The cryopreservation of immature oocytes would generate a readily available, non-seasonal source of female gametes for research and reproduction. In domestic animals, the most promising results on oocyte cryopreservation have been reported in cattle, whereas few studies have been conducted on camel. The aim of the present study was to investigate the effect of green tea extract (GTE) on viability and developmental competence of camel oocytes vitrified at the germinal vesicle (GV) stage. Cumulus oocyte-complexes (COCs) obtained from mature camel ovaries were vitrified in media supplemented with different GTE concentrations (0, 0.5, 1, 1.5 mg/ml). Following vitrification and warming, viable COCs were matured in vitro for 42 h. Some COCs were denuded and stained+ with 1.0% aceto-orcein to evaluate the nuclear maturation, whereas the others were fertilized and cultured in vitro for 7 days to determine the developmental competence. Total antioxidant capacity and lipid peroxidation of the vitrified oocyte were assessed. The current results revealed that 1mg/ml GTE appeared to be the best concentration that increased significantly (P≤0.05) the morphological live survived oocytes(84.07±2.59) and significantly reduced the morphological abnormal oocyte; broken zona pellucida and abnormal cytoplasm (14.28 ±4.13 and
11.91±2.39, respectively). Furthermore, addition of 1mg /ml GTE to the vitrification media elevated significantly (P≤0.05) the fertilization rate (57.14 ±10.92), cleavage rate, morula and blastocyst development (39.15±2.08, 24.60±3.97 and 15.61±3.05, respectively) compared with control group. The current data emphasized the beneficial antioxidant effect of GTE.
Green tea extract at a concentration of 1 mg/ml augmented the total antioxidant capacity and reduced the lipid peroxidation in the vitrified camel oocyte (0.482±0.04 mµ/ml and 9.33±1.77 nmol/ml, respectively) compared with the control oocytes (0.185±0.04 and 25.0±3.06, respectively). Additionally, GTE at a concentration of 1 mg/ml increased the MTT reduction and the ATP content in the vitrified camel oocyte (3.9±0.55 and 882.00±16.67 fmol, respectively) compared with the control oocytes (2.4±0.25 and 607.33.0±44.24 fmol, respectively).In conclusion,addition of 1 mg/ ml GTE to the verification media of camel oocytes improved the developmental competence of camel oocytes possibly by protecting the embryos from oxidative stress. Further studies are required to study the effect of GTE on development of camel embryos.