Epigallocatechin-3-gallate improves the quality of maternally aged oocytes

The decline in female fertility as age advances is intricately linked to the diminished developmental potential of oocytes. Despite this challenge, the strategies available to enhance the quality of aged oocytes remain limited. Epigallocatechin-3-gallate (EGCG), characterised by its anti-inflammatory, antioxidant and tissue protective properties, holds promise as a candidate for improving the quality of maternally aged oocytes. In this study, we explored the precise impact and underlying mechanisms of EGCG on aged oocytes. EGCG exhibited the capacity to enhance the quality of aged oocytes both in vitro and in vivo. Specifically, the application of EGCG in vitro resulted in noteworthy improvements, including an increased rate of first polar body extrusion, enhanced mitochondrial function, refined spindle morphology and a reduction in oxidative stress. These beneficial effects were further validated by the improved fertility observed among aged mice. In addition, our findings propose that EGCG might augment the expression of Arf6. This augmentation, in turn, contributes to the assembly of spindle-associated F-actin, which can contribute to mitigate the aneuploidy induced by the disruption of spindle F-actin within aged oocytes. This work thus contributes not only to understanding the role of EGCG in bolstering oocyte health, but also underscores its potential as a therapeutic intervention to address fertility challenges associated with advanced age. This study delves into the precise impact and underlying mechanisms of EGCG on aged oocytes. Both in vitro and in vivo experiments demonstrate EGCG's capacity to enhance the quality of aged oocytes. In vitro application of EGCG yields remarkable improvements, including heightened rates of first polar body extrusion, refined spindle morphology, enhanced mitochondrial function, and reduced oxidative stress. Besides, EGCG may enhance Arf6 expression through direct interaction in aged oocytes, consequently promoting the assembly of spindle-associated F-actin and mitigating the aneuploidy induced by the disruption of spindle F-actin. In addition, these positive outcomes are corroborated by enhanced fertility observed in aged mice, providing a therapeutic intervention to address fertility challenges associated with advanced age.image