Effect of α-tocopherol supplementation on in vitro maturation of sheep oocytes and in vitro development of preimplantation sheep embryos to the blastocyst stage

Abstract

Purpose To determine the effects of α-tocopherol supplementation to oocyte maturation media and embryo culture media on the yield of ovine embryos. Methods α-tocopherol, at concentrations of 0, 50, 100, 200, 400 and 500 µM was supplemented to ovine oocyte or embryo culture media and cultured at 5% or 20% O 2 levels. Percentages of cleavage, morula and blastocyst, total cell count and comet assay were taken as indicators of developmental competence of embryos. Results 200 µM α-tocopherol in embryo culture medium at 20% O 2 level significantly increased the rates of cleavage (P<0.05), morulae (P<0.05) and blastocyst (P<0.01) formation and blastocyst total cell number (P<0.01) when compared with control. The rates of blastocyst formation were also significantly higher in 100 µM (P<0.01) and 400 µM (P<0.05) supplemented groups than control. Conclusion α-tocopherol supplementation may enhance the in vitro developmental competence of ovine embryos by protecting them from oxidative damage.

Effects of oxygen concentration on in vitro maturation of canine oocytes in a chemically defined serum-free medium

“…Vitamin E in the presence of high oxygen was able to decrease degeneration (PZ0.008) but did not improve the percentage of oocytes in MII. The beneficial effect of vitamin E on oocyte maturation and embryo development was previously reported in animal species regardless of lipid content, including porcine cells (Tao et al 2010), which contain high lipid, or in ovine oocytes (Natarajan et al 2010), which contain relatively low lipid contents.…”

“…Vitamin E (a-tocopherol) as a lipid-soluble antioxidant has been proven to have beneficial effects on oocyte maturation and embryo development in pigs (Tao et al 2010) and alleviates the degeneration rates of bovine and ovine oocytes (Dalvit et al 2005, Natarajan et al 2010. This study investigated the impact of oxidative stress on oocyte nuclear maturation and degeneration.…”

Effect of L-carnitine supplementation on maturation and early embryo development of immature mouse oocytes selected by brilliant cresyle blue staining

“…Oocytes are unavoidably exposed to oxidative stress during in vitro maturation [34]. Hence, during in vitro oocyte culture, oxidative stress must be regulated by addition of antioxidants to culture media.…”

Effect of using ascorbic acid and cysteamine supplementation on in-vitro development of buffalo embryos

“…In sheep, Natarajan [26] stated that there was a relation between the oxygen levels in culture environment and concentration of vitamin C to achieve optimal embryo development.…”