Effect of various antioxidants on ovarian tissue vitrification success in sheep

Abstract

BACKGROUND: Vitrification is a technique of cryopreservation that has been proposed as a promising alternative method for the preservation of oocytes, embryos and gonadal tissue. OBJECTIVE: To determine the effect of different antioxidants on post-thaw viability, morphology of retrieved oocytes and histology of vitrified ovarian tissue.MATERIALS AND METHODS: Four different antioxidants [i.e., resveratrol (20 μM), ZnSO4 (500 μM), curcumin (25 μM) and quercetin (1 μM)] were evaluated after their addition to the vitrification and warming media for their effects on the viability and morphology of retrieved oocytes and the histology of vitrified ovarian tissue. RESULTS: The number of oocytes retrieved from ovarian tissue from the above mentioned antioxidants and vitrified control were 34, 41, 26, 31 and 46 respectively. Among these the number of viable oocytes were found to be 24 (70.6%), 30 (73.1%), 20 (76.9%), 26 (83.9%) and 33 (71.7%) and the number of oocytes found morphologically normal were 24 (70.6%), 26 (63.4%), 18 (69.2%), 21 (67.7%) and 34 (73.9%) for the above mentioned different antioxidants and vitrified control, respectively. Nonsignificant (P>0.05) differences were found between different treatment groups. Histomorphological evaluation of the ovarian cortical tissue showed that the percentage of intact follicles was significantly (P≤0.05) higher in the fresh control (84.19±3.9) than in other groups. Non-significant differences were found between resveratrol (50.2±5.5), curcumin (48.7±5.7), quercetin (51.6±4.8) and the vitrified control (42.7±6.1) groups; however, the ZnSO4 supplemented group (23.1±8.54) differed significantly (P≤0.05) from other antioxidant groups but was non-significant (P>0.05) with the vitrified control group (42.7±6.1). CONCLUSION: The addition of antioxidants resveratrol, curcumin and quercetin at these concentrations tended to non-significantly improve the follicular integrity after vitrification.