"Alpha ketoglutarate mediated regulation of maturation and oxidative balance" in OPU derived Bos indicus oocytes

Alpha-Ketoglutarate (AKG), a pivotal metabolite in the tricarboxylic acid cycle, possesses notable antioxidant properties that reduce oxidative stress. While its benefits in in-vitro maturation (IVM) of porcine, murine, and ovine oocytes are documented, its role in bovine oocytes-especially that derived via ovum pick-up (OPU)-remains unexamined. This is the first study to use OPU-derived oocytes from Sahiwal cattle (Bos indicus) to test 15 µM, 30 µM, and 45 µM AKG concentrations during IVM. Key parameters assessed included oocyte maturation rate, cumulus expansion, intracellular levels of Glutathione (GSH) and reactive oxygen species (ROS), and expression of oxidative stress (NRF2), apoptotic (BAX, BCL2), and maturation (BMP15, GDF9) genes. Results showed that 30 µM AKG significantly enhanced oocyte maturation (77.77% vs 56.09%, P < 0.05, lowered ROS levels (27.96 ± 4.388 vs 49.01 ± 1.870, P < 0.01), and increased GSH accumulation (25.01 ± 0.8467 vs 17.99 ± 1.586, P < 0.001). Gene expression analysis in denuded oocytes revealed significant upregulation of GDF9, BCL2, and NRF2 in the 30 µM group, indicating improved maturation, apoptosis modulation, and oxidative stress reduction. These findings highlight the potential of optimizing AKG in IVM protocols to enhance oocyte quality and developmental competence in bovine reproductive technologies.