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

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.