Vitamin E supplementation may negatively affect preimplantation development and mitochondrial ultrastructure of vitrified murine embryos

Abstract

Objective: To observe the effects of vitamin E on post-vitrification preimplantation development, gross morphology as well as mitochondrial distribution and ultrastructure. Methods: Twenty-four female C57BL/6NTac mice, aged 12-16 weeks, were randomly divided into four groups. Group A did not receive any treatment and served as the control group. Group B was treated with corn oil stripped of tocopherols and served as the vehicle group. Group C was treated with 60 mg/kg body weight of tocotrienol-rich-fraction with corn oil stripped of tocopherols. Group D was treated with 60 mg/kg body weight of alpha-tocopherol with corn oil stripped of tocopherols. All treatments were administered orally for 7 consecutive days. After superovulation and mating with fertile males, 2-cell stage embryos were harvested for vitrification. Post vitrification development in vitro, gross morphology and ultrastructure were compared between groups. Results: The number of 2 and 8-cell embryo, and blastocysts in the treatment and control groups were not significantly different (P>0.05). Following vitrification, all 2-cell embryos had equal-sized blastomeres and intact zona pellucida. Mitochondrial aggregation toward the perinuclear region was seen in all of the treatment groups. Both groups C and D had vacuolated mitochondria, which was reflected in the trend of preimplantation development reduction. Conclusions: Vitamin E supplementation of 60 mg/kg body weight does not improve the viability of healthy embryos according to this study. As a result, the most effective dose of vitamin E supplementation may be determined by the initial quality of the embryos.

Keywords

• mitochondria; preimplantation; embryo; vitrification; vitamin e; alpha-tocopherol; tocotrienol-rich-fraction
• transmission electron microscopy