Antihypertensive activity of milk fermented by Enterococcus faecalis strains isolated from raw milk

A total of 231 microorganisms were isolated from raw cow milk samples and the a ngi oten sin -converting enzyme-inhibitory (ACEI) activity of the resultant fermented milk produced with the isolated microorganisms was assayed. Forty-six of these microorganisms were selected on the basis of high ACEI activity. Four Enterococcus faecalis strains stood out as producers of fermented milk with potent ACEI activity IC50 (the protein concentration that inhibits 50% of ACE activity): 34-59 mu g mL(-1)). Single doses (5mL kg(-1)) of the whey fraction obtained from these fermented milk samples were administered to spontaneously hypertensive rats (SHR) and to normotensive Wistar-Kyoto (WKY) rats in order to investigate their possible anti hypertensive activity. Highly significant decreases in the systolic blood pressure (SBP) and in the diastolic blood pressure (DBP) were observed when the fermented milk was administered to SHR. Nevertheless, the fermented milk did not modify the SBP and the DBP of the WKY rats. Raw cow milk is an excellent source of wild lactic acid bacteria able to produce fermented milk with antihypertensive activity and anti hypertensive activity of milk fermented by Enterococcus faecalis strains was associated with peptides different from Ile-Pro-Pro and Val-Pro-Pro. (c) 2005 Elsevier Ltd. All rights reserved.