JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):81
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263660

P-69. Effect of Octyl Methoxycinnamate on Bovine Oocyte Maturation and Early Embryo Development.

Rafael Martins Tonzar¹, Caroline S Fernandes¹, Amanda T Sampaio¹, Bruno Carrino Suave¹, Anthony Cesar Souza Castilho¹

¹ UNOESTE - Presidente Prudente - SP - Brasil

Objective: This study aimed to evaluate the effects of OMC exposure during in vitro maturation of bovine cumulus–oocyte complexes on cumulus expansion, meiotic progression, apoptosis, ROS production, and early embryonic development.
Methods: Bovine ovaries were obtained from a commercial abattoir and transported in isotonic saline at 37°C. Antral follicles measuring 3–8 mm in diameter were aspirated. Cumulus–oocyte complexes (COCs) grades 1 and 2 were selected and matured in TCM-199 medium supplemented with fetal bovine serum (10%), pyruvate, amikacin, FSH, and LH. Experimental groups were exposed to OMC at concentrations of 1, 10, or 100ng/mL, while the control group received DMSO only. After 22–24 h of in vitro maturation, oocytes were subjected to in vitro fertilization and cultured in synthetic oviductal fluid (SOF) medium for 7 days. Cumulus expansion was quantified using ImageJ^®. Meiotic progression was assessed by fluorescence microscopy after nuclear staining with Hoechst 33342 to visualize chromatin configuration. Apoptotic nuclei were identified using the TUNEL assay combined with fluorescence imaging. Intracellular reactive oxygen species (ROS) levels were measured through fluorescence intensity analysis. Cleavage (Day 3), and blastocyst (Day 7) rates, as well COCs analysis were evaluated across eight biological replicates, with 40 COCs per experimental group.
Results: Overall, cumulus expansion was markedly reduced at 10 and 100ng/mL (p=0.0003), whereas meiotic progression to metaphase II was unaffected. Apoptosis rates increased significantly at 1 ng/mL and exhibited an upward trend at higher concentrations, while reactive oxygen species (ROS) levels remained unchanged. In a similar manner, OMC exposure induced a dose-dependent reduction in developmental competence, with cleavage rates significantly reduced at 10 and 100 ng/mL compared with controls, and blastocyst formation significantly impaired at 100ng/mL.
Conclusion: These findings demonstrate that exposure of bovine COCs to elevated concentrations of OMC during oocyte maturation disrupts cumulus cell function and early embryonic development, underscoring potential reproductive hazards associated with environmental exposure to UV filters in mammals.