Influence of lycopene and cysteamine on sperm and oxidative stress parameters during liquid storage of ram semen at 5°C

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

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

Physicochemical properties, mechanism of action of lycopene and its application in poultry and ruminant production

Lycopene is a kind of natural carotenoid that could achieve antioxidant, anti-cancer, lipid-lowering and immune-improving effects by up-regulating or down-regulating genes related to antioxidant, anti-cancer, lipid-lowering and immunity. Furthermore, lycopene is natural, pollution-free, and has no toxic side effects. The application of lycopene in animal production has shown that it could improve livestock production performance, slaughter performance, immunity, antioxidant capacity, intestinal health, and meat quality. Therefore, lycopene as a new type of feed additive, has broader application prospects in many antibiotic-forbidden environments. This article serves as a reference for the use of lycopene as a health feed additive in animal production by going over its physical and chemical characteristics, antioxidant, lipid-lowering, anti-cancer, and application in animal production.

Effects of different extenders, storage temperatures, and antioxidant supplementation on chilled semen quality: a review

The successful preservation of ram semen is essential to promote genetic variability, ensure semen transportation, and inseminate multiple ewes. Currently, either animal or plant-based lipoprotein-based extenders are used for semen preservation. Animal product-based extenders include milk and egg yolk, while soybean lecithin is a plant-based extender. Although extenders containing products of animal origin better preserve the quality of chilled semen, the in vivo efficacy after 24 h of storage is still of great concern. Storage temperature is another important and effective factor in preserving sperm quality, whereby different storage temperatures are adopted to enhance the storage life of sperm. Low temperatures (4-5 °C) better preserve sperm quality for a longer duration than high temperatures (15, 20, and 25 °C). Moreover, antioxidant supplementation has a positive impact on sperm quality during liquid storage. The current review summarizes the outcomes of various extenders, different storage temperatures, and antioxidant supplementation on the liquid storage of ram sperm.

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.

Lycopene improves testicular damage and sperm quality in experimentally induced varicocele: Relationship with apoptosis, hypoxia, and hyperthermia

Varicocele is considered the main reason for male infertility. Antioxidants are common drugs used to reduce the complications of varicocele in these patients. So, we investigated the effects of lycopene on sperm quality, testicular histology, and the expression of some genes in experimentally induced varicocele. Fifty adult male Wistar rats were divided into three groups: control (n = 12), sham (n = 5), and varicocele (n = 33) groups. After 2 months of induced varicocele, five rats were randomly sacrificed and induced varicocele was investigated in each group. Finally, 35 rats were divided into five groups: the control, varicocele, varicocele reserving solvent, and varicocele reserving lycopene (4 and 10 mg/kg) for 2 months. At the end of the experiment, sperm viability, membrane integrity, the expression of Bax, Bcl2, hypoxia (hypoxia‐inducible factor 1α [HIF1‐α]), heat‐shock protein (heat‐shock protein A2 [HSPA2]) genes, and the histology of testes were measured. The results showed a significant decrease in the sperm viability, membrane integrity, Johnson's score, and the expression of the Bcl2 gene in the varicocele group compared to the control group. Also, there was a significant increase in Bax, HSPA2, and HIF1‐α expressions in the varicocele group compared to the control group. Although the administration of lycopene (10 mg/kg) in rats with varicocele improved sperm viability and membrane integrity, Johnson's score, and Bax expression compared to the varicocele group. Our findings indicated that the administration of lycopene in the varicocele group improved sperm quality and testicular injury induced by varicocele via decreasing apoptosis.

Potential Use of Tannin Extracts as Additives in Semen Destined for Cryopreservation: A Review

Cryopreservation and storage of semen for artificial insemination (AI) result in excessive accumulation of reactive oxygen species (ROS). This leads to a shortened life span and reduced motility of spermatozoa post-thawing, with consequent impairment of their function. However, certain levels of ROS are essential to facilitate the capacitation of spermatozoa required for successful fertilisation. Tannins, as well-known antioxidant compounds, may act as ROS binders/acceptors/scavengers to inhibit the damaging effects of ROS. This review comprises an analysis of the semen cryopreservation protocol and health functions of tannins, as well as the effects of ROS on fresh and cryopreserved semen's longevity and fertilisation. Additionally, we surveyed available evidence of the effects of tannin extract feed supplementation on male fertility. We furthermore interrogated existing theories on tannin use as a potential additive to semen extenders, its relationship with semen quality, and to what degree existing theories have been investigated to develop testable new hypotheses. Emphasis was placed on the effects of tannins on ROS, their involvement in regulating sperm structure and function during cryopreservation, and on post-thaw sperm motility, capacitation, and fertilising ability. The diverse effects of tannins on the reproductive system as a result of their potential metal ion chelation, protein precipitation, and biological antioxidant abilities have been identified. The current data are the first to support the further investigation of the incorporation of tannin-rich plant extracts into semen extenders to enhance the post-thaw survival, motility, and fertilising ability of cryopreserved spermatozoa.

Factors Affecting the Survival of Ram Spermatozoa during Liquid Storage and Options for Improvement

Semen preservation is an essential component of reproductive technologies, as it promotes genetic gain and long-distance semen transport and multiplies the number of ewes able to be inseminated per single ejaculate. However, the reduced temperature during cold storage at 5 or 15 °C inflicts sub-lethal damage to spermatozoa, compromising sperm quality and the success of artificial breeding. New and emerging research in various species has reported the advantages of storing spermatozoa at higher temperatures, such as 23 °C; however, this topic has not been thoroughly investigated for ram spermatozoa. Despite the success of storing spermatozoa at 23 °C, sperm quality can be compromised by the damaging effects of lipid peroxidation, more commonly when metabolism is left unaltered during 23 °C storage. Additionally, given the biosafety concern surrounding the international transport of egg-yolk-containing extenders, further investigation is critical to assess the preservation ability of synthetic extenders and whether pro-survival factors could be supplemented to maximise sperm survival during storage at 23 °C.

Cysteamine enhances quality and fertility potential of rooster semen in cooled storage

This study investigated the effects of supplementing Lake extender with cysteamine (CYS) on rooster semen quality in cold storage and it's fertility performance. Semen samples were diluted with Lake extender supplemented with different concentrations of CYS (0, 1, 2, 4 and 8 mM) and were cooled and stored at 5 °C for a period of 46 h. Motility, membrane functionality, viability, lipid peroxidation, and mitochondria membrane potential were evaluated at 0, 23 and 46 h of storage. Fertility was assessed at 23 h of storage. Although at the beginning time (0 h), parameters were not affected, 1 mM of CYS improved (P ≤ 0.05) total motility, progressive motility and mitochondria membrane potential during 23 and 46 h storage. Moreover, 1 and 2 mM CYS improved (P ≤ 0.05) membrane functionality and viability compared to other groups. Lipid peroxidation was lower (P ≤ 0.05) in samples diluted with 1 and 2 mM CYS compared to the others. Artificial insemination with 23-hrs cooled-stored semen produced the higher (P ≤ 0.05) fertility rate in groups received 1 and 2 mM CYS compared to the control group. In conclusion, addition of 1 and 2 mM CYS to the extender could be helpful to protect rooster semen against structural and functional damages of cooling storage process.

Attenuative Role of Idebenone on Deltamethrin Mediated Peroxidative Toxicity of Ram Semen Stored at 4°C

The current study was conducted to evaluate the different concentrations of deltamethrin (DEL; Exp. 1) and the protective role of idebenone (IDB) supplemented with toxic dose of deltamethrin (Exp. 2) during chilled storage of ram semen. Collected samples were pooled and diluted at 500×106 spermatozoa per mL. In Exp. 1, effect of DEL at 1, 2.5, 5, 10, 20, 40, 80 μM levels was evaluated on different variables of spermatozoa motion characteristics. In Exp. 2, different amounts of IDB (2, 4, and 8 μM) concurrent with constant doses of DEL (10 μM) were examined on semen quality upon chilled preservation up to 72 h. Indices of spermatozoa kinematics, functionality of plasma membrane and viability were recorded. Biochemical metabolites were measured in spermatozoa and its medium (extender) at different time points. In Exp. 1, different parameters of spermatozoa kinematics were affected by exposure to DEL in a dose dependent manner. In Exp. 2, combination of IDB with DEL resulted in a significant (P<0.05) increase in total motility, forward progressive motility and curvilinear path velocity compared to DEL group at 24, 48 and 72 h. Simultaneous administration of IDB with DEL increased the percentage of spermatozoa with functional membrane and viability compared to DEL group at 72 h (P<0.05). The amounts of lipid peroxidation index were lower in medium of combination groups compared to DEL group at 48 h and 72 h (P<0.05). Antioxidant capacity was higher in spermatozoa and medium of IDB treated groups compared to DEL group at 72 h (P<0.05). Amounts of total nitrate-nitrite and superoxide dismutase activity of spermatozoa and medium were not affected by treatment (P>0.05). In conclusion, IDB could ameliorate oxidative and peroxidative damages induced by DEL mild toxicity upon cold preservation of ram semen.

The effects of varying concentrations of glutathione and trehalose in improving microscopic and oxidative stress parameters in Turkey semen during liquid storage at 5 °C

Since turkey reproduction is mainly through artificial insemination, short-term preservation of turkey semen is one of the most important issues in turkey reproduction management. The present study investigates the effects of glutathione (GSH) and trehalose on lipid peroxidation degree and turkey semen quality while being stored at 5 °C for 72 h. To this end, semen samples were collected from 20 turkeys with a weekly frequency for 12 weeks. A glucose-based extender was used to dilute the pooled semen. It was divided into seven equal parts with varying levels of glutathione [0.5, 1 and 2 mM), trehalose [50, 75 and 100] and control [extender without antioxidant]. Subsequently, the divided semen samples were stored at 5 °C for 72 h. Several sperm parameters such as motility and motion parameters, plasma membrane integrity (PMI), plasma membrane functionality, DNA integrity, and oxidative parameters were assessed following storage for 0, 24, 48, and 72 h. The obtained results indicated an improvement in the plasma membrane functionality and DNA integrity, along with the percentages of PMI in GSH-2 mM group in comparison to the control group following storage at 5 °C for 72 h (P ≤ 0.05). It is also notable that the 2 and 1 mM concentrations of GSH increased the spermatozoa motility and motion parameters in comparison to the control group, respectively (P ≤ 0.05). The study results indicated that GSH-2, 1 mM and trehalose- 100 mM concentrations reduced lipid peroxidase levels and increased total antioxidant activity, catalase, superoxide dismutase, and glutathione peroxidase in comparison to the control group (P ≤ 0.05). Our study's data show that improvement of semen parameters and oxidative stress parameters of turkey semen can be improved by glutathione at 2 and 1 mM and trehalose at 75 mM while storing it 5 °C.

Effect of crocin and naringenin supplementation in cryopreservation medium on post-thaw rooster sperm quality and expression of apoptosis associated genes

The aim of our study was to examine the effects of crocin (0.5 (C0.5), 1 (C1) and 1.5 (C1.5) mM) and naringenin (50 (N50), 100 (N100) and 150 (N150) μM) in cryopreservation extender for freezing rooster semen. Sperm motility, viability, abnormalities, membrane functionality, active mitochondria, apoptosis status, lipid peroxidation (LP), GPX, SOD, TAC, the mRNA expression of pro-apoptotic (CASPASE 3) and anti-apoptotic (Bcl-2) genes, fertile eggs, hatched eggs and hatching rate were investigated following freeze-thawing. C1 and N100 resulted in higher (P < 0.05) total motility and progressive motility in comparison to the control group. The C1 and N100 groups improved viability, membrane functionality and reduced lipid peroxidation. We found higher values for active mitochondria with C1 and N100 compared to control group. The C1 and N100 groups showed lower percentages of early apoptosis when compared with control group. Also, C1 and N100 had higher TAC, compared to the control group. The mRNA expressions of BCL-2 in the C1 and N100 groups were significantly higher than that of other treatments. The expression of CASPASES 3 was significantly reduced in C1 and N100 group (P < 0.05) when compared to control group. Significantly higher percentages of fertile eggs, hatched eggs and hatching rate were observed in C1 and N100 compared to the control group. In conclusion, crocin at 1 mM and naringenin at 100 μM seem to improve the post-thawing rooster semen quality, fertility and could protect the sperm by reducing the pro-apoptotic (CASPASE 3) and increasing anti-apoptotic (Bcl-2) genes.

Identification of the Nrf2 in the fathead minnow muscle cell line: role for a regulation in response to H2O2 induced the oxidative stress in fish cell

The Nrf2 (nuclear factor erythroid 2-related factor 2) plays a central role in cell protection against a wide variety of environmental stressors through the Nrf2-Keap1 (Kelch-like ECH-associated protein 1) pathway, but its involvement in modulation of antioxidant system of fish cell is still largely unexplored. The present study focused on the molecular cloning and silencing of the Nrf2 in the fathead minnow muscle cell line (FHM) in response to the oxidative stress induced by H₂O₂. A full-length cDNA of coding Nrf2 was cloned from FHM cells by RT-PCR and RACE approaches. The obtained cDNA covered 2578 bp with an open reading frame (1770 bp) of encoding 589 amino acids. Sequence alignment and phylogenetic analysis revealed a high degree of conservation (51-86%) among 16 fishes. Based on the cloned Nrf2 sequence, the siRNA-242 of targeting Nrf2 with the best knocking down efficiency was designed and detected. Then, the mRNA levels of Keap1, Nrf2, Maf (musculoaponeurotic fibrosarcoma oncogene), and HO-1 (haemoxygenase-1); the activities of T-SOD (total superoxide dismutase), CAT (catalase), and GSH-PX (glutathione peroxidase); the levels of GSH (glutathione) and MDA (malonaldehyde); and the cell cycle and apoptosis were analyzed to investigate the molecular responses after H₂O₂ exposure. These results showed a coordinated transcriptional regulation of Keap1, Maf, and HO-1 and antioxidants (T-SOD, GSH, CAT, and GSH-PX) and MDA levels after H₂O₂ exposure, leading to oxidative damage and apoptosis. These findings provided an insight to understand the mechanisms of Nrf2 against oxidative stress in fish.

Effect of different concentrations of resveratrol on the quality and in vitro fertilizing ability of ram semen stored at 5 °C for up to 168 h

The aim of the study was to investigate the effects of different concentrations of resveratrol on head morphology, motility characteristics, oxidative state and in vitro fertility of cooled ram spermatozoa. Pooled semen from three Najdi rams was diluted with Triladyl® having different concentrations of resveratrol, zero (control), 200 μM (45.65 μg/mL) and 400 μM (91.30 μg/mL) resveratrol, then stored at 5 °C for 168 h. The head morphometric, sperm kinematic parameters, Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and in vitro fertilizing capability of ram spermatozoa were evaluated after 24, 72, 120 and 168 h of cooling storage. The total motility (TM) of the sperm with resveratrol at 200 μM and 400 μM was significantly (p ≤ 0.05) higher than that in the control group at 72 and 120 h of cooling storage. On the other hand, the progressive motility (PM) of the sperm with resveratrol at 200 μM and 400 μM was significantly (p ≤ 0.05) higher than that in the control group at 168 h of cooling storage period. After 168 h of cooling storage, significantly higher straightness (STR) was observed in 400 μM group than two other groups and in 200 μM group than the control group. Both resveratrol groups had higher linearity (LIN) than control one at 120 and 168 h of cooling storage. The length, width and area of sperm head were lower (P ≤ 0.05) in the control compared to the other treatment groups after 120 and 168 h of storage. There was a significant increase in superoxide dismutase (SOD) concentration in the two resveratrol groups compared with the control one over the seven days of cooling storage and the same result was found in the reduced glutathione (GSH) concentration at 24, 72, and 168 h of storage. There was a significant (p ≤ 0.05) decrease in malondialdehyde (MDA) concentration in the 400 μM resveratrol group than that in two other groups over the seven days of storage period. Cleavage and blastocyst rates following in vitro fertilization were significantly higher (p ≤ 0.05) in 400 μM resveratrol than other groups at 72 h for cooling storage period. In conclusion, addition of resveratrol in the extender can protect sperm head morphology, improve kinematic parameters and in vitro fertility, and reduce oxidative stress of ram spermatozoa during liquid storage at 5 °C.

Different concentrations of cysteamine, ergothioneine, and serine modulate quality and fertilizing ability of cryopreserved chicken sperm

The aim of this study was to evaluate the effects of freezing diluents supplemented in three potential amines/amino acids, namely, antioxidant cysteamine (2-aminoethanethiol [AET]), ergothioneine (ERG), and serine (SER), in optimization of chicken sperm cryopreservation. The semen of 36 Pradu Hang Dum males, selected based on their motility vigor score, was frozen by a simple freezing method using nitrogen vapors and dimethylformamide (DMF). In a first experiment, a wide range of AET, ERG, and SER doses were tested. Semen quality was evaluated after incubation at 5°C or after cryopreservation in straws in the Blumberger Hahnen Sperma Verdünner (BHSV) diluent + DMF (6% v/v) with or without AET, ERG, or SER. The best targeted doses of AET, ERG, or SER were then selected for experiment 2 that was focused on cryopreserved semen. Frozen-thawed sperm quality was evaluated by different in vitro tests and by evaluation of fertility. Objective motility parameters were evaluated by computer-assisted sperm analysis. Membrane integrity, acrosome integrity, and mitochondria function were evaluated using appropriate dyes and flow cytometry. Lipid peroxide production was assessed by the thiobarbituric acid test (malondialdehyde production). Fertility obtained with frozen-thawed semen supplemented or not in AET, ERG, or SER was evaluated after artificial insemination of laying hens. ERG and AET decreased sperm lipid peroxidation and decreased fertility, even at low doses. The presence of 4 mmol of SER significantly decreased lipid peroxidation, increased the frozen-thawed sperm quality, and increased fertility after sperm cryopreservation (90% vs. control 84%, P < 0.05). In a third experiment, the use of 1 mmol of sucrose (the best result of our previous study) added to 4 mmol of SER-supplemented extender was tested. This addition allowed to the highest levels of fertility (93%). In conclusion, the addition of 4 mmol of SER in semen cryopreservation diluents decreases peroxidation and improves the efficiency of the process.