426 Late-Breaking: Effect of lycopene supplementation to in vitro maturation media on developmental competence of bovine oocytes after IVF.

Abstract In vitro maturation (IVM) of oocytes results in production of reactive oxygen species (ROS) which has deleterious effects on subsequent steps of in vitro embryo production (IVEP) include in vitro fertilization (IVF) and in vitro embryo culture (IVC). Supplementation of antioxidants during IVM can enhance oocyte maturation and subsequent development. Lycopene, a carotenoid red pigment and a powerful antioxidant is mostly found in ripened tomatoes and watermelon. It has 100 times higher free radicals scavenging ability than other antioxidants. Little information is known about its effect on oocyte maturation and IVEP in livestock. Our aim was to investigate the effect of lycopene supplementation to IVM media on bovine oocyte developmental competence. Cumulus oocyte complexes (COCs) were collected slaughtered bovine ovaries by aspiration of 2-8 mm follicles. Collected COCs were matured in IVM media supplemented with 0.2, 0.5, and 1.0 µM lycopene for 22 h in 5% CO2, 37.8 °C, and humidified atmospheric air. COCs that were matured in IVM media without lycopene supplementation were considered as control. Following IVM, COCs were fertilized by frozen/thawed semen and presumptive zygotes were cultured in vitro for 8 days. Cumulus cell expansion was recorded after IVM. Cleavage and blastocyst rates were recorded on day 3 and 8 post-insemination (pi), respectively. Data was presented as percentages and analyzed by Chi-square test. Oocyte recovery rate was 5.7 oocyte/ovary. The percentage of good quality oocytes (oocytes with more than 3 layers of compact cumulus cells and homogenous ooplasm) was 92.4% (157/170). No significant differences were observed in the percentage of COCs with expanded cumulus cells following IVM. Furthermore, cleavage rates at day 3 pi were not significant among the treatment and the control groups (ranges from 83.3% to 89.2%). Blastocyst rate was higher (P< 0.05) for 1.0 µM lycopene group (48.0%) compared to control (29.7%), 0.2 µM (28.3%), and 0.5 µM (27.8%) supplemented groups. In conclusion, lycopene supplementation to IVM media at 1 µM improved blastocyst development rate following IVM/IVF and IVC in cattle. The positive effect of lycopene on blastocyst rate might be attributed to its antioxidant effect. Further studies are in progress to evaluate the mechanisms by which lycopene exert its beneficial effect on bovine IVEP.