Protective effects of different doses of MitoQ separately and combined with trehalose on oxidative stress and sperm function of cryopreserved Markhoz goat semen

The effects of MitoQ as a mitochondrial-targeted antioxidant in a plant-based extender on buck sperm quality parameters during cryopreservation

Sperm cryopreservation plays an important role in the artificial insemination (AI) industry of small ruminants. It, however the use of frozen-thawed goat semen is limited due to the insufficient number of sperm with good biological functions. Mitochondria are the most sensitive organelles to cryopreservation damage in sperm. This study was conducted to determine the effects of MitoQ, the mitochondrial-targeted antioxidant, in a plant-based extender on the quality parameters of Markhoz goat sperm after the freezing and thawing process. Semen samples were collected and diluted in the extender, divided into five equal aliquots and supplemented with 0, 1, 10, 100 and 1000 nM MitoQ and cryopreserved in liquid nitrogen. After thawing, sperm motility, membrane functionality, abnormal morphology, mitochondrial activity, acrosome integrity, lipid peroxidation (LPO), DNA fragmentation, reactive oxygen species (ROS) concentration, viability and apoptotic-like changes were measured. The use of 10 and 100 nM MitoQ resulted in higher (P≤0.05) total motility (TM), progressive motility (PM), viability, membrane functionality, mitochondrial activity, and acrosome integrity compared to the other groups. On the other hand, LPO, apoptotic-like changes, DNA fragmentation and ROS concentration were lower (P≤0.05) in MQ10 and MQ100 groups compared to the other groups. MitoQ has no effect (P>0.05) on sperm abnormal morphology and velocity parameters. In conclusion, MitoQ can reduce oxidative stress by regulating mitochondrial function during the cryopreservation process of buck sperm and could be an effective additive in the cryopreservation media to protect sperm quality.

Evaluation of the effect of mitoquinone on functional parameters, DNA structure, and genes expression related to the apoptotic and antioxidants of human sperm after freezing-thawing

OBJECTIVE

Sperm freezing is considered as an effective way in assisted reproductive technology (ART) programs, it has detrimental effects on sperm function, due to the production of reactive oxygen species (ROS). This study aimed to investigate the potential of Mitoquinone (MitoQ) in inhibiting the production of mitochondrial ROS during sperm freezing.

METHODS

A total of 20 human normozoosperm samples were collected for this study. The samples were divided into four groups, each containing different concentrations of MitoQ (0, 0.2, 2, and 20 nM), and then subjected to the freezing process. After thawing, the sperm suspensions were evaluated for parameters including motility, morphology, acrosome integrity, adenosine triphosphate (ATP) level, intracellular ROS, viability, chromatin packaging, DNA denaturation, DNA fragmentation, as well as the expression of antioxidants (GPX, SOD) and apoptotic (Bax, Bcl2) genes.

RESULTS

The results showed that total and progressive mobility of sperms significantly increased in the 2 nM group, while significantly decreased in the 20 nM group (p ≤ 0.05). Sperm morphology did not significantly improve across all the tested concentrations (p ≥ 0.05). Intracellular ROS levels showed a significant decrease and increase in the concentrations of 2 and 20 nM, respectively (p ≤ 0.05). Furthermore, a significant increase was observed in viability, ATP, acrosome integrity, chromatin packaging, and non-denatured and non-fragmented DNA after treatment with 2 nM of MitoQ, compared with the control group (p ≤ 0.05). Regarding gene expressions, the relative expressions of oxidative stress genes were increased in the 2 nM group and decreased in the 20 nM group (p ≤ 0.05), while no significant difference was observed in the expressions of apoptotic genes compared with the control group (p ≥ 0.05). All the comparisons were made with respect to the control group.

CONCLUSION

Adding the optimal concentration of MitoQ (2 nM) to the sperm freezing medium not only improves sperm functional parameters and reduces DNA damages, but also stimulates the expression of antioxidant genes, leading to even greater benefits for sperm cryopreservation.