Effect of L-carnitine on the in vitro maturation and fertilization of bovine oocytes.

The present study pointed out to clarify the effects of different L-Carnitine concentrations (0, 0.3, 0.6, and 1 mg/ml) on the in-vitro maturation, fertilization and blastocyst formation rates of bovine oocytes, in addition to assessing the lipid peroxidation rate and total antioxidant enzymes’ capacity. Bovine ovaries were collected from the El-Mounib abattoir in Giza Governorate, Egypt. The oocytes were collected by using the aspiration technique. The oocytes with (4-8mm) diameters were selected, washed, and matured in TCM-199 supplemented with different L-Carnitine concentrations. Afterward the period of maturation, the oocytes were evaluated for nuclear and cytoplasmic maturation; the oocytes were analyzed to determine the levels of Malondialdehyde (MDA), Catalase (CAT), Glutathione (GSH), and Superoxide dismutase (SOD) activities. The in-vitro matured oocytes were fertilized and assessed for the fertilization rate and the embryo developmental potentials. The results revealed that LCarnitine at a concentration of 0.6 mg/ml significantly (P≤0.05) improved the oocyte maturation (M-II) and fertilization rates besides the different stages of embryo development. In addition, L-Carnitine noticeably (P≤0.05) diminished the lipid peroxidation (MDA) and increased the antioxidant enzymatic activity including: Catalase (CAT), glutathione (GSH) and superoxide dismutase (SOD) mainly at a concentration of 0.6 mg/ml. In conclusion, 0.6 mg/ml of L-Carnitine has potentially improving impacts on in-vitro matured and developmental competence of bovine oocytes