After the swim-up, sperm motility (CASA and visual analysis), vitality (eosin-nigrosin), mitochondrial membrane potential (JC1), intracellular ROS, adenosine triphosphate (ATP) levels, and basal metabolism (Seahorse Xfe96) were evaluated. Embryo development and quality were also assessed. Higher cleavage rates were obtained when 1 µM AntiOxBEN2 were added to CAP and FERT media (compared to control, p < 0.04). A positive effect of AntiOxBEN2 on intracellular ROS reduction (p = 0.01), on the increment of mitochondrial membrane potential (p ≤ 0.003) and, consequently, on the sperm quality was identified. However, the highest dose impaired progressive motility, ATP production, and the number of produced embryos. The results demonstrate a beneficial effect of AntiOxBEN2 (1 µM) on sperm capacitation and fertilization processes, thus improving embryonic development. This may constitute a putative novel therapeutic strategy to improve the outcomes of assisted reproductive techniques (ART).