Antihypertensive effect of salt-free soy sauce, a new fermented seasoning, in spontaneously hypertensive rats.
In this study, we focused on the antihypertensive effect of newly fermented salt-free soy sauce (SFS) in spontaneously hypertensive rats (SHRs). A 13-wk oral administration of SFS was performed daily in 8- to 21-wk-old SHRs with a dose of 200 mg/kg of body weight/d. The systolic (SBP) and diastolic (DBP) blood pressures were measured for each week during the experimental period. As a result, a significant (P < 0.01) BP lowering effect was observed from the 5th d to the end of the experiment in the SFS group compared with the control group (DeltaSBP(21-wk): 27 mmHg, DeltaDBP(21-wk): 20 mmHg). In contrast to such substantial effect by SFS intake, angiotensin I-converting enzyme activities in blood and local organs as well as pharmaceutical parameters such as serum Na(+) or K(+) level did not show any significant difference between in both SFS and control groups. Vasoconstriction experiment using thoracic aorta rings from 21-wk SHRs provided an interesting result that the rings from the SFS group evoked a >2-fold higher increase in the angiotensin II-stimulated constrictive response compared with the rings from the control group (P = 0.012), which suggested that the SFS-intake would be effective in possessing a higher vessel tone.


CONCLUSIONS
In this study, we investigated the antihypertensive effect of newly fermented SFS in SHRs. As a result of 13-wk SFS-administration, we found a significant antihypertensive effect of the SFS. This finding strongly demonstrates that the developed SFS would be greatly beneficial for health and useful for health-related industries.
Matsui
Toshiro
T
Faculty of Agriculture, Graduate School of Kyushu Univ., Fukuoka, Japan. tmatsui@agr.kyushu-u.ac.jp
Zhu
Xiao-Lin
XL
Shiraishi
Koso
K
Ueki
Tatsuro
T
Noda
Yoshiharu
Y
Matsumoto
Kiyoshi
K
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000032:analysis; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology; D001794:Blood Pressure; D006973:Hypertension / Q000097:blood / Q000178:diet therapy / Q000503:physiopathology / Q000517:prevention & control*; D066298:In Vitro Techniques; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000097:blood / Q000378:metabolism; D011188:Potassium / Q000097:blood; D011897:Random Allocation; D051381:Rats; D011918:Rats, Inbred SHR; D012964:Sodium / Q000097:blood; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage* / Q000032:analysis; D045730:Soy Foods / Q000032:analysis; D014661:Vasoconstriction / Q000187:drug effects
D000959:Antihypertensive Agents; D017673:Sodium Chloride, Dietary; D000804:Angiotensin II; D012964:Sodium; D007703:Peptidyl-Dipeptidase A; D011188:Potassium