Amaranth as a Source of Antihypertensive Peptides

Abstract

Amaranth is an ancestral crop used by pre-Columbian cultures for 6000 to 8000 years. Its grains have a relevant chemical composition not only from a nutritional point of view but also due to the contribution of components with good techno-functional properties and important potential as bioactive compounds. Numerous studies have shown that amaranth storage proteins possess encrypted sequences that, once released, exhibit different physiological activities. One of the most studied is antihypertensive activity. This review summarizes the progress made over the last years (2008-2020) related to this topic. Studies related to inhibition of different enzymes of the Renin-Angiotensin-Aldosterone system, in particular Angiotensin Converting Enzyme (ACE) and Renin, as well as those referring to potential modulation mechanisms of tissue or local Renin-Angiotensin-Aldosterone system, are analyzed, including in silico, in vitro, in vivo, and ex vivo assays. Furthermore, the potential use of these bioactive peptides or products containing them, in the elaboration of functional food matrices is discussed. Finally, the most relevant conclusions and future requirements in research and development of food products are presented.

Lupin-Derived Bioactive Peptides: Intestinal Transport, Bioavailability and Health Benefits

“…This class of drugs act by inhibiting the release of renin, the conversion of angiotensin I to angiotensin II via inhibition of angiotensin-converting enzyme (ACE) and/or blocking of angiotensin receptors (AR), especially angiotensin receptor-1 (AR-1) and mineralocorticoid receptor (MR) that interact with angiotensin II to promote aldosterone secretion [ 136 ]. Several natural products are currently being explored as potential anti-hypertensive agents, including plant-polyphenols and protein-derived peptides [ 137 , 138 , 139 ]. Hydrolysates of lupin proteins exhibited potential anti-hypertensive effects in an in vitro set-up by inhibiting ACE activity with IC 50 value of 226 µg/mL [ 4 ].…”

The effect of amaranth oil on proteinuria in lupus prone mice

“…The food value of 100g of amaranth oil is noted in Table 1. Notably, compared to cereal alternatives, the grain has more proteins, lipids, and minerals [46]. It is rich in antioxidants and phytochemicals, and has previously been shown to have antihypertensive, antidiabetic, and anticholesteremic effects [47][48][49][50][51][52].…”

“…Finally, amaranth contains bioactive peptides [46,[62][63][64]. Previous researchers found amaranth derived peptides and tetrapeptides with ACE-inhibitory activity Functional Food Science 2021; 1(10):39-49 [65][66][67] Previously, it has been shown that curcumin decreased proteinuria levels [35], but such data with amaranth oil has not been presented.…”

“…Additionally, proteinuria can be decreased with ACE and renin inhibitors [14,25,[27][28]34]. Past studies demonstrated that the bioactive peptides in amaranth proteins display ACE inhibiting effects in vitro and in vivo [46,[62][63]. Quiroga et al found that amaranth peptides also inhibit renin of the RAAS in dose-response fashion via competitive inhibition; inhibition efficacy was determined to be directly related to peptide hydrophobicity [46,64].…”

“…Past studies demonstrated that the bioactive peptides in amaranth proteins display ACE inhibiting effects in vitro and in vivo [46,[62][63]. Quiroga et al found that amaranth peptides also inhibit renin of the RAAS in dose-response fashion via competitive inhibition; inhibition efficacy was determined to be directly related to peptide hydrophobicity [46,64]. Though ACE and RAAS inhibitory activity has been observed, amaranth's effects on proteinuria were not previously explored.…”