Figure 3. Effect of oral administration of EWH or OD-EWH (at a dose of 1 g/kg BW/d) on the levels of renin-angiotensin system (RAS) components in the kidney. The protein levels of (a) ACE2, (b) MasR, (c) AT2R, (d) AT1R, and (e) ACE were normalized to GAPDH and were then normalized to that of the untreated group.
Hypertension is a major public health concern, affecting millions worldwide and increasing the risk of heart disease, stroke, and kidney failure. It is typically characterized by persistent high blood pressure, which can result from multiple mechanisms, including increased activity of the renin-angiotensin system (RAS), inflammation, and oxidative stress. Although pharmaceutical treatments are available, they often come with side effects, making the search for natural, side-effect-free alternatives increasingly important. Egg whites, known for their high-quality protein content, also contain various bioactive peptides with proven antioxidant, anti-inflammatory, and antihypertensive properties. Recent studies have shown that egg white proteins, even after depleting ovotransferrin, can still provide effective antihypertensive peptides.
A study published in on 30 December 2024 by Jianping Wu’s team, University of Alberta, highlights the potential of egg white proteins as a valuable functional food ingredient for addressing high blood pressure.
In this study, the antihypertensive effects of ovotransferrin-depleted egg white hydrolysate (OD-EWH) were evaluated in spontaneously hypertensive rats (SHRs), with egg white hydrolysate (EWH) serving as the reference. The rats were administered 1 g/kg body weight per day of either hydrolysate for 9 days. The results showed that both OD-EWH and EWH significantly reduced systolic blood pressure (SBP), with OD-EWH lowering SBP to 160.47 mmHg and EWH reducing it to 159.42 mmHg, compared to the untreated group (178.07 mmHg). Both treatments also reduced mean arterial pressure (MAP) and diastolic blood pressure (DBP), without affecting heart rate. Further analysis revealed that both hydrolysates upregulated the expression of ACE2, an important enzyme in regulating vascular health, in the aorta. While EWH also decreased ACE and AT1R levels, OD-EWH had no significant effect on these proteins but increased the AT2R level. In the kidneys, both OD-EWH and EWH reduced renal ACE levels, but did not affect ACE2, MasR, or AT1R/AT2R expression. Additionally, OD-EWH significantly enhanced the expression of endothelial nitric oxide synthase (eNOS) in the aorta, suggesting a mechanism for blood pressure reduction through improved nitric oxide production. Both hydrolysates also attenuated vascular oxidative stress, as indicated by reduced nitrotyrosine staining. However, only EWH reduced vascular inflammation markers like VCAM-1, while OD-EWH did not affect markers of inflammation. These findings suggest that OD-EWH may reduce blood pressure through the modulation of the renin-angiotensin system, eNOS activation, and antioxidant effects, making it a promising functional food ingredient for hypertension management.
The study underscores the potential of egg white hydrolysates, especially those depleted of ovotransferrin, as effective natural antihypertensive agents. By modulating the RAS, enhancing eNOS expression, and reducing oxidative stress, OD-EWH offers a promising approach for managing high blood pressure. This research highlights the importance of natural, cost-effective food-based solutions in combating hypertension and opens the door for further innovations in functional food development aimed at improving cardiovascular health.
###
References
DOI
Original Source URL
Funding information
This work was supported by the Natural Sciences and Engineering Research Council of Canada, Grant No. CRDPJ 532150-18, Egg Farmers of Canada, and the Global Egg Corporation.
About
The open-access journal Food Materials Research (e-ISSN 2771-4683) is published by Maximum Academic Press in partnership with Nanjing Agricultural University. The article types include original research papers, reviews, methods, editorials, short communications, and perspectives. All articles published in Food Materials Research represent significant advances in the genetic, molecular, biochemical, physiological processes and pathways related to food materials and sources and will provide scientific information towards overcoming technological limitations in developing conventional and alternative foods.
RSS