Comparative evidence support better antioxidant efficacy of mitochondrial-targeted (Mitoquinone) than cytosolic (Resveratrol) antioxidant in improving in-vitro sperm functions of cryopreserved buffalo (Bubalus bubalis) semen

Effect of Mitoquinone on sperm quality of cryopreserved stallion semen

This study aimed to investigate the effect of mitochondria-targeted antioxidants (Mitoquinone, MitoQ) on the quality of frozen-thawed stallion semen. Semen samples collected from three fertile stallions aged 10 - 13 years, were filtered, centrifuged in a skimmed milk-based extender, and diluted to a final concentration of 50 × 106 sperm/mL in freezing medium. Diluted semen was divided into five experimental groups supplemented with MitoQ at concentrations of 0 (control), 25, 50, 100, and 200 nM and then subjected to freezing after cooling and equilibration. After thawing, semen was evaluated for motility and kinetics at different time points. Sperm viability, plasma membrane, acrosome, DNA integrity, mitochondrial membrane potential, apoptosis, and intracellular reactive oxygen species (ROS) concentrations were evaluated. The results revealed that MitoQ at concentrations of 25, 50, and 100 nM improved (P< 0.01) the total sperm motility after 30 minutes of incubation. In addition, 25 nM MitoQ improved the sperm amplitude of lateral head displacement values (P< 0.01) after 30 minutes of incubation. Conversely, negative effects on sperm motility, kinetics, and viability were observed with the highest tested concentration of MitoQ (200 nM). The various concentrations of MitoQ did not affect the plasma membrane, acrosome, and DNA integrity, or the mitochondrial membrane potential and intracellular ROS concentrations. In conclusion, supplementation of MitoQ during cryopreservation, had a mild positive effect on sperm motility and kinetics especially at a concentration of 25 nM, while the highest concentration (200nM) has a detrimental effect on motility and viability parameters of frozen-thawed stallion sperm.

Effect of Five Different Antioxidants on the Effectiveness of Goat Semen Cryopreservation

The effective combination of semen cryopreservation and artificial insemination has a positive effect on the conservation of germplasm resources, production and breeding, etc. However, during the process of semen cryopreservation, the sperm cells are very susceptible to different degrees of physical, chemical, and oxidative stress damage. Oxidative damage is the most important factor that reduces semen quality, which is affected by factors such as dilution equilibrium, change of osmotic pressure, cold shock, and enzyme action during the freezing-thawing process, which results in the aggregation of a large amount of reactive oxygen species (ROS) in sperm cells and affects the quality of semen after thawing. Therefore, the method of adding antioxidants to semen cryoprotective diluent is usually used to improve the effect of semen cryopreservation. The aim of this experiment was to investigate the effects of adding five antioxidants (GLP, Mito Q, NAC, SLS, and SDS) to semen cryoprotection diluent on the cryopreservation effect of semen from Saanen dairy goats. The optimal preservation concentrations were screened by detecting sperm viability, plasma membrane integrity, antioxidant capacity, and acrosomal enzyme activities after thawing, and the experimental results were as follows: the optimal concentrations of GLP, Mito Q, NAC, SLS, and SDS added to semen cryopreservation diluent at different concentrations were 0.8 mg/mL, 150 nmol/L, 0.6 mg/mL, 0.15 mg/ mL, 0.6 mg/mL, and 0.15 mg/mL. The optimal concentrations of the five antioxidants were added to the diluent and analyzed after 1 week of cryopreservation, and it was found that sperm viability, plasma membrane integrity, and mitochondrial activity were significantly enhanced after thawing compared with the control group (P < 0.05), and their antioxidant capacity was significantly enhanced (P < 0.05). Therefore, the addition of the above five antioxidants to goat sperm cryodilution solution had a better enhancement of sperm cryopreservation. This study provides a useful reference for exploring the improvement of goat semen cryoprotection effect.

Discovering the Potential Value of Coenzyme Q10 as an Adjuvant Treatment in Patients With Depression

PURPOSE/BACKGROUND

Depressive disorder or mental cold is the most common mental disorder, and depression exists all over the world and in all countries and cultures. The results of several studies have shown that using compounds with antioxidant properties has been fruitful in patients with depression. Coenzyme Q10 (CoQ10) is a fat-soluble antioxidant and exerts its antioxidant effect by directly neutralizing free radicals or reducing tocopherol and preventing the inhibition of mitochondrial activity because of oxidative stress. This study aimed to investigate the effects of oral CoQ10 in patients with depression as an adjunctive treatment.

METHODS/PROCEDURES

Sixty-nine patients with moderate and severe depression were randomly divided into 2 CoQ10 groups (36) and placebo (33). The first group of patients received CoQ10 supplements at a dose of 200 mg daily for 8 weeks along with standard interventions and treatments for depression, and the second group received standard treatments for depression along with a placebo. The change in the score of Montgomery-Åsberg Depression Rating Scale depression scale was evaluated 4 and 8 weeks after the intervention. Also, at baseline and 8 weeks later at the end of the study, serum levels of total antioxidant capacity, total thiol groups, nitric oxide, malondialdehyde, and interleukin 6 were assessed.

FINDINGS/RESULTS

The changes in the depression score at the end of the study showed that, in the group receiving the CoQ10 supplement after 8 weeks, there was a reduction in depression symptoms, which was statistically significant compared with before the start of the study Meanwhile, no significant changes were observed in the patients of the placebo group in terms of symptom reduction. Compared with baseline and the placebo condition, serum levels of nitric oxide and total thiol groups significantly decreased and increased, respectively. Also, no statistically significant changes were observed for interleukin 6, malondialdehyde, and total antioxidant capacity.

IMPLICATIONS/CONCLUSIONS

A dose of 200 mg of CoQ10 supplement daily for 8 weeks can reduce depression and fatigue, as well as improve the quality of life of patients with depression. In addition, CoQ10 can significantly improve inflammation and oxidative stress status in patients with depression.

MitoQ preserves the quality and fertility of liquid-preserved ram sperm

Supplementing the semen extender with some antioxidants may preserve sperm quality following liquid preservation. The aim of the current study was to evaluate the influence of the use of MitoQ in the semen extender on quality parameters and fertility of liquid-preserved ram semen. In this study, diluted semen samples were divided into five parts and supplemented with 0, 1, 10, 100 and 1000 nM MitoQ. The prepared samples were stored at 3-5 °C for up to 50 h. Motility, viability, mitochondrial activity, membrane integrity, and malondialdehyde concentration of the chilled sperm were assessed at 0, 25, and 50 h. To evaluate reproductive performance, artificial insemination was performed with semen liquid-preserved for 25 h. In results, at 0 h, no difference between the groups was observed. The use of 10 and 100 nM MitoQ resulted in higher (P ≤ 0.05) total motility, progressive motility, membrane integrity, mitochondrial activity, viability, and lower malondialdehyde concentration than the other groups after 25- and 50-h storage. Pregnancy, parturition and lambing rates were higher (P ≤ 0.05) when ewes were inseminated with 25-h chilled semen samples containing 10 and 100 nM MitoQ compared to the control. Therefore, supplementing the semen extender with MitoQ (10 and 100 nM) could be an efficient method to improve the quality and fertility rate of liquid-preserved ram semen.

Catechol chitosan coated dual-loaded liposomes based on oxidation and saccharification mechanisms for enhancing skin anti-aging effects

Skin aging has become a major urgent problem to be solved. Evidence reveals that oxidation and glycosylation are two dominant inducements of aging. Resveratrol (RES) with outstanding anti-oxidant effect and carnosine (CAR) with superb anti-glycation property were selected as two model drugs to evaluate the feasibility of their synergistic anti-aging effect. RES and CAR at the most desired mass ratio, supplying the most superior synergistic anti-aging effects were further encapsulated in liposomes (LP), which were separately coated with chitosan (CS) and catechol chitosan (Cat-CS) to increase the transdermal penetration. Their anti-aging efficacy was explored in human skin fibroblast (HSF) and human immortalized keratinocytes (HaCaT) cells, as well as the back skin of guinea pigs. Herein, RES and CAR at the mass ratio of 2:1 exhibited the most ideal synergistic anti-aging effect. The constructed liposomes have been shown to possess excellent fundamental properties and sustained-release properties. The aging-related indicator levels in the two cells and guinea pigs were obviously improved for the RES + CAR@Cat-CS-LP group. Additionally, skin appearance, tissue morphology, and collagen content were visibly improved, indicating its perfect anti-aging effect. In conclusion, RES + CAR@Cat-CS-LP is expected to be exploited as a potential anti-aging drug delivery system.

Progress on the roles of zinc in sperm cryopreservation

One of the effective methods for the long-term preservation of mammalian genetic resources is the cryopreservation of semen. However, a number of parameters, including diluents, the rate of freezing and thawing, cryoprotectants, etc., can easily alter the survival of frozen-thawed sperm. Numerous studies have documented the addition of a variety of zinc compounds, to the diluents used to cryopreserve sperm. The primary objective of this review is to briefly describe that adding zinc to diluents as an antioxidant significantly enhances frozen-thawed sperm quality. Second, a summary of the present understanding of zinc's molecular mechanism on semen cryopreservation is provided. Thirdly, this study addresses that nanoparticles of zinc can offer suggestions for raising cryopreservation effectiveness.

Supplementation of Thymoquinone Nanoparticles to Semen Extender Boosts Cryotolerance and Fertilizing Ability of Buffalo Bull Spermatozoa

Thymoquinone nanoparticles (TQNPs) are broadly utilized in numerous pharmaceutical applications. In the present study, we tested the effects of TQNP supplementation on sperm quality and kinematics, acrosome exocytosis, oxidative biomarkers, apoptosis-like and morphological changes of frozen-thawed buffalo sperm, as well as the fertilizing capacity. Semen was collected from buffalo bulls, diluted (1:10; semen/extender), and divided into five aliquots comprising various concentrations of TQNP 0 (CON), 12.5 (TQNP12.5), 25 (TQNP25), 37.5 (TQNP37.5), and 50 (TQNP50) µg/mL, and then cryopreserved and stored in liquid nitrogen (-196 °C). The results revealed that TQNPs (25 to 50 µg/mL) provided the most optimal results in terms of membrane integrity (p < 0.001) and progressive motility (p < 0.01). In contrast, TQNP50 resulted in a greater post-thawed sperm viability (p = 0.02) compared with other groups. The addition of TQNPs to the extender had no discernible effects on sperm morphology measures. Sperm kinematic motion was significantly improved in the TQNP50 group compared to the control group (p < 0.01). TQNPs effectively reduced the content of H2O2 and MDA levels and improved the total antioxidant capacity of post-thawed extended semen (p < 0.01). The addition of TQNP significantly increased the number of intact acrosomes (p < 0.0001) and decreased the number of exocytosed acrosomes (p < 0.0001). A significant reduction in apoptosis-like changes was observed in TQNP groups. The non-return rates of buffalo cows inseminated with TQNP50-treated spermatozoa were higher than those in the control group (p < 0.05; 88% vs. 72%). These findings suggested that the freezing extender supplemented with TQNPs could effectively enhance the cryotolerance and fertility of buffalo sperm.

The mitochondria-targeted antioxidant "MitoQ" preserves quality and reproductive performance of ram spermatozoa cryopreserved in soybean lecithin-based extender

Cryopreservation of ram semen is helpful for distributing proved spermatozoa for reproductive goals, but cold shock has destructive effects on fertility ability of frozen sperm cells. This study was performed to investigate the effect of the novel mitochondria-targeted antioxidant "MitoQ" on ram sperm quality and fertility potential during cryopreservation process. Semen samples were diluted in extenders supplemented with 0, 1, 10, 100 and 1000 nM MitoQ and then frozen according to the standard protocol. Motility and velocity characteristics, lipid peroxidation, acrosome integrity, membrane functionality, mitochondria active potential, viability, apoptosis status, DNA fragmentation, ROS concentration and reproductive performance were evaluated after thawing. In results, 10 and 100 nM MitoQ presented higher (P ≤ 0.05) total motility, progressive motility, average path velocity, acrosome integrity, membrane functionality, mitochondria active potential and viability as well as lower (P ≤ 0.05) lipid peroxidation, apoptosis status, DNA fragmentation and ROS concentration compared to the control group and the other treatments. Moreover, after fertility trial, 10 and 100 nM MitoQ resulted in higher (P ≤ 0.05) pregnancy, parturition and lambing rates than control group. Therefore, MitoQ is able to preserve quality parameters and fertility potential of post-thawed spermatozoa in sheep and it could be an effective additive for supplementation of ram's semen cryopreservation medium during reproductive programs.

Preservation of the quality and fertility potential of post-thawed rooster sperm using MitoQ

Cryopreservation of rooster spermatozoa is an efficient procedure to spread qualified semen samples for reproductive goals in commercial flocks, but the freeze-thawing process reduces the quality and fertility potential of post-thawed sperm cells. This study was aimed to investigate the effect of the mitochondria-targeted antioxidant MitoQ on rooster sperm quality and fertility potential preservation during freeze-thawing process. Semen samples were collected and diluted in the Lake medium, assigned into five equal aliquots, supplemented with 0, 1, 10, 100 and 1000 nM MitoQ, and cryopreserved in liquid nitrogen. After thawing, sperm motility, membrane functionality, abnormal morphology, mitochondria active potential, acrosome integrity, viability, apoptosis status, lipid peroxidation, DNA fragmentation, ROS concentration and fertility potential were evaluated. According to the results, freezing extender supplementation with 10 and 100 nM MitoQ presented higher (P ≤ 0.05) total motility, progressive motility, average path velocity, membrane functionality, mitochondria active potential, acrosome integrity and viability compared to the other groups. On the other hand, lipid peroxidation, apoptosis rate, DNA fragmentation and ROS concentration were lower (P ≤ 0.05) in groups received 10 and 100 nM MitoQ compared to other groups. Moreover, fertility rate was higher in groups received 10 and 100 nM MitoQ compared to control group. Therefore, MitoQ is able to preserve quality parameters and fertility potential of post-thawed spermatozoa in rooster and it could be an effective additive for supplementation of rooster's semen cryopreservation medium during reproductive programs.

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

The mitochondria-targeted antioxidant MitoQ has been regarded as an effective antioxidant agent against cryo-induced oxidative cellular damage. This study aimed to evaluate the use of different doses of MitoQ combined with trehalose to minimize mitochondrial impairment and oxidative stress during sperm cryopreservation of Markhoz goat. For this, semen samples (n = 50) were collected by electroejaculation every 5 days from 5 bucks in 10 replicates. On each collection day, 5 ejaculates (one ejaculate for each buck) were pooled and then diluted in eight different Tris-based extenders as follows: no additives (control), 20, 200, 2000 nM of MitoQ (MT20, MT200, MT 2000, respectively), 150 mM of trehalose (Tr), MT20+Tr, MT200+Tr, MT2000+Tr. The semen samples were frozen using a standard protocol, and sperm function and oxidative stress were evaluated after thawing. The semen extender supplemented with MT200+Tr had higher (P < 0.05) total and progressive motility, acrosome and membrane integrity, superoxide dismutase, glutathione peroxidase, total antioxidant capacity, and lower (P < 0.05) DNA fragmentation, malondialdehyde and intracellular hydrogen peroxide levels than the all other groups except MT200; meanwhile, MT200 was also improved (P < 0.05) in these parameters than in the control group. Furthermore, MT200 and MT200+Tr showed higher (P < 0.05) percentages of live cryopreserved sperm with high mitochondrial activity than other groups. However, abnormality percentage and catalase activity of frozen-thawed sperm were not affected by treatments (P > 0.05). To conclude, we have found that supplementation of 200 nM MitoQ alone or in combination with 150 mM trehalose to semen extender improved the quality of cryopreserved sperm in goats, which is associated with enhanced antioxidant enzymatic defense and mitochondrial activity and reduced DNA fragmentation.

Mitochondria-targeted antioxidant "MitoQ" improves rooster's cooled sperm quality indicators and reproductive performance

The cell membrane of rooster sperm is sensitive to cold due to the high content of polyunsaturated fatty acids, which are very susceptible to lipid peroxidation. The present study was conducted to determine the effect of different concentrations of the mitochondrial-targeting antioxidant "MitoQ" on sperm quality and fertility potential of chilled semen in roosters. Semen samples were collected from 10 roosters, diluted in Lake extender, assigned into 5 groups according to MitoQ concentrations (0, 1, 10, 100 and 1000 nM MitoQ) and stored at 5 ^°C up to 48 h. Motility, mitochondrial activity, viability, membrane integrity, and lipid peroxidation were assessed at 0, 24, and 48 h of cold storage periods. In addition, the fertility potential was assessed using 24 h-cooled semen samples. Our results showed that extender supplementation with MitoQ had no effect (P > 0.05) on chilled semen samples quality parameters at time 0, while at times 24 and 48 h storage, samples contained 100 nM MitoQ presented higher (P ≤ 0.05) total motility, progressive motility, viability and membrane integrity compared to the other groups. In addition, semen samples containing 10 and 100 nM MitoQ showed higher (P ≤ 0.05) mitochondrial activity and lower (P ≤ 0.05) lipid peroxidation than other groups at 24 and 48 h storage. Fertility rate was higher (P ≤ 0.05) when the hens were artificially inseminated with 24 h-chilled semen samples containing 100 nM MitoQ. In conclusion, supplementing Lake Extender with 100 nM MitoQ could be a helpful strategy to preserve chilled semen quality and fertility potential in the rooster.

Mitochondria-Targeted Compounds to Assess and Improve Human Sperm Function

Significance: Currently 10%-15% of couples in reproductive age face infertility issues. More importantly, male factor contributes to 50% of these cases (either alone or in combination with female causes). Among various reasons, impaired sperm function is the main cause for male infertility. Furthermore, mitochondrial dysfunction and oxidative stress due to increased reactive oxygen species (ROS) production, particularly of mitochondrial origin, are believed to be the main contributors. Recent Advances: Mitochondrial dysfunction, particularly due to increased ROS production, has often been linked to impaired sperm function/quality. For decades, different methods and approaches have been developed to assess mitochondrial features that might correlate with sperm functionality. This connection is now completely accepted, with mitochondrial functionality assessment used more commonly as a readout of sperm functionality. More recently, mitochondria-targeted compounds are on the frontline for both assessment and therapeutic approaches. Critical Issues: In this review, we summarize the current methods for assessing key mitochondrial parameters known to reflect sperm quality as well as therapeutic strategies using mitochondria-targeted antioxidants aiming to improve sperm function in various situations, particularly after sperm cryopreservation. Future Directions: Although more systematic research is needed, mitochondria-targeted compounds definitely represent a promising tool to assess as well as to protect and improve sperm function. Antioxid. Redox Signal. 37, 451-480.

Coenzyme Q10 Supplementation enhances testicular volume and hemodynamics, reproductive hormones, sperm quality, and seminal antioxidant capacity in goat bucks under summer hot humid conditions

Oxidative stress (OS) is brought on by heat stress (HS), which weakens antioxidant defense and initiates OS. Since mitochondria are the primary source of reactive oxygen species (ROS), HS-mediated OS may be lessened by targeting mitochondria with particular antioxidants. The purpose of this study was to investigate the effect of oral coenzyme Q10 (CoQ10) supplementation on the reproductive performance of goat bucks under HS conditions. Ten mature bucks were randomly separated into two groups and housed in an environment with a high-temperature humidity index (THI: 88.3 to 94.8; summer season). The first group (n = 5) got the baseline diet while the second group (n = 5) received supplemental oral CoQ10 (3 mg/kg BW; CoQ10 group) daily for six weeks. Testicular blood flow parameters (TBF), testicular volume (TV) and echogenicity (TE), nitric oxide (NO), seminal alanine aminotransferase (ALT) and catalase (CAT) activities, total antioxidant capacity (TAC), malondialdehyde (MDA) content, and semen quality traits were all measured. The examinations started a week before (W-1), on the first supplementation day (W0), and weekly for eight consecutive weeks (W1-W8). There were marked (P < 0.05) increases in TBF (W3-W6) and TV, and a decrease in TE (W3-W5) in the CoQ10 group compared to the CON group. Similarly, testosterone (T) and NO levels (W3-W5) in the CoQ10 group were higher (P < 0.05) than those of the control group. The CoQ10 group demonstrated significant (P < 0.05) increases in seminal CAT (W4-W8) and TAC (W2-W6) activities and decreases in ALT (W4-W7) activity and MDA (W5-W8) concentration as compared to the control group. The CoQ10 group showed improvements (P < 0.05) at W3-W6 for sperm progressive motility, viability, and normal morphology and at W6-W8 for sperm concentration. In conclusion, oral CoQ10 supplementation improved testicular hemodynamics, testosterone production, semen quality, and antioxidant capacity in goat bucks during summer heat stress conditions.

Mitoquinone mitigates paraquat-induced A549 lung epithelial cell injury by promoting MFN1/MFN2-mediated mitochondrial fusion

Paraquat (PQ) poisoning often leads to severe lung injuries, in which the mitochondria damage plays a critical role. Mitoquinone (MitoQ), a newly designed mitochondria-targeted antioxidant, has been proved for its benefit in mitochondria protection. However, the role of MitoQ in PQ-induced lung injury remains unclear. Thus, this study was performed to investigate the effect of MitoQ on PQ-induced lung injury and its underlying mechanisms. Our work showed that PQ caused the inhibition of A549 lung epithelial cell viability in a dose-dependent manner, while MitoQ remarkably mitigated the PQ-induced cell viability suppression. Besides this, PQ-mediated apoptosis of A549 cells was significantly attenuated by MitoQ, as indicated by the TUNEL assay and mitochondria membrane potential assay. Moreover, the intracellular reactive oxygen species (ROS) production was also dramatically suppressed when cotreated MitoQ with PQ. This could be ascribed to enhanced mitochondrial fusion mediated by Mitofusin 1 (MFN1)/Mitofusin 2 (MFN2), because MitoQ preserved mitochondrial network integrity, as reflected by MitoTracker staining, and MitoQ also increased the expression of MFN1/MFN2 in A549 cells after PQ treatment. Our data suggested MitoQ mitigated PQ-induced lung epithelial cell injury by promoting MFN1/MFN2-mediated mitochondrial fusion, and MitoQ might be a potential candidate drug for the treatment of PQ-induced lung injury.

Comparison of the performance of targeted mitochondrial antioxidant mitoquinone and non-targeted antioxidant pentoxifylline in improving rooster sperm parameters during freezing and thawing

Oxidative stress is associated with impaired sperm quality after thawing. Since mitochondria are the main source of reactive oxygen species (ROS) in sperm, the aim of this study was to investigate the effects of targeted mitochondrial antioxidant mitoquinone (MitoQ) and non-targeted mitochondrial antioxidant pentoxifylline (PTX) during cooling and cryopreservation of rooster sperm. Sperm samples were collected from 15 roosters aged 28 wk and diluted with Beltsville extender. After dilution and addition of treatments (50, 100, and 200 pMol MitoQ and 0.5, 0.75, and 1 μM PTX), samples were cooled for 2 h to 4°C and they were first analyzed at this stage and were frozen and re-evaluated after thawing. After the freezing and thawing, level of 100 pMol MitoQ significantly increased total motility (TM), progressive motility (PGM), curvilinear velocity (VCL), membrane integrity, viability, total antioxidant capacity (TAC) and the glutathione peroxidase (GPx), as well as the level of 50 pMol significantly increased TM, PGM, average path velocity (VAP), straight-line velocity (VSL), membrane integrity, viability, and mitochondrial activity. Moreover, these 2 levels (50 and 100 PMol) decreased malondialdehyde and sperm with abnormal morphology. Addition of 0.75 μM PTX also increased total motility compared to the control group and levels of 0.5 and 0.75 μM decreased sperm with abnormal morphology. It could be concluded the addition of MitoQ and PTX can be useful for sperm cryopreservation industry and reduce the harmful effects of freeze-thawing.

Targeted antioxidant delivery modulates mitochondrial functions, ameliorates oxidative stress and preserve sperm quality during cryopreservation

Mitochondria are vital organelles with a multifaceted role in cellular bioenergetics, biosynthesis, signaling and calcium homeostasis. During oxidative phosphorylation, sperm mitochondria generate reactive oxygen species (ROS) at physiological levels mediating signaling pathways essential for sperm fertilizing competence. Moreover, sperm subpopulation with active mitochondria is positively associated with sperm motility, chromatin and plasma membrane integrity, and normal morphology. However, the osmotic and thermal stress, and intracellular ice crystal formation generate excess ROS to cause mitochondrial dysfunction, potentiating cryoprotectant-induced calcium overload in the mitochondrial matrix. It further stimulates the opening of mitochondrial permeability transition pores (mPTP) to release pro-apoptotic factors from mitochondria and initiate apoptotic cascade, with a decrease in Mitochondrial Membrane Potential (MMP) and altered sperm functions. To improve the male reproductive potential, it is essential to address challenges in semen cryopreservation, precisely the deleterious effects of oxidative stress on sperm quality. During semen cryopreservation, the supplementation of extended semen with conventional antioxidants is extensively reported. However, the outcomes of supplementation to improve semen quality are inconclusive across different species, which is chiefly attributed to the unknown bioavailability of antioxidants at the primary site of ROS generation, i.e., mitochondria. Increasing evidence suggests that the targeted delivery of antioxidants to sperm mitochondria is superior in mitigating oxidative stress and improving semen freezability than conventional antioxidants. Therefore, the present review comprehensively describes mitochondrial-targeted antioxidants, their mechanism of action and effects of supplementation on improving semen cryopreservation efficiency in different species. Moreover, it also discusses the significance of active mitochondria in determining sperm fertilizing competence, cryopreservation-induced oxidative stress and mitochondrial dysfunction, and its implications on sperm fertility. The potential of mitochondrial-targeted antioxidants to modulate mitochondrial functions and improve semen quality has been reviewed extensively.