Supplementation with asiatic acid during in vitro maturation improves porcine oocyte developmental competence by regulating oxidative stress.

Asiatic acid is a natural triterpene found in Centella asiatica that acts as an effective free radical scavenger. Our previous research showed that asiatic acid delayed porcine oocyte ageing in vitro and improved preimplantation embryo development competence in vitro; however, the protective effects of asiatic acid against oxidative stress in porcine oocyte maturation are still unclear. Here, we investigated the effects of asiatic acid on porcine oocyte in vitro maturation (IVM) and subsequent embryonic development competence after parthenogenetic activation (PA) and in vitro fertilization (IVF). The results of the present research showed that 10 μM asiatic acid supplementation did not affect the expansion of cumulus cells or polar body extrusion of porcine oocytes, while asiatic acid application significantly increased the subsequent blastocyst formation rate and quality of porcine PA and IVF embryos. Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that induces oxidative stress in porcine oocytes. As expected, asiatic acid supplementation not only decreased intracellular ROS levels but also attenuated H2O2-induced intracellular ROS generation. Further analysis revealed that asiatic acid supplementation enhanced intracellular glutathione production, mitochondrial membrane potential, and ATP generation at the end of IVM. In summary, our results reveal that asiatic acid supplementation exerts beneficial effects on porcine oocytes by regulating oxidative stress during the IVM process and could act as a potential antioxidant in porcine oocytes matured in vitro production systems.