Structure-activity studies of protease activating, lipase inhibiting, bile acid binding and cholesterol-lowering effects of pre-screened cumin seed bioactive peptides

- Cumin seed peptides remarkably increased pepsin proteolytic activity.
- Cumin seed peptides showed anti-obesity properties via lipase inhibitory action.
- Cumin seed peptides demonstrated remarkable bile acid binding abilities.
- Cumin seed peptides had different impacts on the cholesterol-micelle formation.
- Structure-activity relationship studies were conducted to elucidate the mechanisms.

The objective of this study was to evaluate the in vitro physiological properties of pre-screened cumin seed peptides (CSPs) based on in vitro and in silico studies. Results showed that CSPs were capable of increasing the protein digestibility up to 400%. Apart from that, CSP1 and CSP2 showed >50% inhibition of pancreatic lipase activity. These peptides also exerted a similar or greater affinity to bind bile acid than cholestyramine, in addition to giving inhibitory effect (up to 80%) in the formation of cholesterol micelle. Based on the structure-activity relationship studies, the results have postulated that the interaction of peptides at non-catalytic region induced allosteric effects to enhance the pepsin proteolytic activity; the direct contact of the peptide with lipase active sites rendered inhibitory action; and the binding between peptide and bile acids was relied on the hydrophilic and hydrophobic interactions.