Abstract
Oocytes are exposed to various stressors during in vitro maturation (IVM). Antioxidant supplementation during IVM can mitigate oxidative stress. We investigated the effects of supplementing IVM medium with novel flavonoid-enriched antioxidant nanoformulations, namely, EMD-300(®) and EMP3-H200(®), on oocyte IVM and analyzed the expression of oxidative stress, apoptosis, and pluripotency genes in buffalo. Cumulus oocyte complexes (COCs) obtained from buffalo ovaries were matured in IVM medium supplemented with either EMD-300(®) or EMP3-H200(®) at 0.5% and 1.0% for 22 h. Following IVM, nuclear maturation, gene expression, and the levels of total antioxidant capacity (TAC) and malondialdehyde (MDA) were analyzed. Nuclear maturation was lower (p < 0.001) for the 1.0% EMD-300(®) group than other groups. The expressions of the GPX4, SOD, CAT, and ATF6 genes were lower (p < 0.05) in the 0.5% EMD-300(®) and EMP3-H200(®) groups than in the control. OCT4 gene expression was higher (p < 0.05) for the treated groups than control group. The level of TAC in spent IVM medium was higher for the 0.5% EMD-300(®) and EMP3-H200(®) groups than for the control. However, the MDA concentrations were lower. In conclusion, supplementing IVM medium with EMD-300(®) or EMP3-H200(®) at 0.5% improved nuclear maturation of buffalo oocytes better than 1.0%. Our findings suggest that these compounds had antioxidant effects, which assures their ability in protecting oocytes against oxidative stress.