The culture filtrates from Bacillus subtilis natto lowers blood pressure via renin-angiotensin system in spontaneously hypertensive rats fed with a high-cholesterol diet

Antihypertensive effect of the culture filtrates from Bacillus subtilis natto (CFB) associated with renin-angiotensin system (RAS) as well as fibrinolytic and anti-thrombotic activity was examined. By using the spontaneously hypertensive rats fed with a high-cholesterol diet (0.5% cholesterol and 0.5% cholic acid), biomarkers related to the RAS were measured after 11 week-administration of CFB in the diet at 1 or 2% levels. Systolic blood pressure was significantly attenuated by CFB at both levels. Plasma renin activity was significantly suppressed by CFB, and protein expression of renin in kidney also showed tendency of decrease by administration of CFB, although not statistically significant. Renal angiotensin II concentrations were decreased, whereas plasma angiotensin II concentrations showed no differences among groups. Whole blood clotting and euglobulin clot lysis time showed insignificant changes, but downward tendencies by CFB supplementation. Although further study is necessary to clearly elucidate the related mechanism, taken together, these findings support the hypothesis that CFB could be potentially used as dietary supplement to suppress hypertension.