Antihypertensive effect of angiotensin-converting enzyme inhibitory peptides from silver carp (Hypophthalmichthys molitrix) hydrolysate in spontaneously hypertensive rats

In order to utilize silver carp (Hypophthalmichthys molitrix), which is abundant and very cheap fresh-water fish in China, defatted silver carp muscle was hydrolysed by compound protease to achieve angiotensin-converting enzyme (ACE) inhibitory peptides. The protein hydrolysates were fractionated into low and high molecular weight fractions using an ultrafiltration (UF) membrane system. The ACE-inhibitory activity tests showed that the low molecular weight fraction was more effective. Most of the peptides in low molecular weight fraction ranged from 600 to 1600 Da. Anti-hypertensive effects of silver carp ACE-inhibitory peptides on spontaneously hypertensive rats (SHR) following oral administration was determined as the tail systolic blood pressure significantly decreased after peptides ingestion.