Egg White Protein Produces Blood-Pressure-Lowering and Antioxidant Peptides During Digestion
Simulated digestion of hen egg white lysozyme released 38 peptides with potent ACE-inhibitory activity (IC50 = 12.6 μg/ml) and antioxidant properties, suggesting eggs could be a source of cardiovascular-supporting peptides.
Quick Facts
What This Study Found
When hen egg white lysozyme was digested in a simulated gut environment, the resulting peptide fragments showed strong ACE-inhibitory activity with an IC50 of 12.6 μg/ml — meaning a very low concentration was needed to block half the activity of the blood-pressure-raising enzyme ACE. The digest also showed remarkable antioxidant activity.
Using mass spectrometry, the researchers identified 38 distinct peptides in the digest. Several of these matched the known structural requirements for ACE inhibition and antioxidant function, suggesting egg white lysozyme is a rich source of multifunctional bioactive peptides.
Key Numbers
IC50 = 12.6 μg/ml for ACE inhibition · 38 peptides identified · 3 kDa membrane filtration · simulated gastrointestinal digestion
How They Did This
Researchers subjected hen egg white lysozyme to simulated gastrointestinal digestion (mimicking the stomach and intestine). The resulting peptide fragments were filtered through a 3 kDa membrane, and the smaller peptides that passed through were analyzed using MALDI-TOF-TOF mass spectrometry to identify individual peptide sequences. ACE-inhibitory and antioxidant activities were measured in vitro.
Why This Research Matters
ACE inhibitors are one of the most widely prescribed classes of blood pressure medication. Finding natural food-derived peptides with ACE-inhibitory and antioxidant properties could lead to functional foods or supplements that support cardiovascular health through everyday diet — offering a complementary approach to pharmaceutical treatment.
The Bigger Picture
Food-derived bioactive peptides are a rapidly growing area of research, with scientists looking for natural alternatives or supplements to pharmaceutical interventions for hypertension and oxidative stress. Egg proteins are abundant and inexpensive, making them attractive candidates for functional food development. This study adds lysozyme to the list of food proteins that can generate health-promoting peptides during normal digestion.
What This Study Doesn't Tell Us
This is entirely an in-vitro study — the ACE inhibition and antioxidant effects were measured in test tubes, not in living organisms. Whether these peptides survive real human digestion, get absorbed into the bloodstream, and actually lower blood pressure remains unknown. No animal or human studies were conducted.
Questions This Raises
- ?Do these peptides survive real human digestion and get absorbed intact into the bloodstream?
- ?Could consuming egg white lysozyme in meaningful amounts actually lower blood pressure in people?
- ?How do these egg-derived ACE-inhibitory peptides compare in potency to those from milk, fish, or soy proteins?
Trust & Context
- Key Stat:
- IC50 = 12.6 μg/ml The lysozyme digest inhibited ACE at a very low concentration, comparable to some pharmaceutical-grade ACE inhibitors
- Evidence Grade:
- This is a preliminary in-vitro study that identifies peptides and measures their activity in test tubes. No living organism was tested, so the real-world relevance of these findings remains to be established.
- Study Age:
- Published in 2012, this study is part of the foundational research on food-derived ACE-inhibitory peptides. The field has advanced since, but the peptide identification data remains cited in current literature.
- Original Title:
- ACE inhibitory peptides and antioxidant peptides derived from in vitro digestion hydrolysate of hen egg white lysozyme.
- Published In:
- Food chemistry, 135(3), 1245-52 (2012)
- Authors:
- Rao, Shengqi, Sun, Jun, Liu, Yuntao, Zeng, Huawei, Su, Yujie, Yang, Yanjun
- Database ID:
- RPEP-02045
Evidence Hierarchy
Frequently Asked Questions
What is ACE and why does inhibiting it matter for blood pressure?
ACE (angiotensin-converting enzyme) is an enzyme that narrows blood vessels and raises blood pressure. ACE inhibitor drugs are among the most commonly prescribed medications for hypertension. Finding natural food-derived peptides that block ACE could offer dietary approaches to supporting healthy blood pressure.
Does eating eggs actually lower blood pressure based on this study?
This study cannot answer that question. It showed that egg white lysozyme produces ACE-inhibiting peptides in a simulated digestive environment, but whether real human digestion produces the same result, and whether enough peptide reaches the bloodstream to affect blood pressure, would require animal and human studies.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-02045APA
Rao, Shengqi; Sun, Jun; Liu, Yuntao; Zeng, Huawei; Su, Yujie; Yang, Yanjun. (2012). ACE inhibitory peptides and antioxidant peptides derived from in vitro digestion hydrolysate of hen egg white lysozyme.. Food chemistry, 135(3), 1245-52. https://doi.org/10.1016/j.foodchem.2012.05.059
MLA
Rao, Shengqi, et al. "ACE inhibitory peptides and antioxidant peptides derived from in vitro digestion hydrolysate of hen egg white lysozyme.." Food chemistry, 2012. https://doi.org/10.1016/j.foodchem.2012.05.059
RethinkPeptides
RethinkPeptides Research Database. "ACE inhibitory peptides and antioxidant peptides derived fro..." RPEP-02045. Retrieved from https://rethinkpeptides.com/research/rao-2012-ace-inhibitory-peptides-and
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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.