Myoinositol: does it improve sperm mitochondrial function and sperm motility?

Abstract

Objective: To evaluate whether an improvement in mitochondrial membrane potential was associated with sperm motility amelioration and greater sperm recovery after the swim-up procedure. A second purpose was to evaluate the effects of myoinositol (MYO) on sperm apoptosis, quality of chromatin compaction, and DNA integrity.

Methods: Spermatozoa from 20 normozoospermic men and 20 patients with oligo-astheno-teratozoospermia were incubated in vitro with 2 mg/mL of MYO or phosphate-buffered saline as a control for 2 hours. After this incubation period, sperm motility was evaluated. Flow cytometry was used to analyze the mitochondrial membrane potential, phosphatidylserine externalization, chromatin compactness, and DNA fragmentation. We also evaluated the total number of motile spermatozoa recovered after swim-up after incubation with MYO or phosphate-buffered saline.

Results: MYO significantly increased the percentage of spermatozoa with progressive motility in both normozoospermic men and patients with oligo-astheno-teratozoospermia. Motility improvement in the latter group was associated with a significant increase in the percentage of spermatozoa with high mitochondrial membrane potential. MYO had no effects on mitochondrial function in spermatozoa from normozoospermic men. Sperm phosphatidylserine externalization, chromatin compactness, and DNA fragmentation were unaffected by MYO in both groups. After incubation with MYO, the total number of spermatozoa recovered after swim-up had improved significantly in both groups.

Conclusion: These data show that MYO increases sperm motility and the number of spermatozoa retrieved after swim-up in both normozoospermic men and patients with abnormal sperm parameters. In patients with oligo-astheno-teratozoospermia, the improvement in these parameters was associated with improved sperm mitochondrial function. These findings support the use of MYO in both in vivo- and in vitro-assisted reproductive techniques.