Effects of hypotaurine, cysteamine and aminoacids solution on post-thaw microscopic and oxidative stress parameters of Angora goat semen

The Effects of Different Doses of ROCK Inhibitor, Antifreeze Protein III, and Boron Added to Semen Extender on Semen Freezeability of Ankara Bucks

In the presented study, the effects of ROCK inhibitor Y-27632, antifreeze protein III, and boron at two different doses were investigated on the spermatological parameters of Ankara buck semen after freeze−thawing. Ejaculates were collected from bucks using an electroejaculator during the breeding season. The ejaculates that showed appropriate characteristics were pooled and used in the dilution and freezing of semen. The extender groups were formed by adding two different doses of three different additives (ROCK inhibitor Y-27632, 5 and 20 µM; antifreeze protein III, 1 and 4 µg/mL; boron, 0.25 and 1 mM) to the control extender. The semen was diluted with the different extenders at 35−37 °C and loaded into straws. Sperm samples frozen in liquid nitrogen vapors, following equilibration, were stored in liquid nitrogen. It was observed that extender supplementation improved post-thaw motility of Ankara buck semen after freeze−thawing. Differences were significant (p < 0.01) for 5 and 10 µM doses of ROCK inhibitor (71.82% and 74.04 % motility), as well as for 0.25 and 1 mM doses of boron (76.36% and 72.08% motility), compared to the control group (66.15% motility). With respect to the evaluation of acrosomal integrity and mitochondrial activity after freeze−thawing, although supplementation provided protection at all doses, the efficacy was not statistically significant (p > 0.05). It was observed that DNA damage was improved by antifreeze protein III at 1 µg/mL (1.23% ± 0.23%) and by boron at all doses (0.25 mM: 1.83% and 1 mM: 1.18%) compared to the control group (3.37%) (p < 0.01), following the thawing process. In the present study, it was determined that some additives added to the extender provided significant improvements in buck spermatozoa motility and DNA damage after thawing.

Chlorogenic Acid Improves Quality of Chilled Ram Sperm by Mitigating Oxidative Stress

Simple Summary

Sheep sperm is extremely sensitive to reactive oxygen species (ROS) and can produce a large amount of ROS during chilling storage, leading to a decline in semen quality. Adding antioxidants is an important method to improve semen quality. Chlorogenic acid (CGA) is a kind of plant extract with an antioxidant capacity, which can effectively eliminate free radicals and improve the antioxidant capacity of semen. However, its role in the chilling storage of Hu ram semen is not clear. Therefore, CGA with different concentrations was added to chilling storage extender to investigate its effect on chilled ram sperm. The results of this study revealed that CGA with proper concentration had a positive effect on chilled Hu ram sperm and 0.8 mg/mL CGA had the best effect.

Abstract

The purpose of this study was to investigate whether the addition of chlorogenic acid (CGA) to a sheep semen extender could improve the quality of chilled sheep sperm. Ejaculates (n = 80) were collected from five Hu rams with an artificial vagina. The ejaculates were mixed and divided into five equal parts, diluted with a CGA-free Tris–egg yolk extender (control), or supplemented with 0.2, 0.4, 0.8, and 1.2 mg/mL. The sperm kinematic parameters (viability, progressive motility), functional integrity of plasma membrane and acrosome, adenosine triphosphate (ATP) concentration and antioxidant parameters (Catalase (CAT), Superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC), ROS level and Malondialdehyde (MDA) content) were evaluated during storage of the semen. The results indicated that: PM, plasmatic membrane integrity and acrosomal integrity in 0.8 mg/mL CGA were higher (p < 0.05) from day 1 to 5. The ROS level in CGA groups was lower than the control (p < 0.05). CAT, SOD, ATP, and T-AOC were highest at 0.8 mg/mL concentration within 1 to 5 days. The above results indicated that the right concentration of CGA improved the quality of Hu ram sperm during chilling storage.

Fertility in Cystinosis

Cystinosis is a rare inheritable lysosomal storage disorder characterized by cystine accumulation throughout the body, chronic kidney disease necessitating renal replacement therapy mostly during adolescence, and multiple extra-renal complications. The majority of male cystinosis patients are infertile due to azoospermia, in contrast to female patients who are fertile. Over recent decades, the fertility status of male patients has evolved from a primary hypogonadism in the era before the systematic treatment with cysteamine to azoospermia in the majority of cysteamine-treated infantile cystinosis patients. In this review, we provide a state-of-the-art overview on the available clinical, histopathological, animal, and in vitro data. We summarize current insights on both cystinosis males and females, and their clinical implications including the potential effect of cysteamine on fertility. In addition, we identify the remaining challenges and areas for future research.

Effects of Taurine on Sperm Quality during Room Temperature Storage in Hu Sheep

Simple Summary

Hu sheep sperm is highly susceptible to ROS during storage at room temperature. It is very important to use an antioxidant to ameliorate oxidative damage. Tau is an important amino acid peptide antioxidant with a wide range of biological effects. It can effectively scavenge free radicals, regulate reproductive function, improve immunity, and enhance its antioxidant capacity. However, the effects of Tau in the preservation of Hu sheep semen at room temperature are unclear. Therefore, Tau was added to Hu sheep semen preserved at room temperature to explore its effect on semen. The results showed that adding an appropriate concentration of Tau had a positive effect on Hu sheep semen preserved at room temperature; in particular, 20 mM Tau performed best.

Abstract

The present study aimed to investigate whether the presence of Tau protected Hu sheep sperm from ROS stress during storage at room temperature. The semen was diluted with extender (Tris-based) at room temperature, supplemented with different concentrations of Tau (0, 10, 20, 40, 80, or 100 mM), and stored at 15 °C. Sperm quality parameters (sperm progressive motility, kinetic parameters, plasma membrane integrity rate, acrosome integrity rate, and MMP) and antioxidant parameters (ROS, MDA, SOD, CAT, and T-AOC) were evaluated during the preservation of semen. The addition of Tau, especially at a concentration of 20 mM, exerted positive effects on sperm quality parameters and antioxidant parameters compared to the sperm without Tau treatment (control group). The addition of Tau, especially at a concentration of 100 mM, exerted negative effects on sperm quality parameters and antioxidant parameters compared to the control group. Interestingly, the results indicated that the sperm acrosome integrity rate did not change during storage time. In conclusion, the addition of Tau to sperm preserved at room temperature can enhance the antioxidant ability of sperm, reduce the LPO on the 5th day, and improve the quality of semen preserved at room temperature. These results implied that Tau had potential to enhance Hu sheep sperm reproductive performance.

Personalized Metabolic Analysis of Diseases

The metabolic wiring of patient cells is altered drastically in many diseases, including cancer. Understanding the nature of such changes may pave the way for new therapeutic opportunities as well as the development of personalized treatment strategies for patients. In this paper, we propose an algorithm called Metabolitics, which allows systems-level analysis of changes in the biochemical network of cells in disease states. It enables the study of a disease at both reaction- and pathway-level granularities for a detailed and summarized view of disease etiology. Metabolitics employs flux variability analysis with a dynamically built objective function based on biofluid metabolomics measurements in a personalized manner. Moreover, Metabolitics builds supervised classification models to discriminate between patients and healthy subjects based on the computed metabolic network changes. The use of Metabolitics is demonstrated for three distinct diseases, namely, breast cancer, Crohn's disease, and colorectal cancer. Our results show that the constructed supervised learning models successfully differentiate patients from healthy individuals by an average f1-score of 88 percent. Besides, in addition to the confirmation of previously reported breast cancer-associated pathways, we discovered that Biotin Metabolism along with Arginine and Proline Metabolism is subject to a significant increase in flux capacity, which have not been reported before.

Determination of oxidative stress parameters and DNA fragmentation on post-thawed buck semen in the presence of ram seminal plasma and fetal calf serum

The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.

Evaluation of pentoxifylline and Basal Medium Eagle supplemented to diluent on cryopreserved goat spermatozoa

This study investigated the effect of pentoxifylline (PTX) and Basal Medium Eagle (BME) on frozen-thawed goat spermatozoa. Immediately after initial examination of ejaculated semen, samples were pooled and reexamined for quality. Then, samples were divided into eight equal aliquots and diluted with a basic tris-extender containing PTX (3, 6, 9 mM) and BME (5 mM) to reach a final concentration of 25 × 10⁹ and frozen. After 24 hr, the samples were individually thawed at 37°C for 30 s and evaluated for different characteristics. Obtained post-thaw results from Computer-Assisted Sperm Analysis indicate using of 3 and 6 mM PTX led significantly to an improvement in total motility, progressive motility and velocity characteristics of spermatozoa, except the beat/cross frequency (BCF) which indicated statistically no differences (p > .05) among control and treatments. Diluents prepared with BME (5 mM) and PTX alone (3 and 6 mM) improved significantly the membrane integrity-functionality, acrosome integrity and also hyaluronidase activity. Regarding recovery rate, the results showed significantly (p < .05) higher values for diluents containing 3 and 6 mM PTX compared to other groups. Malondialdehyde concentration exhibited also a significant difference (p < .05) in diluents supplemented with 5 mM BME, 3, 6 and 9 mM PTX, and mixture of 3 mM PTX and 5 mM BME which illustrate a similarity for active mitochondria, apoptotic-like and dead spermatozoa. Finally, the ratio of sperm chromatin dispersion stained spermatozoa presented significant differences (p < .05) among treatments in which the diluents added PTX alone demonstrated significantly lower values than control and extenders containing the mixtures of BME and PTX. In conclusion, the observation in this study indicates using of 3 and 6 mM PTX and BME alone may improve significantly (p < .05) the quality of cryopreserved goat spermatozoa.

Supplementation of freezing media with alpha lipoic acid preserves the structural and functional characteristics of sperm against cryodamage in infertile men with asthenoteratozoospermia

The aim of this study was to examine the effects of alpha lipoic acid (ALA) supplementation during semen cryopreservation on the sperm quality, chromatin integrity, oxidative stress, and expression level of BAX, BCL2, HSP70 and iNOS genes in semen samples obtained from infertile men with asthenoteratozoospermia.

METHODS

Twenty freshly ejaculated semen samples were cryopreserved with sperm freezing medium supplemented with 0.00, 0.02, 0.05, 0.1, 0.5, and 1 mmol/mL of ALA. The samples were analyzed according to the WHO guidelines before and after freezing. Sperm ROS production level, DNA fragmentation and cryo-capacitation were assessed using flow cytometry, TUNEL assay and chlortetracycline (CTC) test, respectively. Expression level of stress protein (HSP70), pro-apoptotic Bax, anti-apoptotic Bcl-2, and iNOS genes was assessed by real-time PCR assay.

RESULTS

The effective concentrations of ALA (0.02 and 0.5 mM) significantly improved the motility, viability and morphology of the frozen-thawed sperms compared to the control group treated with 0.00 mM of ALA. During cryopreservation, treatment of semen with 0.02 mM of ALA, as the optimal concentration, significantly decreased DNA fragmentation and oxidative stress level (P < 0.05), protected the acrosome integrity, and led to insignificant reduction in BAX gene expression level and significant increase in expression level of BCL2, HSP70, and iNOS genes compared with control group.

CONCLUSION

Our findings revealed that the adding ALA to semen samples obtained from infertile men with asthenoteratozoospermia plays a significant protective role against cryodamage by preserving the sperm functional parameters.

Application of metabolomics in the diagnosis of breast cancer: a systematic review

Breast cancer (BC) remains the most frequent type of cancer in females worldwide. However, the pathogenesis of BC is still under the cloud, along with the huge challenge of early diagnosis, which is widely acknowledged as the key to a successful therapy. Metabolomics, a newborn innovative technique in recent years, has demonstrated great potential in cancer-related researches. The aim of this review is to look back on clinical and cellular metabolomic studies in the diagnosis of BC over the past decade, and provide a systematic summary of metabolic biomarkers and pathways related to BC diagnosis.

Improvements in morphology and membrane stability obtained from TPP-TAB, a cryopreservation medium treated infertile smoker sperm cells - An in vitro study

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As a first time upto 6 months the sperm cells were stored with new medium from green formulation.

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TPP-TAB of E4 medium reduces ROS damage.

Background

Plants are the major sources of antioxidants, which maintains oxidant: antioxidant state or is to protect from excessive reactive oxygen species in case of cryo medium selection though maintain sperm stability.

Bottleneck

Cryo preservation of infertile smokers is challengeable with the available medium due to over production of ROS hitches, were cause loss of sperm physiology. Hence, a novel medium is needed to store/protect sperm cells of infertile smokers where they attending/ongoing IVF or oncogenic surgical treatment.

Aim

The aim of this study, is to check the stability of sperm cells by TPP-T.arjuna bark (TAB) (E4) cryo medium preserved infertile smoker’s against ROS/cryo injury- as a continuous study.

Materials and methods

42 infertile smoker’s subjects with 28 control subjects were selected. Surface morphology (acrosome) of sperm by scanning electronic microscope, sperm membrane proteins by colorimetric method, sperm head and tail defects by CASA method and finally sperm cell stability is checking its zeta electric potential charges, were all done with E4 cryo medium treated frozen/thawed selected study subjects.

Results

Sperm morphology and zeta potential shows there is no damage along the stability of cells maintained during E4 medium cryopreservation in infertile subjects.

Summary

This is the first study is too established for infertile smokers sperm stability was checked for six months with E4 cryo medium.

Hypotaurine Is a Substrate of GABA Transporter Family Members GAT2/Slc6a13 and TAUT/Slc6a6

Hypotaurine is a precursor of taurine and a physiological antioxidant that circulates in adult and fetal plasma. The purpose of the present study was to clarify whether hypotaurine is a substrate of Slc6a/gamma-aminobutyric acid (GABA) transporter family members. Radiolabeled hypotaurine was synthesized from radiolabeled cysteamine and 2-aminoethanethiol dioxygenase. The uptakes of [³H]GABA, [³H]taurine, and [¹⁴C]hypotaurine by HEK293 cells expressing mouse GAT1/Slc6a1, TAUT/Slc6a6, GAT3/Slc6a11, BGT1/Slc6a12, and GAT2/Slc6a13 were measured. TAUT and GAT2 showed strong [¹⁴C]hypotaurine uptake activity, while BGT1 showed moderate activity, and GAT1 and GAT3 showed slight but significant activity. Mouse TAUT and GAT2 both showed Michaelis constants of 11 µM for hypotaurine uptake. GAT2-expressing cells pretreated with hypotaurine showed resistance to H₂O₂-induced oxidative stress. These results suggest that under physiological conditions, TAUT and GAT2 would be major contributors to hypotaurine transfer across the plasma membrane, and that uptake of hypotaurine via GAT2 contributes to the cellular resistance to oxidative stress.

Protective Effect of Colla corii asini against Lung Injuries Induced by Intratracheal Instillation of Artificial Fine Particles in Rats

Environmental issues pose huge threats to public health, particularly the damage caused by fine particulate matter (PM_2.5). However, the mechanisms of injury require further investigation and medical materials that can protect the lungs from PM_2.5 are needed. We have found that Colla corii asini, a traditional Chinese medicine that has long been used to treat various ailments, is a good candidate to serve this purpose. To understand the mechanisms of PM_2.5-induced lung toxicity and the protective effects of Colla corii asini, we established a rat model of lung injury via intratracheal instillation of artificial PM_2.5 (aPM_2.5). Our results demonstrated that Colla corii asini significantly protected against lung function decline and pathologic changes. Inflammation was ameliorated by suppression of Arg-1 to adjust the disturbed metabolic pathways induced by aPM_2.5, such as arginine and nitrogen metabolism and aminoacyl-tRNA biosynthesis, for 11 weeks. Our work found that metabolomics was a useful tool that contributed to further understanding of PM_2.5-induced respiratory system damage and provided useful information for further pharmacological research on Colla corii asini, which may be valuable for therapeutic intervention.

Influence of Ellagic Acid and Ebselen on Sperm and Oxidative Stress Parameters during Liquid Preservation of Ram Semen

Objective

The purpose of the present study was to assess the effects of ellagic acid and ebselen on sperm and oxidative stress parameters during liquid preservation of ram semen.

Materials and Methods

In this experimental study, sixty ejaculates from six mature Merino rams were used. In experiment 1, the ejaculates were diluted in base extender contained ellagic acid at 0 (control), 0.5, 1, and 2 mM. In experiment 2, ebselen at 0 (control), 10, 20, and 40 μM were added to the extender. Sperm motility, viability, mitochondrial membrane potential, DNA integrity, lipid peroxidation (LPO), the antioxidant potential (AOP), and total glutathione (tGSH) were evaluated at 0, 24, 48, and 72 hours of preservation.

Results

Supplementation of ellagic acid at 1 and 2 mM resulted in higher sperm motility and viability at 0 hours of storage. Ellagic acid at 2 mM led to higher motility and viability compared to controls after 0, 24, and 48 hours of preservation and increased AOP after 24 and 72 hours. Higher tGSH was at 1 mM ellagic acid, compared to control after 72 hours. Addition of ebselen at a concentration of 40 μM increased motility at 24 and 48 hours and 10 μM produced the same effect after 48 and 72 hours of storage as well as higher viability, compared to the controls after 0 hours of storage. Sperm DNA integrity was significantly improved after 24, 48, and 72 hours with the addition of ebselen at 10 μM, and after 72 hours at 40 μM. Addition of 40 mM ebselen also reduced the LPO levels after 24 hours of storage compared to the controls.

Conclusion

The results showed that supplementation of ellagic acid and ebselen in semen extender has a potential effect on sperm and oxidative stress parameters during liquid preservation of ram semen.

Effect of sunflower lecithin on Kalahari Red goat semen during cryopreservation

Soybean lecithin had been used as an alternative to egg yolk in domestic animal semen extender during cryopreservation due to its characteristic phospholipid content which played a major cryoprotective role. This composition of soybean lecithin informed the replacement of soybean with sunflower lecithin (SL) in the extender for the Kalahari Red (KR) buck semen cryopreservation in this study. Effect of different levels of SL on the quality of the KR buck semen during cryopreservation using slow freezing method was evaluated. Semen samples were collected from four KR bucks of between two and two and half of age using artificial vagina, evaluated for motility and then diluted in extenders containing different levels of SL (1.5%, 3.0% and 4.5%) as experimental group and 0% SL or 20% egg yolk as control. Semen parameters including motility, acrosome integrity (AcI), membrane integrity (MI), malondialdehyde (MDA) concentration, cholesterol level and seminal arginase activity were evaluated for. The results showed that motility, acrosome integrity (AI) and membrane integrity were comparable at 0%, (22.00 ± 4.58, 82.00 ± 3.51 and 96.00 ± 2.03); 1.5%, (23.00 ± 2.08, 87.00 ± 3.79 and 89.00 ± 2.08); 3.0%, (13.00 ± 2.52, 81.33 ± 0.41 and 76.67 ± 1.20) and 4.5% (11.00 ± 4.51, 85.33 ± 9.88 and 84.00 ± 8.50), respectively, after thawing. SL at 0% had the highest (P < 0.05) values for MDA, cholesterol and seminal arginase activity (1.10 ± 0.008 nmol/ml, 236.35 ± 4.08 mg/dl and 0.54 ± 3.3 E-3 units/mg protein, respectively). Our data suggest that 1.5% sunflower lecithin can be used in place of soy lecithin as a substitute for egg yolk during the cryopreservation of caprine semen.

ÁCIDO ASCÓRBICO NO DILUIDOR PARA CRIOPRESERVAÇÃO DE SÊMEN CAPRINO

Resumo Objetivou-se determinar o efeito e o melhor nível de inclusão de ácido ascórbico em meio diluidor TRIS-Gema para criopreservação de sêmen caprino. Foram utilizados cinco ejaculados de três bodes da raça Anglo Nubiana. Cada ejaculado foi dividido em quatro alíquotas de 200 µL, compondo quatro tratamentos: um sem adição de ácido ascórbico (controle) e os demais com 0,0528; 0,1056 e 0,1584mg/mL de ácido ascórbico no diluidor TRIS-Gema. Avaliaram-se motilidade espermática progressiva e vigor espermático pós-diluição, pós-resfriamento e pós-descongelamento; integridade de membrana (HOST); integridade acrossomal e teste de termorresistência lento (TTR). Os dados foram submetidos à Análise de Regressão a 5% de probabilidade. Não houve diferença para motilidade progressiva e para vigor espermático, repectivamente, na pós-diluição; pós-resfriamento e pós-descongelamento, assim como para os testes complementares HOST e após 120 minutos do TTR, para motilidade e vigor, no pós-descongelamento (P>0,05). Houve comportamento quadrático com a inclusão do ácido ascórbico para integridade acrossomal (61,58%), com nível ótimo de 0,1006mg/mL de ácido ascórbico (P<0,05). A inclusão de 0,1006mg/mL de ácido ascórbico no diluidor TRIS-Gema melhorou a integridade acrossomal durante o processo de criopreservação, podendo ser uma alternativa na composição dos diluidores seminais caprinos.

The Effect of L-Carnitine, Hypotaurine, and Taurine Supplementation on the Quality of Cryopreserved Chicken Semen

The objective of this study was to investigate the effect of L-carnitine (LC), hypotaurine (HT), and taurine (T) on the quality of frozen-thawed chicken semen. Pooled semen samples were divided into seven aliquots (control, 1 mM LC, 5 mM LC, 1 mM HT, 10 mM HT, 1 mM T, and 10 mM T) and subjected to cryopreservation. Postthaw sperm motility was determined by IVOS system and sperm characteristics were assessed with fluorochromes and flow cytometry. The highest sperm motility and the highest percentage of viable sperm were in the HT1 group (P < 0.01 and P < 0.05) following cryopreservation. After thawing, we observed a higher percentage of sperm without apoptosis and membrane reorganization changes in the LC1 and T1 group when compared to the control (P < 0.05). There was a higher percentage of live sperm without lipid peroxidation (LPO) in all treatments (P < 0.01; P < 0.05), when compared to the control group. The percentage of sperm with high mitochondrial potential significantly increased with LC1, T1, and T10 (P < 0.05). Supplementation of the diluent with LC1, LC5, and T1 significantly (P < 0.05) reduced DNA susceptibility to fragmentation, compared to the control and HT1 groups. These results indicate that the addition of examined antioxidants improves the quality of cryopreserved chicken semen.

Novel personalized pathway-based metabolomics models reveal key metabolic pathways for breast cancer diagnosis

Background

More accurate diagnostic methods are pressingly needed to diagnose breast cancer, the most common malignant cancer in women worldwide. Blood-based metabolomics is a promising diagnostic method for breast cancer. However, many metabolic biomarkers are difficult to replicate among studies.

Methods

We propose that higher-order functional representation of metabolomics data, such as pathway-based metabolomic features, can be used as robust biomarkers for breast cancer. Towards this, we have developed a new computational method that uses personalized pathway dysregulation scores for disease diagnosis. We applied this method to predict breast cancer occurrence, in combination with correlation feature selection (CFS) and classification methods.

Results

The resulting all-stage and early-stage diagnosis models are highly accurate in two sets of testing blood samples, with average AUCs (Area Under the Curve, a receiver operating characteristic curve) of 0.968 and 0.934, sensitivities of 0.946 and 0.954, and specificities of 0.934 and 0.918. These two metabolomics-based pathway models are further validated by RNA-Seq-based TCGA (The Cancer Genome Atlas) breast cancer data, with AUCs of 0.995 and 0.993. Moreover, important metabolic pathways, such as taurine and hypotaurine metabolism and the alanine, aspartate, and glutamate pathway, are revealed as critical biological pathways for early diagnosis of breast cancer.

Conclusions

We have successfully developed a new type of pathway-based model to study metabolomics data for disease diagnosis. Applying this method to blood-based breast cancer metabolomics data, we have discovered crucial metabolic pathway signatures for breast cancer diagnosis, especially early diagnosis. Further, this modeling approach may be generalized to other omics data types for disease diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-016-0289-9) contains supplementary material, which is available to authorized users.

In vitro assessment of soybean lecithin and egg yolk based diluents for cryopreservation of goat semen

Soybean lecithin is a suitable plant-based cryoprotectant for freezing ruminant sperm. Optimum level of lecithin was not clear for goat semen cryopreservation. The objective of this study was to investigate the effects of different levels of soybean lecithin in semen extender on post-thaw sperm quality including CASA-motion parameters, viability, plasma membrane integrity and lipid peroxidation. Semen samples were collected from 4 Mahabadi bucks using an artificial vagina. Different concentrations of soy lecithin (SL, 0.5%, 1%, 1.5%, 2% and 2.5% w/v) were compared to 15% (v/v) egg yolk-based extender (TR-EY). No significant difference was observed for sperm progressive motility, viability or plasma membrane integrity in 1.5% SL media (33.8%, 66%, and 62.7%, respectively) and TR-EY medium (35.4%, 67.2%, and 64.9%, respectively). Sperm motion characteristics (VAP, VSL, VCL, ALH and LIN) and rapid spermatozoa were improved with extender containing 1% and 1.5% SL, compared to TR-EY extender. Furthermore, egg yolk produced significantly higher malondialdehyde (4.02±0.21) than other groups. Results suggest that the optimal lecithin concentration in the semen extender was 1.5% and also soy lecithin can substitute for egg yolk during cryopreservation for caprine sperm.

Effect of two sulfur-containing amino acids, taurine and hypotaurine in European sea bass (Dicentrarchus labrax) sperm cryopreservation

In the present work, taurine and hypotaurine were evaluated as potential additives to improve European sea bass (Dicentrarchus labrax) sperm quality after cryopreservation. For cryopreservation, three different extenders were used: control extender (NAM), supplemented with 1mM taurine or supplemented with 1mM hypotaurine, all of them containing 10% Me₂SO as cryoprotectant. To evaluate sperm quality of fresh and thawed sperm, motility (CASA: computer assisted sperm analysis), viability (SYBR Green/propidium iodide), lipid peroxidation (malondialdehyde level), protein oxidation (carbonyl content), glutathione peroxidase, glutathione reductase and superoxide dismutase activities and DNA fragmentation (comet assay) were quantified. The result demonstrated that 1 mM hypotaurine supplemented extender increased total motility (30.1 ± 3.2%), and that 1 mM taurine extender produced higher velocity (18.1 ± 2.6 μm/s) and linearity (46.0 ± 4.8%) than the control extender (21.8 ± 3.2%, 15.5 ± 1.3 μm/s, 41.8 ± 2.4%, respectively). Cell viability, lipid peroxidation and protein oxidation were not statistically different between treatments. Similar results were obtained for glutathione peroxidase and superoxide dismutase activities. Only glutathione reductase showed differential activity before and after freezing, increasing its activity in thawed sperm. Regarding the comet assay results, taurine and hypotaurine significantly reduced DNA fragmentation (52.8 ± 0.9% and 51.8 ± 0.9%, respectively) in comparison to the control (55.7 ± 0.8%). In conclusion, for European sea bass sperm cryopreservation, extenders supplemented with 1 mM taurine and 1 mM hypotaurine improved some parameters of sperm quality after thawing, resulting in better motility and lower DNA damage than the control, two very important factors related to fertilization success.