Effect of amaranth proteins on the RAS system. In vitro, in vivo and ex vivo assays

• Published in: Food chemistry 2020-03, Vol.308, p.125601-125601, Article 125601
• Main Authors: Suárez, Santiago, Aphalo, Paula, Rinaldi, Gustavo, Añón, Maria Cristina, Quiroga, Alejandra
• Format: Article
• Language: English
• Subjects: Amaranth proteins; Amaranthus - chemistry; Animals; Antihypertensive activity; Antihypertensive Agents - pharmacology; Antihypertensive Agents - therapeutic use; Blood Pressure - drug effects; Hypertension - drug therapy; Male; Peptides - pharmacology; Peptides - therapeutic use; Plant Proteins - pharmacology; Plant Proteins - therapeutic use; Protein hydrolysate; Rats; Rats, Inbred SHR; Renin-angiotensin system; Renin-Angiotensin System - drug effects; Spontaneously hypertensive rats
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2019.125601

•Amaranth peptides produce a very significant decrease in blood pressure in SHR rats.•These peptides have an effect on ACE and renin plasma level and ACE activity.•Amaranth peptides produce depolarization of membranes which causes vasorelaxation.•Synthetic peptide VIKP also acts on b-adrenergic receptors causing vasorelaxation.•Amaranth peptides act at both levels, on blood vessels and on RAS enzymes. The aim of this work was to analyse the hypotensive effect of amaranth protein/peptides on spontaneously hypertensive rats (SHR). The mechanism of action of these peptides was studied in vivo and ex vivo. We also tested the effect of protection against gastrointestinal digestion (GID) exerted by an O:W emulsion on the integrity of the antihypertensive peptides. All samples tested produced a decrease in blood pressure (SBP). The animals treated with emulsion (GE) and emulsion + peptide (GE+VIKP) showed the most significant reduction in the SBP (42 ± 2 mmHg and 35 ± 2 mmHg, respectively). The results presented suggest that after GID, a variety of peptides with biological activities were released or were resistant to this process. These peptides play a role in the regulation of the SBP by acting on plasma ACE, plasma renin and the vascular system. These results support the use of amaranth protein/peptides in the elaboration of functional foods for hypertensive individuals.