75 INFLUENCE OF CRYOPRESERVATION ON THE SUSCEPTIBILITY OF GOAT SPERM AGAINST DIFFERENT REACTIVE OXYGEN SPECIES

2011 ◽  
Vol 23 (1) ◽  
pp. 143 ◽  
Author(s):  
P. A. A. Góes ◽  
M. Nichi ◽  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
A. Dalmazzo ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Dna Fragmentation ◽  
Seminal Plasma ◽  
Semen Quality ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Hydroxyl Radical Scavengers

Semen quality after cryopreservation is one of the main limiting factors for the success of artificial insemination in goats. Previous studies indicate that cryo-injuries may be related to the oxidative stress which is caused by the reactive oxygen species (ROS) and leads to structural and functional damages to the sperm. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality post cryopreservation. The aim of the present study was to verify the resistance of cryopreserved goat spermatozoa to different reactive oxygen species. Semen samples from 5 adult goats were collected and cryopreserved (Botubov®, Biotech Ltda.). After thawing, samples were washed twice with PBS and incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical) with and without the addition of seminal plasma. Samples were analysed for motility using computer-assisted sperm analysis (CASA); the 3–3′ diaminobenzidine stain, as an index of mitochondrial activity; the eosin nigrosin stain, as an index of membrane integrity; the simple stain (Fast green/Bengal rose), as an index of acrosome integrity; sperm chromatin structure assay as an index of DNA fragmentation; and the measurement of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Spearman correlation; P < 0.05). Results showed that cryopreserved goat sperm after thawing is highly susceptible to the hydroxyl radical. No differences were found on CASA variables between the different ROS. On the other hand, lipid peroxidation and DNA fragmentation were higher for samples treated with hydroxyl radical when compared to samples treated with the other ROS. Furthermore, sperm showing low mitochondrial activity were lower also for samples treated with hydroxyl radical. Negative correlations were found between lipid peroxidation, and most of the variables evaluated by the CASA. A positive correlation was found between the percentage of sperm showing low mitochondrial potential and DNA fragmentation, indicating that impaired mitochondrial activity may be related to an increase on DNA fragmentation. Previous studies indicate that fresh goat semen is highly susceptible to the attack of hydrogen peroxide. We observed that after thawing there is a shift towards a higher susceptibility to the hydroxyl radical. This may indicate that seminal plasma in goats may be an important source of hydroxyl radical scavengers and that, due to the dilution of the seminal plasma with the extender, such antioxidant protection may be impaired. Therefore, an alternative to improve semen quality in cryopreserved goat semen would be the treatment with hydroxyl radical scavengers such as vitamins E and C, reduced glutathione, and other non-enzymatic antioxidants. Thanks to CAPES for financial support.

232 INFLUENCE OF SEMINAL PLASMA ON THE SUSCEPTIBILITY OF DOG SPERM AGAINST DIFFERENT REACTIVE OXYGEN SPECIES

2011 ◽  
Vol 23 (1) ◽  
pp. 215
Author(s):  
A. Dalmazzo ◽  
P. A. A. Góes ◽  
M. Nichi ◽  
R. O. C. Silva ◽  
J. R. C. Gurgel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Seminal Plasma ◽  
Superoxide Anion ◽  
The Other ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Acrosome Integrity

Due to the importance of dogs to humans, there is increasing interest in breeders in the use of reproductive biotechnologies. However, most of the biotechnologies would require the removal or dilution of the seminal plasma, which is known to exert both beneficial and deleterious effects on sperm quality. One of the beneficial effects of seminal plasma would be the antioxidant protection because sperm are particularly susceptible to oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids in their membrane. An alternative to overcome the injuries caused by oxidative stress is the antioxidant treatment, which requires the identification of those reactive oxygen species (ROS) that are the most deleterious. The aim of this study was to identify the most harmful ROS to dog semen. Semen samples from 6 adult dogs were collected and centrifuged. Seminal plasma (SP) was removed and samples were incubated (1 h, 37°C) with 4 ROS-inducing mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical) alone or with additional SP. Samples were analysed for motility by computer assisted sperm analysis (CASA). The 3-3′ diaminobenzidine stain was used as an index of mitochondrial activity, the eosin nigrosin stain as an index of membrane integrity, the simple stain (fast green/Bengal rose) as an index of acrosome integrity, sperm chromatin structure assay (SCSA) as an index of DNA fragmentation, and measurement of thiobarbituric acid reactive substances (TBARS) as an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Spearman correlation; P < 0.05). Results showed that dog sperm is differentially modulated depending on the presence of SP. In addition, damage to the different sperm structures depended on the different ROS. Samples incubated with SP showed no differences concerning TBARS (1 233 in SP, 1 260 in Tris; P = 0.99). On the other hand, samples incubated without SP showed higher lipid peroxidation when treated with hydroxyl radical compared with the other ROS. Furthermore, although hydroxyl radical mostly altered mitochondrial activity in samples incubated with SP (DAB IV = 4.3%; P < 0.05 against all other ROS), the most significant ROS in samples incubated without SP was hydrogen peroxide (DAB IV = 4.7%; P < 0.05 against all other ROS). Superoxide anion was less harmful to acrosome integrity in samples incubated with SP and to motility in samples incubated without SP. The present results suggest that seminal plasma may play an important role in the susceptibility of dog sperm to oxidative stress. Moreover, the results indicate that different sperm compartments are susceptible to different ROS. It is concluded that the quality of frozen–thawed dog semen may be improved by treating with a combination of different antioxidants to destroy the chain reaction causing the oxidative stress. FAPESP is acknowledged for financial support.

320 SUSCEPTIBILITY OF GOAT SPERM TO DIFFERENT REACTIVE OXYGEN SPECIES

2010 ◽  
Vol 22 (1) ◽  
pp. 316
Author(s):  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
R. P. Cabral ◽  
D. G. Silva ◽  
C. H. C. Viana ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Semen Quality ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Mitochondrial Potential ◽  
Acrosome Integrity

Semen quality is one of the main limiting factors for the success of artificial insemination in goats. It is well known that reactive oxygen species (ROS) lead to structural and functional damages to sperm, impairing or avoiding fecundation. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality and fertility rates. The aim of the present study was to verify the resistance of goat spermatozoa to different reactive oxygen species. Sperm samples from 4 goats were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analyzed for mitochondrial activity using the 3,3′ diaminobenzidine stain, for membrane integrity using the eosin/nigrosin staining, for acrosome integrity using the simple stain (fast green/Bengal rose), and for lipid peroxidation by dosing thiobarbituric acid reactive substances (TBARS). Results showed that goat sperm is more sensitive to hydrogen peroxide, when compared to superoxide anion, hydroxyl radical, and MDA, when considering acrosome integrity, membrane integrity, and mitochondrial potential (Table 1). On the other hand, TBARS production was increased in samples submitted to hydroxyl radical incubation. Strong negative correlations were found between sperm samples showing impaired mitochondrial potential and both membrane and acrosome integrity (r = -0.97, P < 0.0001 and r = -0.91, P < 0.0001, respectively). The concentration of TBARS correlated negatively with the percentage of sperm showing intact membranes (r = -0.53, P = 0.06), and the later correlated negatively with sperm showing no mitochondrial activity (r = -0.78, P = 0.0006). Results of the present experiment suggest that goat sperm are extremely susceptible to the attack of hydrogen peroxide, being resistant to other ROS. Therefore, an alternative to improve the use of goat semen in reproductive biotechnologies would be the treatment with catalase or glutathione peroxidase, important hydrogen peroxide scavengers. Table 1.Effect of different ROS on goat sperm The authors thank Nutricell for the media used in this experiment.

scholarly journals Reactive oxygen species-induced alterations in H19-Igf2 methylation patterns, seminal plasma metabolites, and semen quality

2018 ◽  
Vol 36 (2) ◽  
pp. 241-253 ◽  
Author(s):  
Mahsa Darbandi ◽  
Sara Darbandi ◽  
Ashok Agarwal ◽  
Saradha Baskaran ◽  
Sulagna Dutta ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Seminal Plasma ◽  
Semen Quality ◽  
Reactive Oxygen ◽  
Plasma Metabolites ◽  
Oxygen Species ◽  
Methylation Patterns

Antioxidant Activity of Hizikia fusiformis on Reactive Oxygen Species Scavenging and Lipid Peroxidation Inhibition

2003 ◽  
Vol 9 (5) ◽  
pp. 339-346 ◽  
Author(s):  
Nalin Siriwardhana ◽  
K.-W. Lee ◽  
Y.-J. Jeon ◽  
S.-H. Kim ◽  
J.-W. Haw
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Radical Scavenging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Hizikia Fusiformis ◽  
Lipid Peroxidation Inhibition

Water and organic extracts (diethyl ether, chloroform, ethyl acetate, acetone, ethanol and methanol) obtained from Hizikia fusiformis were screened on reactive oxygen species (ROS) scavenging assays (1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide and hydroxyl radical) and lipid peroxidation (inhibition of linoleic acid oxidation) inhibitory assays. Water, methanol and ethanol extracts showed significant ROS radical scavenging activities. Water extracts showed high scavenging activities on hydrogen peroxide (around 76%) and DPPH radicals (around 75%) while it presented a moderate scavenging activity on hydroxyl radicals (around 54%). Comparatively higher ROS scavenging activities were recorded in hydroxyl radical and DPPH scavenging assays. DPPH radical scavenging activities were well correlated with the polyphenolic content. ROS scavenging and lipid peroxidation inhibition activities indicated that H. fusiformis might be a valuable natural antioxidative source containing both water and fatsoluble antioxidative components.

315 REACTIVE OXYGEN SPECIES AND OXIDATIVE STRESS IN CANINE SEMEN FRACTIONS

2010 ◽  
Vol 22 (1) ◽  
pp. 313
Author(s):  
C. F. Lucio ◽  
M. Nichi ◽  
F. M. Regazzi ◽  
T. F. Rück ◽  
L. C. G. Silva ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Free Radicals ◽  
Sperm Motility ◽  
Seminal Plasma ◽  
Pearson Correlation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Low Concentrations ◽  
Viable Sperm

Reactive oxygen species (ROS) are physiologically produced by spermatozoa and leukocytes present in the seminal plasma. In low concentrations, ROS play an important role in sperm function because they are required for sperm fertilizing capacity, mainly during sperm capacitation and hyperactivation (Saleh RA and Agarwal A 2002 J. Androl. 23, 737-752). However, an imbalance between the formation of free radicals and the capacity for defense of the antioxidant mechanisms may lead to cell damage (Rover Jr L et al. 2001 Química Nova 24, 112-119). Spermatozoa are sensitive to lipid peroxidation due to its high content of polyunsaturated fatty acids and low concentrations of protective enzymes (Sharma RK and Agarwa LA 1996 Urology 48, 835-850). The aims of the present study were to compare ROS content among the 3 fractions of canine semen and to correlate these values with sperm variables. Semen samples were collected from 15 healthy dogs of distinct breeds aged 2 to 6 years. Sperm analysis was performed through motility, forward progressive velocity, morphology, and the percentage of viable sperm with the use of the eosin/nigrosin stain. The determination of thiobarbituric acid reactive substances (TBARS) was used to estimate the degree of lipid peroxidation in each sperm fraction. Values were compared using ANOVA and Tukey’s test for multiple comparisons at a significance level of 5%. Pearson correlation was used to calculate the relationship between sperm variables in the second fraction. Sperm motility, velocity, and percentage of viable sperm were within the normal range for canine semen: 84±2%, 3.4±0.1%, and 83 ± 2%, respectively. The sperm-rich fraction presented statistically higher concentrations of TBARS (1474.19 ± 245.78 ng mL-1) compared to the first and third fractions (579.41 ± 171.23 and 399.62 ± 58.08 ng mL-1, respectively; P < 0.05), indicating that spermatozoa and epididymal secretions are the main source of free radicals. No statistical correlation among TBARS and sperm motility and velocity were verified. However, a positive correlation was observed between the percentage of sperm proximal droplets and TBARS (r = 0.44, P = 0.7). This result suggests that a high incidence of sperm proximal droplets can enhance ROS formation in seminal plasma. Hence, canine sperm presenting delayed maturation in the epididymes produce higher concentrations of free radicals. In fact, sperm production of ROS occurs mainly by abnormal cells, especially the ones containing cytoplasm residues (Gomez E et al. 1998 Int. J. Androl. 21, 81-94). However, no protective effect of the sperm distal droplets was verified in canine semen as observed elsewhere for the bovine spermatozoa (Nichi M et al. 2007 Theriogenology 67, 334-340). In conclusion, spermatozoa and epididymal fluids are the primordial source of free radicals in canine seminal plasma, mainly when sperm proximal droplets are present.

242 PROTECTIVE EFFECT OF VITAMIN E TREATMENT IN HEAT-STRESSED BOS TAURUS BULLS

2013 ◽  
Vol 25 (1) ◽  
pp. 269 ◽  
Author(s):  
V. H. Barnabe ◽  
R. C. Barnabe ◽  
P. Goes ◽  
E. G. A. Perez ◽  
J. D. A. Losano ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Heat Stress ◽  
Vitamin E ◽  
Bos Taurus ◽  
Semen Quality ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Tropical Conditions

Bos taurus bulls, when raised under tropical conditions, are highly susceptible to heat stress, which leads to impaired semen quality, leading to significant economical losses because, in these regions, the reproductive mounting season occurs mainly during the summer. Previous studies have indicated that oxidative stress (i.e. attack by reactive oxygen species) may be the main mechanism of sperm damage in such conditions. Therefore, treatment with antioxidants may be an important alternative to improve semen quality in heat-stressed B. taurus bulls. The objective of the present study was to evaluate whether the treatment with vitamin E, an important antioxidant, could improve sperm quality in insulated bulls. Towards this aim, eight adult Holstein bulls were submitted for semen collection, and the sperm was submitted for motility evaluation by computer-assisted sperm analysis (Ivos, Hamilton Thorne Inc., Beverly, MA, USA), examination of membrane and acrosomal integrity (eosin/nigrosin and fast green/bengal rose stain, respectively), mitochondrial activity (diaminobenzidine stain; full mitochondrial activity or no mitochondrial activity), and sperm susceptibility to oxidative stress (thiobarbituric acid-reactive substances). Bulls were then insulated (testicles covered in a thermal bag for 3 days) and randomly assigned to two treatment groups: no vitamin E (placebo) and vitamin E (subcutaneous injection of 3000 IU of α-tocopherol each of 10 days). Subsequent semen analysis was performed 1 and 60 days after the insulation. Statistical analysis was performed with SAS (SAS Institute Inc., Cary, NC, USA) repeated-measures ANOVA, and significance of P < 0.05 was adopted. No differences were found on any of the variables before insulation. One day after insulation, animals treated with vitamin E showed a lower percentage of static sperm and a higher percentage of motile sperm when compared with animals treated with the placebo (28 and 63% v. 56 and 34%, respectively; P < 0.05). Also at this time, sperm susceptibility to oxidative stress was lower in animals treated with vitamin E (vitamin E: 410 ng/106 sperm; no vitamin E: 1760 ng/106 sperm; P < 0.05). Sixty days after insulation, sperm susceptibility to oxidative stress was still lower in animals treated with vitamin E when compared with the placebo group (1176 and 192 ng/106 sperm, respectively; P < 0.05). However, no differences were found on the other variables. Results indicate that vitamin E, an antioxidant whose main function is protection of the plasma membrane, may be an alternative to avoid the acute deleterious effects of the heat stress in B. taurus bulls raised under tropical conditions. In addition, even with no heat stress involved, vitamin E treatment may provide constant protection, increasing the resistance of the sperm against the reactive oxygen species.

scholarly journals Antioxidant effects of lycopene on bovine sperm survival and oxidative profile following cryopreservation

2017 ◽  
Vol 62 (No. 8) ◽  
pp. 429-436 ◽  
Author(s):  
E. Tvrda ◽  
A. Mackovich ◽  
H. Greifova ◽  
F. Hashim ◽  
N. Lukac
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Oxidative Dna Damage ◽  
Structural Integrity ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Bovine Sperm ◽  
Sperm Survival

Reactive oxygen species overgeneration as a side effect of semen cryopreservation may lead to lipid peroxidation, protein degradation, DNA fragmentation and cell death, resulting in a decrease of sperm survival and fertilisation ability. Lycopene has been proposed as a potential supplement to semen extenders because of its antioxidant properties. The aim of this study was to evaluate the effects of lycopene on the structural integrity, functional activity and selected oxidative stress parameters of cryopreserved bovine sperm. Thirty bovine ejaculates were split into two aliquots and diluted with a commercial semen extender supplemented with 1.5 mmol/l lycopene or containing no supplement (control), cooled down to 4 °C, frozen and kept in liquid nitrogen. Prior to experiments, frozen straws were thawed at 37 °C for 20 s. Lycopene addition resulted in a higher sperm motility (P &lt; 0.001), progressive motility (P &lt; 0.001) and all secondary motion characteristics (P &lt; 0.001 with respect to the average path velocity, linear velocity, velocity of curvilinear motion, beat cross frequency, path straightness and linearity; P &lt; 0.01 in the case of the amplitude of lateral head displacement). Furthermore, lycopene exhibited protective effects on the sperm membrane (P &lt; 0.05) and acrosomal (P &lt; 0.01) integrity in comparison to control. An assay for metabolic function revealed that lycopene supplementation to the cryopreservation medium resulted in a higher preservation of the sperm mitochondrial activity (P &lt; 0.001). Reactive oxygen species production as well as intracellular superoxide generation were decreased following lycopene addition (P &lt; 0.01 in the case of reactive oxygen species; P &lt; 0.001 with respect to superoxide production). Finally, the presence of lycopene led to a decrease in protein carbonyl production (P &lt; 0.01), lipid peroxidation (P &lt; 0.001) as well as oxidative DNA damage (P &lt; 0.05) when compared to control. In conclusion, lycopene exhibited significant reactive oxygen species-trapping and antioxidant properties which may prevent oxidative damage to frozen-thawed sperm, and, thus, enhance the post-thaw vitality of male reproductive cells in cattle breeding.

317 RESISTANCE AGAINST DIFFERENT REACTIVE OXYGEN SPECIES IN BOVINE EPIDIDYMAL SPERM UNDER DISTINCT MATURATION STATUS

2010 ◽  
Vol 22 (1) ◽  
pp. 314
Author(s):  
M. Nichi ◽  
E. G. A. Perez ◽  
C. H. C. Viana ◽  
A. C. Teodoro ◽  
P. A. A. Goes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Reactive Oxygen ◽  
Lipid Peroxidation Product ◽  
Oxygen Species ◽  
Epididymal Sperm ◽  
Mitochondrial Potential

Oxidative stress is caused by reactive oxygen species (ROS) that may cause structural damage to biomolecules, DNA, lipids, carbohydrates and proteins, as well as other cellular components. Evidence indicates that oxidation products are also deleterious to biological systems. Spermatozoa are particularly susceptible the oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids in its membrane. The mechanisms by which sperm acquire antioxidant capacity are still not completely elucidated. The aim was to study the resistance of sperm derived from different epididymal compartments (caudae and head) to the different ROS and to the lipid peroxidation product malondialdehyde (MDA). Epididymal sperm samples from 4 testicles were collected from the head and caudae epididymides. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical), and MDA. Samples were analyzed for 3-3′ diaminobenzidine stain, as an index of mitochondrial activity; the eosin nigrosin stain, as an index of membrane integrity; the simple stain (fast green/Bengal rose), as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Pearson correlation). Results showed that immature sperm (head epididymides) were significantly more susceptible to the MDA and to the hydroxyl radical in all studied variables, especially acrosomes, membranes, and mitochondrial potential. Semen derived from the caudae epididymides was more susceptible to the hydrogen peroxide and to the MDA, especially regarding mitochondrial potential. In semen from the epididymal head, a positive correlation was found between TBARS and sperm showing no mitochondrial potential (r = 0.66, P = 0.01). On the other hand, negative correlations were found between TBARS and sperm with damaged acrosome and membrane (r = -0.63, P = 0.01 and r = -0.58, P = 0.02, respectively) in samples collected from the caudae epididymides. The present results suggest that sperm susceptibility to the attack of ROS is different throughout maturation. Although immature sperm are more susceptible to the hydroxyl radical, mature sperm are more susceptible to the hydrogen peroxide. Furthermore, MDA, a product of lipid peroxidation, is also deleterious to the sperm, indicating that once oxidative stress starts, further damage may be caused by their products. The authors thankNutricell for the media used in the experiment andFAPESP for financial support (process #06/05736-1).

scholarly journals Vitamin E Delivery Systems Increase Resistance to Oxidative Stress in Red Deer Sperm Cells: Hydrogel and Nanoemulsion Carriers

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1780
Author(s):  
Alejandro Jurado-Campos ◽  
Pedro Javier Soria-Meneses ◽  
Francisca Sánchez-Rubio ◽  
Enrique Niza ◽  
Iván Bravo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Vitamin E ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Sperm Cells ◽  
Oxygen Species ◽  
New Formulation ◽  
Species Production

Oxidative stress has become a major concern in the field of spermatology, and one of the possible solutions to this acute problem would be the use of antioxidant protection; however, more studies are required in this field, as highly contradictory results regarding the addition of antioxidants have been obtained. Vitamin E is a powerful biological antioxidant, but its low stability and high hydrophobicity limit its application in spermatology, making the use of organic solvents necessary, which renders spermatozoa practically motionless. Keeping this in mind, we propose the use of hydrogels (HVEs) and nanoemulsions (NVEs), alone or in combination, as carriers for the controlled release of vitamin E, thus, improving its solubility and stability and preventing oxidative stress in sperm cells. Cryopreserved sperm from six stags was thawed and extended to 30 × 106 sperm/mL in Bovine Gamete Medium (BGM). Once aliquoted, the samples were incubated as follows: control, free vitamin E (1 mM), NVEs (9 mM), HVEs (1 mM), and the combination of HVEs and NVEs (H + N), with or without induced oxidative stress (100 µM Fe2+/ascorbate). The different treatments were analyzed after 0, 2, 5, and 24 h of incubation at 37 °C. Motility (CASA®), viability (YO-PRO-1/IP), mitochondrial membrane potential (Mitotracker Deep Red 633), lipid peroxidation (C11 BODIPY 581/591), intracellular reactive oxygen species production (CM-H2DCFDA), and DNA status (SCSA®) were assessed. Our results show that the deleterious effects of exogenous oxidative stress were prevented by the vitamin E-loaded carriers proposed, while the kinematic sperm parameters (p ˂ 0.05) and sperm viability were always preserved. Moreover, the vitamin E formulations maintained and preserved mitochondrial activity, prevented sperm lipid peroxidation, and decreased reactive oxygen species (ROS) production (p ˂ 0.05) under oxidative stress conditions. Vitamin E formulations were significantly different as regards the free vitamin E samples (p < 0.001), whose sperm kinematic parameters drastically decreased. This is the first time that vitamin E has been formulated as hydrogels. This new formulation could be highly relevant for sperm physiology preservation, signifying an excellent approach against sperm oxidative damage.

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