Angiotensin I Converting Enzyme Inhibitory Peptides from In Vitro Pepsin−Pancreatin Digestion of Soy Protein

Abstract

Angiotensin I converting enzyme (ACE) inhibitory activity was determined in the soy protein isolate (SPI) digest produced by in vitro pepsin-pancreatin sequential digestion. The inhibitory activity was highest within the first 20 min of pepsin digestion and decreased upon subsequent digestion with pancreatin. An IC(50) value of 0.28 +/- 0.04 mg/mL was determined after 180 min of digestion, while no ACE inhibitory activity was measured for the undigested SPI at 0.73 mg/mL. Chromatographic fractionation of the SPI digest resulted in IC(50) values of active fractions ranging from 0.13 +/- 0.03 to 0.93 +/- 0.08 mg/mL. Although many of the fractions showed ACE inhibition, peptides with lower molecular masses and higher hydrophobicities were most active. The findings show that many different peptides with ACE inhibitory activities were produced after in vitro pepsin-pancreatin digestion of SPI and lead to the speculation that physiological gastrointestinal digestion could also yield ACE inhibitory peptides from SPI.

Bioactive, functional and edible film-forming properties of isolated hazelnut (Corylus avellana L.) meal proteins

“…The r 2 values determined between TEAC and IC 50 for antihypertensive activity (r 2 : À0.919), ORAC and IC 50 for antihypertensive activity (r 2 : À0.899) and IC 50 values for antihypertensive and antiproliferative activities (for 48 h) (r 2 : 0.827) also supported the relation among these bioactive properties. In the literature, inconsiderable ACE inhibitory activities were reported for commercial soybean protein isolate (Lo & Li-Chan, 2005), flaxseed meal protein isolate (Marambe, Shand, & Wanasundara, 2008) and pumpkin meal protein isolate (Vastag, Popovic, Popovic, Krimer, & Pericin, 2011) unless they were hydrolyzed by proteases. The ACE inhibitory potential of hazelnut protein extracts was also higher than that of protease digested pea protein isolate (1.36 mg/mL) and comparable with that of protease digested whey protein isolate (0.90 mg/mL) (Vermeirssen, Van Camp, & Verstraete, 2002).…”

Antihypertensive Properties of Plant Protein Derived Peptides

“…In some studies, plant protein hydrolysates generated during pepsin digestion have potent ACE-inhibitory peptides. Lower ACE-inhibitory activity was found after subsequent digestion with pancreatin, suggesting that the active components were hydrolyzed [60,61]. For the pea proteins, high ACE-inhibitory activity is reached at the early stage of pepsin hydrolysis and the level is maintained during the small intestine phase using trypsin-chymotrypsin treatment [62].…”

“…For instance, authors in references [155] and [47] utilized human digestive liquids to model digestion in vitro whereas several reports have concerned implementation of porcine enzyme mixtures [e.g. 60,127,132]. In addition to studying the resistance of antihypertensive peptide sequences against the digestive enzymes, the models have been utilized in order to produce bioactive peptides, plant derived ACE-inhibitory peptides among them.…”

Effects of Soy Protein Hydrolysate on Blood Pressure and Angiotensin-Converting Enzyme Activity in Rats with Chronic Renal Failure

“…In progressive chronic nephropathy, the ACEI enalapril exhibited beneficial effects on blood pressure control, renoprotection, and minimization of proteinuria ( 18 ). An in vitro study showed that many different peptides with ACE inhibitory activities were produced after pepsin-pancreatin digestion ( 19 ). Our previous studies also showed that SPH inhibited ACE activity in spontaneously hypertensive rats ( 9 ).…”