Angiotensin I-Converting Enzyme Inhibitory Peptides Derived from Wakame (Undaria pinnatifida) and Their Antihypertensive Effect in Spontaneously Hypertensive Rats

Abstract

Seven kinds of angiotensin I-converting enzyme (ACE) inhibitory peptides were isolated from the hydrolysates of wakame (Undaria pinnatifida) by Protease S "Amano" (from Bacillus stearothermophilus) by using three-step high-performance liquid chromatography (HPLC) on a reverse-phase column. These peptides were identified by amino acid composition analysis, sequence analysis, and liquid chromatography-mass spectrometry (LC-MS), as Val-Tyr (IC(50) = 35.2 microM), Ile-Tyr (6.1 microM), Ala-Trp (18.8 microM), Phe-Tyr (42.3 microM), Val-Trp (3.3 microM), Ile-Trp (1.5 microM), and Leu-Trp (23.6 microM). These peptides have resistance against gastrointestinal proteases in vitro. Each peptide was determined to have an antihypertensive effect after a single oral administration in spontaneously hypertensive rats (SHR). Among them, the blood pressure significantly decreased by Val-Tyr, Ile-Tyr, Phe-Tyr, and Ile-Trp in a dose of 1 mg/kg of body weight (BW). The present study showed that antihypertensive effect in the hydrolysates of wakame by Protease S "Amano" was attributed to these peptides.

Production of Angiotensin I-Converting Enzyme-Inhibitory Peptides in a Freeze-Thaw Infusion-Treated Soybean

“…5). Previous studies have shown that Ile-Tyr isolated from wakame has high ACE-inhibitory activity (IC 50 value of 6.1 μM) and that the systolic blood pressure of SHR rats was significantly decreased by single oral administration of Ile-Tyr in a dose of 1 mg/kg body weight (Sato et al, 2002). The IC 50 value for Ile-Tyr was 12.99 μM and similar to the previous data.…”

Tryptophan-containing milk protein-derived dipeptides inhibit xanthine oxidase

“…Trp has been described for its central role as a precursor of biomolecules such as melatonin, serotonin and dynorphin [22,39] and for its antioxidant properties [48,60]. Similarly, Val-Trp has been associated with various bioactive properties including angiotensin-converting enzyme (ACE) inhibition [6,37,64,67,74,89,91,93,94] and for -glucosidase inhibition [58,66]. The reverse peptide Trp-Val has also been described as an ACE inhibitor [67] and an anti-oxidant [31].…”

Determination of Antihypertensive Peptides from an Izumi Shrimp Hydrolysate

“…The IC 50 value for the former was 28.3 mM, and for the latter was 6.6 mM. Although the isolation of Val-Trp-Tyr-His-Thr had not previously been reported, Val-Trp had already been isolated from a hydrolysate of wakame, 9) pelagic thresher muscle hydrolysate, 10) hot water extract of wakame, 11) and salmon muscle hydrolysate.…”