Alpha-lipoic acid in ovarian vitrification solution for in vitro culture or autotransplantation as future strategies for the restoration of ovarian function in sheep

Abstract

Vitrification is a promising method for ovarian cortex preservation, however, oxidative stress resulting from excessive free radical production can cause irreversible damage to the ovary and ovarian follicles. Therefore, this study aimed to evaluate the effect of 100 µM and 150 µM concentrations of alpha-lipoic acid (ALA) in the vitrification solution of sheep ovaries, after in vitro culture (IVC - 7 days) or autotransplantation (TRP - 15 days). For this, after IVC and TRP, the ovary was evaluated for follicular morphology and development; stromal cell density and proliferation; presence of mature and new vessels; tissue fibrosis, as well as, levels of reactive oxygen species (ROS), malonaldehyde (MDA), and nitrite in the culture medium after IVC. The results showed that ALA 100 µM or 150 µM maintained the morphology of primordial follicles and promoted follicular development after IVC. Although stromal cell density was not altered after IVC of the ovary vitrified with ALA 100 µM, a reduction was observed after TRP. The proliferation of these cells was also reduced after IVC or after TRP. The data also showed that after TRP, revascularization increased in the ovary vitrified with ALA 150 µM, but high levels of ROS and signs of fibrosis were observed. In conclusion, ALA is an excellent antioxidant agent that can be added to the vitrification solution to alleviate some of the negative effects observed after in vitro culture or autotransplantation of ovine ovarian tissue.