Effect of green tea (Camellia sinensis) extract and pre-freezing equilibration time on the post-thawing quality of ram semen cryopreserved in a soybean lecithin-based extender

Exploratory Metabolomics and Lipidomics Profiling Contributes to Understanding How Curcumin Improves Quality of Goat Semen Stored at 16 °C in Tropical Areas

Reactive oxygen species (ROS) exert a vital role in sperm quality during semen preservation, where excessive ROS leads to oxidative damage and undermines sperm integrity. Curcumin, a botanical extract, is capable of neutralizing ROS and enhancing the activity of antioxidant enzymes. This study was aimed at evaluating the effects of curcumin on sperm viability, acrosome integrity, and antioxidant levels, as well as metabolomic and lipidomic profiles. The results demonstrated that curcumin at 25 µmol/L significantly enhanced sperm motility, plasma membrane, and acrosome integrity, elevated the levels of antioxidant enzymes (T-AOC, CAT, SOD), and decreased ROS production (p < 0.05). Metabolomic analysis identified 93 distinct metabolites that showed significant differences between the control and curcumin-treated groups. KEGG pathways emphasized the participation of these metabolites in key metabolic processes such as the citric acid cycle, cholesterol metabolism, and fatty acid metabolism. Curcumin treatment brought about notable variations in lipid profiles, including increased levels of phosphatidylcholine, acylcarnitine, and triglyceride over the storage time, suggesting enhanced lipid anabolic activity. Overall, the supplementation of curcumin at 25 µmol/L effectively mitigates oxidative stress and prolongs the viability of semen storage at 16 °C by modulating specific metabolic and lipid profiles.

Effects of dietary Moringa oleifera leaf extract on semen characteristics, fertility, and hatchability in aged broiler breeder roosters

Declining semen quality will have a negative impact on the fertility of aged roosters. Various factors influence this decrease in quality. This study was conducted to investigate the effects of different levels of Moringa plant extract on semen characteristics, fertility, and hatchability in aged broiler breeder roosters. A total of 24 roosters were fed 1 of 4 dietary supplements for 10 wk: Control, 100 μL/kg (Moringa oleifera leaf extract [MOLE]-100), 200 μL/kg (MOLE-200), or 400 μL/kg body weight (MOLE-400) of Moringa oleifera extract. Results showed supplementation with MOLE-200 significantly improved (P < 0.05) semen concentration, total motility, progressive motility, sperm membrane integrity compared to other treatments. However, semen volume and body weight were unaffected (P > 0.05). Sperm lipid peroxidation, as indicated by malondialdehyde concentration, was lowest in MOLE-200. There was a significant difference observed among the treatments in terms of total antioxidant capacity (TAC) results. The testosterone concentration in the MOLE-200 treatment was significantly higher than the other treatments (P < 0.05). However, no significant differences were observed in the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) hormones among the experimental treatments. Fertility and hatchability rates were measured at the end of the trial. Fertility, defined as the number of fertilized eggs, was greatest in the MOLE-200 treatment compared to the other treatments. Similarly, hatchability (hatched chicks/fertilized eggs %) was highest at 88.02% for MOLE-200. In conclusion, dietary supplementation with M. oleifera extract improved semen quality, fertility, and hatchability in aged broiler breeder roosters.

Mogroside V alleviates the heat stress-induced disruption of the porcine oocyte in vitro maturation

Heat stress (HS) is a stressor that negatively affect female reproduction. Specially, oocytes are very sensitive to HS. It has been demonstrated that some active compounds can protect oocyte from HS. We previously found that Mogroside V (MV), extracted from Siraitia grosvenorii (Luo Han Guo), can protect oocyte from many kinds of stresses. However, how MV alleviates HS-induced disruption of oocyte maturation remains unknown. In this study, we treated the HS-induced porcine oocytes with MV to examine their maturation and quality. Our findings demonstrate that MV can effectively alleviate HS-induced porcine oocyte abnormal cumulus cell expansion, decrease of first polar body extrusion rate, spindle assembly and chromosome separation abnormalities, indicating MV attenuates oocyte mature defects. We further observed that MV can effectively alleviate HS-induced cortical granule distribution abnormality and decrease of blastocyst formation rate after parthenogenesis activation. In addition, MV treatment reversed mitochondrial dysfunction and lipid droplet content decrease, reduced reactive oxygen species levels, early apoptosis and DNA damage in porcine oocytes after HS. Collectively, this study suggests that MV can effectively protect porcine oocytes from HS.

Effects of dietary basil (Ocimum basilicum) supplementation on reproductive hormones, semen parameters, and testicular development in Zandi male lambs

This study investigated the potential impact of feeding whole plant basil on sperm quality and the concentration of certain reproductive hormones in male lambs. A total of 18 Zandi male lambs with an initial weight of 28.8 ± 2.03 kg were included in a completely randomized design with three treatments and six repetitions. The experimental treatments included: 1) control (basal diet without basil), 2) diet containing 12.5 % basil, and 3) diet containing 25 % basil. The results showed that feeding basil to male lambs significantly increased testosterone concentration and decreased blood cortisol levels (P < 0.05). Additionally, feeding high levels of basil significantly improved sperm concentration, motility, and viability in the experimental samples, while reducing the level of complete abnormalities and malondialdehyde concentration (P < 0.05). The findings suggest that dietary supplementation of 25 % whole plant basil could be a useful strategy to improve sperm quality and increase testosterone secretion while reducing cortisol levels in male lambs.

Influence of nano-formulations of clove bud (Syzygium aromaticum) extract on freezing ability, antioxidant capacity, caspase-3 activity, acrosome reaction and fertility of frozen rabbit semen

The current study aimed to investigate the impact of nano-formulations of clove bud ethanolic extract (CBENF) in the extender on sperm characteristics, antioxidant capacity, oxidative biomarkers, enzymatic activity, apoptosis and fertility of post-thawed rabbit semen. Twelve mature male rabbits semen samples were pooled and cryopreserved in a Tris-egg yolk-based extender containing varying concentrations of CBENF (0, 25, 50, 75 and 100 μg/mL). After the equilibration and freezing-thawing process, CBENF (100 μg /mL) significantly enhanced progressive motility, viability and membrane integrity. Conversely, sperm abnormality was significantly reduced by CBENF supplementation. Total antioxidant capacity was increased in the post-thawed sperm medium, while nitric oxide and malondialdehyde were decreased in all CBENF concentrations. The lactic dehydrogenase and caspase-3 activities were decreased, whereas the number of live spermatozoa with an intact acrosome was increased in all CBENF concentrations. Conception rate and litter size per doe were higher in doe rabbits inseminated with semen supplemented with 100 μg CBENF/mL than un-supplemented group (76% vs. 52% and 8.4 vs. 7.7/doe), with no statistical differences. These findings suggest that supplementing rabbit extenders with 100 μg of CBENF/mL could be an effective strategy for enhancing freeze-thawing rabbit sperm attributes and fertility.

Recent approaches in the use of antioxidants and proteomic modifications in ram semen preservation

Sperm preservation is a well-established technique in reproductive biotechnology that is widely used to maintain the genetic quality of male individuals. However, there are several factors during the preservation process that can affect the vitality, functionality, and quality of sperm, thereby reducing their fertility potential after thawing. One of these factors is the synthesis of high levels of oxidative stress (OS) during semen preservation, which can have detrimental effects on sperm health and functionality. To counter the negative impact of OS on sperm, researchers have explored the supplementation of several exogenous antioxidants in the extenders used to preserve ram sperm. This approach has shown promising results in improving sperm health, functionality, and fertility potential in ram. Additionally, the preservation process can induce modifications in the ram sperm proteome. By employing targeted proteomics techniques, researchers have been able to identify and modify specific proteins in cryopreserved ram sperm, potentially offering further improvements in the quality of the cryopreserved ram sperm. In summary, this review provides a comprehensive overview of the antioxidants and targeted proteomics modifications that have been investigated for enhancing ram sperm preservation. These advancements aim to mitigate the negative effects of OS and optimize the techniques used in preserving ram sperm.

Grape Seed Proanthocyanidins Improve the Quality of Fresh and Cryopreserved Semen in Bulls

Oxidative stress leads to a decrease in semen quality during semen cryopreservation and fresh semen production. Grape seed proanthocyanidins (GSPs) are endowed with well-recognized antioxidant, anti-inflammatory, anti-cancer, and anti-aging activities. Therefore, the objective of this experiment was to explore the effects of GSPs on the quality of fresh and cryopreserved semen to provide a basis for GSPs as a new dietary additive and semen diluent additive for males' reproduction. Fresh semen from three healthy bulls aged 3 to 5 years old were gathered and mixed with semen diluents dissolved with 0 µg/mL, 30 µg/mL, 40 µg/mL, 50 µg/mL, and 60 µg/mL GSPs respectively. The motility, physiological structures (acrosome integrity, membrane integrity, mitochondrial activity), and antioxidant capacity of frozen-thawed sperm were measured after storage in liquid nitrogen for 7 days (d). Bulls were fed with 20 mg/kg body weight (BW) GSPs in their diet for 60 days; the weight of the bull is about 600 kg. Then, the reproductive performance and antioxidant indexes of bulls were measured before and after feeding. The results demonstrated that GSPs supplementation significantly increased sperm motility, physiological structures, GSH-Px, and CAT enzyme activities and significantly decreased MDA content in sperm during semen cryopreservation. The optimal concentration of GSPs was 40 µg/mL (p < 0.05). After 20 mg/kg (body weight) GSP supplementation, sperm motility was significantly heightened (p < 0.05), the sperm deformity rate was significantly reduced (p < 0.05), and antioxidant enzyme activities (such as SOD, CAT, and GSH-Px) were significantly enhanced (p < 0.05), and the production of MDA was significantly suppressed (p < 0.05) in serum compared with that before feeding. In conclusion, these results reveal that a certain concentration of GSPs has a good protective effect on sperm damage caused by semen cryopreservation and the reproductive performance reduction caused by stress in bulls, which may be attributed to the antioxidant function of GSPs. In summary, GSPs are a useful cryoprotective adjuvant and dietary additive for bull sperm quality.

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.

Effect of different sources of dietary zinc on sperm quality and oxidative parameters

Zinc has a critical physiological role in sperm function. The purpose of this study was to investigate the effect of different sources of zinc on sperm quality. For this purpose, 18 Zandi lambs with an average weight of 32 ± 1.2 kg were subjected to three treatments in a completely randomized design. Experimental treatments include (1) control treatment of basal diet without zinc supplementation, (2) basal diet with 40 mg/kg of zinc supplementation from zinc sulfate source and (3) basal diet with 40 mg/kg of zinc supplementation with organic source. At the end of feeding period, lambs were slaughtered. To determine the effect of experimental treatments on sperm quality, the testes were transferred to the laboratory. After that, epididymal spermatozoa were evaluated for sperm motility parameters, abnormal morphology, viability, membrane functionality, malondialdehyde (MDA) and antioxidant activity [glutathione peroxidase (GPx), superoxide dismutase (SOD), total antioxidant capacity (TAC)], sperm concentration and testosterone level. Zinc sulfate administration decreased MDA levels compared to other treatments and increased GPx and TAC activity compared to the control (P < 0.05), although SOD activity was not affected by any supplementation. Also, the use of zinc sulfate supplementation increased the percentage of total and progressive motility compared to the control group (P < 0.05). Membrane integrity and sperm viability were also affected by zinc sulfate supplementation (P < 0.05). Therefore, the results of this study showed that the use of zinc sulfate, can improve sperm motility and survival indices and its antioxidant capacity.

The effects of purslane (Portulaca oleracea) and fennel (Foeniculum vulgare Mill) hydroalcoholic extracts on the functional parameters of human spermatozoa after vitrification

OBJECTIVE

Reactive oxygen species (ROS) are produced during cryopreservation of human sperm and impair sperm function. Antioxidant compounds, such as fennel and purslane, reduce the damaging effects of ROS. This study aimed to evaluate motility parameters, plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), intracellular ROS, and DNA damage to determine the optimum concentrations of hydroalcoholic extracts of fennel and purslane for human spermatozoa cryopreservation.

METHODS

Twenty human sperm samples were used and divided into seven equal groups consisting of fennel hydroalcoholic extract (5, 10, and 15 mg/L), purslane hydroalcoholic extract (25, 50, and 100 mg/L), and no additive.

RESULTS

Supplementation of 25 mg/L and 50 mg/L purslane extract and 10 mg/L fennel extract in cryopreservation extender significantly increased the motility and PMI of sperm with a significant reduction in intracellular ROS compared to control groups (p<0.05). A 50 mg/L concentration of purslane extract elevated progressive motility and MMP compared to the control group (p<0.05). No significant differences were seen for motion patterns and DNA damage of frozen-thawed human sperm in extender containing these extracts.

CONCLUSION

The results showed that supplementation of 50 mg/L purslane extract and 10 mg/L fennel extract in semen cryopreservation extender has the potential to decrease intracellular ROS and subsequently elevate the motility and PMI of human sperm.

Protective effect of rosiglitazone on microscopic and oxidative stress parameters of ram sperm after freeze-thawing

The purpose of this study was to investigate the effects of rosiglitazone on ram semen after cryopreservation on the quality of thawed sperm. Sperm motility, membrane functionality, viability, total abnormality, acrosome membrane integrity, mitochondrial activity, reactive oxygen species production, ATP content and apoptotic features were assessed after thawing. Rosiglitazone at concentration of 60 µM resulted in the highest (P < 0.05) total motility, progressive motility and straight-line velocity. The percentages of average path velocity and curvilinear velocity were greater in the 60 µM group. Different concentrations of rosiglitazone did not have significant effects on amplitude of the lateral head displacement, linearity and straightness. The highest amounts of membrane functionality and mitochondrial activity after freeze-thawing were observed in groups containing 60 µM. By increasing the rosiglitazone level to 80 µM, no positive effect was observed in most of the evaluated parameters. The lowest ROS concentration was recorded in 60 µM rosiglitazone group (P < 0.05). The group containing 60 µM rosiglitazone also produced the lowest significant percentage of apoptosis-like changes and dead sperm. A greater (P < 0.05) percentage of acrosome integrity in frozen-thawed spermatozoa was observed in the 60 µM rosiglitazone group. There was no significant difference between 40 and 60 µM rosiglitazone in intact acrosome of ram thawed semen. The result showed that supplementation in ram semen extender with rosiglitazone had a positive role in the regulation of ram sperm motility and had strong protective effect on the sperm membrane and acrosome integrity.

Green Tea Extract in the Extender Improved the Post-Thawed Semen Quality and Decreased Amino Acid Mutation of Kacang Buck Sperm

This study was the first to combine the addition of antioxidants to a skim milk–egg yolk (SM–EY) extender and different equilibration periods to obtain higher quality post-thawed Kacang buck semen. This study aimed to determine the effects of green tea extract (GTE) on the quality of frozen Kacang goat sperm equilibrated for one and two hours. The pool of Kacang buck ejaculate was equally divided into four portions and was diluted in an SM–EY extender that contained four doses of 0, 0.05, 0.10, and 0.15 mg of GTE/100 mL for T0, T1, T2, and T3 groups, respectively. The aliquots were treated for an equilibration period of 1–2 h before further processing as frozen semen. Post-thawed semen quality was evaluated for sperm quality. The Sanger method was used for DNA sequencing, and the amino acid sequence was read using MEGA v.7.0. The post-thawed semen of the T2 group that was equilibrated for one hour had the highest semen quality. Pre-freezing motility had the highest determination coefficient compared to post-thawed sperm motility. This study is the first to report amino acid mutation due to freeze–thawing. The frequency of amino acid mutations revealed that T2 was the least mutated amino acid. Glycine, valine, leucine, serine, and asparagine strongly correlated to post-thawed sperm motility. It can be concluded that a combination of 0.1 mg GTE/100 mL extender as an antioxidant and one-hour equilibration period resulted in the best post-thawed Kacang buck semen quality.

The effect of Caulerpa sertularioides extract on bull sperm freezablity and subsequent embryo development

Artificial insemination is a valuable and essential tool in genetic improvement programs, and its success requires proper semen collection, freezing, and thawing procedures. Nowadays, despite applying of advanced protocols for semen cryopreservation, post-thawing sperm quantitative and qualitative parameters are not satisfactorily comparable to fresh sperm. The present study was designed to evaluate the effects of the supplementation of an alcoholic extract of Caulerpa sertolarioides alga into the tris-egg yolk-based Simmental bull sperm freezing media. The pooled semen samples were divided into five groups, of which four were supplemented with 500, 1000, 1500, and 2000 ppm alga extract and one allocated as a control. Total motility, progressive motility, plasma membrane integrity, DNA integrity, apoptosis, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and total antioxidant capacity (TAC) of sperm were measured. The frozen sperm from each group were used for IVF on the slaughterhouse-derived oocytes. Fertilization, cleavage, and blastocyst rates were assessed for all groups. Total motility, progressive motility, and velocity curvilinear (VCL) parameters were higher (p ≤ 0.05) in group 1000 ppm than the control group. Velocity in a straight path (VSL) was higher (p ≤ 0.05) in all treatment groups except in 500 ppm compared to the control group. Average path velocity (VAP) was higher (p ≤ 0.05) in 1000 and 1500 ppm groups than in the control group. Straightness (STR) showed a higher value (p ≤ 0.05) in 1000 and 2000 ppm than the control group. Groups 500 and 1000 ppm showed more viable sperm than the control group (p ≤ 0.05). DNA damage was lower (p ≤ 0.05) in group 1000 ppm than in the control group. HOST was higher (p ≤ 0.05) in all groups than in the control group. SOD, GPx, and TAC were higher (p ≤ 0.05) in 1000 ppm than the control and all other groups. Apoptosis was not significantly different among the treatment and control groups. In conclusion, supplementation of alcoholic extract of Caulerpa sertularioides into the Simmental bull freezing extender ameliorated the sperm parameters after the freeze-thawing process. Moreover, the results of this study indicated that the best dose to achieve the antioxidant properties of the alga extract in Simmental bull sperm freezing media was 1000 ppm. It was also evident that 1000 ppm alga extract supplementation into the bull sperm improved fertilization, cleavage, and blastocyst rates.

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.

Effects of phytogenic feed additives on the reproductive performance of animals

The reproductive performance of ruminants is economically significant, and its improvement is a primary goal of the livestock industry to ensure its sustainability. Several approaches have been developed to use phytogenics as feed additives for several proposes, such as reducing methane emissions, and as an alternative to antibiotics. Phytogenics have potent antioxidant, anti-inflammatory, immunomodulatory, and metabolism-regulatory properties, and they are present at high levels in animal feeds. This current review considers the potential use of medicinal herbs on the reproductive performance of animals. The influence of diet on the fertility complications commonly noted in ruminants is of global interest. Although the effects of phytogenics on ruminant digestion and absorption are well-explored, their impact on reproductive performance remains poorly investigated. This review focuses on the influence of phytogenics on semen quality, hormonal profiles, and hematobiochemical indices in male ruminants. Based on available data, phytogenics are perceived to improve oocyte quality, reproductive performance, and pregnancy. However, further more comprehensive research on the benefits and potential hazards of the use of phytogenics is required to improve reproductive performance in ruminants.

Does ergothioneine and thawing temperatures improve rooster semen post-thawed quality?

The present study focuses on the effect of different levels of ergothioneine and thawing temperature on rooster semen cryopreservation. Semen was diluted in Lake extender containing ergothioneine at 5, 10, 15, and 20 µM and cryopreserved. Two thawing temperatures (37°C for 30 s and 60°C for 5 s) were consequently examined. Sperm motility parameter, membrane integrity, abnormal morphology, viability, apoptotic status, mitochondria activity, and lipid peroxidation were determined after freeze-thaw process. Ergothioneine levels of 5 and 10 µM led to higher (P < 0.05) total motility (66.58 ± 1.44 and 72.11±1.44, respectively) and average path velocity (VAP) (34.54 ± 0.89, 37.28 ± 0.89, respectively). Higher (P < 0.05) significant membrane integrity and mitochondria activity after freeze-thawing were observed in the groups supplemented with 10 µM ergothioneine (68.62 ± 1.24 and 69.12 ± 1.26, respectively). Also, 5 and 10 µM of ergothioneine led to the lowest significant percentage of apoptotic and dead sperm. The total motility and progressive motility resulted in significantly (P < 0.05) higher amount when sperm were thawed with 60°C (60.58 ± 0.91 and 24.76 ± 0.53, respectively) compared to thawed sperm in 37°C. The membrane integrity, viability and mitochondria activity led to significantly (P < 0.05) higher when sperm were thawed with 60°C (58.2 ± 0.78, 63.21 ± 0.80 and 56.85 ± 0.79, respectively). It could be concluded the addition of 5 and 10 µM ergothioneine in the semen extender and thawing temperature at 60˚C in 5 s can be an efficient strategy to preserve rooster cryopreserved semen quality.

Beneficial Influence of Soybean Lecithin Nanoparticles on Rooster Frozen-Thawed Semen Quality and Fertility

Simple Summary

Soy lecithin (SL) can be used in to prevent spermatozoa cryodamage during cryopreservation by mitigating the efflux of cholesterol or phospholipids, thus reducing the formation of intracellular ice crystals. SL nanoparticles (nano-SL) have a smaller particle size and higher solubilizing capacity as compared with those that have not undergone nanotreatment. Thus, they allow for a better interaction or coating of sperm, decreasing cold shock injury during freezing–thawing processes. The objective of this study was to determine the optimal concentration of nano-SL. In order to achieve this, we assessed the quality of frozen–thawed semen in vitro and in vivo. We found that a nano-SL dosage of 1.0% in the semen extender had an affirmative influence on post-thawing quality in roosters, improving various parameters related to sperm motion, protecting the membrane and acrosome integrities, increasing mitochondrial activity and antioxidant capacity, and reducing the oxidative stress caused by the cryopreservation process. Moreover, enrichment of 1.0% nano-SL in the semen extender improved the fertilizing capacity of rooster sperm after artificial insemination.

Abstract

The present study aimed to investigate the impact of different concentrations (0%, 0.5%, 1.0%, 1.5%, and 2.0%) of nano-soybean lecithin (SL) in the extender on sperm quality, sperm motion characteristics, and fertility outcomes of post-thawed rooster semen. Adult Ross broiler breeder roosters (n = 20) were subjected to semen collections twice a week for three weeks. At each collection, semen samples were pooled and allocated into five treatments corresponding to different nano-SL concentrations (control, SL0.5, SL1.0, SL1.5, and SL2.0). Sperm parameters, including motility (collected using a computer-assisted sperm analysis system), plasma membrane and acrosome integrities, and mitochondrial activity were assessed. Sperm malondialdehyde (MDA) and antioxidant activities (total antioxidant capacity (TAC); superoxide dismutase (SOD); glutathione peroxidase (GPx)) were evaluated. The fertility and hatchability obtained with frozen–thawed rooster semen supplemented with the optimum nano-SL concentration were assessed after artificial insemination. The results showed that the addition of 1% nano-SL into the extender led to a higher semen motility in roosters, improved plasma membrane and acrosome integrities, and higher mitochondrial activity of post-thawed rooster semen in comparison to controls (p < 0.05). The MDA levels in the SL0.5 and SL1.0 groups were lower than the other groups (p < 0.05). TAC activities in SL0.5, SL1.0, and SL1.5 groups were significantly higher than those in the other groups (p < 0.05). It was observed that the concentration of SOD was higher in the SL1.0 group than in the other groups (p < 0.05). The activity of GPx was not influenced in any of the cases (p > 0.05). Moreover, the percentages of fertility and hatchability in the SL1.0 group were higher (56.36% and 58.06%) than those in the control group (42.72% and 40.43%). In summary, the addition of nano-SL to the extenders enhanced the post-thawed semen quality and fertility of roosters by reducing the level of oxidative stress. The optimum nano-SL concentration was 1.0%. These results may be beneficial for improving the efficacy of semen cryopreservation procedures in poultry breeding.

Plant Extracts as Alternative Additives for Sperm Preservation

Sperm preservation is a crucial factor for the success of assisted reproductive technology (ART) in humans, livestock, and wildlife. Irrespective of the extender and the storage conditions used, semen handling and preservation negatively affect sperm quality. Moreover, oxidative stress, which often arises during semen storage, significantly reduces sperm function and compromises the sperm fertilizing ability by inducing oxidative damage to proteins, lipids, and nucleic acids. Plant extracts have recently emerged as a cheap and natural source of additives to preserve and enhance sperm function during semen storage. The present work provides an update on the use of these natural compounds as alternative additives for sperm preservation in 13 animal species, including humans. A detailed description of the effects of 45 plant species, belonging to 28 families, on sperm function during semen storage is presented. The plant material and extraction method employed, dosage, possible toxic effects, and antimicrobial properties are provided.

Poloxamer 188 and hydroxyethyl starch have a cryoprotective synergic effect improving post-thawing quality and fertility of rooster spermatozoa

Poloxamer and hydroxyethyl starch have cytoprotective effects. In the present study, effectiveness was evaluated of these compounds as a cryoprotectant for rooster semen. In Experiment 1 (E1), poloxamer 188 (1%, P188), poloxamer 407 (1%, P407), and control groups were compared after sperm cryopreservation. Experiment 2 (E2) was conducted with 3%, 5%, and 7% of hydroxyethyl starch (H3, H5, H7), also combined with P188 (H3P188, H5P188, H7P188), based on results from E1. Sperm motility was assessed using CASA, abnormal forms and hypo-osmotic swelling (HOS) were evaluated using microscopy, and viability, apoptotic-like changes, and mitochondrial activity were determined using flow cytometry. In E2, there were assessments of fertility and hatching capacity. Results from E1 indicated total and progressive motility, velocity, membrane functionality, viability, and mitochondrial activity were greater with inclusion of P188 in semen extender, with less apoptotic-like changes (P < 0.05). In E2, HES inclusion in semen extender improved total motility, membrane functionality, and mitochondrial activity (P < 0.05), especially H5, which also markedly increased sperm viability and decreased apoptotic-like changes. The combination of P188 with HES increased sperm quality overall, with inclusion of H5P188 resulting in increases of progressive motility and VSL (P < 0.05). The H5 inclusion also increased proportion of fertilized eggs (P < 0.05). Furthermore, the combination of HES and P188 increased proportions of fertilized and hatched eggs compared with the control, with inclusion of H5P188 having the greatest effects. In conclusion, supplementation of semen extender with H5P188 increases post-thawing quality and fertility of rooster sperm, being a safe and effective method for the poultry industry.

Green tea extract increases the quality and reduced DNA mutation of post-thawed Kacang buck sperm

The study aimed to determine the addition of green tea extract (GTE) in extender on the quality and DNA mutation of post-thawed Kacang buck sperm. The sperm DNA mutation was observed on nicotinamide adenine dinucleotide hydride (NADH) dehydrogenase 1 (ND1) of mitochondrial Deoxyribonucleic Acid (mtDNA). A pool of 12 Kacang buck ejaculates was diluted in skim milk-egg yolk extender contained 0, 0.05, 0.10, and 0.15 mg of GTE/100 mL for T0, T1, T2, and T3 group, respectively. Each of the aliquot groups was packaged in 0.25 mL French mini straw contained 60 million alive sperm and froze according to the protocol. The ND1 mtDNA amplification of samples was carried out Polymerase Chain Reaction machine, followed by DNA sequencing using the Sanger method. Meanwhile, the phylogenetic tree was constructed using the neighbor-joining (NJ) method with MEGA 7.0 software. The results showed that the T2 group maintained the highest quality for Kacang buck post-thawed semen. There was the highest percentages of sperms viability, motility, intact plasma membrane (IPM), the lowest of malondialdehyde (MDA) concentration, sperm DNA fragmentation (SDF), the total and types of ND1 mtDNA mutation frequency. The phylogenetic tree analysis revealed that the clade of the T2 group was most closely related to the sequence reference. However, there was no correlation between the semen quality parameters (sperm viability, motility, IPM, MDA concentration, and SDF) with ND1 mtDNA mutation of post-thawed Kacang buck semen. It could be concluded that GTE was useful as an antioxidant for Kacang buck semen extender for frozen sperm.

Green tea extract as a cryoprotectant additive to preserve the motility and DNA integrity of human spermatozoa

Cryopreservation impairs sperm quality and functions, including motility and DNA integrity. Antioxidant additives in sperm freezing media have previously brought improvements in postthawed sperm quality. Green tea extract (GTE) is widely considered as an excellent antioxidant, and its beneficial role has been proven in other human cells. This study aims to evaluate the GTE as a potential additive in cryopreservation media of human spermatozoa. In part one, the semen of 20 normozoospermic men was used to optimize the concentration of GTE that maintains sperm motility and DNA integrity against oxidative stress, induced by hydrogen peroxide (H2O2). Spermatozoa were treated with GTE at different concentrations before incubation with H2O2. In part two, the semen of 45 patients was cryopreserved with or without 1.0 ng ml-1 GTE. After 2 weeks, the semen was thawed, and the effect on sperm motility and DNA fragmentation was observed. Our data showed that GTE significantly protected sperm motility and DNA integrity against oxidative stress induced by H2O2when added at a final concentration of 1.0 ng ml-1. We found that the addition of 1.0 ng ml-1 GTE to cryopreservation media significantly increased sperm motility and DNA integrity (both P < 0.05). More interestingly, patients with high sperm DNA damage benefited similarly from the GTE supplementation. However, there was no significant change in the reactive oxygen species (ROS) level. In conclusion, supplementing sperm freezing media with GTE has a significant protective effect on human sperm motility and DNA integrity, which may be of clinical interest.

Protective effects of Tribulus terrestris and Cinnamomum zeylanicum extracts and trehalose added to diluents on goat epididymal sperm freezability

This study investigates the effect of adding Tribulus terrestris ethanol extract (TEE) and Cinnamomum zeylanicum ethanol extract (CEE) and trehalose on freezability of goat epididymal spermatozoa. In Experiment 1, the treatments consist of basic extender containing 25, 50 or 100 μg/ml of TEE or CEE. The control contained no additives. Experiment 2 was carried out to compare the effect of best concentrations resulted in the first experiment with 150 mM trehalose added to basic extender. The results of experiment 1 showed that supplementation of 50 μg/ml TEE and 50 μg/ml CEE increased significantly the percentages of motility, progressive motility and viability of cryopreserved spermatozoa, while the level of malondialdehyde concentration was decreased. Moreover, the 50 μg/ml TEE treatment indicate significantly) P < 0.05) the lowest DNA fragmentation among the other treatments. The data obtained from experiment 2 show that all treatments increased significantly) P < 0.05) the percentages of total motility, viability and membrane integrity, and concurrently decreased the rate of MDA compared to control. In addition, the rates of viability and progressive motility were significantly (P < 0.05) higher in diluents contained herb extracts and trehalose. Regarding DNA fragmentation, the results demonstrate that using the extracts and trehalose in diluents decreased the DNA damages and thereby improved the rate of intact sperm heads. In conclusion, the results of this study indicate that 50 μg/ml of Tribulus terrestris and Cinnamomum zeylanicum ethanolic extracts alone and plus trehalose improved the spermatozoa quality and could be used for cryopreservation.

Cellular and Functional Physiopathology of Bull Sperm With Altered Sperm Freezability

The objective of this study was to ascertain the cellular and functional parameters as well as ROS related changes in sperm from bulls with varied sperm freezability phenotypes. Using principal component analysis (PCA), the variables were reduced to two principal components, of which PC1 explained 48% of the variance, and PC2 explained 24% of the variance, and clustered animals into two distinct groups of good freezability (GF) and poor freezability (PF). In ROS associated pathophysiology, there were more dead superoxide anion positive (Dead SO+) sperm in GF bulls than those in PF (15.72 and 12.00%; P = 0.024), and that Dead SO+ and live hydrogen positive cells (live H₂O₂+) were positively correlated with freezability, respectively (R² = 0.55, P < 0.0130) and (r_s = 0.63, P = 0.0498). Related to sperm functional integrity, sperm from PF bulls had greater dead intact acrosome (DIAC) than those from GF bulls (26.29 and 16.10%; P = 0.028) whereas sperm from GF bulls tended to have greater live intact acrosome (LIAC) than those from PF bulls (64.47 and 50.05%; P = 0.084). Sperm with dead reacted acrosome (DRAC) in PF bulls were greater compared to those in GF (19.27 and 11.48%; P = 0.007). While DIAC (R² = 0.56, P = 0.0124) and DRAC (R² = 0.57, P < 0.0111) were negatively correlated with freezability phenotype, LIAC (R² = 0.36, P = 0.0628) was positively correlated. Protamine deficiency (PRM) was similar between sperm from GF and PF bulls (7.20 and 0.64%; P = 0.206) and (r_s = 0.70, P = 0.0251) was correlated with freezability. Sperm characteristics associated with cryotolerance are important for advancing both fundamental andrology and assisted reproductive technologies across mammals.

Does alpha-lipoic acid-loaded nanostructured lipid carriers improve post-thawed sperm quality and ameliorate apoptosis-related genes of rooster sperm?

Oxidative stress could be prevented by antioxidant-loaded nanoparticles. The purpose of this study was to assess the effects of 10 (A10), 20 (A20), 30 (A30), 40 (A40), and 50 (A50) μM alpha-lipoic acid and alpha-lipoic acid nanostructured lipid carriers (ALN) at 10 (ALN10), 20 (ALN20), 30 (ALN30), 40 (ALN40), and 50 (ALN50) μM on post-thawed sperm quality, fertility, and apoptosis-related genes of rooster sperm. The extender supplemented with ALN30 led to higher total and progressive motility, straight-line velocity, and linearity in comparison to the control group. The ALN30 resulted in higher percentage of mitochondria activity and glutathione peroxidase level compared with control (P < 0.05). The extender supplemented with ALN30 led to lower percentage of apoptotic sperm, when compared with the control. CASPASE 3 expression in ALN30 was lower (P < 0.05) than the other groups. The results showed that BCL-2 mRNA expression of sperm was significantly (P < 0.05) higher in ALN30 compared with the other groups (P < 0.05). Higher percentages of fertility and hatchability rates were observed in ALN30 group. The results indicate that ALN30 could be regarded as a novel potential cryoprotectant for the cryopreservation of rooster semen. Therefore, nanostructured lipid carriers improve not only the active compound (such as alpha-lipoic acid) of biomedical applicability but also the potential for industrial application in sperm cryopreservation.

Poloxamer 188 exerts a cryoprotective effect on rooster sperm and allows decreasing glycerol concentration in the freezing extender

Glycerol is the most widely used cryoprotectant for rooster sperm because it declines the mechanical damage to sperm during the freezing process. Despite its high molecular weight and viscosity, which may be cytotoxic, glycerol can cause damage to cells during the cryopreservation process, resulting in less fertility. Poloxamer 188 (P188) is an embryo cryopreservation supplement effective in many species and also for cell lines and plant cells. We tested the suitability of P188 in the cryopreservation of rooster sperm, considering post-thawing motility, abnormalities, membrane functionality (hypo-osmotic swelling test), mitochondrial activity, viability, apoptosis status, reactive oxygen species production, and ATP content after thawing and the fertility and hatchability after AI. We carried out a factorial experiment with glycerol concentrations of 2% glycerol (G2) and 8% glycerol (G8) and P188 concentrations of 0% (P0), 0.1% (P0.1), 0.5% (P0.5), and 1% (P1) as fixed effects, with replicate (seven) as a random effect. Interactions between glycerol and P188 were found, with G2P1 yielding higher quality and fertility. G8P0.5 yielded better in most parameters, however, not reaching G2P1. G2P1 showed significantly higher results for total and progressive motility, kinetic parameters (average path velocity, straight-line velocity, and linearity), membrane functionality, viability, mitochondrial activity, and ATP content and lower apoptosis, dead sperm, and reactive oxygen species production. G2P1 resulted in the highest percentages of fertilized and hatched eggs, with no effects in the hatched eggs ratio. Interestingly, G2 was less efficient in many parameters than G8 when combined with P0 and P0.1, being equivalent to G8 with P0.5 and superior to any G8 treatment as G2P1. In conclusion, P188 could improve rooster semen cryopreservation and allow reduction of glycerol in extenders, with a consequent impact in the poultry industry.

The role of environmental optimization for storing bulls' sperm cells

Artificial insemination has achieved a dynamic increase in genetic progress, and this is due to the improvement of sperm preservation technology. In recent years, a lot of attention has been paid to optimizing bull sperm storage environment and objectifying methods of sperm quality analysis. This review presents bull sperm preservation methods and ways to modify their storage environment. The main purpose of sperm preparation for artificial insemination is to obtain sperm with a high percentage of viable, motile sperm with normal morphology and low DNA fragmentation rates. Currently conducted experiments indicate the possibility of improving the quality of insemination doses produced using various components enriching common diluents. However, despite extensive research, no better results have been achieved than obtaining insemination doses with sperm viability that exceeds just over 60%. Obtaining a very good quality of frozen semen seems to be still unachievable today.

Ram semen preserved at 0°C with soybean lecithin Tris-based extender substituted for egg yolk

OBJECTIVE

The present study evaluated the preservation of ram semen at 0°C using soybean lecithin with a Tris-fructose extender.

METHODS

Semen was collected by artificial vagina ejaculation from six rams with proven fertility. High quality ejaculates were diluted by soybean lecithin (0.25%, 0.5%, 0.75%, 1.0%, 1.25%) using Tris-fructose extender and control (Tris-fructose egg yolk extender), respectively. The ejaculates were diluted to a concentration of 5×108 sperm/mL, followed by cooling to 0°C in 90 min and maintaining the temperature for 12 days. The diluted semen samples were examined and recorded for sperm progressive motility, acrosome integrity at 0, 24, 72, 144, 216, 288 h, respectively. Two hundred and twenty-three ewes were inseminated for 216 h with optimal soybean lecithin concentrated semen or control via trans-cervical insemination.

RESULTS

The results showed that there were no differences in sperm progressive motility at 0, 24, 72, and 144 h (p>0.05). After 216 h, the sperm progressive motility in the control group and 0.5% concentration groups was significantly higher when compared to 0.25% concentration (p<0.05). The 0.5% concentration group demonstrated the highest survival rate and had no difference with the control group (p>0.05). At 216 h, the sperm progressive motility of all groups was still above 50%. The acrosome integrity of all groups was decreased with prolongation of storage time, but there was no difference at each time point (p>0.05). There was no significant difference in the lambing rate and pregnancy rate between the 0.5% concentration group and the control group (p>0.05).

CONCLUSION

These results suggest that ram sperm is capable of fertilization after preservation at 0°C with 0.5% of soybean lecithin in Tris-based extender substituted for egg yolk and produce normal offspring after insemination.

Pre-freezing equilibration for 22 h improves post-thaw sperm functions in cryopreserved ram semen by reducing cholesterol efflux

Failure of cervical insemination with cryopreserved semen is hindering implementation of AI in sheep in field condition. Here the effect of equilibration time and catalase on post-thaw qualities of ram semen was investigated. Pooled semen was diluted (800 × 10⁶ sperm mL^-1) with a TES-Tris-fructose extender with 6% glycerol, 15% egg yolk and supplemented with 0, 50, 100 and 200 U mL^-1 catalase and packaged into 0.25 mL straws. In experiment 1, straws were equilibrated at 5 °C either for 3 h in a cold cabinet (E3) or for 10 (E10) and 22 h (E22) inside a refrigerator. In experiment 2, all straws were equilibrated for 22 h inside refrigerator. Straws were frozen at -25 °C min^-1 up to -125 °C using a cell freezer and finally plunged into liquid nitrogen. The post-thaw total and rapid motility were higher (P < 0.05) in E22 compared to E3 and E10. Sperm kinetics was comparable between E3 and E22, but lower in E10. Similarly, acrosome integrity, functional membrane integrity, percent high cholesterol (mCHO) and live-high mitochondrial membrane potential (MMP) were higher (P < 0.05) while live-high intracellular calcium and acrosome-reacted sperm were lower in E22 compared to E3 and E10. The percent rapid motile, high mCHO and live-high MMP were significantly (P < 0.05) lower in catalase-treated samples compared to the control, while the membrane integrity was comparable within the groups. In conclusion, pre-freezing equilibration for 22 h compared to 3 or 10 h resulted in higher post-thaw sperm functions while catalase had negative impact on cryopreservation of ram semen.

A review for physiological activities of EGCG and the role in improving fertility in humans/mammals

Epigallocatechin-3-gallate (EGCG) is a secondary metabolite in green tea, which has various physiological activities, including antioxidant, antitumor, and antiviral activities. Studies have shown that EGCG has a preventive effect on infertility by protecting germ cells and oocytes from damage. EGCG functions mainly through the regulation of ROS (reactive oxygen species) levels, which affect the expression of catalase (CAT), superoxide dismutase 1(SOD1), superoxide dismutase 2(SOD2), and glutathione peroxidase (GPx), has positive influence on other enzyme activities in germ cells and oocytes, and actively alters antioxidant activities. These enzymes above can inhibit the activation of extracellular signal-regulated proteins (Erk), induce apoptosis, and control the production of ROS in tissue cells. Here, we present a comprehensive overview of the mechanisms underlying the main physiological activities of EGCG, including antioxidant, antitumor, and antiviral activities, and their potential roles in male and female reproductive systems and fertility. This paper discusses the mechanisms by which EGCG retards the infertility of germ cells and oocytes and provides a supportive recommendation for improving fertility in humans and animals. We hope it will provide useful references for related research in mammalian reproduction.

Effect of quercetin loaded liposomes or nanostructured lipid carrier (NLC) on post-thawed sperm quality and fertility of rooster sperm

The aim of this study was to investigate the effects of 10, 15 and 20 μM quercetin, alone or loaded in nanoliposomes or in nanostructured lipid carrier (NLC) on sperm rooster cryopreservation and fertility performance. Sperm motility, viability, abnormalities, membrane integrity, mitochondrial activity, apoptosis status, lipid peroxidation (LP), GPX, SOD, TAC and fertility and hatchability rate were investigated after freeze-thawing. A significantly higher percentage (P < 0.05) of sperm total motility was obtained in sperm cryopreserved with 15 μM quercetin loaded NLC compared to diluent with 10 and 20 μM quercetin and to 10, 15 and 20 μM quercetin loaded nanoliposomes, 20 μM quercetin loaded NLC and control group. Also, 15 μM quercetin loaded NLC was significantly higher in progressive motility, VSL, VAP and VCL parameters compared to control group. The percentage of viability, membrane integrity, mitochondria activity, TAC, and GPx increased in semen exposed to 15 μM quercetin loaded NLC group. Likewise, the lowest level (P < 0.05) of malondialdehyde (MDA) was acquired in samples treated with 15 μM quercetin and quercetin loaded NLC group in comparison to the control group. Abnormal form, SOD, and early apoptosis were not (P > 0.05) affected by different levels of quercetin. Fertility and hatchability rate showed higher levels in 15 μM quercetin and quercetin loaded NLC group compared with control group. In conclusion, it seems that quercetin loaded NLC enhanced the antioxidant effect of quercetin by improving post-thawed sperm quality and fertility of rooster sperm.

Positive effect of natural antioxidant oregonin from Alnus incana bark on ram semen quality stored at 5 °C for 48 h

The maintenance of high vitality and motility of ram's spermatozoa during storage at low temperatures has a crucial role for successful fertilization. This study evaluates the effect of the natural antioxidant oregonin on ram semen quality, stored at 5 °C for 48 h. Еighteen ejaculates (three repetitions for 6 ejaculates) from three local breed rams, collecting by artificial vagina, with volume > 1 ml, concentration > 1 × 10⁹/ml and mass motility >3.5 were used for chilling. Each ejaculate was separated in two equal parts, diluted with Tris-glucose-glycerol-egg yolk extender with no oregonin or supplemented with 100μМ oregonin until adjustment of the sperm concentration to 200 × 10⁶ cells/ml and stored at 5 °C for 48 h. The semen quality assessment was based on the main kinematic (by CASA analysis), morphological parameters (by BrightVit kit staining) and mitochondrial status (by MitoView staining) of the spermatozoa on 0, 24 and 48 h of storage, and on in vivo fertility test. Oregonin did not impair the morphology and kept sustained motility of ram spermatozoa stored at 5 °C for 48 h. The curvilinear velocity indicated faster movement of the oregonin treated sperms that corresponded with high percent of spermatozoa with active mitochondria in these samples. The fertilizing capacity of spermatozoa was preserved and pregnancy rate in the experimental group was 80% versus 60% in control. In conclusion, this study provides a new data about positive effect of the natural antioxidant oregonin, supplemented to the extender, on chilled ram semen quality, including fertilizing ability.

Effect of green tea extract in extender of Simmental bull semen on pregnancy rate of recipients

OBJECTIVE

The aim of this study was to ascertain the effects of adding green tea extract (GTE) to skim milk-egg yolk (SM-EY) extender on both the quality of post-thawed bull semen and the pregnancy rates of the recipient cows.

METHODS

Twelve ejaculates from four Simmental bulls, aged 3 to 5 years and weighing 900 to 950 kg, were diluted SM-EY extender, added with 0, 0.05, 0.1, and 0.15 mg GTE/100 mL extender and then frozen. After four weeks storage in liquid nitrogen, the sperm were thawed and evaluated for viability, motility, intact plasma membrane (IPM), and DNA fragmentation. Meanwhile, the estrus cycles of 48 recipient cows were synchronized by intramuscular administration of a single injection of 5 mg prostaglandin F2α. Estrus cows were divided into four equal groups and inseminated artificially 18 to 20 h after the onset of estrus by using semen from each extender group. Pregnancy was diagnosed by measuring serum progesterone levels at 21 days, followed by transrectal palpation 90 days after insemination.

RESULTS

The findings revealed that adding 0.1 mg of GTE/100 mL extender produced the highest percentages of sperm viability (70.67%±1.75%), motility (69.17%±1.47%), and IPM (69.23%±1.21%) and the lowest percentage of DNA fragmentation (3.00%±0.50%). The pregnancy diagnosis revealed that all cows (36/36) inseminated using frozen semen in GTE addition extender were pregnant (pregnancy rate 100%), whereas the pregnancy rate of the control group was 83.33% (10/12).

CONCLUSION

It may be concluded that 0.1 mg GTE/100 mL extender yields the best quality of spermatozoa and that all variants doses of GTE in extender produce a higher pregnancy rate among recipient cows.

Supplementation of green tea extract (GTE) in extender improves structural and functional characteristics, total antioxidant capacity and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa

The aim of this study was to elucidate the beneficial effects of green tea extract (GTE) in tris citric acid extender on post thaw structural and functional characteristics, DNA fragmentation (%), total antioxidant capacity (TAC, μM/L), lipid peroxidation (LPO, μM/mL) levels and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa. GTE is a acknowledged natural antioxidant, act as a free radical scavenger and protects spermatozoa against oxidative stress. Three mature and donor buffalo bulls were used in this experiment. Two ejaculates were collected per bull on each collection day, followed by initial evaluation for consistency (colour), volume (mL), progressive motility and concentration (x10⁹) and were diluted in five extenders @ 50 x 10⁶/ mL (C = control, no GTE; T1 = treatment 1, GTE 0.1%; T2 = treatment 2, GTE 0.5%; T3 = treatment 3, GTE 0.75% and T4 = treatment 4, GTE1.0%). The experiment was repeated thrice. Data analysis showed that sperm progressive motility (%), plasma membrane integrity (%), supravital plasma membrane integrity (%), viable sperm with intact acrosome (%) and TAC were significantly higher (P < 0.05) in extender supplemented with T4 as compared to control. Furthermore, sperm DNA fragmentation and occurrance of LPO in buffalo bull spermatozoa were significantly lowered in T4 than control. In vitro longevity (%) of spermatozoa was significantly higher in T4 compared to control during 45 and 90 min of incubation at 37 °C. In vivo fertility rate of buffalo bull spermatozoa was significantly higher in T4 compared to control (64.96 vs. 48.40%, P < 0.05). It is concluded that supplementation of tris citric acid extender with 1.0% GTE improved structural and functional characteristics, TAC, in vitro longevity (%) and in vivo fertility, whereas decreased DNA fragmentation and LPO occurrence in buffalo bull spermatozoa after freezing and thawing protocol.

Does fennel extract ameliorate oxidative stress frozen-thawed ram sperm?

The aim of this study was to evaluate the quality of ram semen after cryopreservation with different levels of fennel (Foeniculum vulgare) extract (0 (F0), 5 (F5), 10 (F10) and 15 (F15) mg/L) and sperm concentrations (200 (C200) and 400 (C400) × 10⁶ sperm/mL) in a soy lecithin (SL)-based extender. Twenty ejaculates were collected from four ghezel rams and diluted with eight sperm concentrations/fennel combinations: F0C200, F5C200, F10C200, F15C200, F0C400, F5C400, F10C400 and F15C400. Sperm motility, abnormality, plasma membrane, viability, mitochondrial activity, lipid peroxidation (LPO), mitochondrial activity and apoptotic changes were evaluated after freeze-thawing process. It was observed that F10C400 significantly improved total and progressive motility, VSL, membrane integrity of post-thawed ram sperm. MDA level was lower in F5C200 and F10C400 compared to other treatments. The higher percentage of live sperm and the lower percentage of apoptotic sperm were obtained in F10C200 compared to F0C200, F5C200 F15C400, F0C400, F5C400 and F15C400. Extender F10C200 resulted in the highest mitochondria activity compared to the rest of the extenders except F10C400. We conclude that a combination of 10 mg/mL fennel (Foeniculum vulgare) extract and sperm concentration of 200 × 10⁶ sperm/mL can improve the ram semen quality cryopreserved in a soybean lecithin based extender.

Improvement of post-thawed sperm quality in broiler breeder roosters by ellagic acid-loaded liposomes

Liposomes could improve the delivery of substances to sperm. This study was conducted to investigate the effect of the antioxidant ellagic acid and ellagic acid-loaded liposomes on post-thawed sperm quality in broiler breeder roosters. Semen was diluted in Beltsville extender containing ellagic acid or ellagic acid-loaded liposomes (ellagic acid at 0 (control), 0.5, 1, and 2 mM) and cryopreserved. Sperm quality was evaluated post-thawing: motility characteristics (Computer-Assisted Semen Analysis), membrane functionality (HOS test), abnormal morphology, mitochondrial activity (Rhodamine 123), apoptotic status (Annexin V/Propidium iodide), malondialdehyde, and antioxidant activities (glutathione peroxidase (GPx), superoxide dismutase (SOD), and total antioxidant capacity (TAC)). The results showed that 1 mM ellagic acid-loaded liposomes improved total motility, membrane functionality, and viability comparing to 0.5 and 2 mM ellagic acid, 2 mM ellagic acid-loaded liposomes, and control group. Mitochondrial activity was significantly higher for 1 mM ellagic acid-loaded liposomes compared to the rest of the treatments, except 1 mM ellagic acid. Ellagic acid at 1 mM in both forms significantly increased GPx and TAC after freeze-thawing (no significant variation for SOD), and also yielded the lower proportion of apoptotic and dead cells. In conclusion, ellagic acid improved post-thawed sperm quality in broiler breeder roosters. The use of liposomes could further enhance the effects of ellagic acid.

Effect of different olive oil-derived antioxidants (hydroxytyrosol and 3,4-dihydroxyphenylglycol) on the quality of frozen-thawed ram sperm

The aim of the present study was to evaluate the effect of the addition of different concentrations of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during the freezing-thawing process. Sperm was collected, pooled and diluted with commercial extenders and then divided into aliquots supplemented with different concentrations (10 μg/ml, 30 μg/ml, 50 μg/ml and 70 μg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. A control group, without antioxidant, was also prepared. Sperm motility, viability, acrosome integrity, mitochondrial membrane potential and lipid peroxidation (LPO) were assessed. The results showed that frozen-thawed ram spermatozoa exhibited lower values for motility, membrane integrity, acrosome and mitochondrial membrane potential than fresh samples (P ≤ 0.01). However, when antioxidants were added, thawed spermatozoa exhibited relatively low LPO, recording values similar to fresh spermatozoa; by contrast, the control group of frozen-thawed spermatozoa without antioxidants exhibited significantly higher LPO (P ≤ 0.01). The addition of a HT+DHPG mixture (MIX) had a negative impact on sperm membrane and acrosome integrity, suggesting that a pure antioxidant supplementation has the potential to offer superior results. In conclusion, HT and DHPG exhibited a positive effect on the frozen-thawed spermatozoa inasmuch as they reduced the LPO. These olive oil-derived antioxidants have the potential to improve frozen-thawed sperm quality, although further studies should be carried out to analyse the antioxidant effect at different times after thawing.

Effect of egg yolk plasma and soybean lecithin on rooster frozen-thawed sperm quality and fertility

This experiment was conducted to study the effects of egg yolk plasma (10%, 15% and 20%), soybean lecithin (0.5%, 1% and 1.5%) and whole egg yolk (WEY) (control) on post-thawed sperm quality, hatchability and fertility outcomes. In experiment 1, sperm motility, abnormalities, membrane integrity, viability, apoptosis status, mitochondrial activity were studied following freeze-thawing. The best quality of frozen-thawed rooster sperm was chosen to be used for the assessment of the hatchability and fertility rate in experiment 2. The significantly higher percentages of post-thawing sperm total and progressive sperm motilities, membrane integrity, viability were observed in 1% soybean lecithin and 20% egg yolk plasma in comparison with 0.5 and 1% soybean lecithin, 10% egg yolk plasma and control, except for 15% egg yolk plasma (P < 0.05). Using 20% egg yolk plasma in the extender improved mitochondrial activity. Supplementation of 1% soybean lecithin and 20% egg yolk plasma into the extender resulted in the least percentages of dead sperm (P < 0.05). Sperm abnormalities and early apoptosis did not differ in various extender supplementations. In experiment 2, higher percentages of hatchability and fertility rate were observed in semen containing 1% soybean lecithin and 20% egg yolk plasma compared with the WEY group. The results showed that supplementation of the rooster sperm extender with 1% soybean lecithin and 20% egg yolk plasma resulted in higher quality of frozen-thawed sperm.

Effect of lecithin nanoliposome or soybean lecithin supplemented by pomegranate extract on post-thaw flow cytometric, microscopic and oxidative parameters in ram semen

This investigation was carried out to study the effect of soybean lecithin 1.5% (wt/vol) (0, 2.5, 5 and 7.5 mg l-1 pomegranate extract (PE)) or PE-loaded lecithin nanoliposome (0, 2.5, 5 and 7.5 mg l-1) to Tris-based extender. Sperm motility (CASA), viability, membrane integrity (HOS test), abnormalities, mitochondrial activity, apoptosis status, lipid peroxidation, total antioxidant capacity (TAC)) and antioxidant activities (GPX, SOD) were investigated following freeze-thawing. No significant differences were detected in motility parameters, viability, membrane integrity, and mitochondria activity after thawing sperm between soybean lecithin and lecithin nanoliposomes. It was shown that PE5 significantly improved sperm total and progressive motility, membrane integrity, viability, mitochondria activity, TAC and reduced lipid peroxidation (malondialdehyde concentration). Moreover, the percentage of apoptotic sperm in PE5 extenders was significantly the lowest among other treatments. Sperm abnormalities, SOD and GPX were not affected by the antioxidant supplements. For apoptotic status, no differences were observed between soybean lecithin and lecithin nanoliposome. We showed that lecithin nanoliposome extender can be a beneficial alternative extender to protect ram sperm during cryopreservation without any adverse effects. It was also observed that regarding pomegranate concentration, PE5 can improve the quality of ram semen after thawing.