Effect of zeaxanthin on porcine embryonic development during in vitro maturation

Zeaxanthin is a common carotenoid, which is a powerful antioxidant that protects against damage caused by reactive oxygen species. The aim of the present study was to investigate the effects of zeaxanthin supplementation on in vitro maturation of porcine embryo development. We investigated nuclear maturation, intracellular glutathione (GSH), and reactive oxygen species (ROS) levels during in vitro maturation, and subsequent embryonic development following parthenogenetic activation and in vitro fertilization (IVF). The oocytes were maturated and used at the metaphase II stage. After 42 hours of in vitro maturation, the zeaxanthin-treated group (0.5 mmol/L) showed significant increases in nuclear maturation (89.6%) than the control group (83.4%) (P<0.05). The intracellular GSH levels increased significantly (P<0.05) as zeaxanthin concentrations increased; ROS generation levels decreased with increased zeaxanthin concentrations, but there were no significant differences. There were no significant differences in subsequent embryonic development, cleavage rate, blastocyst stage rate, and total blastocyst cell numbers following parthenogenetic activation and IVF when in vitro maturation media was supplemented with zeaxanthin. These results suggest that treatment with zeaxanthin during in vitro maturation improved the nuclear maturation of porcine oocytes by increasing the intracellular GSH level, thereby slightly decreasing the intracellular ROS level.