Cryopreservation of ram semen: baicalein efficiency on oxidative stress, chromatin integrity, viability and motility post thaw.

Baicalein (B) has potential antioxidant properties, but it has not been tested as a ram semen extender. This study aimed to assess the impact of B on various sperm parameters and determine its potential influence on semen quality after the freeze-thawing process. During the breeding season, ejaculates were obtained from four rams with the aid of an artificial vagina. The collected mixed semen samples were divided into four groups: control (C; 0), B0.5 (0.5 mM), B1 (1 mM), and B2 (2 mM). After semen extension, the samples were loaded into 0.25 mL straws and stored for 2 h at 4°C prior to freezing in liquid nitrogen vapor and thawed in a water bath at 37°C. Among the groups, B0.5 demonstrated the highest progressive motility results, while B1 and B2 exhibited reduced motility (p < 0.05). In terms of high mitochondrial membrane potential, plasma membrane and acrosome integrity, and viability, B0.5 showed significantly superior outcomes to the other B groups (p < 0.05), although it was not significantly better than C. B1 displayed the highest plasma membrane integrity levels (p < 0.05). Notably, B2 displayed the lowest total antioxidant status levels among the groups (p < 0.05). The findings of this study suggested that the in vitro spermatological characteristics of ram spermatozoa such as progressive motility and chromatin integrity can be protected from the freeze-thawing process by using the 0.5 mM dose of baicalein as a semen extender. The treatment of sperm freezing might benefit from further in-depth research on the role of B in the improvement of cryoinjury and its underlying processes.

Reduction of cryopreservation-induced structural, functional and molecular damages in ram sperm by hydrated C60 fullerene.

This study aimed to investigate the morphological, functional and molecular changes in frozen-thawed ram sperm using an extender containing different concentrations of hydrated carbon 60 fullerene (C60 HyFn), a nanotechnological product. Semen taken from each of the seven Akkaraman rams were pooled. Semen collection was done twice a week and it continued for 3 weeks. Each pooled semen sample was divided into six equal groups and diluted with tris + egg yolk extender including 0 (control), 200, 400, 800 nM, 1 and 5 µM concentrations of C60 HyFn at 37°C. They were then frozen in liquid nitrogen vapour at -140°C, stored in liquid nitrogen container (-196°C) and thawed at 37°C for 25 s before analysis. In comparison with control, C60 HyFn addition prior to freezing procedure provided significant increases in total and progressive motility rates, glutathione peroxidase, catalase activities and percentage of highly active mitochondria, and significant decreases in dead and abnormal sperm rates, lipid peroxidation, caspase-3 and DNA fragmentation levels in frozen-thawed ram semen. When compared to control, C60 HyFn supplementation significantly down-regulated the expression levels of miR-200a and KCNJ11, and significantly up-regulated the expression levels of miR-3958-3p (at the concentrations of 200, 400, 800 nM and 1 µM), CatSper1 (at the concentrations of 200, 400 nM and 5 µM), CatSper2 (at the concentrations of 1 and 5 µM), CatSper3 (at the concentrations of 200, 400 nM, 1 and 5 µM), CatSper4 (at all concentrations), ANO1 (at the concentrations of 800 nM, 1 and 5 µM) and TRPV5 (at the concentrations of 200, 400 and 800 nM). The addition of C60 HyFn had no effect on global DNA methylation rates. As a result, C60 HyFn supplementation to ram semen extenders may be beneficial in reducing some of the functional, structural and molecular damages in sperm induced by the freeze-thawing procedure.

Investigation of the effects of syringic acid supplemented to Tris semen diluent on ram semen freezability.

To the best of our knowledge, no research has been conducted to test the effects of syringic acid (SA) on ram semen freezing within the scope of natural antioxidants added to semen extenders. Therefore, this study had two main objectives. First, to test whether adding SA to ram semen freezing extender has a protective effect and contributes positively to sperm kinetic, plasma and acrosome integrity, mitochondrial membrane potential, lipid peroxidation, oxidant and antioxidant and DNA damage parameters after thawing. Second, it was to determine at what concentration the SA supplemented to the extender could be applied by in vitro studies by preserving the fertilization ability of frozen semen at the highest level. In the study, six individuals of Sönmez rams were used. The semen was collected from the rams using an artificial vagina and pooled. The pooled semen was divided into five different groups and extended with 0, 0.5, 1, 2 and 4 mM SA (control C, SA0.5, SA1, SA2 and SA4, respectively). After dilution, the semen samples were kept at 4°C for 3 h, then loaded into 0.25 mL straws and frozen in liquid nitrogen vapour. The SA1 and SA2 groups were higher plasma membrane and acrosome integrity (PMAI), high mitochondrial membrane potential (HMMP), plasma membrane integrity and motility compared to other groups (p < .05). It was observed that SA supplemented to the Tris extender significantly reduced DNA damage, and the lowest values were obtained especially in the SA1 and SA2 treatments (p < .05). Also, lowest MDA level was determined at the SA1 and this was statistically significant compared to SA4 and C (p < .05). In conclusion, it was revealed that SA added to Tris semen extender at 1 and 2 mM treatment doses increased progressive and total motility and preserved PMAI, plasma membrane integrity, HMMP and DNA integrity.

Investigation of Changes in Spermatozoon Characteristics, Chromatin Structure, and Antioxidant/Oxidant Parameters after Freeze-Thawing of Hesperidin (Vitamin P) Doses Added to Ram Semen.

We conducted this study to determine the potential cryopreservative effects of different hesperidin (vitamin P; H) doses on ram semen after freeze-thawing. Semen samples were obtained from Sönmez rams using an artificial vagina. The samples were divided into six groups: control, 10, 50, 100, 250, and 500 µg/mL H (C, H10, H50, H100, H250, and H500, respectively). At the end of the study, sperm motility and kinetic parameters, acrosome integrity (AI), mitochondrial membrane potential (MMP), viability, lipid peroxidation levels (LPL), chromatin damage, oxidant parameters, and antioxidant parameters were assayed. None of the doses of H added to the semen extender showed any enhancing effects on progressive motility compared to C (p > 0.05). In fact, H500 had negative effects (p < 0.05). Moreover, AI was the highest at the H10 dose, while LPL values were the lowest at the same dose (p < 0.05). The doses of H10 and H50 added to the Tris extender medium showed positive effects on sperm cell chromatin damage. Consequently, we can say that H doses used in this study are not effective on semen progressive motility, but the H10 dose is effective on AI and chromatin damage by reducing LPL.

Thymoquinone improves motility, plasma membrane integrity and DNA integrity of frozen-thawed ram semen.

The aim of this study was to determine the effects of thymoquinone (TQ), which is the most essential active compound of Nigella sativa, on the spermatological parameters of ram semen during cryopreservation. Ejaculates were collected from five Sonmez rams using an artificial vagina and extended with Tris-based extender not containing TQ (control, 0 µg/ml TQ) and containing 10, 25, 50 and 100 µg/ml TQ. The extended semen samples were equilibrated in a + 4°C cold cabinet for 2 h. After 2 h, the samples were loaded into 0.25 ml French straws. The straws were frozen by liquid nitrogen vapour and stored in a liquid nitrogen container (-196°C). The frozen straws were thawed in a water bath (37°C for 30 s) and evaluated in terms of motility characteristics, plasma membrane and acrosome integrity, mitochondrial reactive oxygen species levels, lipid peroxidation levels, DNA damage and biochemical alterations (oxidative stress index, malondialdehyde and glutathione). TQ100 had higher total motility (53.59 ± 3.01) and progressive motility (19.84 ± 1.44; not significantly different from TQ25 and TQ50) compared to the control and TQ10 (p Ë‚ 0.05). According to the results of the analyses on motility characteristics, there were significant differences between the groups in terms of curvilinear velocity (VCL), amplitude of lateral head displacement (ALH) and linearity (LIN; p Ë‚ 0.05). The highest DNA damage was detected in the control group (p Ë‚ 0.05). TQ50 had higher plasma membrane and acrosome integrity (59.56 ± 5.92) compared to the control and TQ25 (p < 0.05) but not significantly different from TQ10 and TQ100. The lowest mitochondrial reactive oxygen species levels were detected in TQ50 and TQ100 (p Ë‚ 0.05). There were no significant differences among the groups in terms of their oxidative stress index, lipid peroxidation, malondialdehyde and glutathione levels (p > 0.05). According to the results, it could be concluded that supplementing 50 or 100 µg/ml TQ to Tris extenders that were used for ram semen cryopreservation showed a positive effect on motility, plasma membrane integrity and acrosome integrity, and it reduced DNA damage and mitochondrial reactive oxygen species levels.

Protective role of the dried white mulberry extract on the reproductive damage and fertility in rats treated with carmustine.

The present study investigated the protective effect of dried white Mulberry extract (DWME) against carmustine (Crm) induced biochemical alterations and spermatological, histopathological, and fertility damage in Wistar albino rats. Male rats were divided into four groups (control, Crm, Crm + DWME, and DWME group). It was found that Crm decreased the motility. Crm decreased the concentration (not different from control group) compared to DWME groups. Total blood MDA levels were reduced during the recovery period. Also, the recovery period reduced the MDA levels in the Crm group/testicular tissue. The GSH levels in the Crm + DWME group were the highest among all groups in the testicular tissue/experiment period. In the immunohistochemical evaluation of the testicular tissue, a high level of caspase-3 was observed in the cells that underwent meiosis in the Crm group. The most pronounced DNA damage was also detected in the Crm group. The Crm + DWME group showed the highest number of offspring born during recovery period. In conclusion, dried white mulberry extract protects against the spermatological damages caused by carmustine. Moreover, recovery period played a positive effect on spermatological parameters and fertility.

Red pine (Pinus brutia Ten) bark tree extract preserves sperm quality by reducing oxidative stress and preventing chromatin damage.

This study aimed to investigate the effectiveness of using red pine bark tree extract (P; Pinus brutia Ten) as a TRIS extender in an attempt to prevent oxidative stress in bull spermatozoa after freezing. Semen specimens were obtained from Simmental bulls via an artificial vagina and pooled. They were separated into five specimens and diluted with Tris extender consisting of P (200, 100, 50 and 25 µg/ml) and P free (control; C) up to a final concentration of 16 × 106 per straw. All specimens were equilibrated for a period of 4 hr at a temperature of 4°C, following which they were filled in 0.25-ml French straws and frozen. Addition of P resulted in favourable tail length in comparison with C (p < .05). The lowest malondialdehyde levels and the highest glutathione levels were detected in all P groups (p < .05). Supplementation with P did not show advanced results in terms of total, progressive sperm motility and total abnormality in comparison with C (p > .05). In conclusion, it has been shown that although P added to a Tris extender does not have a positive effect on sperm motility, it prevents chromatin damage by reducing oxidative stress, in addition to reducing head abnormalities when used at the amount of 50 µg/ml.

The effect of cysteine and glutathione on sperm and oxidative stress parameters of post-thawed bull semen.

The aim of this study was to determine the effects of antioxidants such as reduced glutathione (GSH) and cysteine in Laiciphose® extender on semen parameters, fertilizing ability, lipid peroxidation (LPO) level and glutathione peroxidise (GPx) activity of post-thawed bull semen. Totally 54 ejaculates of three bulls were used in the study. Five groups, namely; GSH (0.5 and 2 mM), cysteine (5 and 10 mM) and control group, were conducted to test the antioxidants in Laiciphose®. Insemination doses were processed that each 0.25-mL straw contained 15 x 106 sperm. The addition of antioxidants did not present any significant effect on the percentages of post-thaw sperm morphology (acrosome and total abnormalities), subjective, CASA and progressive motilities, as well as sperm motility characteristics (VAP, VSL, VCL, LIN and ALH), compared to the control groups (P > 0.05). GSH 0.5mM (55.5±7.38%) and cysteine 10 mM (48±5.65%) led to lower rates of DNA damage, compared to control (P < 0.05). As regards to MDA level, cysteine at 10 mM dose gave the highest level (4.99±0.44 nmol/L) (P < 0.001). GPx activity was demonstrated to be higher level upon the addition of 5 mM cysteine when compared to the other groups (P < 0.05). With respect to fertility results based on 60-day non-returns, the supplementation of antioxidants did not present significant differences (P > 0.05). The results of this study may provide an useful information for the future studies in this area. So, further studies could be suggested to achieve better information in terms of the DNA damage and fertilizing capacity of bull sperm frozen with effective antioxidants.

The effect of raffinose and methionine on frozen/thawed Angora buck (Capra hircus ancryrensis) semen quality, lipid peroxidation and antioxidant enzyme activities.

The aim of the present study was to determine the effects of different doses of raffinose and methionine on post-thawed semen quality, lipid peroxidation and antioxidant enzyme activities of Angora buck (Capra hircus ancryrensis) sperm following cryopreservation. Ejaculates collected from three Angora bucks were evaluated and pooled at 37 degrees C. Semen samples, which were diluted with a Tris-based extender containing the additives raffinose (2.5, 5, 10mM) and methionine (2.5, 5, 10mM) and an extender containing no antioxidants (control), were cooled to 5 degrees C and frozen in 0.25 ml French straws. Frozen straws were thawed individually at 37 degrees C for 20s in a water bath for evaluation. The freezing extender supplemented with 2.5 and 5mM methionine led to higher percentages of CASA motility (63.6+/-7.0; 63.4+/-3.1%, respectively), in comparison to the controls (P<0.01) following the freeze-thawing process. The addition of antioxidants did not provide any significant effect on the percentages of post-thaw subjective and CASA progressive motilities as well as sperm motion characteristics (VSL and VCL), compared to the control groups (P>0.05). The freezing extender with raffinose (5 and 10mM) and methionine at three different doses (2.5, 5 and 10mM) led to lower percentages of acrosome abnormalities, in comparison to the controls (P<0.001). In the comet test, raffinose (5 and 10mM) and methionine (10mM) gave scores lower than those of the controls, and thereby reduced DNA damage (P<0.05). Malondialdehyde formation was found to be lower (1.8+/-0.1 nmol/L) in the group of 5mM raffinose, compared to the controls following the freeze-thawing process (P<0.01). The additives did not show any effectiveness on the maintenance of SOD, GSH-PX and GSH activities, when compared to the controls (P>0.05). In conclusion, methionine and raffinose play a cryoprotective role against sperm CASA motility, acrosome abnormality and DNA damage. Raffinose 5mM exhibited antioxidative properties, decreasing MDA levels. Further studies are required to obtain more concrete results on the characterization of microscopic parameters and antioxidant activities in cryopreserved goat sperm with different additives.