In vitro production of bovine embryos in culture medium containing different concentrations of antioxidant extracted from Lippia oil origanoides

In vitro production of embryos has sought alternatives to increase the blastocyst rate, including the addition of antioxidants to the culture media. This study aimed to evaluate the rate of cleavage and in vitro production of bovine blastocysts, using maturation and culture media containing cysteamine and antioxidants extracted from Lippia origanoides oil. Ovaries were used slaughterhouse cattle, transported in saline 0.9% NaCl and there 38.0°C to the laboratory. The follicular aspiration was performed with a needle (12Gx40) coupled to a 5ml disposable syringe, and follicular fluid was placed in 15mL tubes for 10 minutes for sedimentation of oocytes. The supernatant was removed and the excess was washed in TCM-HEPES 199. Only degree 1 and 2 oocytes were selected, according to the analysis of complex cumulus oophorus cells and quality cytoplasm. The oocytes were washed in: TCM bicarbonate supplemented with 10% fetal bovine serum, 22mg/ml sodium pyruvate, 50ug/ml gentamicin sulfate, 5µg/ml of LH, 1µg/ml of FSH, 10ug/ml estradiol and 2.5mg/ml of Lippia origanoides antioxidant and then were incubated in atmosphere with 5%CO2, 38.5°C for 22 to 24 hours. Then, the oocytes were inseminated with 1x106 sperm in vitro fertilization medium and incubated in a humidified atmosphere with 5% CO2, 38.5°C for 18 to 20 hours. After this period, the oocytes were denuded and directed to five treatments containing m-SOF (modified) without adding antioxidant (T1), medium supplemented with 50uM/ml cysteamine (T2) and medium supplemented with 2.5; 5.0 and 1ug/ml of antioxidant Lippia origanoides(T3, T4 and T5, respectively). The Shapiro-Wilk test was used to assess the normality of continuous variables. Statistical analysis was performed using the ANOVA (post hoc Tukey) and Kruskal-Wallis. The significance level was set at P 0.05) and were 74.5; 72.5; 66.7; 67.3 and 64.2%, respectively for T1, T2, T3, T4 and T5. Blastocyst production rates were 40.4; 28.6; 24.1; 30.7 and 33.8 % for T1, T2, T3, T4 and T5, respectively. The production rate of blastocyst in T1 was higher (P 0.05). Despite the treatments supplemented with antioxidant Lippia origanoides present satisfactory cleavage rates, the final production of blastocysts in the groups supplemented with antioxidants was lower than that found in the control group. Thus, in this study, the use of Lippia origanoides oil did not show good results for blastocyst rate on in vitro embryos.