angiotensin receptor

angiotensin ii

aqueous extract

renal

ace inhibitors

converting enzyme

hypertensive rats

blood pressure regulation

Nutrition Research

It has been previously documented that the thermolysin digest of “Katsuobushi,” or dried bonito, a traditional Japanese food, potently inhibits the angiotensin I-converting enzyme (ACE). This hydrolyzate “Katsuobushi oligopeptide (KO)” has antihypertensive effects in hypertensive subjects at a dose of 3 g/day. In order to reduce the amount of KO required to produce an effect, we obtained a stronger KO (S-type KO) by ultra-filtration. The S-type KO had two-fold higher ACE-inhibitory activity, and also showed two-fold higher antihypertensive activity in the spontaneously hypertensive rat after oral administration, compared with the original KO. In a human study, the antihypertensive effects of 1.5 g/day of S-type KO were monitored against a placebo in a double-blind, randomized, cross-over study in 61 borderline and mildly hypertensive subjects. S-type KO showed antihypertensive activity without any side-effects. Thus, the ACE-inhibitory S-type KO demonstrated more potent antihypertensive effects than the original formulation.

Effects of an ace-inhibitory agent, katsuobushi oligopeptide, in the spontaneously hypertensive rat and in borderline and mildly hypertensive subjects