Effects of the seminal plasma zinc content and catalase activity on the semen quality of water buffalo (Bubalus bubalis) bulls

Progress on the roles of zinc in sperm cryopreservation

One of the effective methods for the long-term preservation of mammalian genetic resources is the cryopreservation of semen. However, a number of parameters, including diluents, the rate of freezing and thawing, cryoprotectants, etc., can easily alter the survival of frozen-thawed sperm. Numerous studies have documented the addition of a variety of zinc compounds, to the diluents used to cryopreserve sperm. The primary objective of this review is to briefly describe that adding zinc to diluents as an antioxidant significantly enhances frozen-thawed sperm quality. Second, a summary of the present understanding of zinc's molecular mechanism on semen cryopreservation is provided. Thirdly, this study addresses that nanoparticles of zinc can offer suggestions for raising cryopreservation effectiveness.

Effect of different sources of dietary zinc on sperm quality and oxidative parameters

Zinc has a critical physiological role in sperm function. The purpose of this study was to investigate the effect of different sources of zinc on sperm quality. For this purpose, 18 Zandi lambs with an average weight of 32 ± 1.2 kg were subjected to three treatments in a completely randomized design. Experimental treatments include (1) control treatment of basal diet without zinc supplementation, (2) basal diet with 40 mg/kg of zinc supplementation from zinc sulfate source and (3) basal diet with 40 mg/kg of zinc supplementation with organic source. At the end of feeding period, lambs were slaughtered. To determine the effect of experimental treatments on sperm quality, the testes were transferred to the laboratory. After that, epididymal spermatozoa were evaluated for sperm motility parameters, abnormal morphology, viability, membrane functionality, malondialdehyde (MDA) and antioxidant activity [glutathione peroxidase (GPx), superoxide dismutase (SOD), total antioxidant capacity (TAC)], sperm concentration and testosterone level. Zinc sulfate administration decreased MDA levels compared to other treatments and increased GPx and TAC activity compared to the control (P < 0.05), although SOD activity was not affected by any supplementation. Also, the use of zinc sulfate supplementation increased the percentage of total and progressive motility compared to the control group (P < 0.05). Membrane integrity and sperm viability were also affected by zinc sulfate supplementation (P < 0.05). Therefore, the results of this study showed that the use of zinc sulfate, can improve sperm motility and survival indices and its antioxidant capacity.

An overview of the role of metallic and nonmetallic nanoparticles and their salts during sperm cryopreservation and in vitro embryo manipulation

The cryopreservation of spermatozoa and the in vitro embryo production are valuable tools used in a variety of species, including humans, livestock, fish, and aquatic invertebrates. Sperm cryopreservation has been used to maintain or increase the genetic diversity of threatened species. Reactive oxygen species (ROS) are molecules derived from oxygen, being formed as byproducts of cellular metabolism. During cryopreservation of sperm and other in vitro manipulations of oocytes and embryos, ROS production is dramatically increased. In cells, low, medium, and high levels of ROS lead to different outcomes, apoptosis, auto-phagocytosis, and necrosis, respectively. ROS produced by cells can be neutralized by intracellular antioxidant systems, including enzymes as well as non-enzymatic antioxidants. Free radicals and oxidative stress can be major factors influencing in vitro manipulations. In this review, we discuss the role that metallic and nonmetallic nanoparticles and their salts play in the modulation of oxidative stress during in vitro embryo production and cryopreservation of sperm.

Proteomic analysis of donkey sperm reveals changes in acrosome enzymes and redox regulation during cryopreservation

Sperm cryoinjuries caused by cryopreservation restrict the application of donkey frozen semen in artificial insemination (AI). Identification of differentially represented proteins in fresh and frozen-thawed spermatozoa is of great significance to optimize the cryopreservation process and modify the component of cryopreservation extender. In this study, protein samples prepared from fresh (F) and frozen-thawed (FT) donkey spermatozoa were compared. 2682 proteins were quantitatively identified by tandem mass spectrometry (TMT) polypeptide labeling technique and LC-MS/MS method, of which 28 were more abundant in thawed samples and 147 in fresh spermatozoa. The differential abundant proteins (DAPs) were analyzed by bioinformatics. Most of the DAPs in intensive bioinformatic analysis were involved in the process of regulation of biological process and metabolism. Functional protein analysis showed that DAPs process mainly protein hydrolase activity and oxidoreductase activity. Cellular Component analysis showed that DAPs were related to vesicle transport and membrane system. This is the first analysis and study on differential proteomics of donkey sperm proteins before and after cryopreservation, which has a certain guiding significance for studying the mechanism of sperm damage caused by cryopreservation and improving the freezing and thawing procedure. SIGNIFICANCE: In recent years, the commercial value of donkey products has been discovered. Improving the breeding efficiency of donkeys can save the stock of donkeys which is decreasing rapidly, and allow people to continuously benefit from the nutritional value brought by donkey milk. Sperm cryopreservation technology has laid the foundation for encouraging the spread of artificial insemination in donkey reproduction, but the freezing and thawing process causes damage to sperm, which dramatically reducing the viability of frozen sperm and leading to low fertility. At present, the mechanism of damage to donkey sperm caused by cryopreservation is still unclear, and studying this mechanism can provide a direction for improving the quality of frozen semen. Protein is a potential key factor affecting sperm cryopreservation activity. Studying changes in the sperm proteome during cryopreservation can provide promising evidence for revealing sperm cryopreservation damage, which is of great significance for optimizing the cryopreservation process, improving the composition of cryopreservation extender, and seeking directions for improving the quality of frozen semen.

Differences between some biochemical components in seminal plasma of first and second ejaculations in dual-purpose Simmental (Fleckvieh) bulls and their relationships with semen quality parameters

This study aimed to evaluate differences in seminal plasma zinc (Zn), copper (Cu), iron (Fe), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels in the first and second ejaculations and their relationships with semen quality parameters in Fleckvieh bulls. Repetitive ejaculates were separately collected, analyzed, and frozen from the sires. Progressive motility of frozen-thawed semen (PMFT) was considered the main factor for more data classification into three following groups: <40.00%, 40.00 - 50.00%, and >50.00%. Seminal plasma trace elements and enzymes were determined using atomic absorption spectrometry and ELISA, respectively. The results revealed significant differences between the first and second ejaculations. Semen concentration, SOD, GPx, and Fe were different in ejaculations. Although PMFT groups in different ejaculations did not show significant differences, there was significant alteration between different PMFT groups and first and second ejaculations. All frozen-thawed semen CASA parameters (except lateral head displacement) were associated with fresh motility parameters and before and after thawing sperm viability. Also, a correlation between seminal Zn concentration with fresh semen gross and progressive motility, average path velocity, and beat cross frequency, Cu with SOD and Fe and semen concentration was observed. CAT was associated with fresh and frozen-thawed sperm motility parameters except for lateral head displacement and angular displacement. Although our findings showed differences between the first and second ejaculations in some parameters, PMFT, which is the most important indicator for estimating bull fertility, was not different between them.

Effect of Zinc Supplementation on Semen Quality, Sperm Antioxidant Ability, and Seminal and Blood Plasma Mineral Profiles in Cashmere Goats

This study evaluated the effects of the different dietary zinc (Zn) levels on semen quality, on spermatozoa and seminal plasma antioxidant status, and on the seminal and blood plasma mineral status in mature male Cashmere goats during the breeding season. Twenty-eight mature male Liaoning Cashmere goats were divided into four groups based on body weight (56.2 ± 2.45 kg) and semen characteristics; these goats were fed with basal diet supplemented with 0, 20, 40, or 80 mg Zn/kg DM (zinc sulfate) for 3 months. Results showed that the Zn-supplemented diets linearly increased the semen volume (0.98, 1.04, 1.27, and 1.17 ml for the 0, 20, 40, and 80 mg Zn/kg DM supplementation, respectively) (P < 0.05) and the total sperm output (3.87, 4.52, 5.73, and 5.33 × 10⁹/ml for the 0, 20, 40, and 80 mg Zn/kg DM supplementation, respectively) (P < 0.05); by contrast, Zn supplementation exerted no effect on sperm concentration, motility, and abnormal sperms rate. The activities of copper zinc superoxide dismutase (CuZn-SOD) (linear P < 0.05) and glutathione peroxidase (GSH-Px) (linear P < 0.05; quadratic P < 0.01) were highest in the intermediate supplementation (40 mg Zn/kg DM). Moreover, the malondialdehyde (MDA) content of spermatozoa decreased linearly (P < 0.01) with the increase in Zn supplementation. In seminal plasma, the highest GSH-Px activity was observed in 20 mg Zn/kg DM supplementation (P < 0.05). Catalase (CAT) activities both in the spermatozoa and seminal plasma showed no difference in all treatments. Seminal plasma Zn level was highest in 40 mg Zn/kg DM (linear P = 0.068), and K increased linearly (P = 0.001) with increasing Zn level. Furthermore, blood plasma Zn (linear P < 0.01; quadratic P < 0.05), Fe (linear P < 0.05; quadratic P < 0.05), and Mg (linear P < 0.05) increased with increasing Zn supplementation. These results indicated that dietary Zn supplementation in Cashmere goats during the breeding season improved the semen quality and quantity, elevated the antioxidative indices and Zn concentration, and decreased the MDA content both in spermatozoa and seminal plasma.

Human Sperm Characteristics with Regard to Cobalt, Chromium, and Lead in Semen and Activity of Catalase in Seminal Plasma

We analyzed cobalt (Co), chromium (Cr), and lead (Pb) concentrations in human semen and catalase CAT activity in seminal plasma and the effects of their relations on the sperm quality. We obtained semen samples from men (n = 168) undergoing routine infertility evaluation. Studies included two groups based on the ejaculate parameters: I (n = 39; normal ejaculate; normozoospermia); II (n = 129; pathological spermiogram). We examined relationships and differences between Co, Cr, and Pb concentrations in seminal plasma, CAT activity, and semen parameters. We did not establish differences in Co, Cr, and Pb concentrations and CAT activity from men between normozoospermic and those with pathological spermiogram. We found a significantly lower Co concentration and CAT activity in males with normal sperm motility than in asthenozoospermic males. We found significantly lower Co and a higher Pb concentration in males with normal morphology of spermatozoa than in teratozoospermic males. We found a significantly higher Pb concentration in the individuals with consumption of alcohol than in those without consumption. There were significant correlations between Co and Pb concentrations, sperm progressive motility (A + B, i.e., fast and slow progressive motility; Co-negatively; Pb-positively), and normal morphology of spermatozoa (Co-negatively; Pb-positively). We found a significant negative correlation between Cr concentration and slow progressive motility, and between CAT activity and volume of ejaculate. Co, Cr, and Pb levels and CAT activity were related to sperm characteristics and male fertility. The impact of alcohol may be manifested by a disturbance in Pb equilibrium in the body. Co and Pb influence progressive motility and normal morphology of human spermatozoa. Thus, Co and Pb levels in semen may be a useful diagnostic in male infertility. Most of the results of this study are in contrast to expectations. Namely, Pb is a toxic element and its harmful effects (poor semen quality) may be expected already at relatively low level of Pb exposure and are particularly visible with increasing of Pb. Co and Cr(III) are essential elements and harmful effects may be expected at their deficiency and/or overexposure.

Progressive motility – a potential predictive parameter for semen fertilization capacity in bovines

We examined the association between progressive motility of spermatozoa andin vitrofertilization (IVF) competence of bovine ejaculates. Fresh semen was evaluated using a computerized sperm quality analyzer for bulls using progressive motility as the primary parameter. Ejaculates with high progressive motility (HPM; >81%) were compared with those with low progressive motility (LPM; <62%). Semen concentration and sperm velocity were lower (P< 0.05) in HPM versus LPM ejaculates. Volume and motile sperm concentration did not differ between groups (P> 0.05). Examination of sperm morphology revealed a higher proportion of spermatozoa with abnormal morphology (P< 0.01) in LPM versus HPM ejaculates, the predominant abnormal feature being a bent tail (P< 0.05). Sperm viability, acrosome integrity and DNA fragmentation did not differ between HPM and LPM samples. Mitochondrial membrane potential was higher (P< 0.01) in HPM versus LPM semen. Zinc concentrations in the seminal plasma correlated with progressive motility (R2= 0.463,P= 0.03). In addition, representative ejaculates from HPM and LPM groups were cryopreserved in straws and used for IVF. The proportions of embryos cleaved to 2- and 4-cell stages (88.1 ± 1.1 versus 80.5 ± 1.7,P= 0.001) and developed to blastocysts (33.5 ± 1.6 versus 23.5 ± 2.2,P= 0.026) were higher for HPM than LPM semen. The total cell number of embryos and blastocyst apoptotic index did not differ between groups. Although sperm progressive motility is associated with IVF competence, further examination is required to determine whether progressive motility can serve as a predictor of semen fertilization capacityin vivo.