Antihypertensive Metabolites From Lactic Acid Bacteria
from: Lactic Acid Bacteria and Bifidobacteria: Current Progress in Advanced Research (Edited by: Kenji Sonomoto and Atsushi Yokota). Caister Academic Press, U.K. (2011)
Many studies have suggested milk fermented with lactic acid bacteria has beneficial effects on the health status of animals and humans. This paper reviews the potential of antihypertensive peptides in milk fermented with lactic acid bacteria. Most of the antihypertensive effects of these peptides can be explained by their inhibition of angiotensin converting enzyme. Well characterized antihypertensive peptides released by Lactobacillus helveticus fermented milk are mainly reviewed in this chapter. Studies on Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), released in L. helveticus fermented milk, and their use in animal and clinical studies are discussed in more detail. In addition, processing of VPP and IPP by proteolytic enzymes of L. helveticus is discussed. A long peptide containing VPP and IPP sequences generated from β-casein by an extracellular proteinase was thought to be processed intracellularly by the following enzymes: an endopeptidase was expected for C-terminal processing, and an aminopeptidase and X-prolyl dipeptidyl aminopeptidase for N-terminal processing. Genome analyses of these proteolytic enzymes in L. helveticus enabled comparisons to corresponding genome sequences reported in other lactic acid bacteria; from this, it was suggested that the proteolytic system to process VPP and IPP is specific to L. helveticus. The regulatory system observed in the production of VPP and IPP during L. helveticus fermentation is also discussed read more ...