Yolk Lipoproteins Research Articles

Development of egg yolk lipoprotein hydrolysate for nano-delivery of curcumin: Structure-function relationship

Curcumin is a lipophilic polyphenol extracted from the rhizomes of the turmeric plant, exhibiting versatile biological activities. However, its poor solubility, stability, and bioaccessibility present barriers to its effective use in foods or nutraceutical supplements. Egg yolk lipoprotein is a class of natural protein-lecithin composite found in egg yolks with a strong affinity for different hydrophobic active ingredients. In this study, egg yolk lipoprotein hydrolysate was employed to encapsulate hydrophobic curcumin, thereby increasing its solubility, stability, and bioaccessibility. The resulting curcumin-loaded nanoparticles had an average size of 680.9 nm, a zeta potential of around −30 mV, and an encapsulation rate of up to 68.4 %. The solubility of curcumin in water increased by 80 times while maintaining excellent thermal and storage stability. Fluorescence and infrared spectroscopy analysis demonstrated that the assembly process was driven by hydrophobic interactions and hydrogen bonds. The bioavailability of curcumin in nanoparticles has been improved to 30 %, a tenfold increase. These results suggested that egg yolk lipoprotein hydrolysate, a novel peptide-lecithin complex nanoparticle, can improve the stability and bioavailability of hydrophobic polyphenols.

Molecular Modeling of the Adsorption of an Egg Yolk Protein on a Water-Oil Interface.

Egg yolk contains several molecular species with emulsifying properties, such as proteins and phospholipids. In particular, these molecules have both polar and nonpolar parts and thus can act as surfactants. One of the most surface-active proteins from egg yolk low-density lipoproteins is the so-called Apovitellenin-1. Experimental studies have been hindered by difficulties in isolating individual species from egg yolk lipoproteins. The purpose of this work was to assess the emulsifying properties of Apovitellenin-1 and any potential cooperative or competitive behavior in the presence of phospholipids. To do so, molecular simulations were carried out in a liquid-liquid interfacial system consisting of water and soybean oil, with varying concentrations of phospholipids and for different spatial configurations. To evaluate the conformational stability of the protein at the water-oil interface, the Gibbs free energy was computed from Metadynamics simulations as a function of the distance from the interface and of the radius of gyration. Moreover, a detailed analysis was also performed to determine which peptide residues were responsible for the protein adsorption at the oil-water interface as well as the lowering of the interfacial tension. Lastly, we combined the simulation results with a thermodynamic model to predict the interfacial tension behavior at increasing protein bulk concentration, which cannot be measured experimentally.

Effect of egg yolk lipoproteins on foaming properties and interfacial behavior of egg white: Insights into implications for aerated food production

Chicken eggs are often used as an ingredient in oil-containing aerated foods. Different egg yolk lipids have different influence on the foaming properties of egg white, but the exact mechanism behind this influence is not well understood. In this study, we aimed to investigate how high and low-density lipoproteins present in egg yolks impact the macroscopic foam characteristics, rheological properties, and air/water (a/w) interfacial behavior in egg white foams. We found that the addition of low-density lipoprotein (LDL) at a concentration as low as 0.1 % led to a significant decrease in foaming ability (FA) by 284.67–66.67 %. Conversely, high-density lipoproteins (HDL) improved the FA from 284.67 % to 340.67 % within the concentration range of 0.024–0.16 %. Rheological properties showed that the addition of LDL caused a decrease in the viscoelasticity of the interfacial membrane, while HDL had no significant effect on viscoelasticity. Interfacial behavior results suggested that LDL and HDL were detrimental to the diffusion of protein molecules at the a/w interface. This implied that the effects of LDL and HDL on the foaming properties of EWP were mainly due to the competitive adsorption of lipids and proteins at the A/W interface, as well as the interactions between them. This work provides new insights into the effect mechanism of different forms of egg yolk lipids on the foaming properties of egg white, which can be beneficial for regulating oil-containing aerated foods to meet production demands.

ANTIOXIDANT ACTIVITY OF QUINOXALYL HYDRAZONES OF 2-HYDROXYIMINO-1,3-DICARBONYL COMPOUNDS

Biosimilarity and pharmacokinetic descriptors were obtained using SwissADME and ADMETlab 2.0 web services. Analysis of the obtained descriptors shows that, according to Lipinski’s rule, quinoxalyl hydrazones of 2-hydroximino-1,3-dioxocompounds may be promising candidates for drug development for oral administration. Analysis of the pharmacokinetic descriptors of the structures studied shows that, according to the in silico predictions, the compounds can penetrate the blood-brain barrier, be absorbed in the gastrointestinal tract, bind to plasma proteins, be rapidly eliminated from target cells and inhibit CYP3A4, CYP1A2, CYP2C19 and CYP2D6 isoenzymes. The antioxidant activity of quinoxalyl hydrazone derivatives with different benzoyl, ester and acetyl moieties has been studied. Pharmacological screening of the obtained compounds was performed in vitro in the model of Fe2+-induced lipid peroxidation. The data of pharmacological screening indicate clearly pronounced inhibition of lipid peroxidation in the system of yolk lipoproteins by the compounds obtained, which indicates a significant contribution of quinoxalone scaffold in the manifestation of antioxidant properties. Variations in the structure of the starting 1,3-dicarbonyl compounds did not result in significant changes in the antioxidant activity of the obtained hydrazones. The compounds obtained can be promising compounds with marked antioxidant activity for further in vivo studies, including investigation of acute and chronic toxicity. The leading compound is tolyl-substituted quinoxalyl hydrazone IIb

Effects of CaCl2 on the rheology, microstructure and protein structures of rapidly salted separated egg yolk

Bivalent or trivalent metal salts can enhance the oil output and sandiness of salted eggs. We added CaCl2 to the salting solution to improve the quality of rapidly salted separated egg yolk and investigated its effect on rheological, microstructure, and protein structure. According to the findings, adding CaCl2 to the salting solution can promote the precipitation of egg yolk water, increase its viscosity, induce protein aggregation, and increase the denaturation temperature of the protein. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) revealed that the inner boundary of egg yolk salted with CaCl2 was clearer and that the number and size of salted egg yolk lipoprotein aggregates were larger than those of egg yolk salted without CaCl2. Analysis using Fourier transform infrared spectroscopy (FTIR) demonstrated that CaCl2 caused the interconversion of the secondary-level structure. CaCl2 can have an impact on the microenvironment of amino acid residues, according to the results of 3D fluorescence and UV absorption spectra. Therefore, adding CaCl2 can accelerate the loss of water and change the structure of lipoprotein in egg yolk, which improves the sandiness and oil yield of salted separated egg yolk.

Identifying lipid particle sub-types in live Caenorhabditis elegans with two-photon fluorescence lifetime imaging.

Fat metabolism is an important modifier of aging and longevity in Caenorhabditis elegans. Given the anatomy and hermaphroditic nature of C. elegans, a major challenge is to distinguish fats that serve the energetic needs of the parent from those that are allocated to the progeny. Broadband coherent anti-Stokes Raman scattering (BCARS) microscopy has revealed that the composition and dynamics of lipid particles are heterogeneous both within and between different tissues of this organism. Using BCARS, we have previously succeeded in distinguishing lipid-rich particles that serve as energetic reservoirs of the parent from those that are destined for the progeny. While BCARS microscopy produces high-resolution images with very high information content, it is not yet a widely available platform. Here we report a new approach combining the lipophilic vital dye Nile Red and two-photon fluorescence lifetime imaging microscopy (2p-FLIM) for the in vivo discrimination of lipid particle sub-types. While it is widely accepted that Nile Red staining yields unreliable results for detecting lipid structures in live C. elegans due to strong interference of autofluorescence and non-specific staining signals, our results show that simple FLIM phasor analysis can effectively separate those signals and is capable of differentiating the non-polar lipid-dominant (lipid-storage), polar lipid-dominant (yolk lipoprotein) particles, and the intermediates that have been observed using BCARS microscopy. An advantage of this approach is that images can be acquired using common, commercially available 2p-FLIM systems within about 10% of the time required to generate a BCARS image. Our work provides a novel, broadly accessible approach for analyzing lipid-containing structures in a complex, live whole organism context.

ИЗУЧЕНИЕ ХИМИЧЕСКОГО СОСТАВА И БИОЛОГИЧЕСКОГО ДЕЙСТВИЯ ГИДРОЛАТА HYSSOPUS OFFICINALIS L.

Products of plant raw materials processing, in particular hyssop herb are becoming more and more popular nowadays. This plant raw material is used in traditional medicine in many countries all over of the world and is included as an officinal raw material in pharmacopoeias of several European countries: France, Portugal, Romania, Sweden and Germany. Hyssop hydrolat is used in perfumery, cosmetics and food industries, but it is not used in medicine yet, due to the lack of a complex research. This article presents the results of a research of the chemical composition, antibacterial and antioxidant activity of Hyssopus officinalis L. hydrolate. The main aim of the article is to study the chemical composition, antibacterial and antioxidant activity of hydrolate of Hyssopus officinalis L. Materials and methods. The object of the research is a hydrolate of hyssop obtained by the method of steam distillation from freshly harvested raw materials of hyssop (Hyssopus officinalis L.). The study of the chemical composition of the hydrolate was carried out by gas-liquid chromatography. The antibacterial activity of the hydrolate was assessed by the growth and luminescence characteristics of the marine luminescent bacteria Aliivibrio fischeri F1 and recombinant bioluminescent test-objects based on E. coli MG1655. Antioxidant activity was determined by the method of non-enzymatic initiation of lipid peroxidation in a model biological system of yolk lipoproteins. Results. The concentration of essential oil in the hyssop’s hydrolate was defined as 0.032%. It was found that the hydrolate contains isopinocamphone, pinocamphone; β-cariophillen; β-pinen; sabinen and 1.8-cineol. The dynamics of the accumulation of lipid peroxide products in the presence of hyssop’s hydrolate was significantly lower in comparison with the control by 39.47%, which indicates the ability of this hydrolate to suppress free radical oxidation processes, and thus exhibit antioxidant activity. Conclusion. As a result of the research, hydrolate of Hyssopus officinalis L. was found to exhibit antibacterial and antioxidant properties. Prospects for further research are the development of medicines and cosmetics based on hydrolate of Hyssopus officinalis L. with antibacterial and antioxidant properties.

Антиоксидантная активность некоторых фармпрепаратов, применяемых в офтальмологии

Purpose. Identification of antioxidant activity (AOA) in known pharmaceutical drugs used for eye treatment and comparative evaluation of their antioxidant properties. Material and methods. The experimental part of the work was carried out on a model system using a suspension of yolk lipoproteins. This model has several advantages: availability, ease of isolation, storage stability, and reproducibility. The clinical part of work consisted in inclusion of these drugs in the treatment course of patients with inflammatory eye diseases. Results. In this experiment, a high AOA of several drugs was found. As a result, it may be possible to expand their spectrum of applications in treatment of ophthalmic pathology. Conclusions. In several cases, the antioxidant activity of previously known and widely used in ophthalmological practice pharmaceutical drugs was found. The discovery of new properties in known drugs makes it possible to expand the spectrum of their application, considering the identified antioxidant properties. The inclusion of drugs with an antioxidant effect in the treatment course for patients with inflammatory eye diseases can reduce the duration of treatment and increase its effectiveness. Keywords: antioxidants; medicines; initiators of oxidation, lipoproteins

Egg Production and Quality, Lipid Metabolites, Antioxidant Status and Immune Response of Laying Hens Fed Diets with Various Levels of Soaked Flax Seed Meal

Flax seed meal is a valuable source of fatty acids, particularly omega-3 such as alpha-linolenic acid (ALA), but its mucilage contents limit its use. This study assessed the effect of different levels of soaked flax seed meal (SFSM) on the production and health parameters in Rhode Island Red laying hens. A total of 120 hens were divided into three groups and fed diets containing 0, 6, and 12% SFSM for 10 weeks. The impact was determined based on the egg production and quality, lipid metabolites, antioxidant status, immune response, fertility, and hatchability. Diets containing up to 12% SFSM had no adverse effects on the laying rate, egg weight and mass, and feed conversion ratio (FCR). Hens supplemented with a diet containing 12% SFSM exhibited an improved egg-specific gravity, shell thickness, and yolk color. Moreover, egg albumen (%) and blood and meat spots were significantly increased. The Haugh unit score decreased substantially in chickens supplemented with a diet containing 12% SFSM. Moreover, the blood plasma and yolk lipid profiles were significantly reduced dose-dependently. The inclusion of SFSM improved the yolk lipoprotein by increasing the plasma and yolk high- density lipoprotein (HDL) and HDL/LDL (low-density lipoprotein). However, the antioxidant markers, namely, malondialdehyde (MDA), and the ratio between total antioxidants capacity (TAC)/MDA, were negatively affected in hens fed a 12% SFSM diet. Furthermore, the birds fed a 12% SFSM diet had a better immune response based on the phagocytic activity, phagocytic index, lymphocyte transformation test, lysozyme activity, and antibody titer for Newcastle disease virus. The fertility and hatchability increased significantly by 4.81 and 6.74%, respectively, when the hens were fed a diet of 12% SFSM compared with the control. In conclusion, up to 12% of SFSM in hens’ diets had no adverse effects on the productive and reproductive performances; at the same time, they improved the yolk color, plasma lipid profiles, yolk lipid profiles, and immune parameters.

Cytoprotective and Antioxidant Effects of Meconic Acid in Model Systems.

We studied the antioxidant and cytoprotective effects of meconic acid in the model systems. Meconic acid, similar to commercial drug Mexidol, reduced the intensity of chemiluminescence in the model system of yolk lipoproteins. Meconic acid also reduced the toxic effect of glutamate on neurons in the primary cerebellar culture, but had no effect on cell viability under normal conditions.

Synthesis and antioxidant activity of derivatives of 8Н -[1,2,4]triazolo[4,3-в][1,2,4]triazin-7-ones

Oxidative stress is usually connected with many severe diseases, such as atherosclerosis, hypertension, Alzheimer’s disease etc. Therefore, the search for new antioxidants is a very important pharmacological task. The aim of the study – to synthesize new derivatives of 8-(41-hydroxy-3R-benzylidenamino)-6-tertbutyl-8Н-[1,2,4]triazolo[4,3-b][1,2,4]triazine-7-ones and to evaluate their antioxidant properties in screening test in vitro as compared with ionol and ascorbic acid. By interaction of equimolar amounts of 8-amino-6-tert-butyl-8H-[1,2,4]triazolo[4,3-b][1,2,4]triazin7-one with the corresponding aromatic and heterocyclic aldehydes in ethanol, a series of Schiff bases with the key fragment 8H-[1,2,4]triazolo[4,3-b][1,2,4]triazin-7-one were synthesized. The structure and purity of all the substances obtained were confirmed by 1H NMR spectroscopy. Screening of compound’s antioxidant activity (AOA) was studied in vitro by their ability to inhibit lipoperoxide formation, induced by FeSO4 in yolk lipoproteins emulsion. It is shown, that, depending on the structure, the test substances exhibit both antioxidant and prooxidant properties. The regularities of the chemical structure – pharmacological action are established. It is shown that the introduction of electron-withdrawing substituents (F, Cl, Br and COOMe) into the benzene ring leads to a decrease in the antioxidant properties as to the base molecule 6-tert-butyl-8(benzylideneamino)-8Н-[1,2,4]triazolo[4,3-b][1,2,4]triazin-7-оne 8 а without substitutes. The most active were derivatives of 8-(benzylideneamino)-6-~{tert}-butyl-[1,2,4]triazolo[4,3-b][1,2,4]triazin7-ones, which had a hydroxyl group and an additional oxyalkyl fragment in the third position of the benzene ring (8 l, 8 o). The data obtained substantiate the feasibility of further studying the most active derivatives of 6-tertbutyl-8-(benzylideneamino)-8Н-[1,2,4]triazolo[4,3-b][1,2,4]triazin-7-оnes as potential antioxidant agents.

High-density lipoproteins from egg yolk's effect on hyperlipidemia in a high-fat-diet obese mouse using lipidomic analysis

Obesity induced by consuming a high-fat diet (HFD) is a major risk for nonalcoholic fatty liver disease, which has become a worldwide health problem. To study the effects of high-density lipoproteins of egg yolk (EYHDL) on mice with HFD induced obesity, lipidomic analyses using ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was done with serum and liver samples on 60 and 100 days. The results showed that EYHDL significantly alleviated mouse obesity by decreasing adipose tissue accumulation, serum low-density lipoproteins cholesterol, total cholesterol, hepatic triglycerides and development of hepatic steatosis. The EYHDL group was separated from HFD on the orthogonal partial least squares-discriminant analysis score plots, suggesting the beneficial effect of EYHDL on dyslipidemia in obese mice. Volcano plots combined with S-plots showed that the potential biomarkers contributing to these differences were diglycerides, phosphatidylcholines, phosphatidylinositols and lysophosphatidylcholines. On the basis of these biomarkers, glycerophospholipid metabolism is probably the main pathway regulated by EYHDL in obese mice. In summary, EYHDL alleviated hyperlipidemia in obese mice by regulating the phosphatidylcholines and neutral glycerolipids composition, and the lipid biomarkers can be used to better assess the mechanism and therapy for HFD-induced obesity.

Variation of egg proteins between bird varieties by using SDS-PAGE

Proteins are essential constituents of all organisms; both egg white proteins and egg yolk are source of protein. The aim of this study was conducted to perform preliminary studies to analyses and compare egg white proteins and yolk proteins from different avian species (guineafowl, dwarf hens, local hen, Shami, turkey, duck, geese, partridge and quail) via or with SDS-PAGE (Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis ). 18 Fresh eggs of different poultry species (guineafowl, dwarf hens, local hen, Shami, turkey, duck, geese, partridge and quail) were collected from various farms in the Sulaimani province. Data on egg proteins were analyzed using Statistical Xlstate used for dendrogram construction and PCA. The main egg white proteins were Ovomicin, Ovotransferrin, Ovalbumin, Flavoprotein, α- chymotrypsinogen, and Trypsin inhibitor. The main lipoproteins were Apovitellenin VI, Apovitellenin Vb, Apovitellenin V, Apovitellenin IIIa, Apovitellenin III, Apovitellin 7, B-Livetin, Apovitellenin IIa, Apovitellenin II, and Apovitellenin I. All these lipoproteins were observed in the nine birds species. The egg white proteins and yolk lipoproteins for nine species were examined. It can be concluded the large differences were found in a mount of egg white proteins and yolk lipoproteins of the nine species of birds.

Interactions of ostrich egg yolk lipoproteins with seminal plasma of fractionated ejaculates and their effects on post-thaw boar semen quality.

Electrophoretic methods were used to identify protein complexes formed between ostrich egg yolk lipoprotein fractions (LPFo) with seminal plasma (SP) of fractionated ejaculates, and to investigate the effect of these complexes on boar semen quality after cryopreservation. Chromatographic SP fractions (F1, F2 and F3), with or without LPFo solution, were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Comparative electrophoretic analyses of the SP revealed marked differences in the SDS-PAGE protein profiles among boars. Electrophoretic analyses showed that the interactions of LPFo with SP resulted in the appearance of high-intensity protein bands. Spermatozoa were exposed to SP chromatographic fractions originating from F1, F2 and F3, and the whole SP (wSP) before being frozen. Spermatozoa exposed to F1 and F2 exhibited significantly higher post-thaw motility compared to those treated with either F3 or wSP. In most of the boars the proportions of membrane- -intact frozen-thawed spermatozoa differed among the treatments, being significantly lower in the wSP-treated samples. The incidence of frozen-thawed spermatozoa with DNA fragmentation was less prevalent in samples exposed to F3 or the wSP. The results of this study confirmed that the interactions of LPFo with fractionated SP during the cooling period contributed to alterations in the sperm membranes, rendering them less susceptible to temperature-related injury.

Delayed Feeding Alters Transcriptional and Post-Transcriptional Regulation of Hepatic Metabolic Pathways in Peri-Hatch Broiler Chicks.

Hepatic fatty acid oxidation of yolk lipoproteins provides the main energy source for chick embryos. Post-hatching these yolk lipids are rapidly exhausted and metabolism switches to a carbohydrate-based energy source. We recently demonstrated that many microRNAs (miRNAs) are key regulators of hepatic metabolic pathways during this metabolic switching. MiRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression in most eukaryotes. To further elucidate the roles of miRNAs in the metabolic switch, we used delayed feeding for 48 h to impede the hepatic metabolic switch. We found that hepatic expression of several miRNAs including miR-33, miR-20b, miR-34a, and miR-454 was affected by delaying feed consumption for 48 h. For example, we found that delayed feeding resulted in increased miR-20b expression and conversely reduced expression of its target FADS1, an enzyme involved in fatty acid synthesis. Interestingly, the expression of a previously identified miR-20b regulator FOXO3 was also higher in delayed fed chicks. FOXO3 also functions in protection of cells from oxidative stress. Delayed fed chicks also had much higher levels of plasma ketone bodies than their normal fed counterparts. This suggests that delayed fed chicks rely almost exclusively on lipid oxidation for energy production and are likely under higher oxidative stress. Thus, it is possible that FOXO3 may function to both limit lipogenesis as well as to help protect against oxidative stress in peri-hatch chicks until the initiation of feed consumption. This is further supported by evidence that the FOXO3-regulated histone deacetylase (HDAC2) was found to recognize the FASN (involved in fatty acid synthesis) chicken promoter in a yeast one-hybrid assay. Expression of FASN mRNA was lower in delayed fed chicks until feed consumption. The present study demonstrated that many transcriptional and post-transcriptional mechanisms, including miRNA, form a complex interconnected regulatory network that is involved in controlling lipid and glucose molecular pathways during the metabolic transition in peri-hatch chicks.

PRY-1/Axin signaling regulates lipid metabolism in Caenorhabditis elegans.

The nematode Caenorhabditis elegans constitutes a leading animal model to study how signaling pathway components function in conserved biological processes. Here, we describe the role of an Axin family member, PRY-1, in lipid metabolism. Axins are scaffolding proteins that play crucial roles in signal transduction pathways by physically interacting with multiple factors and coordinating the assembly of protein complexes. Genome-wide transcriptome profiling of a pry-1 mutant revealed differentially regulated genes that are associated with lipid metabolism such as vitellogenins (yolk lipoproteins), fatty acid desaturases, lipases, and fatty acid transporters. Consistent with these categorizations, we found that pry-1 is crucial for the maintenance of lipid levels. Knockdowns of vit genes in a pry-1 mutant background restored lipid levels, suggesting that vitellogenins contribute to PRY-1 function in lipid metabolic processes. Additionally, lowered expression of desaturases and lipidomic analysis provided evidence that fatty acid synthesis is reduced in pry-1 mutants. Accordingly, an exogenous supply of oleic acid restored depleted lipids in somatic tissues of worms. Overall, our findings demonstrate that PRY-1/Axin signaling is essential for lipid metabolism and involves the regulation of yolk proteins.

Low Density Lipoproteins at 2% Concentration Can Replace Whole Egg Yolk in TES-Tris-Milk Extender for Freezing Buffalo Sperm Cells

Background: Over the years, the most commonly used extenders for semen cryopreservation contain egg yolk as cryoprotectant. However, more recent studies have used the low density lipoproteins, extract of hen egg yolk which is responsible for the cryoprotective effect. Nevertheless, little was known about its required minimum concentration as well as its interaction with other extra cellular cryoprotectants, like skimmed milk. The present study aimed at investigating the effect of replacing whole egg yolk by adding low density lipoproteins at low concentrations, in TES-Tris-skim milk based extender, on the post-thaw quality of buffalo bull sperm.Materials, Methods & Results: Eighteen ejaculates were collected from six buffalo bulls and diluted with TES-Tris-skim milk based extender containing LDL, extracted from hen egg yolks, at the concentrations of 2%, 4%, 8% and 14%, against a control extender containing 20% fresh egg yolk. After semen collection, analyses of subjective motility, vigor, force tourbillon, sperm concentration (Neubauer chamber) and sperm morphology (phase contrast microscopy) were performed. The diluted semen was packaged in 0.25 mL straws, and cooling was performed on computerized machine (TK 4000®), using a cooling rate of -0.25°C/min to 5°C. Semen was kept in balance at 5°C for 4 h. The straws were frozen in an ice chest, kept at 5 cm from the surface of liquid nitrogen for 20 min and then immersed in liquid nitrogen. The samples were kept in cryogenic container until thawing. Post-thaw kinetic parameters during incubation at 37°C (CASA), sperm membrane integrity (SYBR-14/PI), membrane functionality (hypo-osmotic swelling test) and DNA fragmentation (%DFI - SCSA) were evaluated after thawing. Immediately post-thaw, total motility was higher in the control (56.53 ± 9.73) than in the tested extenders; however, after 30 min the difference was no longer detected. All other kinetic parameters presented significantly better results in extenders containing 2%, 4% and 8% LDL, compared with the control. There was no difference between treatments regarding the integrity of membranes or fragmentation of the DNA after freezing/thawing procedures.Discussion: The molecules of low density lipoproteins of egg yolk have the known action of sequestering BSP ( binder of sperm proteins) protein, due to the chemical affinity of their main components, phosphatidylcholine and phosphatidylethanolamine. The BSP are responsible for removing cholesterol from the plasma membrane of the sperm, preparing it for the sperm capacitation phase. Low density lipoproteins by inhibiting the action of the BSP increase the stability of the plasma membrane during the freeze-thaw process. The milk caseins micelles have a similar ability to bind the BSP, but with lower affinity. The present study has shown that the use of purified low density lipoproteins has an advantage over the use of whole egg yolk, especially with regard to the kinetic parameters of the spermatozoa after thawing. Furthermore, it was observed that low concentrations of low density lipoproteins, such as 2%, in extenders containing skim milk, could preserve the sperm cell during the freeze-thawing process like that higher LDL concentrations and whole egg yolk. Further studies are needed to determine if the cryoprotectant action found in this study was a result of the synergistic action of skim milk with lipoproteins or even at low concentrations like 2% the lipoproteins can provide protection to the buffalo spermatozoa during freezing, as it has been reproduced in other domestic species. In conclusion, our results indicated that the extender TES-Tris-skim milk containing 2% LDL extracted from egg yolk could be used successfully in the cryopreservation of buffalo sperm cells.

Freezability and fertility of frozen-thawed boar semen supplemented with ostrich egg yolk lipoproteins.

Lipoproteins, isolated from ostrich egg yolk (LPFo), provide excellent protection for boar spermatozoa against cryo-induced damage. The present study was performed to investigate the effects of LPFo on the freezability and fertilizing capacity of frozen-thawed (FT) boar semen after post-cervical artificial inseminations (post-CAIs). Semen, collected from 7 Polish Large White (PLW) and 4 Polish Landrace (PLR), was frozen in an extender containing LPFo. Post-CAIs were performed in 38 multiparous sows, using a catheter-cannula kit. Sows were inseminated 2× within one oestrus, and fertility parameters were recorded after farrowing. Neither boar (within breed) nor breed affected the quality of the pre-freeze (PF) semen, such as total motility (TMOT), mitochondria membrane potential (MMP), plasma membrane integrity (PMI), osmotic resistance test (ORT) and DNA fragmentation. Differences in the freezability of boar semen were observed among the boars, whereas there were no marked breed effects. Post-thaw TMOT markedly declined over storage time in most of the boars, particularly at 60 min after thawing. Inseminations of post-weaned oestrus sows resulted in pregnancy and farrowing rates of 84.2% and 81.6%, respectively. Neither the mean number of piglets born (NB) nor the mean number of piglets born alive (NBA) was affected by boar or breed. The total number of piglets born was 365, resulting in 11.8 NB piglets, whereas the total number of piglets born alive was 353, with 11.4 NBA piglets per litter. The findings of this study reaffirm the variations in the freezability of boar semen. In this study the supplementation of ostrich egg yolk lipoproteins to the freezing extender of boar semen produced high proportions of functionally viable FT spermatozoa that were capable of providing acceptable fertility results after post-CAIs in multiparous sows.

The experimental study of antihypoxic and antioxidant indolinoren activity

Topicality. The modern medicine prefers the diuretics, which along with the diuretic effect exhibit other pharmacological activities: e.g., anti-inflammatory, antispasmodic, antioxidant, antihypoxic, which complements their pharmacodynamics.Aim. To study the antihypoxic investigation and antioxidant activities of the new potential diuretic substance – indolinoren. Materials and methods. The investigation of an antihypoxic activity was conducted on nonlinear white male rats with weight of 180-200 g using the on the model of hypoxia with hypercapnia. The antioxidant activity research was carried out in vitro using the system model of yolk lipoprotein. As reference drugs mexidol and ionol were used. Results and discussions. It was established that indolinoren at dose of 29.5 mg/kg reveals antihypoxic properties, as evidenced by a significant extension (2 times) of lifespan of animals compared to the control group. While studying the antioxidant properties it was found that indolinoren significantly reduces the accumulation of TBA-reactive products taken in all experimental doses (50, 100, 200 mg/ml) that may indicate suppression of lipid peroxidation. Conclusions. The presence of antioxidant and antihypoxic properties complement pharmacodynamics of indolinoren – perspective diuretic agent.

Metabolic Activity of Boar Semen Stored in Different Extenders Supplemented with Ostrich Egg Yolk Lipoproteins.

IntroductionThe aim of this study was to evaluate the effect of lipoprotein fraction isolated from ostrich egg yolk (LPFo) on the metabolic activity of boar spermatozoa following liquid semen storage in different extenders and temperatures.Material and MethodsBoar ejaculates were extended in Androhep, Beltsville thawing solution (BTS), and Martín-Rillo and Alias (MR-A) without (control) or with the addition of LPFo and stored for three days at either 5°C or 16°C. The analysed sperm parameters included total motility (TMOT), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), oxygen consumption, and adenosine triphosphate (ATP) production.ResultsThe sperm metabolic activity seemed to be higher in the LPFo-based extenders following storage for three days, irrespective of the storage temperature. Compared with the LPFo-free extenders, significantly higher (P < 0.05) sperm PMI and MMP were observed in BTS and MR-A extenders supplemented with LPFo during storage for three days at 5°C. Spermatozoa stored in the BTS-LPFo extender exhibited higher (P < 0.05) TMOT and oxygen consumption, whereas higher (P < 0.05) PMI was observed in spermatozoa stored in Androhep-LPFo and MR-A-LPFo for three days at 16°C. No significant differences (P > 0.05) in ATP content were observed between the LPFo-free and LPFo-based extenders during storage.ConclusionsSupplementation of LPFo to semen extenders had varying effects on the metabolic activity of boar spermatozoa stored at different temperatures. It can be suggested that the interactions of various components of the extenders and seminal plasma with LPFo exert beneficial effects on the sperm metabolic activity during liquid storage of boar semen.