Effect of α-tocopherol and l-ascorbic acid on in-vitro maturation of vitrified bovine oocytes

The aim of the study was to evaluate the effects of vitamin E (α-Tocopherol) and Vitamin C (L-Ascorbic Acid) on the rates of in-vitro maturation in respect to cumulus cell expansion and polar body formation of vitrified bovine oocytes. A total of 264 vitrified oocytes were equally divided in to four experimental groups and subjected to in-vitro maturation as vitrified control (without antioxidant), and groups supplemented with Vitamin E @100µM, Vitamin C @ 100µM and combination of Vitamin E @100µM + Vitamin C @ 100µM. In another group, 66 numbers of non-vitrified Cumulus Oocyte Complexes (COCs) were in-vitro cultured in TCM-199 medium and was considered as the control group. TCM-199 supplemented with Oestradiol 17β + p-FSH + Follicular fluid + Gentamicin + Sodium pyruvate + Cysteamine + FBS were taken as base medium. In-vitro maturation was conducted for 24 hrs at 38.5°C in presence of 5% CO2 in a CO2 incubator. Among the treatment groups, the group with vitamin E @ 100 µM + vitamin C @ 100 µM supplemented in TCM-199 showed the highest rate of in-vitro maturation of vitrified bovine follicular oocytes. Both vitamin E (100 µM) and vitamin C (100 µM) supplemented in TCM-199 improved the rate of in-vitro maturation of vitrified bovine follicular oocytes compared to the vitrified control group. It was concluded that supplementation of α-Tocopherol and L-Ascorbic acid with TCM-199 enhances the rate of in-vitro maturation of vitrified-thawed bovine oocytes.