Depressor effect of wheat germ hydrolysate and its novel angiotensin I-converting enzyme inhibitory peptide, Ile-Val-Tyr, and the metabolism in rat and human plasma.
We report here the antihypertensive effect of wheat germ (WG) hydrolysate and its dominant peptide, Ile-Val-Tyr (IVY), with potent angiotensin I-converting enzyme (ACE) inhibitory activity. The toxicity test of AG50W fraction purified from the WG hydrolysate and IVY in ddy mice revealed that 1 week median lethal concentrations of AG fraction and IVY were less than 100 and 10 mg/kg, respectively. As a result of an intravenous administration test of both inhibitors in spontaneously hypertensive rat (SHR), the mean arterial blood pressure (MAP) significantly decreased with the dose; the MAP reduction of 10.3 and 19.2 mmHg was observed at a dose of 50 mg/kg of AG fraction and 5 mg/kg of IVY, respectively. In addition to this behavior, the MAP gradually decreased after the 5 mg/kg of IVY injection (time to give a maximum reduction; 8 min), and the reduction was held for 20 min. By using rat and human plasma, IVY was found to be metabolized by the action of aminopeptidase in plasma to form a subsequent ACE inhibitor, Val-Tyr (VY). Thus, the intake of IVY as a physiologically functional food would serve in the lowering of blood pressure (BP) by the combined depressor effect of itself and its metabolite after the absorption.
Matsui
T
T
Institute of Food Biotechnology, Division of Bioresource and Bioenvironmental Sciences, Graduate School Kyushu University, Fukuoka, Japan.
Li
C H
CH
Tanaka
T
T
Maki
T
T
Osajima
Y
Y
Matsumoto
K
K
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000097:blood / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000097:blood / Q000737:chemistry / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D051379:Mice; D009842:Oligopeptides / Q000097:blood / Q000494:pharmacology*; D010940:Plant Proteins / Q000097:blood / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D014908:Triticum / Q000737:chemistry
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D009842:Oligopeptides; D010940:Plant Proteins; C409454:isoleucyl-valyl-tyrosine