Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation-From Field Trials to Research Bench

Effects of apigenin and trans-ferulic acid on microscopic and oxidative stress parameters in the semen of water buffalo bulls during cryopreservation

Cryopreservation involves exposing sperm to stressful conditions that affect cell viability. The high quality of the Azerbaijani water buffalo's by-products, such as buffalo milk, makes it a species of significant importance. Our focus is on protecting its genetic resources by preserving its sperm, as their numbers will decrease in the coming years and they are at risk of extinction. This study's goal was to ascertain how apigenin (A) and trans-ferulic acid (t-FA) affected the semen quality of Azari water buffalo bulls under cryopreservation. Pooled buffalo sperm (n = 35 ejaculations) were diluted in a Tris-based diluent also containing varying amounts of apigenin (0.2, 0.4, 0.6, and 0.8 mM) and trans-ferulic acid (2.5, 5, 10 and 20 mM). Following a freeze-thaw procedure, samples were assayed for total antioxidant capacity (TAC), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione activity (GSH), glutathione peroxidase (GPx), progressive motility and total motility, motility properties, plasma membrane functionality, and viability. Sixty days after insemination, the rectal examination was performed on 38 buffaloes that had undergone sexual breeding to confirm pregnancy. The results of the study show that the addition of A-0.2, A-0.4, and t-FA-10 to buffalo semen increases the percentage of intact plasma membrane, motility, and sperm viability, as well as the levels of GSH, GPx, CAT. and TAC. In addition, there is a decrease in MDA and DNA damage after cryopreservation. Furthermore, the results show that 0.4 mM apigenin significantly increases conception rates compared to the control group. The base extender of Tris supplemented with A (0.4 and 0.2 mM) and t-FA (10 mM) improves the antioxidant indices of both frozen and thawed buffalo sperm, which in turn improves post-thawing sperm quality and in vivo fertility improves buffalo sperm.

The characterization of CellROX™ probes could be a crucial factor in ram sperm quality assessment

Several authors have demonstrated that low levels of reactive oxygen species (ROS) are necessary for the physiological functions of sperm, such as capacitation, hyperactivation, acrosomal reaction and fertilization. However, high levels of ROS are associated with oxidative stress and detrimental effects on fertility. Consequently, deep characterization of ROS presence using different fluorescent probes could be crucial. In this sense, the study of intracellular ROS localization and the relationships between ROS and other conventional parameters could improve the characterization of sperm quality for semen preservation protocols in rams. In this work, a multiparametric study was carried out by analyzing four experimental groups of ram sperm with different initial qualities: fresh semen (from both breeding and nonbreeding seasons), frozen-thawed semen and, a positive control group treated with hydrogen peroxide (300 μM) as a marker of extreme damage. Sperm analyses, including viability, apoptosis, lipid peroxidation, motility and kinetic parameters, were applied to compare several experimental groups with different sperm qualities. After that, the signals from two different ROS probes: CellROX™ Deep Red (CRDR) and Green (CRG), were examined by flow cytometry (percentage of cells that express ROS) and fluorescence microscopy (intracellular ROS location). Comparing conventional parameters, fresh samples from the breeding season showed the highest sperm quality, while the positive control samples showed the worst sperm quality. Concerning the ROS probes, the CRDR levels were higher in fresh samples from the breeding season than in the positive control and cryopreserved samples. Surprisingly, CRG presented its highest level (P < 0.05) in the positive control group treated with peroxide by flow cytometry. CRDR and CRG presented opposite labeling patterns that were corroborated by fluorescence microscopy, which determined that the probes localized in different parts of sperm. CRDR was found in the sperm mitochondrial region, while CRG was observed in the cell nucleus, suggesting that ROS localization is an important factor. Finally, our study indicates that CRDR is correlated with proper viability and sperm motility, and could be associated with high mitochondrial activity, while CRG is associated with sperm damage.

Oxidative stress affects the beginning of the growth of cancer cells through a variety of routes

Oxidative stress is a physiological condition that occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the cell's antioxidant defense system. ROS are highly reactive molecules that can cause damage to cellular structures such as DNA, proteins, and lipids. the regulation of ROS levels and the antioxidant defense system is crucial for cancer prevention and treatment. Strategies to enhance antioxidant defenses or induce oxidative stress selectively in cancer cells are being developed as potential therapeutic approaches. targeting oxidative stress in cancer treatment is an active area of research with several potential therapeutic approaches being investigated. Developing selective and effective therapies that target oxidative stress in cancer cells while sparing normal cells will be crucial for improving cancer treatment outcomes.

Effect of Honey, Coenzyme Q10, and β-Carotene/α-Tocopherol as Novel Additives in Rabbit-Sperm Cryopreservation Extender

The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation. Accordingly, we used honey (1.25, 2.5, 5, and 10%), coenzyme Q10 (100 and 200 μM), and β-carotene/α-tocopherol (500 μM/620 μM and 250 μM/310 μM) as candidate components for rabbit-sperm extenders during cryopreservation. Ejaculates from commercial adult rabbit bucks (n = 5) were cryopreserved using conventional freezing. Several post-thawing sperm parameters were assessed, including total motility, membrane integrity, viability, nuclear membrane integrity, acrosome reaction, and mitochondrial membrane potential and activation. Additionally, we performed hormonal analyses of the seminal plasma. Moreover, we analyzed the post-thawing levels of a molecular marker of sperm quality, proAKAP4, which was used in rabbits for the first time. Our findings showed that the 2.5% honey supplementation increased the post-thawing sperm motility (13.75 ± 3.75%) compared to the greater concentrations employed. However, the post-thawing motility was negatively affected by the coenzyme Q10 (0%, in both groups) but was not affected by the β-carotene/α-tocopherol supplementation (22 ± 18.15%, and 11.67 ± 10.17%). In conclusion, the cryopreservation protocols of this study did not help to maintain the sperm parameters after thawing. Further studies are required to identify novel protocols to mitigate the damage caused to rabbit sperm during cryopreservation.

Effect of In Vitro Addition of Melatonin and Glutathione on Seminal Parameters of Rams in Diluted Semen and after Thawing

The present study aimed to evaluate the effects of melatonin (MLT), glutathione (GSH), and their combination on ram semen quality after thawing. During eight weekly sessions, semen from three Merino rams was pooled, diluted with an egg-yolk-based semen extender, and divided into four groups: control, 1 mM MLT, 5 mM GSH, and 1 mM MLT + 5 mM GSH. Diluted semen was evaluated before and after the freezing process. The supplementation of diluted semen with GSH at 5 mM had a deleterious effect on total motility progressive (TPM), curvilinear velocity (VCL), straight-line velocity (VSL), average-path velocity (VAP), linearity (LIN), and straightness (STR) and increased slow spermatozoa (%). MLT at 1 mM also had a negative effect on TPM, VSL, and STR in diluted semen. In thawed semen, 1 mM MLT increased the TPM compared with the control group. VSL was lower in the 5 mM GSH group than in the 1 mM MLT group. Additionally, the combination of both antioxidants attenuated the negative effect of 5 mM GSH on TPM, VSL, and BCF. These results indicate that 5 mM GSH impairs or does not improve sperm kinetic parameters in either diluted or thawed semen. They also suggest that MLT combined with GSH plays a protective role against these effects.

Enhancing post-thaw quality of ram epididymal sperm by supplementation of rutin in cryopreservation extender

The purpose of this study was to examine the effect of different rutin concentrations on rams epididymal sperm. A local slaughterhouse provided 50 pair of testes from 25 rams. The testes were sent to the lab at room temperature. Spermatozoa were extracted by suspending portions of cauda epididymis in tris solution. Ram sperm was cryopreserved (in liquid nitrogen) in a tris extender containing rutin at 0, 0.5, 0.75, 1, and 1.25 mM. Rutin showed superior sperm total and progressive motility, beat cross frequency, straight line velocity, velocity average pathway and membrane integrity values at 0.75 and 1 mM. The morphology of the sperm and the superoxide dismutase levels did not significantly change with different treatments. Moreover, rutin at 0.75 and 1 mM was also shown to have the highest level of mitochondrial activity. The results showed ATP, total antioxidant capacity, and glutathione peroxidase levels were significantly greater in the rutin 0.75 and 1 mM groups (P < 0.05). Rutin at 0.75 and 1 mM levels had the lowest reactive oxygen species concentrations. Rutin at 0.75 and 1 mM substantially increased the proportion of viable sperm (P < 0.05). The lowest amount of apoptosis was observed in 0.75 and 1 mM rutin. Rutin at 0.75 and 1 mM yielded the least significant percentage of dead sperm. It may be inferred that adding 0.75 and 1 mM to the sperm extender can enhance the quality of the epididymal sperm in rams after the cryopreservation process.

Changes on proteomic and metabolomic profiling of cryopreserved sperm effected by melatonin

Cryopreservation may reduce sperm fertility due to cryodamage including physical-chemical and oxidative stress damages. As a powerful antioxidant, melatonin has been reported to improve cryoprotective effect of sperm. However, the molecular mechanism of melatonin on cryopreserved ram sperm hasn't been fully understand. Give this, this study aimed to investigate the postthaw motility parameters, antioxidative enzyme activities and lipid peroxidation, as well as proteomic, metabolomic changes of Huang-huai ram spermatozoa with freezing medium supplemented with melatonin. Melatonin was firstly replenished to the medium to yield five different final concentrations: 0.1, 0.5, 1.0, 1.5, and 2.0 mM. A control (NC) group without melatonin replenishment was included. Protective effects of melatonin as evidenced by postthaw motility, activities of T-AOC, T-SOD, GSH-Px, CAT, contents of MDA, 4-HNE, as well as acrosome integrity, plasma membrane integrity, with 0.5 mM being the most effective concentration (MC group). Furthermore, 29 differentially abundant proteins involving in sperm functions were screened among Fresh, NC and MC groups of samples (n = 5) based on the 4D-LFQ, with 7 of them upregulated in Fresh and MC groups. 26 differentially abundant metabolites were obtained involving in sperm metabolism among the three groups of samples (n = 8) based on the UHPLC-QE-MS, with 18 of them upregulated in Fresh and MC groups. According to the bioinformatic analysis, melatonin may have positive effects on frozen ram spermatozoa by regulating the abundance changes of vital proteins and metabolites related to sperm function. Particularly, several proteins such as PRCP, NDUFB8, NDUFB9, SDHC, DCTN1, TUBB6, TUBA3E, SSNA1, as well as metabolites like L-histidine, L-targinine, ursolic acid, xanthine may be potential novel biomarkers for evaluating the postthaw quality of ram spermatozoa. In conclusion, a dose-dependent replenishment of melatonin to freezing medium protected ram spermatozoa during cryopreservation, which can improve motility, antioxidant enzyme activities, reduce levels of lipid peroxidation products, modify the proteomic and metabolomic profiling of cryopreserved ram spermatozoa through reduction of oxidative stress, maintenance of OXPHOS and microtubule structure. SIGNIFICANCE: Melatonin, a powerful antioxidant protects ram spermatozoa from cryopreservation injuries in a dose-dependent manner, with 0.5 mM being the most effective concentration. Furthermore, sequencing results based on the 4D-LFQ combined with the UHPLC-QE-MS indicated that melatonin modifies proteomic and metabolomic profiling of ram sperm during cryopreservation. According to the bioinformatic analysis, melatonin may have positive effects on frozen ram spermatozoa by regulating the expression changes of vital proteins and metabolites related to sperm metabolism and function. Particularly, several potential novel biomarkers for evaluating the postthaw quality of ram spermatozoa were acquired, proteins such as PRCP, NDUFB8, NDUFB9, SDHC, DCTN1, TUBB6, TUBA3E, SSNA1, as well as metabolites like L-histidine, L-targinine, ursolic acid, xanthine.

Quercetin: Putative effects on the function of cryopreserved sperms in domestic animals

Quercetin is one of the most used antioxidant flavonoids and largely exists in many fruits and vegetables because of its capability to scavenge the free reactive oxygen species (ROSs) by repressing lipid peroxy radical fusion, metal ion chelating through enzyme inhibition, and adopting the repair mechanisms. It also exhibits various biological actions, including antioxidative, anti-inflammatory and antimicrobial activities. Furthermore, it contributes well to sustaining the endogenous cellular antioxidant defence system. The process of cryopreservation is associated with increased oxidative stress, and some steps are potential sources of ROSs, including the method of semen collection, handling, cryopreservation culture media, and thawing, which result in impaired sperm function. Several antioxidants have been proposed to counteract the harmful impact of ROS during semen cryopreservation. The antioxidant capability of quercetin has been verified in different animal species for providing valuable defence to sperm during the cryopreservation process. The beneficial properties of quercetin on various parameters of fresh and post-thaw sperm in different species are clarified in this review. More in-depth investigations are required to clarify quercetin's mechanism of action in different animal species.

Application of ultrasound technique to evaluate the testicular function and its correlation to the sperm quality after different collection frequency in rams

The frequency of semen collection is a crucial factor to consider in the rams performance inside breeding centers workout. To evaluate this factor, ram Breeding Soundness Evaluation could include sperm quality evaluation and new predictive and non-invasive tools such as ultrasound technique. In this work, an advanced ultrasonography technology, analyzing the testicular volume, echotexture, and vascular function, was used in three different frequencies of semen collection (abstinence frequency, AF; standard frequency, SF; and intensive frequency, IF). Semen samples were cooled (15°C, 6 h) and evaluated in terms of production, motility, viability, apoptosis, and content of reactive oxygen species. Correlation coefficients were calculated between ultrasonography measurements of echotexture and blood flow and sperm quality parameters. Our results showed an increase in the testicular echotexture when the frequency of semen collection was intensified. Doppler parameters (PSV, RI, PI, TABF) increased (P ≤ 0.05) when the frequency of semen collection was intensified. The sperm motility and functionality decreased in the samples of IF (P ≤ 0.05), evidencing the frequency of semen collection's influence. Moreover, moderate positive correlations were established among echotexture and different Doppler parameters with motility parameters in SF. Furthermore, the influence of abstinence days on AI success was analyzed in a field assay. The highest fertility rates were obtained when males had two to five abstinence days. To conclude, frequency of semen collection could be influenced in terms of semen quantity and sperm quality, showing changes in parenchyma echotexture and testicular vascularization. The standard semen collection frequency was the most adequate option. In addition, ultrasonography may be a predictive tool for estimating variations in the sperm quality of donor rams subjected to different frequencies of semen collection in reproduction centers.

Animal Reproduction: Semen Quality Assessment

Semen quality is of fundamental importance for successful conception and embryonic development [...]

Frequency of Semen Collection Affects Ram Sperm Cryoresistance

The improvement of frozen-thawed sperm quality has been mostly approached from the view of cryopreservation protocol optimization in terms of cryoprotectant solutions, freezing-thawing rates and antioxidant supplementation, while the impact of sperm collection frequency remains unknown in rams. In this work, a multiparametric study was carried out in cooled and frozen-thawed semen to evaluate sperm quality after different semen collection frequencies during a month: zero sperm collection (0 CW), four sperm collections per week (4 CW), and ten sperm collections per week (10 CW). Traditional analyses have been applied, in combination with novel technologies related to redox balance. Frozen-thawed semen quality showed a significant decrease (p < 0.05) in 0 CW and 10 CW in comparison to 4 CW, concerning motility and kinetics parameters. However, apoptosis showed a significant increase (p < 0.05) in 10 CW in comparison to 0 CW and 4 CW. The employment methods related to redox balance provided us with the definitive probe to ensure the influence of collection frequency on balance redox after thawing. Specifically, glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity showed a significant decrease (p < 0.05) in 10 CW compared to 0 CW and 4 CW. The characterization of alternative strategies to sperm cryopreservation based on consideration of male sexual regimes, could improve the quality of frozen-thawed sperm.

Comprehensive Flow-Cytometric Quality Assessment of Ram Sperm Intended for Gene Banking Using Standard and Novel Fertility Biomarkers

Flow cytometry becomes a common method for analysis of spermatozoa quality. Standard sperm characteristics such as viability, acrosome and chromatin integrity, oxidative damage (ROS) etc. can be easily assess in any animal semen samples. Moreover, several fertility-related markers were observed in humans and some other mammals. However, these fertility biomarkers have not been previously studied in ram. The aim of this study was to optimize the flow-cytometric analysis of these standard and novel markers in ram semen. Ram semen samples from Slovak native sheep breeds were analyzed using CASA system for motility and concentration and were subsequently stained with several fluorescent dyes or specific antibodies to evaluate sperm viability (SYBR-14), apoptosis (Annexin V, YO-PRO-1, FLICA, Caspases 3/7), acrosome status (PNA, LCA, GAPDHS), capacitation (merocyanine 540, FLUO-4 AM), mitochondrial activity (MitoTracker Green, rhodamine 123, JC-1), ROS (CM-H2DCFDA, DHE, MitoSOX Red, BODIPY), chromatin (acridine orange), leukocyte content, ubiquitination and aggresome formation, and overexpression of negative biomarkers (MKRN1, SPTRX-3, PAWP, H3K4me2). Analyzed semen samples were divided into two groups according to viability as indicators of semen quality: Group 1 (viability over 60%) and Group 2 (viability under 60%). Significant (p < 0.05) differences were found between these groups in sperm motility and concentration, apoptosis, acrosome integrity (only PNA), mitochondrial activity, ROS production (except for DHE), leukocyte and aggresome content, and high PAWP expression. In conclusion, several standard and novel fluorescent probes have been confirmed to be suitable for multiplex ram semen analysis by flow cytometry as well as several antibodies have been validated for the specific detection of ubiquitin, PAWP and H3K4me2 in ram spermatozoa.