RESUMO
BACKGROUND: Although oocyte vitrification has become an essential part of infertility treatments, the formation of reactive oxygen species can reduce the quality of oocytes. OBJECTIVE: Protective effects of vitamin E or clove bud extract in the vitrification and warming media of vitrified mature oocytes were evaluated on blastocysts derived from the warmed oocytes. MATERIALS AND METHODS: Oocytes were vitrified-warmed with vitamin E (0, 50, 100, 200 and 400 mM) or hydroethanolic extract of clove bud (0, 5, 10, 20 and 40 µg/ml) in vitrification and warming media, and resultant blastocysts were evaluated. RESULTS: Mid concentrations of these antioxidants (10 and 20 µg/ml of clove bud extract and 100 and 200 µM of vitamin E) improved the blastocyst formation (P<0.05). The expression of catalase (P<0.01) and superoxide dismutase-1 (Sod1) genes, as well as the inner cell mass number (P<0.05), were significantly less in the blastocyst of the control (untreated) vitrified oocytes, however these levels were restored to normal by clove bud extract. In both antioxidant groups Bcl2l1 gene expression was promoted in comparison to the controls (P<0.05). CONCLUSION: Clove bud extract, with antioxidant and anti-apoptotic properties, may serve to prevent or reduce oxidative stress condition of oocyte vitrification.
