Alpha-lipoic acid improves the maturation and the developmental potential of goat oocytes in vitro

Oxidative stress inevitably occurs during oocyte maturation in vitro. α-lipoic acid (α-LA) has a strong antioxidant capacity, but the effect of α-LA on parthenogenetic activation of oocytes was rarely reported. This study aims to investigate the effect of supplementing α-LA to in vitro maturation medium on the subsequent developmental ability of goat parthenogenetic embryos during oocytes maturation. In the study, the goat cumulus-oocyte complex was divided into the experimental (with 25 μmol/L α-LA) and the control (without α-LA) groups. Oxidase expression was measured using RT-qPCR. After 18-22 hr of maturation, the oocytes were then parthenogenetic activated. The total antioxidant capacity of embryos was measured after 0, 24, 48, 72 and 96 hr of culture. Rates of oocyte maturation and the rates of development for parthenogenetic embryos in the α-LA group were significantly improved by 7.88% (p < .05) and 5.41% (p < .05) compared with those in the control group, respectively. After 24 hr, the difference in total antioxidant capacity was extremely significant in both groups. An evident decrease in the control group and a minor decrease in the α-LA group were observed (p < .01). The ratio of inner cell mass cells to the total cell number of blastocysts in the α-LA group increased compared with that in the control group (p < .05) on day 8. α-LA significantly promoted the expression of SOD and GPX4 of parthenogenetic blastocysts and maturated oocytes. α-LA (25 μmol/L) improved the maturation rate and the developmental competence of the parthenogenetic activation of oocytes, which might be mediated by maintaining the total antioxidant ability of oocytes during the culture period.