Potential of a Renin Inhibitory Peptide from the Red Seaweed Palmaria palmata as a Functional Food Ingredient Following Confirmation and Characterization of a Hypotensive Effect in Spontaneously Hypertensive Rats

Abstract

This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.

Bioactive Peptides

“…Also, the dipeptide DY in aqueous extracts from bamboo shoots has been shown to reduce SBP by 18 mmHg in SHRs when administered at 10 mg/kg body weight/day [120]. In another study, Fitzgerald et al [121] isolated the peptide IRLIIVLMPILMA from hydrolyzed Palmaria palmata with papain. The peptide reduced systolic blood pressure by 33 mmHg in SHR.…”

“…Therefore, inhibition of ACE reduces high blood pressure. Other peptides such as IRLIIVLMPILMA inhibit renin [121], an enzyme that cleaves a dipeptide from angiotensinogen to yield angiotensin I [131]. Some antihypertensive peptides enhance nitric oxide production [132,133] while other peptides including RVPSL block angiotensin II receptors [134].…”

Bioactive Peptides Derived from Seaweed Protein and Their Health Benefits: Antihypertensive, Antioxidant, and Antidiabetic Properties

“…Cardiovascular diseases (CVD), including heart diseases and stroke are major syndromes that affect the human circulatory system (Collins and others ). The major risk factor for CVD is hypertension, which is the elevation of arterial blood pressure (Kim and Wijesekara ; Fitzgerald and others ; Cheung and others ; Collins and others ) and it affects 15% to 20% of the global population (Ko and others ). Renin and angiotensin converting enzyme (ACE) are the 2 key enzymes in renin‐angiotensin system (RAS), the endocrine system that regulates peripheral blood pressure (Harnedy and FitzGerald ; Cheung and others ).…”

Isolation and identification of a novel peptide from zein with antioxidant and antihypertensive activities

“…1 Biologically active peptides can be released after gastrointestinal digestion, food processing and microbial proteolysis of various animal and plant proteins. 2 Bioactive peptides are the main products of hydrolysis of diverse food proteins. Peptides may have various properties, such as antioxidative, antithrombotic, opiate-like, mineral binding, immunomodulatory, antimicrobial, hypocholesterolemic and antihypertensive activities.…”