Health-promoting activities of Moringa oleifera Lam. seeds protein hydrolysates and its ultra-filtered peptide fractions

Abstract

Moringa oleifera (MO) seeds treated as a new resource food rich in protein (37.48%), but, little know the bioactive benefits and peptide composition of protein hydrolysates. In this study, ultrafiltrated peptide fractions of MO seed proteins hydrolysates (MOSPH) were analyzed for their antioxidant, anti-hypertension and sleep-promoting activities. LC-MS/MS was used to identify the peptide composition of the molecular weight (MW) <3 kDa fraction. The results showed that MOSPH and the lower MW peptides fraction, especially the MW <3 kDa fraction, exhibited higher free radical scavenging and reducing capacity, in vitro angiotensin I-converting enzyme (ACE) inhibitory capacity and vasodilatory and anti-hypertensive effects on spontaneously hypertensive rats (SHR) after the development of hypertension, sleep-promoting and anticonvulsant effects in male ICR mice. Furthermore, four potential bioactive peptides (pepsite score > 0.3) from MW <3 kDa fraction of MOSPH were explored via in silico approach, of which a novel dual-function peptide IWHHTFYNELR (IR-11) exhibited higher ACE inhibitory activity (IC50 = 1.057 mg/mL) and DPPH•-clearing activity (IC50 = 0.404 mg/mL). Molecular docking indicates that IR-11 interacted with ACE and DPPH• through hydrogen bonding and hydrophobic forces. Our results suggested that MO seed proteins peptides can be a potent functional agents for developing new functional food.