Evaluating the Effects of Sea Cucumber Extract Supplementation on the Developmental Competence of Aged Oocytes During In Vitro Fertilization and In Vitro Maturation

Ovarian aging, characterized by declines in oocyte quantity and quality, results in reduced fertility, particularly in women over 38 years of age. Oxidative stress and endoplasmic reticulum (ER) stress are major contributors, necessitating strategies to support the developmental competence of aged oocytes. Holothuria lessoni, a sea cucumber species rich in bioactive compounds, offers antioxidant and cytoprotective potential that may help counteract these oxidative and ER stress-related declines. Aged oocytes from BL6 hybrid female mice were fertilized in vitro and cultured with sea cucumber extract at concentrations of 0, 15, 20, and 25 ppm. Embryo development was evaluated at 24-, 48-, 72-, 96-, and 120-hours post-fertilization. Gas chromatography–mass spectrometry (GC-MS) was used to characterize extract composition, while quantitative reverse transcription polymerase chain reaction (qRT-PCR) of blastocyst expression of HSP90, and GPX1. In silico protein–protein interaction and pathway analyses were performed using bioinformatics databases. GC-MS revealed multiple bioactive constituents, including fatty acids, esters, squalene, and siloxane derivatives. A concentration of 20 ppm yielded the best developmental outcomes, with 100% of embryos reaching the two-cell stage and 29% forming blastocysts, along with superior blastocyst morphology, while 25 ppm reduced embryo quality. At 20 ppm, HSP90 and GPX1 were upregulated 20-fold and 6.58-fold, respectively, whereas 25 ppm further increased GPX1 but decreased HSP90 expression. Network analysis identified TP53, TNF, and IL1B as central regulators in oxidative stress-related pathways. Holothuria lessoni extract at 20 ppm enhanced early embryonic development of aged murine oocytes, likely by modulating oxidative stress and proteostasis via HSF1–HSP90 and Nrf2–GPX1 pathways. Further studies are required to optimize dosing and confirm downstream molecular targets for later developmental stages.