Effect of resveratrol on vitrified in vitro produced bovine embryos: Recovering the initial quality.

Abstract

Although vitrification is the current routine method for human embryo cryopreservation, it may cause detrimental effects. The aim of this study was to evaluate the effect of supplementing in vitro culture (IVC) media and/or vitrification solutions (VS) with Resveratrol on the presence of apoptotic markers, reactive oxygen species (ROS) level, glutathione (GSH) content and relative gene abundance. Abattoir-derived oocytes were matured and fertilized in vitro according to a standard procedure. Zygotes were cultured in IVC medium supplemented with or without 0.5\u202fμM Resveratrol (CR, C- respectively). On day 7, blastocysts were vitrified using the minimum volume vitrification method supplementing VS with (C-VR, CRVR) or without (C-V-, CRV-) 0.5\u202fμM Resveratrol. After warming, embryonic quality parameters were evaluated. Survival rates were significantly lower in CRVR group compared with CRV- group, but no differences in hatching rate were observed between groups. Vitrification/warming process did not alter total cell number or the presence of apoptotic or dead cells, but CRV- and CRVR groups presented a significant increase in dead cells (P\u202f<\u202f0.05 by ANOVA). Resveratrol supplementation in VS (C-VR) restored GSH content (P\u202f<\u202f0.05) to the level found in the CR group. Vitrification/warming process significantly increased the expression of FOXO3A, PNPLA2, BCL2L1 and BAX genes (P\u202f<\u202f0.05). Resveratrol addition to IVC medium or VS partially compensated this increase for FOXO3A and PNPLA2 (P\u202f<\u202f0.05) but not for BCL2L1 and BAX. In conclusion, supplementation of IVC media or VS with 0.5\u202fμM resveratrol may help embryos to partially restore the initial quality they had before the cryopreservation process.