Antihypertensive peptides derived from egg proteins.

There have been studies of antihypertensive peptides derived from food proteins, but very few described the production of bioactive peptides from egg proteins. The first 2 antihypertensive peptides isolated in egg were obtained by enzymatic hydrolysis of ovalbumin. They correspond to the sequences Phe-Arg-Ala-Asp-His-Pro-Phe-Leu (ovokinin) and Arg-Ala-Asp-His-Phe-Leu (ovokinin 2-7). Both exhibited endothelium-dependent vasodilatory activity. Ovokinin (2-7) had higher antihypertensive potency than ovokinin in spontaneously hypertensive rats (SHR). Modifications in the sequence of ovokinin (2-7) improved the bioavailability of this peptide. It was also demonstrated that different ovalbumin hydrolysates can inhibit angiotensin I-converting enzyme (ACE). We recently obtained an egg white hydrolysate that inhibited the enzyme in vitro. It was obtained by treating egg white with pepsin and it exhibited antihypertensive activity in SHR. Some ACE-inhibitory peptides obtained from this hydrolysate (Tyr-Arg-Glu-Glu-Arg-Tyr-Pro-Ile-Leu, Arg-Ala-Asp-His-Pro-Phe-Leu, and Ile-Val-Phe) also showed antihypertensive activity in these rats. The egg products mentioned could be used as functional food ingredients with potential therapeutic benefit in the prevention and treatment of hypertension.