The effect of low-level laser irradiation on sperm motility, and integrity of the plasma membrane and acrosome in cryopreserved bovine sperm

Effects of melatonin on sperm quality, enzyme activity, antioxidant gene expression and fertility of cryopreserved bovine semen

Melatonin (MLT) has strong antioxidant capacity and can reduce the damage caused by oxidative stress in sperm, but there is still little content in the field we have studied. In this study, we are committed to scientific research on adding melatonin to Belgian blue bull semen diluent for cryopreservation. Different concentrations (0, 0.1, 0.3, 0.5 or 0.7 mg/mL) of MLT were added diluent. Sperm kinetic parameters, enzyme activity, antioxidant gene expression and fertility were analyzed after thawing. The results showed that MLT concentration of 0.3 mg/mL exerted positive effects on post-thaw kinetic parameters. Compared with other groups, 0.3 mg/mL MLT treated sperm acrosome and plasma membrane integrity, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels significantly increased. Meanwhile, the mRNA expression of antioxidant genes SOD2, CAT and GPx increased in the 0.3 mg/mL MLT treatment group, and the mRNA expression of apoptosis genes Caspase-3 and Bax were significantly reduced. In addition, in vitro fertilization (IVF) embryo cleavage, blastocyst rate and artificial insemination (AI) pregnancy rate were higher in 0.3 mg/mL MLT. Therefore, MLT showed cryoprotective capacity to the freezing diluent used for Belgian blue bull sperm during the process of freezing-thawing, and the optimal concentration of MLT for the frozen diluent was 0.3 mg/mL.

β-Nicotinamide mononucleotide improves chilled ram sperm quality in vitro by reducing oxidative stress damage

OBJECTIVE

The present study aimed to investigate the effect of β-nicotinamide mononucleotide (NMN) supplementation on ram sperm quality during storage at 4°C in vitro.

METHODS

Tris-citric acid-glucose solution containing different doses of NMN (0, 30, 60, 90, and 120 μM) was used to dilute semen collected from rams and it was stored at 4°C. Sperm motility, plasma membrane integrity as well as acrosome integrity were evaluated at 0, 24, and 48 h time points after storage at 4°C. In addition, sperm mitochondrial activity, lipid peroxidation (LPO), malondialdehyde (MDA) content, reactive oxygen species (ROS) content, glutathione (GSH) content, superoxide dismutase (SOD) activity, and apoptosis were measured at 48 h time point after storage at 4°C.

RESULTS

Results demonstrate that the values obtained for sperm motility, acrosome integrity, and plasma membrane integrity in the NMN treatments were significantly higher than control (p<0.05). The addition of 60 μM NMN significantly improved ram sperm mitochondrial activity and reduced LPO, MDA content, and ROS content compared to control (p<0.05). Interestingly, sperm GSH content and SOD activity for the 60 μM NMN treatment were much higher than those observed for control. NMN treatment also decreased the level of Cleaved-Caspase 3, Cleaved-Caspase 9, and Bax while increasing Bcl-2 level in sperm at 48 h time point after storage at 4°C.

CONCLUSION

Ram sperm quality can be maintained during storage at 4°C with the addition of NMN at 60 μM to the semen extender. NMN also reduces oxidative stress and apoptosis. Overall, these findings suggest that NMN is efficient in improving the viability of ram sperm during storage at 4°C in vitro.

The effects of photobiomodulation on the improvement of sperm parameters: A review study

The prevalence of male infertility has become a significant clinical concern worldwide, with a noticeable upward trend in recent times. The rates of fertilization and subsequent development of embryos are dependent on many parameters associated with the quality and viability of sperm. Photobiomodulation (PBM) is a promising approach with a great potential for translational applications in the treatment of spermatozoa exhibiting low quality and motility. In this study, a comprehensive analysis of the existing literature, specifically examining the mechanisms of action of PBM has been presented. Our objective was to enhance knowledge in the field of laser light therapy in order to promote the usage of irradiation in clinical settings in a more effective way. Within the realm of reproductive science, the utilization of PBM has been employed to enhance the metabolic processes, motility, and viability of spermatozoa. This is attributed to its advantageous effects on mitochondria, resulting in the activation of the mitochondrial respiratory chain and subsequent synthesis of ATP. This therapeutic approach can be highly advantageous in circumventing the reliance on chemical substances within the culture medium for spermatozoa while also facilitating the viability and motility of spermatozoa, particularly in circumstances involving thawing or samples with significant immotility.

Improving human sperm motility via red and near-infrared laser irradiation: in-vitro study

Improved sperm motility is necessary for successful sperm passage through the female genital system, efficacious fertilization, and a greater probability of pregnancy. By stimulating the mitochondrial respiratory chain, low-level laser photobiomodulation has been shown to increase sperm motility and velocity. The respiratory chain in mitochondria is the primary site of action for cytochrome c oxidase because it can absorb light in the visible and infrared ranges. The present study aimed to investigate the effects of red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both on human spermatozoa motility and DNA integrity at different doses. An in-vitro controlled trial was performed in Al Zahraa university hospital laboratory using thirty fresh human semen specimens. Samples were exposed to red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both for various irradiation times. Sperm motility for the test and control aliquots was assessed as recommended in the manual of WHO-2021. Sperm chromatin integrity was evaluated using the Sperm Chromatin Structure Assay. Results revealed almost 70%, 80% and 100% increase in the total motility after 3 min of the 650-nm, 980-nm and the combined laser irradiation, respectively. Additionally, the Sperm Chromatin Dispersion assay was carried out on sperm heads utilizing human sperm DNA fragmentation, demonstrating that none of the three laser types had any discernible effects.

Photobiomodulation (800 nm Light-Emitting Diode) Treatment Promotes Bone Mesenchymal Stem Cell Proliferation Via Long Noncoding RNA MEG3-MicroRNA-217-5P Pathway

Background: Patients with osteoporosis (OP) have a high risk of bone fracture. Abnormal bone mesenchymal stem cell (BMSC) differentiation is an essential process of OP development. In recent years, photobiomodulation has been shown to effectively promote BMSC proliferation. However, the mechanism by which photobiomodulation promotes BMSC proliferation is unclear. Long noncoding RNAs (lncRNAs) are essential mediators in multiple biological processes. The lncRNA maternally expressed gene 3 (MEG3) is a novel lncRNA gene and is related to cell proliferation. Studies have indicated that MEG3 serves as a promotor in BMSC proliferation. Objective: To investigate the effects and mechanisms of 800 nm light-emitting diode (LED) photobiomodulation in BMSC proliferation. Materials and methods: The BMSCs collected from mouse tibias and femurs were irradiated by 800 nm LED for 180 sec. CCK-8 assay was used to detect the cell viability. A dual-luciferase reporter assay was used to determine IncRNA MEG3 acted as a miR-217-5p sponge. We used reverse transcription-polymerase chain reaction (RT-PCR) and western blot to detect the mRNA and protein levels of MEG3, miR-217-5p, Notch2, Hes1, Hey2. Results: In the present study, we revealed that photobiomodulation (800 nm LED) could increase the mRNA level of MEG3, and protein levels of Notch2, Hes1, and Hey2. Moreover, we also identified that upregulated MEG3 could act as a miR-217-5p sponge to activate the Notch signaling pathway. Conclusions: The current study revealed the MEG3-related mechanism of photobiomodulation treatment in OP and identified potential gene therapies for OP.

Cryopreservation of Semen in Domestic Animals: A Review of Current Challenges, Applications, and Prospective Strategies

Cryopreservation is a way to preserve germplasm with applications in agriculture, biotechnology, and conservation of endangered animals. Cryopreservation has been available for over a century, yet, using current methods, only around 50% of spermatozoa retain their viability after cryopreservation. This loss is associated with damage to different sperm components including the plasma membrane, nucleus, mitochondria, proteins, mRNAs, and microRNAs. To mitigate this damage, conventional strategies use chemical additives that include classical cryoprotectants such as glycerol, as well as antioxidants, fatty acids, sugars, amino acids, and membrane stabilizers. However, clearly current protocols do not prevent all damage. This may be due to the imperfect function of antioxidants and the probable conversion of media components to more toxic forms during cryopreservation.

Restoring Sperm Quality Post-Cryopreservation Using Mitochondrial-Targeted Compounds

While critical for male fertility preservation, cryopreservation damage reduces sperm quality and fertilization potential. This study investigated whether the addition of mitochondrial-targeted, antioxidant compounds, also known as Mitochondrial activators, to the cryopreservation medium could protect sperm quality during cryopreservation. For this, semen samples from men undergoing IVF/ICSI treatment, which were donated for research, underwent cryopreservation in the absence or presence of BGP-15, MitoQ and L-carnitine. Fresh semen and thawed sperm samples from the same participant were analyzed for indicators of sperm quality: sperm viability, kinetics, mitochondrial reactive oxygen species (ROS) levels, Mitochondrial Membrane Potential (MMP) and DNA damage. Cryopreservation significantly reduced sperm viability and motility and predicted mucous penetration. BGP-15, MitoQ and L-carnitine improved sperm motility, whilst the addition of L-Carnitine prevented the loss of sperm viability during cryopreservation. Both BGP-15 and L-carnitine reduced sperm DNA oxidative damage, but only BGP-15 significantly reduced DNA fragmentation. More importantly, BGP-15 increased sperm predictive mucous penetration and MMP and reduced DNA oxidation. Our results show that the addition of BGP-15 or L-carnitine to the cryopreservation medium improves sperm quality post-thawing, highlighting the potential of mitochondrial antioxidants to improve long-term fertility preservation in males.

Sperm kinetics of Egyptian buffalo bulls (Bubalus bubalis) affected by the red laser postfreezing

OBJECTIVE

To improve the fertilizing ability of frozen buffalo semen using the more beneficial, accurate, and cheap technique of laser irradiation at specific wavelengths and exposure times.

MATERIALS AND METHODS

The red laser source (625 nm) was used in this study with 5 watts output power and for the irradiation of the semen samples for 5 min; the laser focus spot area was 1 cm².Thirty straws belonging to five buffalo bulls were used in this study.

RESULTS

The results show that total motility (%) and progressive motility (%) increased insignificantly after 5 min of exposure (73.8 ± 1.4 and 60.4 ± 1.1, respectively) compared to the control sample (70.9 ± 0.9 and 57.5 ± 1.7, respectively). All velocity parameters (velocity average path,velocity curved line, and velocity straight line µm/sec) recorded a significant (p < 0.05) increase in samples measured 5 min after exposure (52.3 ± 1.3, 83.5 ± 2.0, and 43.5 ± 1.2, respectively) compared to the untreated ones (47.1 ± 2.0, 76.3 ± 3.1, and 38.6 ± 1.9, respectively).

CONCLUSION

The application of the red laser light on buffalo semen postthawing resulted in a positive correlation with almost every motility parameter; it may be recommended to apply this technique pre-in vitro fertilization for embryo production of buffalo species.

Comparative Effect of Photobiomodulation on Human Semen Samples Pre- and Post-Cryopreservation

The primary objective of this study is to evaluate and to compare the effects of photobiomodulation (PBM) on sperm parameters both before and after cryopreservation. In this regard, 24 freshly ejaculated semen samples from normozoospermic men were included in this study. Each semen sample was randomly divided into three groups (1 ml aliquot for each group): the control group (group one) underwent conventional sperm cryopreservation (n = 24), group two underwent pre-freezing PBM exposure (810 nm, diode laser, and 0.6 J/cm²) (n = 24), and group three underwent post freezing and thawing PBM exposure (n = 24). Indicators of sperm quality, including total sperm motility (TSM), progressive sperm motility (PSM), DNA fragmentation, lipid peroxidation levels, apoptosis-like changes, and gene expression levels of protamine (PRM) 1, PRM2, and adducin 1 alpha (ADD1), were investigated in a blinded style. Due to the beneficial effect of pre-freezing PBM therapy, group 2 exhibited the highest TSM and PSM levels compared to groups 1 and 3. At the same time, DNA fragmentation and lipid peroxidation were significantly reduced in the group 2 compared to the group 1 (p = 0.024 p = 0.016, respectively). Evaluation of apoptotic/necrotic changes revealed that parameters including early apoptosis, dead, and necrotic cells decreased in the group 2 compared to the either groups 1 (p = 0. 008, p = 0. 032, p = 0. 02, respectively) or group 3 (p = 0.037, p = 0.108, p = 0.083). There were no significant differences in the expression levels of PRM1, PRM2, and ADD1 among the study groups. Based on our results, PBM therapy prior to cryopreservation, even in the normal semen samples, plays a significant protective role against cryo-damage by preserving the functional parameters of spermatozoa.

Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla

Cryopreservation, the most common method of preserving stem cells, requires post-processing because it produces trauma to the cells. Post-thawing trauma typically induces cell death, elevates reactive oxygen species (ROS) concentration, and lowers mitochondrial membrane potential (MMP). Although this trauma has been solved using antioxidants, we attempted to use photobiomodulation (PBM) instead of chemical treatment. We used a 950-nm near-infrared LED to create a PBM device and chose a pulsed-wave mode of 30 Hz and a 30% duty cycle. Near-infrared radiation (NIR) at 950 nm was effective in reducing cell death caused by hydrogen peroxide induced-oxidative stress. Cryodamage also leads to apoptosis of cells, which can be avoided by irradiation at 950 nm NIR. Irradiation as post-processing for cryopreservation had an antioxidant effect that reduced both cellular and mitochondrial ROS. It also increased mitochondrial mass and activated mitochondrial activity, resulting in increased MMP, ATP generation, and increased cytochrome c oxidase activity. In addition, NIR increased alkaline phosphatase (ALP) activity, a biomarker of differentiation. As a result, we identified that 950 nm NIR PBM solves cryodamage in human stem cells from the apical papilla, indicating its potential as an alternative to antioxidants for treatment of post-thawing trauma, and further estimated its mechanism.

Evaluation of Microscopic, Flow Cytometric, and Oxidative Parameters of the Frozen-Thawed Bull Sperm in a Freezing Extender Containing Myo-Inositol

Introduction: This research was conducted to assess the effect of myo-inositol (MYO) in the freezing extender on the semen quality and oxidative stress parameters of frozen-thawed bull sperm. Materials and Methods: Semen samples were obtained from four bulls (n = 24, six ejaculates per bull), twice a week, and diluted into four equal aliquots in freezing extenders containing different concentrations of MYO (0, 2, 3, and 4 mg/mL). After a freezing/thawing process, velocity parameters, plasma membrane integrity, apoptosis status, malondialdehyde level, and oxidative stress parameters were assessed. Results: Supplementation of freezing extender with 3 mg/mL MYO resulted in higher rapid motility (62.22% ± 2.63%), progressive motility (77.45% ± 2.65%), viability (78% ± 0.91%), plasma membrane integrity (86 ± 0.85), catalase (20.03 ± 0.39 U/mL) activity, and lower significance of lipid peroxidation (3.60 ± 0.15 nmol/dL) than those of the control group (p < 0.05). A significantly lower percentage of normal morphology and intact acrosomes were observed for frozen-thawed semen in the extender supplemented with 4 mg/mL MYO than those of the control group (p < 0.05). Freezing of the sperm in the extender containing 3 mg/mL of MYO leads to a higher percentage of live cells (38.3 ± 2.76). Beat-cross-frequency, amplitude of lateral head displacement, linearity, total antioxidant capacity, total peroxidase activity, early apoptotic status, and superoxide dismutase activities were not affected by MYO levels in the extenders (p > 0.05). Conclusion: The findings of this study suggest that the supplementation of the freezing extender with 3 mg/mL MYO resulted in a higher quality of frozen-thawed bull sperm.

Effects of Pulsed-Wave Photobiomodulation Therapy on Human Spermatozoa

BACKGROUND AND OBJECTIVES

Previous studies reported that photobiomodulation (PBM) positively affects the mitochondrial respiratory chain in sperm, resulting in improved motility and velocity. As laser settings are not yet fully established, the present study aimed at optimizing PBM on human sperm. In addition, possible side-effects of PBM on sperm DNA fragmentation level and acrosomal integrity have been analyzed.

STUDY DESIGN/MATERIALS AND METHODS

A pulsed laser-probe (wavelength 655 nm, output power 25 mW/cm², impulse duration 200 nanoseconds) was used. Native fresh liquefied semen samples underwent radiation with energy doses of 0 (control), 4, 6, and 10 J/cm². Sperm parameters were assessed at 0, 30, 60, 90, and 120 minutes after radiation using a computer-assisted sperm analysis system. Motility and velocity of sperm from asthenozoospermic patients (n = 42) and normozoospermic controls (n = 22) were measured. The amount of DNA strand breaks was analyzed using ligation-mediated quantitative polymerase chain reaction in patients with asthenozoospermia (n = 18) and normozoospermia (n = 13). Post-irradiance acrosomal integrity was investigated using flow cytometry based on CD46 protein expression (n = 7).

RESULTS

Exposure to laser energy-doses of 4 and 6 J/cm² improved sperm motility and velocity in asthenozoospermic patients. PBM exhibited no significant effect on DNA fragmentation level and expression of CD46 serving as a biomarker for acrosome integrity.

CONCLUSION

PBM improves sperm motility parameters by maintaining DNA and acrosome integrity and, therefore, represents a promising new tool for assisted reproductive therapy. In particular, improving sperm motility in asthenozoospermic patients by PBM in future may contribute to increasing the chance for successful intrauterine insemination. The present trial has no clinical registration number, as only in vitro studies were performed. The study was approved by the local ethics committee and performed according to the Declaration of Helsinki. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Effect of continuous wave, quasi-continuous wave and pulsed laser radiation on functional characteristics of fish spermatozoa

For the first time, using sturgeon sperm as a model system, sensitive to optical radiation, the comparative studies of biological effect of continuous wave, quasi-continuous wave, nano- and picosecond laser radiation under conditions with equal average irradiance (3 mW/cm²) and wavelength (532 nm) have been carried out. Analyzing the parameters of spermatozoa motion it has been shown that, depending on the energy dose and mode of laser operation, the radiation may have both stimulatory and inhibitory effect on the velocity of motion and spermatozoa motility duration as well as on sustaining of functional characteristics of cold-stored sperm. The possibility of increasing the fertilization rate due to use of the sperm preliminary treated with laser radiation is demonstrated. For the first time, the possibility of enhancement of biological effect going from continuous wave to quasi-continuous wave laser radiation at equal irradiance and wavelength has experimentally been proven. It is shown that the difference in biological effect of continuous wave, quasi-continuous wave, nano- and picosecond laser radiation is due to amplitude (peak) values of intensity. Using fluorescence analysis and luminol-dependent chemiluminescence assay, evidence for the participation of endogenous flavins and metal-free porphyrins in sensitized ROS formation (singlet oxygen, hydrogen peroxide, and hydroxyl radicals) in sturgeon sperm was obtained. Mechanisms of photochemical and photothermal reactions explaining the difference in efficacy of action of laser radiation in above modes are discussed.

Photobiomodulation preconditioned human semen protects sperm cells against detrimental effects of cryopreservation

The biological consequences of semen samples preconditioning with photobiomodulation (PBM) were studied on human sperm cells post cryopreservation. Donated semen samples were collected from 22 married men with normal sperm parameters according to World Health Organization (WHO) criteria. Included samples were divided into control and PBM-preconditioning (one session, 810 nm, diode laser, and 0.6 J/cm²) groups before cryopreservation procedure. Progressive sperm motility (PSM), morphology, viability, sperm mitochondrial membrane potential(MMP), intracellular reactive oxygen species (ROS) and lipid peroxidation of sperm cells were assessed post thawing. PBM preconditioning of cryopreserved semen samples most prominently increased the PSM percentage 30 min post thawing (p = 0.000).Application of PBM before cryopreservation significantly increased the number of viable spermatozoa (p = 0.000), increased significantly the number of spermatozoa with high MMP (p = 0.004) and decreased significantly the number of spermatozoa with low MMP post-thawing(P = 0. 007)compared to control group. Cryopreserved human sperm cells with PBM preconditioning showed significant decrease in the levels of intracellular ROS (47.66 ± 2.14 versus 60.42 ± 3.16, p = 0.002) and lipid peroxidation (3.06 ± 0.13 versus 3.68 ± 0.27, p = 0.05)compared to control group. Our findings, as the first evidence, indicated that PBM-preconditioning of human semen before cryopreservation provides a real and substantial advantage. This might lead to a novel strategy in improving PBM application in the procedures of assisted reproductive technologies.

Medium-term effects of the diluted pig semen irradiation with red LED light on the integrity of nucleoprotein structure and resilience to withstand thermal stress

This study sought to evaluate the effects of irradiating pig seminal doses with red LED light irradiation on their quality and longevity over liquid-storage at 17 °C. For this purpose, boar ejaculates were diluted in a commercial extender at a final concentration of 3 × 10⁷ sperm/mL and stored at 17 °C for 96 h. Upon arrival to our laboratory (5-6 h within collection), 1.5 mL-aliquots were subjected to irradiation with a temperature-controlled red light-emitting diode (LED) for 1 min, 5 min or 10 min. Controls consisted of non-irradiated spermatozoa. Aliquots were then stored at 17 °C for 96 h, and plasma membrane and acrosome integrity, motility and free cysteine radicals of sperm head proteins were evaluated every 24 h. In addition, the sperm resilience to withstand thermal stress following irradiation was evaluated at 24 h, 48 h, 72 h and 96 h by incubating stored seminal doses at 37 °C for 120 min. In our experimental conditions, light-stimulation for 5 min and 10 min counteracted the decrease in thermal stress observed in non-irradiated samples during the first 48 h of storage. Moreover, all irradiation protocols counteracted the decrease in percentages of spermatozoa with altered acrosomes observed in non-irradiated samples after 72 h of storage. The effects of light-stimulation upon sperm motility parameters were less consistent. While liquid-storage also led to an increase in the free cysteine levels of sperm head proteins, this increment was partially mitigated through light-stimulation for 5 min and 10 min. Our results suggest that effects linked with red LED light irradiation would be consistently maintained in our experimental conditions for the first 48 h. Finally, the maintenance of light effect appears to depend upon the specific experimental design, the analyzed sperm parameters and the utilized irradiation patterns.

Irradiating frozen-thawed stallion sperm with red-light increases their resilience to withstand post-thaw incubation at 38 °C

The aim of this study was to evaluate whether red-light stimulation increases the longevity and resilience of cryopreserved stallion sperm to withstand post-thaw incubation for 120 min. Sixteen frozen straws of 0.5 mL from eight stallions were used. Samples were cryopreserved, thawed through incubation at 38 °C for 30 s and divided into the control and samples exposed to red-light using a triple LED photo-activation system (wavelength: 620-630 nm). Three irradiation protocols consisting of different light-dark-light intervals (1-1-1, 2-2-2 and 3-3-3 min) were tested. Sperm quality parameters were analyzed immediately after light-stimulation (0 min) and after 120 min of incubation at 38 °C. Sperm motility was evaluated using a Computerized Semen Analysis System (CASA), and flow cytometry and different fluorochromes were used to evaluate the integrity and lipid disorder of plasma membrane, mitochondrial membrane potential and intracellular levels of peroxides and superoxides. Irradiation significantly increased the percentages of spermatozoa with high mitochondrial membrane potential (1-1-1 pattern) and the intracellular levels of peroxides (2-2-2 pattern) at 0 min. In addition, sperm kinematic parameters (2-2-2 and 3-3-3 patterns) and percentages of viable spermatozoa with low membrane lipid disorder (3-3-3 pattern) were significantly higher in irradiated samples than in the control at 120 min. Our results indicate that red-light stimulation could help increase the resilience of frozen-thawed stallion sperm to withstand post-thaw incubation at 38 °C for 120 min and that these effects rely on the irradiation pattern. Further research should evaluate whether light-stimulation could also have a positive on fertility rates after artificial insemination.

Photobiomodulation therapy for male infertility

Male infertility is a worldwide critical condition that affects about the 7.5% of males in Europe leading to an increment of the couples referring to reproductive medicine units to achieve pregnancy. Moreover, in the recent years, an increased number of patients have required to freeze their gametes in order to preserve their fertility. Photobiomodulation (PBM) therapy is a potential treatment that has been used for different clinical application basically aimed at biostimulating cells and tissues. Here, we report a deep overview of the published studies, focusing on PBM mechanism of action, with the aim of expanding the knowledge in the field of laser light for a rational utilization of irradiation in the clinical practice. In the field of reproductive science, PBM was employed to increment spermatozoa's metabolism, motility, and viability, due to its beneficial action on mitochondria, leading to an activation of the mitochondrial respiratory chain and to the ATP production. This treatment can be particularly useful to avoid the use of chemicals in the spermatozoa culture medium as well as to promote the spermatozoa survival and movement especially after thawing or in largely immotile sperm samples.

Grape Seed Procyanidin Extract (GSPE) Improves Goat Sperm Quality When Preserved at 4 °C

Simple Summary

Artificial insemination (AI) is widely used in goats, stimulating the development of semen preservation techniques. Oxidative stress is considered to be the main cause of sperm quality decline over time. In this study, we explored the effect of grape seed procyanidin extract (GSPE) during the liquid preservation of goat semen. The results showed that adding GSPE into the basic diluent enhanced sperm quality by eliminating oxidative stress. The most suitable concentration for the preservation of goat semen at 4 °C was 30 mg/L. This work suggests that promotes the viability of goat semen stored at low temperatures and provides a theoretical foundation for the development of more efficient diluents.

Abstract

Grape seed procyanidin extract (GSPE) has been shown to possess antioxidative effects. This experiment was designed to study the effect of GSPE during the liquid storage of goat semen. Semen samples were collected from six sexually mature goats. The samples were treated with different concentrations of GSPE (10, 30, 50, and 70 mg/L) in basic diluent and stored at 4 °C for 120 h; samples without GSPE were used as the control group. The results showed that sperm motility, acrosome membrane integrity, mitochondrial activity, plasma membrane integrity, total antioxidative capacity (T-AOC), catalase (CAT) activity, and superoxide dismutase (SOD) activity in the treatment groups were significantly higher than in the control group, whereas malondialdehyde (MDA) content was lower than in the control group (p < 0.05). In the treatment group, sperm quality in the 30 mg/L GSPE group was significantly higher than the other groups (p < 0.05). Furthermore, artificial insemination (AI) results showed that litter sizes were higher in the 30 mg/L GSPE group than in the control group (p < 0.05). In summary, this experiment showed that adding GSPE to the basic diluent improved sperm quality and that 30 mg/L of GSPE was the most suitable concentration for the liquid preservation of goat semen at 4 °C.

Sperm cryopreservation: A review on current molecular cryobiology and advanced approaches

The cryopreservation of spermatozoa was introduced in the 1960s as a route to fertility preservation. Despite the extensive progress that has been made in this field, the biological and biochemical mechanisms involved in cryopreservation have not been thoroughly elucidated to date. Various factors during the freezing process, including sudden temperature changes, ice formation and osmotic stress, have been proposed as reasons for poor sperm quality post-thaw. Little is known regarding the new aspects of sperm cryobiology, such as epigenetic and proteomic modulation of sperm and trans-generational effects of sperm freezing. This article reviews recent reports on molecular and cellular modifications of spermatozoa during cryopreservation in order to collate the existing understanding in this field. The aim is to discuss current freezing techniques and novel strategies that have been developed for sperm protection against cryo-damage, as well as evaluating the probable effects of sperm freezing on offspring health.

Effectiveness of low level laser therapy for treating male infertility

In half of the cases, the infertility of the couple is due to the disorder of the male fertility. The leading factors that cause male infertility are urogenital infections, disorders of the immune system, testicular and prostate pathology, as well as endocrine disorders. Low level laser therapy (LLLT) is a very effective physical therapy method, used in many areas of medicine, including obstetrics and gynaecology, andrology and urology; and it is recommended as an integral part of the complex treatment of infertility. The literature review showed that LLLT is beneficial in treating male infertility. Laser can significantly improve the survival, motility and speed of movement of spermatozoa. Laser therapy of patients with prostatitis and vesiculitis can eliminate infiltrative-exudative changes, improve reproductive and copulatory functions. Local illumination of red (635 nm) and infrared (904 nm) spectra should be combined with intravenous laser blood illumination (ILBI) of red (635 nm) and ultraviolet (UV) (365 nm) spectra.

Sperm motility is enhanced by Low Level Laser and Light Emitting Diode photobiomodulation with a dose-dependent response and differential effects in fresh and frozen samples

Background

The effects of Low Level Light Therapy (LLLT) on cellular function arise predominantly from stimulation of ATP production and reduction of oxidative stress. These effects are dose dependent and a function of beam irradiance and irradiation time. Human sperm motility has been shown to increase with LLLT irradiation. The objective of this study was to investigate the effects of laser and Light Emitting Diode (LED) LLLT photobiomodulation on human spermatozoa motility and DNA integrity.

Methods

An in-vitro controlled trial was performed within an IVF clinic laboratory using three human semen specimens, one fresh and two frozen. Sperm were exposed to light from a GaAlAs single laser (810 nm 200 mW) and an LED cluster (660 nm and 850 nm total power 2 W) for various irradiation times. Sperm motility for the test and control aliquots was assessed using a SQA-IIB analyser, but fertilizing ability was not. Sperm chromatin integrity was tested using the Sperm Chromatin Structure Assay.

Results

The Sperm Motility Index and Total Functional Sperm Count increased up to four fold compared to controls with inhibitory effects observed at higher doses (longer irradiation times). The maximum effect varied with irradiance and irradiation time and whether the sample was fresh or frozen.

Discussion

Human sperm motility is modified by exposure to LLLT and this motility modification is dependent upon beam irradiance and irradiation time as well as the condition of the sample. A higher stimulatory dose provides a rapid increase in motility that is short in duration, while a lower stimulatory dose provides a slower increase in motility. An inhibitory does causes reduced motility. Future research could consider animal models, such as the mouse, to test fertilization capacity and the safety of resulting fetuses.

Improvement of dairy cow embryo yield with low level laser irradiation

The goal of this study is to estimate the effects of low-level laser irradiation (LLLI) on the superovulatory response according to the number of corpora lutea (CL), follicles (F) and the embryo yield. In recent years, while searching for new, more efficient and organic methods to improve superovulatory response and embryo yield with respect to the conventional methods, low-level laser irradiation (LLLI) is a more sensitive and less costly technology that can be used to improve animal reproduction, namely, artificial insemination and the embryo production system. The dairy-cow donors were treated for superovulation with Pluset®, at any time during the oestrus cycle, and the total dose per donor was 700 IU. The first group of the donors (n=25), test group (TG), was irradiated on the sacroiliac area for 180 seconds per day, from the 1st to 11th superovulatory treatment (ST) days in a row, with LLLI in the 870-970-nm wavelength, 65.93 J/cm dose, frequencies in the 20-2000 Hz range and pulse durations commonly in the range of about 1 second. For the second control group (CG) (n=25), the ST was performed without LLLI. After the ST, The mean number of CL in the right side ovaries in the TG was 25.43% (p<0.05) greater than in those of the CG. The number of total recovered and transferable embryos was greater in the TG compared with the CG by 28.97% (p<0.05) and 15.8% (p>0.05), respectively. With respect to conventional methods, LLLI can be used to improve the superovulatory response and embryo yield as a supplementary environment and animal-friendly method of treatment.

Red light improves spermatozoa motility and does not induce oxidative DNA damage

The ability to successfully fertilize ova relies upon the swimming ability of spermatozoa. Both in humans and in animals, sperm motility has been used as a metric for the viability of semen samples. Recently, several studies have examined the efficacy of low dosage red light exposure for cellular repair and increasing sperm motility. Of prime importance to the practical application of this technique is the absence of DNA damage caused by radiation exposure. In this study, we examine the effect of 633 nm coherent, red laser light on sperm motility using a novel wavelet-based algorithm that allows for direct measurement of curvilinear velocity under red light illumination. This new algorithm gives results comparable to the standard computer-assisted sperm analysis (CASA) system. We then assess the safety of red light treatment of sperm by analyzing, (1) the levels of double-strand breaks in the DNA, and (2) oxidative damage in the sperm DNA. The results demonstrate that for the parameters used there are insignificant differences in oxidative DNA damage as a result of irradiation.

Effects of photobiomodulation therapy (PBMT) on bovine sperm function

Fertilization rates and subsequent embryo development rely on sperm factors related to semen quality and viability. Photobiomodulation therapy (PBMT) is based on emission of electromagnetic waves of a laser optical system that interact with cells and tissues resulting in biological effects. This interaction is mediated by photoacceptors that absorb the electromagnetic energy. Effects are dependent of irradiation parameters, target cell type, and species. In sperm, PBMT improves several features like motility and viability, affecting sperm aerobic metabolism and energy production. The aim of this study was to investigate, under same conditions, how different output powers (5, 7.5, and 10 mW) and time of irradiation (5 and 10 min) of laser (He-Ne laser, 633 nm) may affect frozen/thawed bovine sperm functions. Results showed significant effects depending on power while using 10 min of irradiation on motility parameters and mitochondrial potential. However, no effect was observed using 5 min of irradiation, regardless of power applied. In conclusion, PBMT is effective to modulate bovine sperm function. The effectiveness is dependent on the interaction between power applied and duration of irradiation, showing that these two parameters simultaneously influence sperm function. In this context, when using the same fluency and energy with different combinations of power and time of exposure, we observed distinct effects, revealing that biological effects should be also based on simple parameters rather than only composite parameters such as fluency, irradiance and energy. Laser irradiation of frozen/thawed bovine semen led to an increase on mitochondrial function and motility parameters that could potentially improve fertility rates.

Helium-neon laser irradiation of cryopreserved ram sperm enhances cytochrome c oxidase activity and ATP levels improving semen quality

This study examines whether and how helium-neon laser irradiation (at fluences of 3.96-9 J/cm(2)) of cryopreserved ram sperm helps improve semen quality. Pools (n = 7) of cryopreserved ram sperm were divided into four aliquots and subjected to the treatments: no irradiation (control) or irradiation with three different energy doses. After treatment, the thawed sperm samples were compared in terms of viability, mass and progressive sperm motility, osmotic resistance, as well as DNA and acrosome integrity. In response to irradiation at 6.12 J/cm(2), mass sperm motility, progressive motility and viability increased (P < 0.05), with no significant changes observed in the other investigated properties. In parallel, an increase (P < 0.05) in ATP content was detected in the 6.12 J/cm(2)-irradiated semen samples. Because mitochondria are the main cell photoreceptors with a major role played by cytochrome c oxidase (COX), the COX reaction was monitored using cytochrome c as a substrate in both control and irradiated samples. Laser treatment resulted in a general increase in COX affinity for its substrate as well as an increase in COX activity (Vmax values), the highest activity obtained for sperm samples irradiated at 6.12 J/cm(2) (P < 0.05). Interestingly, in these irradiated sperm samples, COX activity and ATP contents were positively correlated, and, more importantly, they also showed positive correlation with motility, suggesting that the improved sperm quality observed was related to mitochondria-laser light interactions.

Influence of biostimulation and temporary weaning on follicular dynamics and pregnancy rates in Nelore cows (Bos taurus indicus)

The objective of this study was to evaluate the effect of biostimulation and temporary weaning on the follicular dynamics and pregnancy rates in Nelore cows. We used three groups of 75 cows: a control group without biostimulation and suckling calves (WB), a group that was biostimulated and had suckling calves (BE) and a group that was biostimulated and subjected to temporary weaning for 56 h (BETW). Ovarian dynamics were examined using ultrasonography. All groups showed follicular atresia. The interval between beginning of the treatment and wave emergence was 3.25 ± 0.30 days for BE, 3.40 ± 0.27 days for BETW and 3.37 ± 0.50 days for WB. The time between implant removal and ovulation was 64.50 ± 1.88 h for BE, 66.75 ± 1.35 h for BETW and 60.85 ± 3.10 h for WB. Eight cows were submitted to ultrasound analysis, and the percentages of cows that had ovulatory follicles of the new follicular wave with maximum diameters greater than 0.80 cm were 100 % (8/8) in BE (1.28 ± 0.12 cm), 100 % (8/8) in BETW (1.52 ± 0.07 cm) and 87.5 % (7/8) in WB (1.21 ± 0.10 cm). The pregnancy rate was 52 % (39/75) in BE, 69.3 % (52/75) in BETW and 37.3 % (28/75) in WB. The association of biostimulation and temporary weaning increased follicular development, ovulation synchronisation and, consequently, the pregnancy rate in beef cows.