Effect of high‐density lipoprotein on oocyte maturation and bovine embryo development in vitro

High‐density lipoprotein (HDL) is the main lipoprotein in the follicular fluid, and it has anti‐inflammatory, antioxidant and cryoprotectant properties. The anti‐inflammatory potential and antioxidant potential are derived from its lipid composition, especially the apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1). The aim of this study was to evaluate the effect of HDL during in vitro maturation (IVM) on oocyte maturation and early bovine embryo development. For this, cumulus–oocyte complexes (COCs) were obtained from bovine ovaries collected at a local slaughterhouse. COCs (n = 2,250) were allocated into three groups (n = 50 COCs/group) according to the addition of HDL protein (HDL‐P) during IVM for 22 hr: 0 (control), 50 and 150 mg/dl. After IVM, COCs were inseminated (in vitro fertilization) and cultivated for 7 days. Total cholesterol concentration, total protein, triglycerides and ApoAI concentrations on IVM medium increased proportionally to HDL‐P addition. However, PON1 activity was not detected in any treatment. The addition of HDL‐P did not affect nuclear maturation rate, endogenous reactive oxygen species and glutathione levels in COCs (p > 0.05). The highest HDL‐P concentration (150 mg/dl) decreased cleavage and blastocyst rate (p < 0.05). Moreover, the HDL‐P 150 mg/dl group had lower cellular count/blastocyst than the 50 mg/dl group (p < 0.05). However, the addition of HDL‐P did not affect relative gene expression of evaluated genes. In conclusion, the complex HDL/ApoAI obtained from human plasma, in the absence of PON1 activity during in vitro oocyte maturation, decreased initial embryo development.