Blood Concentration of Food-Derived Peptides following Oral Intake of Chicken Collagen Hydrolysate and its Angiotensin-Converting Enzyme Inhibitory Activity in Healthy Volunteers

In this study, we investigated the concentration of food derived-peptides in blood following oral intake of chicken collagen hydrolysate (chicken-collagen octa peptides; C-COP) and measured the angiotensin-converting enzyme (ACE) inhibitory activity of these peptides. Healthy volunteers ingested the C-COP solution (25 g/60 kg body weight) after fasting for 12 h. The peptide-formed hydroxyproline (Hyp) significantly increased and reached maximum levels (91.1 mu M) 2 h after consumption. Pro-Hyp, Leu-Hyp, Pro-Hyp-Gly, Phe-Gly, Ala-Hyp, Hyp-Gly, Glu-Hyp-Gly, Ala-Hyp-Gly and Ser-Hyp-Gly were detected in human blood, possessing ACE-inhibitory activity of them, Ala-Hyp (IC50: 0.177 mM) had the strongest ACE inhibitory activity. Thus, C-COP appears to absorb with the peptides by enzymatic digestion in blood, thereby inhibiting ACE, suggesting that food-derived collagen peptides are related to antihypertensive effects.