Naoyuki Yamamoto 교수

Peptides derived from alpha s1- and beta-caseins by the Lactobacillus helveticus CP790 proteinase were investigated for their inhibitory activities against angiotensin I-converting enzyme. The antihypertensive effect of casein hydrolysates in strain SHR spontaneously hypertensive rats was also investigated. Both alpha s1- and beta-casein hydrolysates inhibited this enzyme. Some of these peptides showed enzyme inhibitory activity, and one of them from beta-casein inhibited the enzyme greatly; the

Whey peptides in a yogurt-like product fermented by Lactobacillus helveticus CPN4 were fractionated by a Sep-pak C-18 cartridge followed by two-step reverse-phase HPLC. The antihypertensive activity was measured by systolic blood pressure in spontaneously hypertensive rats after oral administration of each fraction. Five major peptides in the final fraction were further purified by reverse-phase HPLC and were measured for these antihypertensive activities in spontaneously hypertensive rats. The

This paper reviews the angiotensin I converting enzyme inhibitory peptides originated from food materials and enzymatic hydrolysate of different kinds of proteins. Focus was put on the peptides derived from milk casein by the action of the proteolytic system of lactic acid bacteria. Some of the peptides exhibit significant antihypertensive effects in spontaneously hypertensive rats. Some new topics relating to these antihypertensive peptides are introduced. The possible significance of bioactive

This paper reviews bioactive peptides, biogenic peptides, opioid peptides, immunostimulating peptides, mineral soluble peptides, antihypertensive peptides and antimicrobial peptides originating from food materials and enzymatic hydrolysis of proteins. Antihypertensive peptides are extensively reviewed and have been divided into angiotensin I-converting enzyme inhibitory peptides and others. These peptides are produced in the enzymatic hydrolysate of treated food materials such as milk, animal an

Japan has a long history of using foods with health benefits and Japanese people are well-known for their longevity. In 1991, the Ministry of Health, Labor and Welfare introduced a functional food regulation called “foods for specified health uses” (FOSHU) in Japan. After the introduction of the functional food system, many clinically proven FOSHU products with health benefits have been developed and launched in the market. As a result, the net sales of FOSHU products reached 6.2 billion dollars

We describe a clinical trial to study the efficacy of a casein hydrolysate, prepared using an Aspergillus oryzae protease, containing the major angiotensin-I-converting enzyme inhibitory peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) in a single-blind, placebo-controlled study. A total of 131 volunteers with high-normal blood pressure and mild hypertension were randomly divided into four groups (n 32 or 33 in each group). Each volunteer was given two tablets containing four different dosages o

Most fermented milk prepared by strains of Lactobacillus helveticus showed significant antihypertensive effect in spontaneously hypertensive rats (SHR) by oral administration. However, milk fermented by other species of lactic acid bacteria did not show significant antihypertensive effects. Most of the whey fractions of the milk fermented by L. helveticus or Lactobacillus delbrueckii subsp. bulgaricus showed higher angiotensin I-converting enzyme (ACE) inhibitory activity than the activity of mi

This paper reviews the angiotensin I-converting enzyme inhibitory peptides originated from milk proteins. Focus was put on the peptides derived from milk casein by the action of some proteolytic enzymes and fermented products by lactic acid bacteria. Some of the angiotensin I-converting enzyme inhibitory peptides exhibit significant antihypertensive effects in spontaneously hypertensive rats. However, there were some antihypertensive peptides with low inhibitory activity of this enzyme. Key fact

A cell-wall-associated proteinase from Lactobacillus helveticus CP790, grown in skim milk, was purified to homogeneity by DEAE ion exchange chromatography in the presence of EDTA. Its molecular weight was estimated to be 45,000 by SDS-PAGE and also by the recovery of proteinase activity only from this fraction of SDS-PAGE gel slices of crude extract. It had maximum activity at pH 6.5 and 42 degrees C. Since the activity was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), it was su

Pharmaceutical angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce arterial stiffness; the possible effect of food-derived putative ACE inhibitory peptides on this degenerative process, however, has not been reported. In the present study, casein hydrolysate containing the lactotripeptides, Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), which has been found to have an antihypertensive effect in a number of clinical studies, was investigated for its ability to improve hemodynamic p

Commensal intestinal microbiota interacts with gut epithelial cells in the host by binding to specific host receptors.

One acid-sensitive variant of Lactobacillus helveticus, designated L. helveticus CPN4, was isolated from L. helveticus CP790 using neomycin resistance as a selective marker. In a milk medium, the variant strain showed similar growth to the parent strain until the pH reached 4.5, afterwards growth was slower than the parent strain. The variant strain had lower activity of membrane bound adenosine triphosphatase (ATPase, EC 3.6.1.3) over several batch growth ranges from pH 3.5 to 7.5. Membrane ves