Carnosine is a dipeptide synthesized in the body from β-alanine and L-histidine. It is found in high concentrations in the brain, muscle, and gastrointestinal tissues of humans and is present in all vertebrates. Carnosine has a number of beneficial antioxidant properties. For example, carnosine scavenges reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydes created by peroxidation of fatty acid cell membranes during oxidative stress. Carnosine can oppose glycation, and it can chelate divalent metal ions. Carnosine alleviates diabetic nephropathy by protecting podocyte and mesangial cells, and can slow down aging. Its component, the amino acid beta-alanine, is particularly interesting as a dietary supplement for athletes because it increases muscle carnosine, and improves effectiveness of exercise and stimulation and contraction in muscles. Carnosine is widely used among athletes in the form of supplements, but rarely in the population of cardiovascular or diabetic patients. Much less is known, if any, about its potential use in enriched food. In the present review, we aimed to provide recent knowledge on carnosine properties and distribution, its metabolism (synthesis and degradation), and analytical methods for carnosine determination, since one of the difficulties is the measurement of carnosine concentration in human samples. Furthermore, the potential mechanisms of carnosine’s biological effects in musculature, metabolism and on immunomodulation are discussed. Finally, this review provides a section on carnosine supplementation in the form of functional food and potential health benefits and up to the present, neglected clinical use of carnosine.

The research investigates the possibilities of enriching eggs with n-3 polyunsaturated fatty acids, selenium, vitamin E, and lutein. The research was carried out on 100 TETRA SL laying hens divided into two groups (C and E). Hens in treatment C (control group) were fed a standard feeding mixture that contained 5% soybean oil, 0.32 mg/kg organic selenium, 25.20 mg/kg vitamin E, and 20.5 mg/kg lutein (Marigold flower extract). Hens in treatment E (experimental group) were fed a mixture in which soybean oil was replaced by 1.5% fish oil + 1.5% rapeseed oil + 2.0% linseed oil. The content of other nutricines amounted to 0.47 mg/kg organic selenium, 125.2 mg/kg vitamin E, and 120.5 mg/kg lutein. Portions of total n-3 polyunsaturated fatty acids in enriched eggs were significantly increased when compared to conventional eggs (480.65:204.58 mg/100 g; p < 0.001). The content of selenium, vitamin E, and lutein was significantly higher (p < 0.001) in enriched eggs than in conventional eggs. The content of selenium in egg albumen was increased by 1.81 times, and in the yolk, it was increased by 1.18 times. At the same time, the content of vitamin E was 2.74 times higher, and lutein was 8.94 times higher in enriched eggs than in conventional eggs.

This research elaborates the process of enriching table eggs with n-3 polyunsaturated fatty acids (n-3 PUFA) and presents the effect of such enriched eggs on human health. The experiment was performed on 480 TETRA SL laying hens divided into three groups. Feeding mixtures contained 5% of oils (K = soybean oil, P1 = 3.5% linseed oil + 1.5% fish oil, P2 = 3% linseed oil + 2% fish oil). Referring to the content of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), eggs of P1 and P2 groups were significantly richer in n-3 PUFA than eggs of the control group (p = 0.001). Atherogenic (AI), thrombogenic (TI), and hypo/hypercholesterolemic (HHI) indexes of egg yolks were more favourable in enriched eggs than in conventional eggs. Fatty acid profiles in the blood of examinees that consumed conventional and enriched eggs (treatments K and P1, respectively) differed significantly in total saturated fatty acids (ΣSFA) (p = 0.041) and in the content of ALA (p = 0.010). The consumption of n-3 PUFA-enriched eggs lowered the Σn-6 PUFA/Σn-3 PUFA ratio in the examinees’ blood serum (27%) and had a favourable effect on some blood biochemical indicators. This research confirmed the assumption that the use of a combination of fish and linseed oil in mixtures for laying hens in an amount of up to 5% will increase the content of omega-3 in table eggs, but it was not confirmed that the consumption of these eggs in a short period of time (21 days) has a positive effect on human health.

Objective: The present study aimed to evaluate the effects of enriched hen egg consumption on endothelium-dependent vasodilation (EDV) and the role of cyclooxygenases in EDV in the microcirculation of young healthy individuals. This study hypothesizes that Nutri4 eggs will improve endothelial function, which will be manifested by changes in microcirculatory flow measured by a laser Doppler flowmeter (LDF) during reactive hyperemia in response to vascular occlusion, in which n-3 PUFA plays an important role as well as its degradation pathway by cyclooxygenases. Materials and Methods: Participants consumed three eggs per day for three weeks: The control group (CTRL, n = 14) consumed regular hen eggs (approximately 0.330 mg of lutein, 1.785 mg of vitamin E, 0.054 mg of selenium and 438 mg of n-3 PUFAs daily) and Nutri4 group (n = 20) consumed enriched eggs (approximately 1.85 mg of lutein, 0.06 mg of selenium, 3.29 mg of vitamin E, and 1026 mg of n-3 PUFAs daily). Skin microvascular blood flow in response to EDV (post-occlusive reactive hyperemia (PORH) and iontophoresis of acetylcholine (AChID)) and sodium nitroprusside (SNPID; endothelium-independent) was assessed by laser Doppler flowmetry before and after dietary protocol and in a separate group of participants who were administered perorally 100 mg of indomethacin before microvascular response assessment. Arterial blood pressure, heart rate, serum lipid, and liver enzymes, anthropometric measurements, protein expression of cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2), neuronal nitric oxide synthases (nNOS), inducible nitric oxide synthases (iNOS), and endothelial nitric oxide synthases (eNOS) were measured before and after dietary protocol. Results: PORH and AChID were significantly enhanced, and SNPID remained unchanged in the Nutri4 group, while none was changed in the CTRL following a respective diet. PORH decreased after administration of indomethacin in Nutri4 after dietary protocol. Protein expression of COX-2 was significantly higher in the Nutri4 group compared to the CTRL after the dietary protocol. Conclusion: Consumption of enriched eggs improves microvascular EDV in healthy young subjects. Results suggest an element of n-3 PUFAs metabolites via the cyclooxygenases pathway in enhanced reactive hyperemia.