This study investigated the impact of a standardized extract of Asparagus officinalis stem

(EAS) on bovine oocytes' developmental competence and oxidative stress. Previous

studies have shown that EAS can induce Heat Shock Protein 70 (HSP70) expression and

reduce reactive oxygen species (ROS) levels in somatic cells, but its effect on

reproductive cells is unknown. Bovine oocytes were matured with varying concentrations

of EAS for 22 hours at 38.5℃ (control) and then used for in vitro fertilization to observe

developmental rates. The HSP70 gene and protein expression were also analyzed. The

total cell number (TCN) of blastocysts was counted on day 8. EAS supplementation

significantly increased HSP70 gene and protein expression in oocytes matured under

control conditions. However, there was no significant effect on developmental rates or

TCN of blastocysts, indicating EAS has less toxicity to oocytes. Next, oocytes were

matured under heat stress (HS) conditions (41 ℃) with EAS supplementation. EAS

significantly reduced the HS-induced increase in ROS levels of matured oocytes

(P

affected. In conclusion, the study suggests that EAS can enhance the developmental

competence of bovine oocytes under heat-stress conditions by regulating intracellular

redox balance. EAS may be used as a potential supplement for improving oocyte quality

in assisted reproductive technologies.