Effect of Lycopene on Cytoplasmic Maturation of Porcine OocytesIn Vitro

Abstract

The aim of the present study was to improve cytoplasmic maturation of porcine oocytes by the addition of lycopene into in vitro maturation (IVM) media. We designed six experimental groups; IVM medium was supplemented with 10 IU/ml FSH, FSH and 10 IU/ml human chorionic gonadotrophin (hCG), or FSH and 7 μm lycopene in the first half of the IVM culture (0-22 h) followed by further culture (22-44 h) with or without hCG. The addition of lycopene into IVM media delayed the interruption of communication between an oocyte and the cumulus cells. Although meiotic competence was similar among the six groups, the glutathione level of matured oocytes was significantly higher in the lycopene-supplemented group (9.89 pmol per oocyte) than that in other groups (7.25 and 7.81 pmol per oocyte). Fertilization rate was significantly improved in lycopene-supplemented groups (58.3%) more than that in the group supplemented with FSH only (43.1%), whereas there were no differences in developmental competence among the groups (blastocyst rate: 20.1-29.5%). These results indicate that insufficient cytoplasmic maturation during conventional IVM resulted by disconnection of the gap junction between an oocyte and the cumulus cells in the early phase during IVM culture. We concluded that lycopene induced a prolonged sustainment of gap junctional communication between an oocyte and the cumulus cells during porcine IVM culture, which was an effective cytoplasmic maturation of porcine IVM oocytes.