Artificial Neural Network-Guided Discovery of Antioxidant Peptides from Peony (Paeonia ostii) Seed Meal: Peptidomics, Molecular Mechanism, and Cellular Validation

TL;DR

This study uses artificial neural networks to discover antioxidant peptides from peony seed meal, validating their activity and molecular mechanisms.

Contribution

A novel ANN-guided workflow for discovering antioxidant peptides from underutilized plant by-products is presented.

Findings

Neutrase hydrolysis optimized via ANN produced a hydrolysate with strong antioxidant activity.

Four peptides (FRF, WQFR, FEFR, RWL) showed favorable binding to antioxidant targets and protected cells from oxidative damage.

Molecular simulations confirmed stable interactions between peptides and Keap1.

Abstract

Peony seed meal (PSM), a protein-rich by-product of oil extraction from Paeonia ostii, represents an underutilized resource with significant potential for functional ingredient development. In this study, an integrated strategy combining artificial neural network (ANN)-guided hydrolysis, peptidomics, molecular simulation, and cellular validation was employed to identify antioxidant peptides from PSM. Neutrase was selected as the optimal protease, and hydrolysis conditions were optimized using a backpropagation ANN model (R = 0.9935), yielding a hydrolysate with strong radical-scavenging activity (DPPH• IC50 = 0.30 mg/mL; ABTS•+ IC50 = 0.07 mg/mL). LC–MS/MS identified 364 peptides, predominantly low-molecular-weight sequences. In silico screening highlighted four candidates (FRF, WQFR, FEFR, and RWL) with favorable binding toward ABTS•+, DPPH•, and Keap1. Molecular docking and 100 ns molecular dynamics simulations confirmed stable peptide–Keap1 interactions, particularly for FRF. Cellular assays demonstrated that FRF and RWL significantly protected HepG2 cells against H2O2-induced oxidative damage by restoring antioxidant enzyme activities (SOD, CAT, and GSH-Px). Collectively, this study establishes a systematic workflow for discovering plant-derived antioxidant peptides and supports the sustainable valorization of PSM as a functional food ingredient.

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