Metformin and rosiglitazone affect motility, lipid peroxidation and mitochondrial activity of thawed equine spermatozoa.

This research investigates the effect of metformin and rosiglitazone, two antidiabetic drugs, on the vitality and oxidative status of frozen-thawed stallion semen. It shows that the right dosage of metformin can improve sperm motility and reduce lipid peroxidation, factors important for successful horse breeding.

Objective of Research and Methodology

• The study aimed to evaluate the impact of metformin and rosiglitazone (two antidiabetic compounds) supplementation on the quality and oxidative status of thawed stallion semen.
• The researchers collected a total of 15 ejaculates from five horses and supplemented these with varying doses of metformin and rosiglitazone prior to freezing. A control group was also set up without any supplementation.
• The sperm was then cryopreserved using a programmable freezing protocol. Post-freezing, various parameters of the sperm, including motility, vitality, plasma membrane integrity and mitochondrial activity, reactive oxygen species and lipid peroxidation, were evaluated.

Key Findings

• The study found that metformin at a dose of 20mM (M20) increased the total motility of thawed semen. However, at higher 100mM concentration (M100), motility decreased along with most of the sperm kinetic parameters.
• Both metformin at 20mM and rosiglitazone at 100µM (R100) resulted in a reduction in lipid peroxidation. Metformin at 100mM resulted in a higher population of spermatozoa with both low and high mitochondrial membrane potential (ΔΨM).
• None of the treatments, except rosiglitazone at 50 µM (R50), resulted in the overproduction of reactive oxygen species (ROS).

Conclusion

• In sum, the researchers concluded that supplementation with a dose of 20 mM metformin in the freezing extender for stallion semen can improve overall motility and reduce lipid peroxidation of thawed spermatozoa.
• This finding could have important implications for horse breeding, as maintaining sperm energy homeostasis is crucial to improving the efficiency of stallion sperm preservation.