Amaranth is a highly nutritious and non-allergenic crop with remarkable nutraceutical properties. Seed protein extracts following enzymatic digestion have been shown to inhibit Angiotensin Converting Enzyme (ACE). A possible mechanism of action of ACE inhibitor (ACEi) peptides involving the induction of Nitric Oxide (NO) production through endogenous Nitric Oxide Synthase (eNOS) activation has been proposed. The presence of lunasin, a peptide with proven antitumoral properties, has been confirmed in amaranth seeds and the gene encoding the amaranth lunasin peptide appears homologous to the bifunctional inhibitor/lipid transfer protein/seed storage 2S of the albumin family. Amaranth consumption has been shown to improve the plasma lipid profiles in animals. Methanolic extracts of amaranth have demonstrated anti-hyperlipidemic, anti-diabetic and anti-helmintic properties, while aqueous extracts have demonstrated anti-diarrheic, anti-fungal and anti-malarial properties. Specific polyphenols such as rutin, isoquercetin and nicotiflorin and some phenolic acids and amides with antioxidant effects have also been found in amaranth seeds. The aim of this mini-review is to provide an overview of the nutraceutical properties of amaranth.
Keywords: ACE-inhibitory peptides, amaranth, bioactive peptides, lunasin, nutraceuticals, polyphenols, rutin, Proteins Fractions, Antihypertensive Effect, Anti-Hyperlipidemic Effects