Parallel bioassay-guided discovery and mechanistic characterization of a dual DPP-IV and ACE inhibitory peptide from defatted Nigella sativa seed cake
Journal
Journal of Ethnopharmacology
Journal Volume
374
ISSN
0378-8741
Date Issued
2027-02
Author(s)
Nuril Albi, Vahrus
Sutopo, Christoper Caesar Yudho
Wardani, Agustin Krisna
Hsu, Jue-Liang
Abstract
Ethnopharmacological relevance: Nigella sativa L. (black cumin) has long been used in traditional Islamic, Unani, and Ayurvedic medicine for managing metabolic disorders. Although its medicinal properties have been largely attributed to seed oil and phytochemicals, the protein-rich defatted seed cake generated during oil production remains an underutilized by-product with largely unexplored bioactive peptide potential. Aim of the study: This study aimed to identify and characterize multifunctional peptides from defatted N. sativa seed proteins with dual inhibitory activity against dipeptidyl peptidase-IV (DPP-IV) and angiotensin-I converting enzyme (ACE). Materials and methods: Following protease screening, the thermolysin hydrolysate was subjected to parallel bioassay-guided fractionation by strong cation exchange chromatography and reversed-phase HPLC. Peptides were identified by LC-MS/MS and de novo sequencing, prioritized in silico, synthesized, and evaluated by enzyme inhibition, kinetics, docking, and pre-incubation assays. Results: Thermolysin generated the most potent DPP-IV inhibitory hydrolysate. Comparative LC-MS/MS analysis identified LYDGELRQGQL (LL-11) in both active fractions. LL-11 exhibited dual inhibitory activities against DPP-IV (IC50 = 1.15 ± 0.25 mM) and ACE (IC50 = 49.98 ± 4.04 μM), acting as a noncompetitive DPP-IV inhibitor and a competitive ACE inhibitor. Molecular docking and enzyme pre-incubation studies supported distinct enzyme-specific binding and stability profiles. Conclusion: LL-11 is a dual-functional peptide identified from defatted N. sativa seed cake. The integrated workflow highlights this underutilized by-product as a sustainable source of bioactive ingredients with potential relevance to the dietary management of diabetes and hypertension. However, further cell-based and in vivo validation is warranted to establish the physiological relevance of LL-11. © 2026 Published by Elsevier B.V.
Subjects
Angiotensin-converting enzyme
Bioactive peptide
Black cumin
Dipeptidyl peptidase-IV
Metabolic disorders
Nigella sativa
Publisher
Elsevier Ireland Ltd
Description
Article number 122478
Type
journal article