Effect of acteoside on the re-localization and abnormal morphology of mitochondria in porcine oocytes during in vitro maturation.

Abstract

The aim of this study is to investigate the effect of acteoside, an antioxidant, on in vitro maturation (IVM) of oocytes to improve early parthenogenetic embryonic developmental competence. Porcine immature oocytes (total 770) were cultured in IVM medium with acteoside at various concentrations, 0 (control), 10, 30, and 50μM. Each group was assessed for maturation and subsequent development rates, reactive oxygen species (ROS) level (15 oocytes per group and four independent experiments performed), ultrastructure observation (15 oocytes per group), mitochondrial activity (30 oocytes per groups and three independent experiments performed), and expression patterns of apoptosis-related genes (100 expended parthenogenetic embryos per group and three independent experiment performed). Main outcome measures were the rates of IVM, blastocyst formation, ROS, mitochondria, and expression of apoptosis-related genes in oocytes treated with acteoside. Addition of acteoside during IVM did not change the maturation efficiency of oocytes but improved the rate of blastocyst formation with significantly decreased ROS level. Moreover, in acteoside-treated oocytes, cytoplasmic maturation was improved with morphologically uniform distribution of mitochondria and lipid droplets in cytoplasm. Acteoside supplementation also increased the mRNA expression levels of antiapoptotic genes and reduced those of pro-apoptotic genes. Acteoside supplementation in IVM medium improves the oocyte quality and subsequent development of pre-implantation embryos that would eventually contribute to produce embryos with high embryonic development competence.