Ergostane steroid, as one of the major contributor to cranberry derived extracellular vesicle nanoparticles, restores ovarian function of murine premature ovarian failure

BACKGROUND: A high-fat and high-sugar (HFHS) diet can induce ovarian insufficiency and premature ovarian failure (POF) by inducing the abnormal expression of multiple metabolic pathways that makes treatment difficult. We previously evaluated cranberry (Vaccinium, Va)-derived extracellular vesicle nanoparticles (Va-PENs) for their therapeutic potential in HFHS diet-induced POF in mice and herein examined, in greater detail, the molecular mechanism(s) underlying Va-PENs action in the treatment of the condition. METHODS: Va-PENs were isolated, purified, and subsequently fed to our HFHS-POF model mice. Conventional H&E and immunohistochemical staining methods were used to observe the pathologic changes and protein expression in the murine ovarian tissues. Liquid chromatography/tandem mass spectrometry high-throughput metabolomic analysis was used to investigate the distribution and content of various metabolites in Va-PENs, cranberry, and murine serum. Quantitative polymerase chain reaction and western-blot analyses were used to determine the mRNA and protein expression levels in cell proliferation and aging and mitochondrial function in ovarian granulosa cells of the model mice. RESULTS: Oral administration of Va-PENs significantly improved the pathologic aging status of ovarian granulosa cells in the HFHS-POF mice, reduced the proportion of atretic follicles, and corrected sex hormone (anti-Müllerian hormone, estradiol, and follicle-stimulating hormone) concentrations and blood lipid disorders. High-throughput metabolomic analysis revealed ergostane steroids (particularly campestanol) as key bioactive components shared between Va-PENs and cranberry. Oral delivery of campestanol replicated the therapeutic effects of Va-PENs, restoring granulosa cell morphology, inhibiting follicular atresia, normalizing sex hormone levels, and reducing cellular senescence markers by modulating the expression of the cell cycle/senescence pathway. CONCLUSION: Our findings indicated that Va-PENs exerted potent therapeutic effects in mice with HFHS diet-induced POF. One of the potential mechanisms was ergostane steroid, as one of the major contributor to Va-PENs, significant reduction in HFHS-POF symptoms via modulating the expression of the cell cycle/senescence pathway. This study presents a safe, plant-derived, nanovesicle-based strategy for restoring ovarian function after the induction of POF.