Zinc oxide-curcumin nanoparticles supplementation during oocyte maturation improves bovine in vitro embryo production

This work investigated the effect of zinc oxide nanoparticles functionalized with curcumin (ZnO_(np)+CUR) supplementation during the in vitro maturation (IVM) of bovine oocytes on the in vitro embryo production and the cellular antioxidant response. A total of 1,625 cumulus-oocyte complexes (COCs) were cultured in the maturation medium in the absence (0 µM - control) or presence of different concentrations of ZnO_(np)+CUR (3 µM, 6 µM or 12 µM). After IVM, COCs were destined either to 1) in vitro embryo production or 2) analysis of reactive oxygen species production, superoxide dismutase (SOD) activity, catalase (CAT) activity and total antioxidant capacity (FRAP). The results demonstrated that the addition of 6 and 12 µM ZnO_(np)+CUR during in vitro maturation showed a higher rate of blastocyst production when compared to the control (p < 0.05). However, only 12 µM ZnO_(np)+CUR treatment showed higher rates of embryo production when compared to 3µM ZnO_(np)+CUR treatment. Supplementation of IVM medium with 6 µM ZnO_(np)+CUR reduced ROS production (p < 0.05) compared to control and 12 µM ZnO_(np)+CUR treatments. Also, the treatment containing ZnO_(np)+CUR at 12 µM had lower SOD activity after IVM than control treatment. In conclusion, the best outcome for in vitro embryo production was obtained when 6 and 12 µM ZnO_(np)+CUR was added during IVM of bovine oocytes. However, this improvement in in vitro embryo production was not associated with either the reduction of ROS production or SOD and CAT activities.