Palm tocotrienol-rich-fraction yields higher numbers of normal embryos whereas alpha-tocopherol produces higher preimplantation survival in murine embryos

Abstract

Vitamin E contains isomers of tocotrienols and tocopherols. Studies have shown that palm tocotrienol-rich-fraction (TRF) improves preimplantation development of murine embryos. The aim of this study is to investigate the effects of TRF and α-tocopherol supplementation on preimplantation embryonic morphology, development and mitochondrial ultrastructure. Female C57Bl/6 mice were supplemented with 60 mg/kg body weight per day TRF and α-tocopherol for seven days. The females were superovulated and mated with fertile males to obtain 2-cell stage embryos. Initial assessment of normal and abnormal morphology was carried out on 2-cell embryos. The embryos were then cultured until the blastocyst stage. At the 8-cell stage, embryos were subjected to Transmission Electron Microscopy (TEM) to observe their mitochondria. Results showed that palm TRF produced significantly higher numbers of normal 2-cell embryos compared with α-tocopherol (80.9% vs 31.4%) at p< 0.01. Alpha-tocopherol produced higher survival rate to the blastocyst stage compared with palm TRF (42.2% vs 20.6%) at p< 0.01. The TRF group showed more vacuolated mitochondria at 8-cell stage compared to the α-tocopherol group, which may have contributed to a decline in preimplantation survival rates.