Lactotripeptides are two naturally occurring milk peptides: Isoleucine
Isoleucine is an α-amino acid with the chemical formula HO2CCHCHCH2CH3. It is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested. Its codons are AUU, AUC and AUA....

Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...

-Proline (IPP) and Valine
Valine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...

-Proline-Proline (VPP). These lactotripeptides are derived from casein
Casein is the name for a family of related phosphoprotein proteins . These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk....

, which is a milk protein also found in dairy products. Although most normal dairy products contain lactotripeptides, they are inactive within the original milk proteins. Dairy peptides can be effectively released through enzymatic predigestion – a process by which milk protein is enzymatically broken down into smaller pieces. Some clinical studies have suggested that these lactotripeptides help promote healthy blood pressure levels as part of a healthy diet and lifestyle. However, other clinical trials have seen no effects from these compounds.

Proposed mechanism

Dairy peptides are proposed to inhibit the activity of the angiotensin
Angiotensin, a peptide hormone, causes blood vessels to constrict, and drives blood pressure up. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex...

-converting enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

Angiotensin-converting enzyme
Angiotensin I-converting enzyme , an exopeptidase, is a circulating enzyme that participates in the body's renin-angiotensin system , which mediates extracellular volume , and arterial vasoconstriction...

). ACE is part of the renin-angiotensin system
Renin-angiotensin system
The renin-angiotensin system or the renin-angiotensin-aldosterone system is a hormone system that regulates blood pressure and water balance....

— a natural mechanism that helps regulate blood pressure in the body. In certain individuals, the renin-angiotensin system can become overactive, often due to stress, an unhealthy diet, and/or unhealthy lifestyle. Under such conditions, ACE becomes overactive and converts more angiotensin I into angiotensin II. Angiotensin II causes blood vessels to constrict, and so increases blood pressure, which has potential to lead to hypertension. But, when ACE activity is inhibited, the formation of angiotensin II is reduced. This then helps the blood vessels to relax and expand back to a normal healthy state, so blood pressure is lowered.

Clinical trials

Several human trials aimed to evaluate the effect of lactotripeptides on blood pressure. Some trials show a blood pressure-lowering effect of lactotripeptides in people with mild to moderate hypertension, however others see no effect from these peptides.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.