Effects of green tea polyphenols and α-tocopherol on the quality of chilled cat spermatozoa and sperm IZUMO1 protein expression during long-term preservation

Transmembrane protein 95 as a promising molecular marker of ram sperm functionality

The optimization of preservation protocols (refrigeration and freezing) in ovine species is necessary for a wider diffusion of artificial insemination in this species. Besides the ram sperm quality assays, the characterization of novel proteins could be crucial for improving these protocols employing biomarkers. The protein transmembrane 95 (TMEM95) is a sperm membrane protein associated with oocyte-sperm fusion previously described in bull or mouse. However, this protein has not yet been characterized in the ram until now. In this work, different experimental groups based on sperm functionality: capacitated, refrigerated at different times (5 °C 24 h, 5 °C 48 h, and 5 °C 72 h), and frozen-thawed sperm samples were analyzed and compared to initial sperm quality samples (15 °C 3 h) to characterize the expression of this novel protein and its relationship with other sperm quality markers (motility, kinetic parameters, viability, apoptosis-like events, mitochondrial function, acrosome-reacted, zinc content as marker of capacitation). In addition, capacitation status was tested by Fluozin-3, a novel fluorescent probe measuring zinc content used for the first time in ram sperm. After capacitation induction, as expected, acrosome reactive spermatozoa and zinc signature 2 and 3 were significantly increased, while linearity was significantly (P < 0.05) decreased compared to non-capacitated samples. Concerning TMEM95, its profile was significantly (P < 0.05) increased after the capacitation process, confirming its relationship with this spermatozoa status. Attending to preservation processes, as expected, semen quality decreased progressively during liquid storage, and a significant (P < 0.05) decrease was observed at 24 h according to fast progressive motility and linearity. TMEM95 profile showed the same decrease tendency, showing a significant reduction (P < 0.05) at 48 h with respect to the control samples. Finally, after the cryopreservation process, the semen quality of the thawed samples suffered a detrimental effect compared to the initial control sample, concerting all studied parameters accomplished by a significant (P < 0.05) decrease in TMEM95 profile compared to initial control samples. When we analyzed the TMEM95 correlation with other sperm quality markers, the highest positive correlations observed were with low sperm quality parameters in capacitated samples, such as apoptosis-like changes and acrosome-reaction. On the other hand, the highest positive correlations observed between TMEM95 and sperm quality parameters in preservation process samples were observed with suitable sperm quality parameters (motility, viability, and mitochondrial functionality). According to our results, this novel protein could be considered a predictor of early damage in ram sperm preservation protocols (cooling and freezing), considering its relationship with capacitation and membrane integrity status.

Sesame oil as a partial substitute for egg yolk in goat semen extenders

This study aimed to evaluate the effects of replacing egg yolk extender with sesame oil on the quality of sperm in goats following incubation at 37°C, chilling at 4°C, and freezing. Semen samples were collected from four intact male goats. The individual semen sample was divided into six groups consisting of a control group and five treatment groups with different egg yolk-to-sesame oil ratios. Seminal plasma was removed, and the sperm pellet was diluted with experimental semen extenders. The control group contained an extender of 10 % egg yolk (SO0), and the experimental extenders were composed of 8.75 % egg yolk and 1.25 % sesame oil (SO1.25); 7.5 % egg yolk and 2.5 % sesame oil (SO2.5); 5 % egg yolk and 5 % sesame oil (SO5); 2.5 % egg yolk and 7.5 % sesame oil (SO7.5); and 10 % sesame oil (SO10). Each group of semen was divided into three groups, incubated at 37°C for 1 h, chilled at 4°C for 4 h, or frozen for 24 h. Five replicates were performed. Sperm quality was evaluated, including motility, viability, and functional membrane integrity. The SO1.25 group achieved the highest sperm quality rate among the treatment groups, and the extender did not have a negative effect compared to the control. However, the total replacement of egg yolk with sesame oil in an extender resulted in the lowest sperm quality. In conclusion, the ratios of egg yolk and sesame oil that were acceptable for goat semen cryopreservation were 8.75 % and 1.25 %, respectively.

Detection of Protein Biomarkers Relevant to Sperm Characteristics and Fertility in Semen in Three Wild Felidae: The Flat-Headed Cat (Prionailurus planiceps), Fishing Cat (Prionailurus viverrinus), and Asiatic Golden Cat (Catopuma temminckii)

Effective wild cat conservation programs with assisted reproductive technologies are being developed in different parts of the world. The flat-headed cat, fishing cat, and Asiatic golden cat are three species among nine wild Felidae in Thailand that are in need of urgent conservation efforts. Here, we assessed routine sperm characteristics and we report the detection of protein biomarkers related to the fertilization process, IZUMO1 and the CRISP family, and apoptotic markers, active or cleaved caspase-3, in semen samples collected from these wild cats. IZUMO1 was located in the equatorial segment of the sperm head, which is the region involved in gamete interaction. The highest levels of IZUMO1 were found in both the sperm pellet and the seminal plasma of the flat-headed cat, as determined by immunoblotting. CRISP2, a sperm-egg fusion assisting protein, and CRISP3 were found in both the sperm pellet and the seminal plasma, and the highest levels were observed in the fishing cat. Positive correlations between certain semen parameters and IZUMO1, CRISP2, and CRISP3 expression were also demonstrated. Cleaved caspase-3 was found in all sperm samples in all three species and was associated with an increase in DNA fragmentation and a decrease in certain semen characteristics such as motility, viability, and intact acrosomes. Our results suggest that the analysis of IZUMO1, the CRISP family, and cleaved caspase-3, along with the routine sperm characteristics, may allow for better success in breeding management in wild Felidae, particularly in the flat-headed cat and the fishing cat.

Shelf-life extension of soy sauce by using chitosan oligosaccharides combined with tea polyphenols

Chitosan oligosaccharides (COs) and tea polyphenols (TPs) have antioxidant and antibacterial activities. This study aims to explore the preservative effects of 0.1 % COs alone and combined with 0.08 % TPs on soy sauce during room-temperature storage. Soy sauce treated with 0.1 % COs alone and combined with 0.08 % TPs had lower total bacterial count, Escherichia coli count and pH, and higher amino acid nitrogen and overall likeness score than those of the control group during room-temperature storage. Treatment with 0.1 % COs combined with 0.08 % TPs extended the shelf life of soy sauce by at least 15 months compared with the control group. Results showed 0.1 % COs combined with 0.08 % TPs may be a feasible method to extend the shelf life of soy sauce during room-temperature storage.

Green tea extract addition into a Tris-based egg yolk extender improves Bali bull sperm quality

OBJECTIVE

The conservation of Bali bulls, the Indonesian native breed of cattle, is crucial for cattle breeding in Indonesia. To guarantee the spread of Bali bulls through artificial insemination the quality of the frozen semen must be high. To this end, adding an extender material to semen that increases spermatozoa's survival during cryopreservation is important. Green tea extract (GTE) can be used as cryoprotectant because its high antioxidant activity can help avoid reactive oxygen species formation.

METHODS

Semen of five Bali bulls from the National Artificial Insemination Center at Singosari, Indonesia was collected routinely twice a week. First, fresh semen inspection was performed to determine the feasibility of using Bali bulls as animal samples. The extender used in this study was Tris-based egg yolk. The samples were divided into four treatments: T0, no GTE added to the extender; T1, 0.05 mg GTE plus 100 mL extender; T2, 0.10 mg GTE plus 100 mL extender; and T3, 0.15 mg GTE plus 100 mL extender. The semen freezing process was conducted according to standard procedures and sperm quality parameters, i.e., sperm motility, viability, abnormalities, and membrane integrity observed pre-freezing and post-thawing.

RESULTS

There were significant differences in total motility, progressive motility, viability, and integrity membrane of Bali bull sperm at both pre-freezing and post-thawing after adding GTE into the extender. In contrast, there were no differences in abnormalities among treatments.

CONCLUSION

Adding GTE at a 0.15 mg into 100 mL Tris-based egg yolk extender can improve the quality of cryopreserved Bali bull sperm.

The Addition of Opuntia ficus-indica Ethanolic Extract to a Skimmed Milk-Based Extender Impacts Ram Sperm Quality

Recently, researchers have focused on the use of natural antioxidants to improve semen quality as a key element for successful artificial insemination. In this context, the first aim of this study was to determine the antioxidant activity and composition (minerals, vitamins, and sugars) of Opuntia ficus-indica cladode ethanolic extract (ETHEX). A further purpose of the study was to investigate the effect of ETHEX supplementation on the quality of liquid ram semen extended with skim milk (SM) at 5°C. The antioxidant activity of ETHEX was studied using free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH•) assay. The mineral composition and the sugar and vitamin contents of ETHEX were determined using an inductively coupled plasma optical emission spectrometry (ICP-OES) and HPLC-DAD-RID analytical instruments. As a second part, semen was collected from five Boujaâd rams with an artificial vagina. The ejaculates with more than 70% motility were pooled, extended with skim milk (SM) extender without (control) or supplemented with 1-8% of ETHEX (37°C; 0.8 × 109 sperm/mL). Sperm quality parameters were assessed at 8, 24, 48, and 72 h. The results showed that ETHEX had a higher antioxidant activity compared to those of ascorbic acid and butylated hydroxytoluene (BHT). Furthermore, ETHEX contains a considerable amount of minerals, vitamins, and sugars. The inclusion of 1 or 2% ETHEX in SM increased the sperm motility, viability, and membrane integrity and decreased the abnormality of spontaneous and catalyzed lipids peroxidation (p < 0.05) up to 72 h. In addition, semen diluted with 1 and 2% ETHEX decreased the level of DNA fragmentation compared to the control group (p < 0.05). In conclusion, the ETHEX could be recommended to improve the quality of liquid ram spermatozoa. However, its effects on artificial insemination should be further studied.

Effects of water-soluble curcuminoid-rich extract in a solid dispersion form (CRE-SD) on the sperm characteristics, longevity and casein kinase II catalytic subunit alpha protein stability in chilled goat semen

The present study evaluated the effects of water-soluble curcuminoid-rich extract in a solid dispersion form (CRE-SD) on goat sperm qualities and sperm protein CSNK2A2 expression during liquid storage. Semen was collected from five fertile goats, using an artificial vagina. Ejaculates with a motility above 70% were cooled to 4 °C using TRIS-citric acid-fructose diluent with 10% egg yolk containing various concentrations of CRE-SD (0, 0.1, 1, 10 and 100 μg/mL). Chilled sperm were evaluated for sperm characteristics, casein kinase II catalytic subunit alpha (CSNK2A2) protein level and oxidative status up to 15 days. After 12 days of preservation, sperm motility, viability, acrosomal integrity and mitochondrial activity were significantly higher in the group preserved with 10 μg/mL CRE-SD as compared with the control group. Supplementation of CRE-SD at this concentration was also able to conserve the CSNK2A2 a significantly higher than that in control group until 9 days of cold storage, possibly by reducing oxidative stress. The molecular mass of the sperm CSNK2A2 protein detected in this study was 37 kDa; it was mostly located in the post-acrosomal region, midpiece and flagellum. These results demonstrate the possibility to use the CRE-SD as a natural antioxidant during liquid semen storage in goats.

Association between tea consumption and semen quality among 1385 healthy Chinese men

Information on the association between tea drinking and semen quality is limited. Little is reported on whether tea drinking is benefit to sperm quality. This cross-sectional and longitudinal study was conducted between April 2017 and July 2018. Participants were healthy men who were screened as potential sperm donors recruited at the Hubei Province Human Sperm Bank of China. A structured questionnaires containing sociodemographic information, daily habits, sperm collection-related information was completed for each participant at interview. Repeated semen samples were taken to examine the sperm parameters, including sperm volume, sperm concentration, sperm count, progressive motility, and total motility. A total of 1385 men with 6466 sperm samples were included in this study. Two groups were compared: tea drinking men (389, 28.1%) and non-tea drinking men (996, 71.9%). Compared with subjects who never drink tea, the analyses showed that sperm concentration and total sperm count were higher in tea-consuming subjects. A 10-year period or more duration of tea drinking significantly increased semen concentrations by 16.27% (P < 0.05). Sperm concentration was increased in subjects with a frequency of tea drinking of 3 days or more per week (P < 0.05) or, among men who were occasional alcohol drinkers, when tea concentration was weak (P < 0.05). No evidence of trend effects (P for trend > 0.05) or interaction effects (P for interaction > 0.05) between tea consumption and sperm quality, respectively. Our findings provide evidence that tea drinking may improve male reproductive health. Long-term, frequent, weak tea drinking tends to increase sperm quality among men with low BMI or health-related behaviors like smoking or alcohol intake.