Soyabean protein hydrolysate prevents the development of hypertension in spontaneously hypertensive rats

Abstract

The aim of the present study was to investigate the anti-hypertensive and angiotensin-converting enzyme (ACE) inhibition effects of soyabean protein hydrolysate in spontaneously hypertensive rats (SHR). Soyabean protein hydrolysate was prepared by peptic hydrolysis and was added into the feed of SHR (0 % for the S0 group, 0·5 % for the S1 group, and 1 % for the S2 group) for 12 weeks. Systolic blood pressure and mean blood pressure of the S1 (164·3 (SEM 4·7); 128·0 (SEM 5·0) mmHg) and S2 (156·8 (SEM 1·6); 120·8 (SEM 3·4) mmHg) groups were significantly lower than those of the S0 group (199·4 (SEM 5·2); 158·3 (SEM 7·0) mmHg) at the end of the study. In the analysis of ACE activity, plasma and heart ACE activities of the S1 and S2 groups were significantly lower than those of the S0 group, and there were no significant differences in aorta, kidney, and lung ACE activities among all SHR. Soyabean protein hydrolysate had no significant effect on plasma lipids, electrolytes, or on left ventricular wall or aorta wall thickness. The results suggest that the long-term administration of soyabean protein hydrolysate might retard the development of hypertension in SHR by its inhibitory effect on ACE in vivo.

Renoprotective Effects of Soy Protein Hydrolysates in N.OMEGA.-Nitro-L-Arginine Methyl Ester Hydrochloride-Induced Hypertensive Rats

“…Our previous studies found that soy protein may lower blood pressure and retard the loss of renal function in rats with chronic renal failure ( 9 ). In a spontaneously hypertensive rat model, we found that the hydrophilic portion of soy protein hydrolysate (SPH) retarded the development of hypertension by its ACE-inhibitory activity ( 10). Soy protein was also reported to have beneficial effects on the inflammatory and nutritional statuses in patients with end-stage renal failure (11).…”

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

“…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 ). Separation of the hydrophilic hydrolysate from peptic-digested soy protein afforded some ACE inhibitory peptides, including Ile-Ala, Tyr-Leu-AlaGly-Asn-Gln, Phe-Phe-Leu, Ile-Tyr-Leu-Leu, and Val-MetAsp-Lys-Pro-Gln-Gly ( 20 ).…”

“…In a spontaneously hypertensive rat model, we found that the ACE inhibitory activity of the hydrophilic portion of soy protein hydrolysate (SPH) retarded the development of hypertension ( 9 ). Soy protein was also reported to have beneficial effects on inflammation and on the nutritional status of patients with end-stage renal failure ( 3 ).…”

Novel Angiotensin I-Converting Enzyme Inhibitory Peptides Found in a Thermolysin-Treated Elastin with Antihypertensive Activity

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18] Many ACE inhibitory peptides have been isolated from the thermolysin (TLN) hydrolysate of dried bonito, 9,19,20) sesame, 7) and soy bean protein. 10) In particular, supplements containing dried bonito peptide LKPNM (IC 50 ¼ 17 mM) and sesame peptide LVY (IC 50 ¼ 1:8 mM) are commercially available in Japan.…”