Aristolochic acid I exposure decreases oocyte quality

Area of Science:

• Reproductive Biology
• Toxicology
• Cell Biology

Background:

• Oocyte quality is crucial for successful pregnancy.
• Oocyte maturation is vulnerable to environmental toxins.
• Aristolochic acids (AAs) from traditional medicines may impact reproductive health.

Purpose of the Study:

• To investigate the effects of Aristolochic acid I (AAI) on mouse oocyte maturation.
• To elucidate the underlying mechanisms of AAI-induced oocyte damage.

Main Methods:

• In vitro culture of mouse oocytes exposed to AAI.
• Assessment of oocyte quality parameters: aneuploidy, spindle organization, chiasma patterns, and first polar body extrusion.
• Evaluation of mitochondrial function: mitochondrial membrane potential, ATP synthesis, and reactive oxygen species (ROS) levels.
• Analysis of fertilization and embryo development rates.

Main Results:

• AAI exposure significantly reduced oocyte quality, increasing aneuploidy and disrupting spindle organization and chiasma patterns.
• First polar body extrusion and fertilization rates were decreased following AAI exposure.
• Embryo development potential was markedly reduced.
• AAI impaired mitochondrial function, decreasing membrane potential and ATP synthesis while increasing ROS levels.

Conclusions:

• AAI exposure negatively impacts mouse oocyte maturation and quality.
• Impaired mitochondrial function, characterized by reduced ATP and increased ROS, is a key mechanism underlying AAI toxicity.
• AAI-induced oocyte damage poses risks to fertilization and subsequent embryo development.