Addition of beta-mercaptoethanol or Trolox at the morula/blastocyst stage improves the quality of bovine blastocysts and prevents induction of apoptosis and degeneration by prooxidant agents.

This study was conducted to evaluate the effect of beta-mercaptoethanol (a stimulator of glutathione synthesis) and Trolox (an hydrosoluble analogue of Vitamin E) on bovine embryos cultured from the morula stage (Day 5 post-insemination; pi) under oxidative stress conditions. Culture of embryos with increased doses of Trolox showed a dose-dependent embryotoxicity on Day 8 pi. The use of 400 microM Trolox as well as beta-mercaptoethanol at 100 microM prevented at least partly (P < 0.