Total oxidative status of mouse vitrified pre-antral follicles with pre-treatment of alpha lipoic acid

ABSTRACT

Cryopreservation of pre-antral follicles is a hopeful technique to preserve female fertility. The aim of the present study was to evaluate reactive oxygen species [ROS] and total antioxidant capacity [TAC] levels of mouse vitrified pre-antral follicles in the presence of alpha lipoic acid [ALA]. Isolated pre-antral follicles [140-150 micro m in diameter] were divided into vitrified-warmed and fresh groups. Each group was subjected to in vitro maturation with or without ALA for 12 days, followed by adding human chronic gonadotropin to induce ovulation. In vitro fertilization was performed to evaluate their developmental competence. In parallel, the amount of ROS and TAC were assessed after 0, 24, 48, 72, and 96 h of culture by 2',7'-dichlorofluorescin assay and ferric reducing/antioxidant power assay, respectively. The respective rates of survival, antrum formation, and metaphase II oocytes were significantly higher in ALA-supplemented groups compared to the groups not treated with ALA. TAC and ROS levels were significantly decreased and increased, respectively during the culture period up to 96 h in the absence of ALA in both vitrified and non-vitrified samples. However, with pretreatment of ALA, TAC levels were increased significantly and remained constant up to 96 h in vitrified-warmed pre-antral follicles, while ROS levels completely returned to the level of starting point after 96 h of culture in the presence of ALA. Pretreatment of ALA positively influences development of pre-antral follicles in vitrified and nonvitrified samples through increasing follicular TAC level and decreasing ROS levels