Identification of novel antihypertensive peptides in milk fermented with Enterococcus faecalis

Several novel peptides with demonstrated antihypertensive activity have been identified in milk fermented with Enterococcus faecalis CECT 5727. Two of the identified peptides, corresponding to β-casein f(133–138) (LHLPLP) and β-casein f(58–76) (LVYPFPGPIPNSLPQNIPP), showed angiotensin converting enzyme-inhibitory (ACEI) activity (IC50) values as low as 5 μm. These peptides demonstrated antihypertensive activity when they were orally administered to spontaneously hypertensive rats. In particular, β-casein f(133–138), yielded a significant antihypertensive effect in these animals. The maximal decreases in systolic blood pressure (21.87±4.51 mmHg, ) and diastolic blood pressure (28.5±3.20 mmHg, ) were observed 4 and 2 h, respectively, after the administration of 2 mg kg−1 of this peptide. The presence of these antihypertensive peptides in fermented milk prepared with other selected strains of E. faecalis (CECT 5728, 5826 and 5827) was confirmed by HPLC-MS.This work has received financial support from the projects AGL2004-06903-C02-01 and FIT-06000-2002-30. A. Quirós was the recipient of a fellowship of the I3P Programme from the Consejo Superior de Investigaciones Científicas