Supplementation with lipoamide during in vitro maturation improves bovine oocyte maturation and subsequent embryonic development: potential link to PI3K/AKT signaling

Oxidative stress during oocyte in vitro maturation (IVM) is still concerned. Lipoamide (LAM) has been widely studied as an agent for alleviating various diseases associated with oxidative disruption. This work aimed to evaluate the potential effects of LAM on bovine oocyte IVM and its mechanisms. Different concentrations of LAM (0, 10, 50, 100, and 200 μmol/L) were supplemented to bovine oocyte IVM medium. The IVF derived zygote cleavage and blastocyst formation rate in the 100 μmol/L LAM treatment group was increased compared with the control group (P < 0.05).There was no statistical difference in PBI between 100 μmol/L LAM treatment and the control group, although the treatment tended to increase it (P = 0.059). Further revealed that LAM increased the expression of PI3K and phosphorylated-AKT1 (pAKT1), improved mitochondrial profile, and reduced apoptosis in bovine oocytes. Meanwhile, the reactive oxygen species (ROS) as well as the 8-Hydroxydeoxyguanosine (8-OHdG, DNA damage-specific marker) displayed lower levels accumulation in LAM-exposed oocytes. Taken together, the results show that administration of LAM (100 μmol/L) during IVM can ameliorate the developmental competence of bovine oocyte through the potential regulation of oxidative stress, apoptosis, DNA damage, and PI3K/AKT signaling.