The citrus flavonoid hesperetin has a variety of pharmacological actions, including
antioxidant, antiinflammatory, and anticancer activities. This study investigated whether hesperetin prevents aging of oocytes in vitro in which it determined the
maturation of nuclear and cytoplasm and the developmental capacity of embryo by
modulating the reactive oxygen species (ROS) level. Porcine oocytes were matured in vitro for 44 hr (control) and for an additional 24 hr in the presence of 0, 1, 10, 100, and 250 μM hesperetin (aging, H‐1, H‐10, H‐100, and H‐250, respectively). Although there was no difference in the rate of maturation among all the groups, both the control and H‐100 groups significantly increased in the rate of cleavage and blastocyst formation compared to the aging group. The H‐100 group significantly decreased ROS activity and increases the level of glutathione (GSH) and expression of the antioxidant genes (PRDX5, NFE2L, SOD1, and SOD2) compared with the aging group. The H‐100 groups prevented aberrant spindle organization and chromosomal misalignment, blocked the decrease in the level of phosphorylated‐p44/42 mitogenactivated protein kinase and increased the messenger RNA expression of cytoplasmic maturation factor genes (GDF9, CCNB1, BMP15, and MOS). Subsequently, both the control and H‐100 groups significantly increased the total cell number and decreased the apoptosis cells at the blastocyst stage compared with aging group. The results indicate that hesperetin improves the quality of porcine oocytes by protecting them against oxidative stress during aging in vitro.