Alpha lipoic acid (ALA) effects on developmental competence of equine preantral follicles in short-term culture.

The study explores how different concentrations of alpha lipoic acid (ALA) influence the development and morphology of equine preantral follicles and the proliferative activity of granulosa cells after a brief culture period.

Methodology

• The research involves selecting ovaries for study from five seasonal anestrous mares that were harvested at a local abattoir.
• Nine fragments of ovarian tissue from each mare were used. One fragment was immediately fixed in Bouin for immediate histological and immunohistochemistry analyses (this was the noncultured group).
• The other eight fragments were anaerobically cultured for either two or six days in either a medium (MEM) or the same medium plus alpha lipoic acid (ALA) in various concentrations (50, 100 or 250 µM).
• After each culture period, fragments were used for histology and proliferating cell nuclear antigen (PCNA) analyses.

Key Findings

• After 2 days of culture, the 50 and 100 µM ALA groups showed the highest percentage of normal primordial follicles (97.2% and 95.1% respectively). These were comparable to the noncultured group, indicating that these ALA concentrations preserved the morphological integrity of the follicles.
• The overall percentage of normal follicles was greater in the 50 and 100 µM ALA groups than in the MEM-only group after 2 days of culture.
• After six days of culture, the highest proliferative activity of granulosa cells (essential for antral follicle development) was seen in the MEM (92.9%), 50 µM ALA (100%) and 100 µM ALA (96.4%) groups.

Conclusion

• These findings suggest that the application of 50 and 100 µM ALA can preserve the morphological integrity of equine primordial follicles for up to two days of in vitro culture.
• Additionally, granulosa cells of developing follicles remain highly proliferative after being cultured in MEM with or without ALA for up to six days, as demonstrated by a high stain intensity for the proliferative marker, PCNA.

The research thus demonstrates the potential benefits of alpha lipoic acid supplementation for equine preantral follicle culture. The addition of ALA to the culture medium appears to support the normal development and granulosa cell activity of horse follicles, potentially contributing to improved in vitro maturation outcomes in reproductive veterinary medicine.