Novel Antihypertensive Peptides Derived from Chicken Foot Proteins

Scope Chicken foot proteins have recently been demonstrated by the group to be a great source of hydrolysates with antihypertensive properties. The aim of this study was to isolate and identify angiotensin I-converting enzyme inhibitory (ACEI) peptides from chicken foot hydrolysate Hpp11 and to test their antihypertensive properties. Methods and Results Peptides are separated into fractions according to their molecular size and hydrophobicity by ultrafiltration and RP-HPLC, respectively. Subsequent peptide identification in the two fractions that present the highest ACEI activities is carried out by HPLC-MS. Ten of the identified peptides are synthesized and five of them show ACEI (IC50) values lower than 100 mu m. The antihypertensive effects of these ACEI peptides after oral administration is evaluated in spontaneously rats. The peptides AVFQHNCQE and QVGPLIGRYCG exhibit antihypertensive activity when administered at an oral dose of 10 mg kg(-1) body weight. The maximal decrease in systolic blood pressure is recorded 6 h after their administration (-25.07 +/- 4.21 and -10.94 +/- 1.96 mmHg, respectively). Conclusion These results suggest that AVFQHNCQE and QVGPLIGRYCG could be used as functional ingredients with antihypertensive effects, although it would be necessary to perform bioavailability and clinical studies to demonstrate their efficiency in humans.