Effect of γ-aminobutyric acid and nattokinase-enriched fermented beans on the blood pressure of spontaneously hypertensive and normotensive Wistar–Kyoto rats

摘要

Abstract In this study we have evaluated the changes in arterial blood pressure in spontaneously hypertensive rats (SHR) caused by the short-term intake of Bacillus subtilis B060-fermented beans with significant γ-aminobutyric acid (GABA) and nattokinase activity. After being weaned, 7-week-old male {SHR} and 7-week-old male Wistar–Kyoto (WKY) rats were randomized into seven groups. Until the 8th week of life, the rats in each group were given one of the following: Group 1, high dose of {GABA} and nattokinase in the {SHR} (SHD); Group 2, medium dose of {GABA} and nattokinase in the {SHR} (SMD); Group 3, low dose of {GABA} and nattokinase in the {SHR} (SLD); Group 4, negative control in the {SHR} (SD); Group 5, positive control in the {SHR} (SM); Group 6, high dose of {GABA} and nattokinase in the {WKY} (WHD); and Group 7, negative control in the {WKY} (WD). Distilled water served as the negative control, and captopril (50?mg/kg), a known {ACE} inhibitor, served as the positive control. Systolic blood pressure and diastolic blood pressure values were measured weekly from the 8th week to the 16th week of life using the tail-cuff method. A definite decrease in systolic and diastolic blood pressure values could be observed in the rats treated with captopril and in the rats that received {GABA} and nattokinase. The greatest antihypertensive effect was observed when the pharmacological treatment was administered. The effect of the daily intake of fermented beans containing {GABA} and nattokinase may be helpful in controlling blood pressure levels in hypertensive model animals. The fermentation of beans with B. subtilis {B060} may therefore constitute a successful strategy for producing a functional food with antihypertensive activity.