Antioxidant and anti-hypertension activities of protein hydrolysate from sea cucumber, Holothuria parva using enzymatic hydrolysis

Bioactive peptides of marine organisms have recently attracted great attention from scientists and industries. In this study, tissue protein of sea cucumber Holothuria parva muscle were hydrolyzed using bacterial alcalase enzyme and then sea cucumber protein hydrolysis (SPH) was separated by ultrafiltration membranes (30, 10 and 3 kDa) and four fractions with different molecular weight; FI (> 30 kDa), FII (10 < MW < 30 kDa), FIII (3 < MW < 10 kDa) and FIV (< 3 kDa) were obtained. The antioxidant and ACE-inhibitory of SPH and four fractions products FI, FII, FIII, and FIV were evaluated. The results show that the protein content of four fractions FI, FII, FIII, and FIV were 47.33, 57.08, 47.66, and 15.5 mg/ml, respectively. The results of biological analyzes showed that SPH exhibited the highest hydroxyl radical scavenger (48% at 10 µg/ml) and ferric ions (229.03% µg/mg) followed by FIV by (35% at 10 µg/ml). The highest ferric reducing was seen at SPH with (229.03 % at 10 µg/ml) followed by FIV (146/94% at 10 µg/ml). The DPPH scavenging activity of SPH, FI, and FII were 7.32%, 27.4%, and 6.77% at 10 µg/ml, respectively. The Angiotensin-I-converting enzyme (ACE) inhibitory activity of 1mg FI, FII, FIII, and FIV were 7.60, 3.73, 7.86, and 13.60 mg/ml, respectively. The fraction with molecular weight below 3 kDa exhibited higher ACE inhibitory activity. The results of the current study showed that the H. parva muscle protein and their hydrolysis products has a suitable capacity for use in medical purposes.