Antioxidant β-cryptoxanthin enhances porcine oocyte maturation and subsequent embryo development in vitro

Oxidative stress is partly responsible for the poor quality of IVM oocytes. The present study investigated the effects of the antioxidant β-cryptoxanthin on the IVM of porcine oocytes and the in vitro development of the ensuing embryos. Oocytes were matured in IVM medium containing different concentrations of β-cryptoxanthin (0, 0.1, 1, 10 or 100 μM). Treatment with 1 µM β-cryptoxanthin (Group 1B) improved polar body extrusion and the expression of maturation-related genes in cumulus cells and oocytes compared with control. In addition, levels of reactive oxygen species decreased significantly in Group 1B, whereas there were significant increases in glutathione levels and expression of the antioxidant genes superoxide dismutase 1 and peroxiredoxin 5 in this group. After parthenogenetic activation, although the cleavage rate did not differ between the control and 1B groups, the blastocyst formation rate was higher in the latter. Moreover, the total number of cells per blastocyst and relative mRNA levels of pluripotency marker and antioxidant genes were significantly higher in the 1B compared with control group. These results demonstrate that β-cryptoxanthin decreases oxidative stress in porcine oocytes and improves their quality and developmental potential.