Protective effect of the superoxide dismutase mimetic MnTBAP during sperm vitrification process.

Sperm cryopreservation is widely used in assisted reproduction and male infertility therapy; however, it induces oxidative stress affecting sperm quality. This work evaluated the effect of the antioxidant MnTBAP during vitrification steps in human spermatozoa. First, the effect of MnTBAP on viability and ROS production was evaluated. Then, the spermatozoa were vitrified in straws with the vitrification, warming and post-warming incubation media separately supplemented with MnTBAP. An untreated control was included. The sperm viability, ROS production, total and progressive motility were evaluated. The results showed that the direct exposure of spermatozoa to MnTBAP significantly decreases the ROS levels in comparison with the untreated control without affecting the viability. The supplementation of the vitrification medium with MnTBAP did not affect the parameters analysed. However, the supplementation of the warming and incubation post-warming media resulted in a decrease in ROS production and maintained viability and motility for 4 hr after warming with concentrations up to 100 µM of MnTBAP. Higher concentrations of MnTBAP caused a decrease in total motility. In conclusion, the use of MnTBAP during the warming or post-warming incubation media has beneficial effect decreasing ROS levels and maintaining the viability and motility during the vitrification procedure.

Antioxidant effects of penicillamine against in vitro-induced oxidative stress in human spermatozoa.

Oxidative stress contributes importantly to the aetiology of male infertility, impairing sperm function. The protective effect of antioxidants on seminal parameters has been established, and the antioxidant penicillamine has shown beneficial effects; however, its protective effect on human spermatozoa exposed to oxidative stress has not been reported. The objective of this work was to evaluate the effect of penicillamine on human spermatozoa exposed in vitro to oxidative stress. First, the effect of penicillamine on spermatozoa from normozoospermic donors was evaluated. Then, the effect of penicillamine on spermatozoa exposed to oxidative stress induced separately by ionomycin and hydrogen peroxide (H2 O2 ) was analysed. An untreated control and a control treated only with the oxidative stress inducer were included. Reactive oxygen species (ROS) levels, viability, mitochondrial membrane potential (MMP) and motility were analysed. The results showed that penicillamine, added to the incubation medium, decreased the ROS levels induced by ionomycin and H2 O2 , and this effect was associated with better preservation of MMP, motility, and ATP levels. These results highlight the potential advantages of penicillamine supplementation of sperm culture medium, especially for semen samples with high ROS levels and also in circumstances where laboratory handling can cause an increase in ROS production.