Indole-3-propionic acid supplementation during in vitro maturation improves in vitro production of porcine embryos.

Abstract

BACKGROUND: Oxidative stress is a critical factor affecting the maturation and developmental competence of porcine oocytes during in vitro culture, reducing the efficiency of blastocyst formation. Antioxidant supplementation in the culture medium has been proposed to mitigate oxidative stress and improve developmental outcomes. This study aimed to evaluate the effects of indole-3-propionic acid (IPA), a potent antioxidant, on porcine oocyte maturation, fertilization, and subsequent blastocyst development under in vitro conditions. METHODS: Porcine cumulus-oocyte complexes (COCs) were matured for 44 h in maturation medium supplemented with IPA at various concentrations (0.5, 1, 5, and 10 &#xb5;M). As a control, COCs were cultured in maturation medium containing the IPA dilution vehicle (ethanol) without IPA. After maturation culture, in vitro fertilization and embryo culture were performed to evaluate fertilization rate and developmental competence. Meiotic competence, fertilization status, blastocyst formation, and DNA integrity of oocytes and blastocysts were evaluated. To further investigate the protective effect of IPA against oxidative stress, COCs were exposed to 1 mM HOin a maturation medium supplemented with or without IPA (0.5 &#xb5;M) during maturation culture. After maturation, intracellular reactive oxygen species (ROS) and glutathione (GSH) levels in oocytes were assessed. RESULTS: Supplementation with 0.5 &#x3bc;M IPA in the in vitro maturation medium significantly enhanced the rates of oocyte maturation, fertilization, and blastocyst formation compared with the control group (p&#x2009;<&#x2009;0.05). In addition, IPA supplementation at concentrations ranging from 0.5 to 5 &#xb5;M significantly reduced DNA fragmentation in both matured oocytes and blastocysts. Furthermore, IPA supplementation effectively reduced the intracellular ROS levels elevated by HOwhile significantly increasing intracellular GSH levels (p&#x2009;<&#x2009;0.05). These findings indicate that IPA supplementation protects porcine oocytes from oxidative stress during in vitro maturation by reducing ROS generation and enhancing GSH levels. Consequently, IPA improves oocyte quality, fertilization potential, and developmental competence of embryos. CONCLUSIONS: This study demonstrates the potential of IPA as a beneficial supplement to in vitro maturation medium for improving the efficiency of porcine embryo production by enhancing oocyte quality and protecting against oxidative damage.