Consumption of Nutritionally Enriched Hen Eggs Enhances Endothelium-Dependent Vasodilation via Cyclooxygenase Metabolites in Healthy Young People—A Randomized Study

Abstract

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.

Patients with Chronic Coronary Syndrome Can Benefit from Consumption of Enriched Chicken Eggs: The Effects on Microvascular Function, Inflammatory Biomarkers, and Oxidative Status—Randomized Clinical Study

“…The improvement in endothelial function in our subjects may be explained by changes in iNOS levels. An increase in the expression of the nNOS isoform was found in our previous studies in healthy young adults who consumed Nutri4 eggs [13]. Although the overexpression of iNOS has been associated with septic shock, some autoimmune diseases, and even malignancies, it also has beneficial effects and is necessary for normal cellular function [49].…”

“…Measurements of lutein serum concentrations were performed according to the protocol by Tzeng et al using high-performance liquid chromatography (HPLC; HPLC LC-30 NEXERA, Shimadzu, Japan, 2018), which was adopted and described in earlier papers by our research group [13]. HPLC analysis was performed at the Department of Chemistry, Josip Juraj Strossmayer University of Osijek.…”

“…The underlying mechanism in most cases is the impaired production or bioavailability of nitric oxide (NO) and/or the altered production of vasoactive prostaglandins/eicosanoids [13,14]. NO mediates endothelium-dependent vasodilation and inhibits platelet adhesion and aggrega-tion [13], leukocyte adhesion/infiltration, and vascular smooth muscle cell proliferation. NO also prevents the oxidation of LDL cholesterol [15].…”