In vitro effects of aspartic acid, coenzyme Q10 and zinc on sperm function

Introduction D-aspartic acid (D-AA) is involved in the regulation of spermatogenesis by influencing hormonal biosynthesis and secretion, resulting in an increased sperm concentration and progressive motility. Coenzyme Q10 (CoQ10) correlates positively with sperm concentration and motility at high concentrations, and it plays an antioxidant role, improving sperm motility and fertilization rate in ICSI cycles. Finally, low concentrations of zinc (Zn) have been found in azoospermic patients, while higher concentrations improve sperm motility, concentration and viability. On these premises, the aim of this study was to evaluate the in vitro effects of these three compounds on spermatozoa. Methods We enrolled ten patients with oligo-astheno-teratozoospermia (OAT) and five normozoospermic subjects (age range: 20–45 years), without infection/inflammation of the male accessory glands, varicocele or other andrological diseases. Spermatozoa were incubated for 3 h with BWW (group A), BWWCethanolC PBS (group A1) (control groups) or D-AA (500 mg/ml), CoQ10 (40 mg/ml) and Zn (10 g/ml) (group B). After incubation, the following parameters were assessed: sperm progressive motility, non conventional sperm parameters (mitochondrial membrane potential, degree of viability and/or apoptosis, sperm DNA fragmentation, lipid peroxidation). Subsequently, sperm selection was performed by swim-up technique in all groups. Results In OAT, progressive motility and the number of motile spermatozoa recovered by swim-up increased in group B compared to groups A and A1 (P!0.05). This was associated with an improvement of lipid peroxidation in group B vs A or A1 (P!0.05). The other sperm parameters did not change. No significant change was observed in normozoospermic subjects. Conclusions These results showed that D-AACCoQ10CZn act with antioxidant mechanism, ensuring a higher rate of motile spermatozoa recovered after swim-up, probably related to the improvement of progressive motility. These results suggest the use of this combination in both in vivo- and in vitro-assisted reproductive techniques.