Melatonin enhances the developmental potential of immature oocytes from older reproductive-aged women by improving mitochondrial function.

Aims: To evaluate whether melatonin (MT) supplementation during in vitro maturation (IVM) of human oocytes can reverse the age-related decline in oocyte quality. Main methods: We enrolled 172 patients aged ≥35 years (older reproductive-aged women) and 83 patients aged <35 years (young women) who underwent in vitro fertilization between 2019 and 2022. We conducted IVM with and without 10 µM MT in immature oocytes of different ages. Oocyte fertilization and embryo development were observed using a stereomicroscope. We assessed the immunofluorescence intensity of mitochondrial function, measured the copy number of mitochondrial DNA (mtDNA), and examined the spindle and chromosome composition in in vitro mature stage II (IVM-MII) oocytes using immunofluorescence and second-generation sequencing. Key findings: MT supplementation significantly improved the redox level in the IVM medium and IVM-MII oocytes in older reproductive-aged women. It also significantly increased the proportion of circular mtDNA and the adenosine triphosphate content in IVM-MII oocytes. In addition, the IVM-MII oocytes obtained with MT supplementation showed a significant improvement in the normal composition of the spindle and chromosomes. Thus, the aged immature oocytes also showed significantly improved maturation and blastocyst formation rates owing to the role of MT. Significance: Supplementation with 10 µM MT in the IVM medium reverses the age-related decline in oocyte quality. Our findings provide a viable solution for enhancing fertility in older reproductive-aged women.

Comparison of IVF and IVM outcomes in the same patient treated with a modified IVM protocol along with an oocytes-maturing system containing melatonin: A pilot study.

AIM: To compare embryonic developmental competence and clinical outcomes of oocytes matured in vivo (IVF oocytes) and those matured in vitro (IVM oocytes) from the same IVM/IVF cycles, and to analyze the clinical efficiency of a melatonin-supplemented in vitro maturation system combined with a modified IVM/IVF protocol. MAIN METHODS: We randomly recruited 22 patients undergoing IVM/IVF treatment protocol in our medical centre. The fertilization, cleavage and blastocyst formation rates, as well as clinical pregnancy, implantation and live birth/ongoing pregnancy rates were analysed and compared between IVF and IVM oocytes. We evaluated mitochondrial function indicators by fluorescence staining and confocal microscopy, including mitochondrial membrane potential, reactive oxygen species and calcium (Ca2+) levels in 15 IVF and 15 IVM oocytes. KEY FINDINGS: There were no significant differences in fertilization or blastocyst formation rates between the IVF and IVM groups, whereas the cleavage rate was significantly higher in the IVF versus IVM group (100% vs 93.4 ± 10.9%, p = 0.03). There were no significant differences in the clinical pregnancy, implantation or live birth/ongoing pregnancy rates between the two groups. The cumulative clinical pregnancy and ongoing pregnancy/live birth rate per pick-up oocyte in the IVM/IVF treatment cycles were 68.2% (15/22) and 54.5% (12/22), respectively. The reactive oxygen species and Ca2+ levels were significantly increased, and mitochondrial membrane potential was significantly decreased, in IVM compared with IVF oocytes. SIGNIFICANCE: The modified IVM/IVF protocol can be effectively applied to the treatment of some indicated patients and achieve ideal clinical outcomes, even though the developmental potential of IVM oocytes may not be as high as IVF oocytes.

Isolation of new polyacetylenes from the roots of Eurycoma longifolia via high-speed counter-current chromatography.

Eurycoma longifolia is a tropical plant of diverse applications in folk medicine, which occurs in Southeast Asia. In this study, pre-purified fraction (0.86g) of the crude extracts from the roots of E. longifolia, was subjected to preparative high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 5:2:5:2 (v/v). Longifolione A (1, 19mg, purity 96.0%) and longifolione C (3, 317mg, purity 96.2%), together with longifolione B (2, purity 77.6%) were isolated in one run. The whole mobile and stationary phase was then blown out, concentrated in vacuo, and subjected to second HSCCC purification. Using HEMWat at a volume ratio of 6:1:6:1.2 (v/v), this fraction yielded two more new polyacetylenenes, longifolione D (4, 5mg purity 94.5%) and longifolione E (5, 33mg purity 96.3%). All of these five compounds are new natural products and isolated from E. longifolia for the first time. The established protocol for large-scale isolation of these polyacetylenes from E. longifolia was simple, efficient, and economical.