Kinetics of in vitro enzyme inhibition and blood pressure-lowering effects of salmon (Salmo salar) protein hydrolysates in spontaneously hypertensive rats

• Published in: Journal of Functional Foods
• Main Authors: Abraham T. Girgih, Ifeanyi D. Nwachukwu, Fida M. Hasan, Tayo N. Fagbemi, Sunday A. Malomo, Tom A. Gill, Rotimi E. Aluko
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Salmon; Protein hydrolysate; Enzyme inhibition kinetics; Systolic blood pressure; Spontaneously hypertensive rats; Mass spectrometry; Nutrition. Foods and food supply; TX341-641; Salmo salar
• Online Access: https://doi.org/10.1016/j.jff.2015.10.018; https://doaj.org/article/477d03bb118d49ab9f5f7042ed2e24c3

A salmon protein hydrolysate (SPH) was produced from consecutive enzymatic hydrolysis of salmon muscle proteins with pepsin followed by trypsin + chymotrypsin. The SPH was separated into four (SF1-SF4) reverse-phase HPLC peptide fractions. The SF3 peptide fraction was the most active against both angiotensin I-converting enzyme (ACE) and renin activities during in vitro tests. SPH and SF3 inhibited ACE activity uncompetitively but renin inhibition was non-competitive. SPH and SF3 were orally administered (200 and 30 mg/kg body weight, respectively) to spontaneously hypertensive rats, followed by systolic blood pressure (SBP) measurements. The SF3 significantly (p < 0.05) reduced SBP by a maximum value of −42.1 ± 3.4 mmHg when compared to −21.1 ± 4.5 mmHg for SPH 2 h after oral administration. Mass spectrometry analysis showed some differences in the peptide ion composition, which may have contributed to the observed differences in SBP-reducing effects of SPH and SF3.