# Identification of Food-Derived Electrophilic Chalcones as Nrf2 Activators Using Comprehensive Virtual Screening Techniques

## TL;DR

This study identifies three food-derived chalcone compounds that activate Nrf2, a key antioxidant pathway, using virtual screening and experimental validation.

## Contribution

A semi-supervised KNN model and virtual screening approach were used to identify Nrf2-activating chalcones from food-derived electrophilic compounds.

## Key findings

- 4HD, ISO, and butein significantly reduced reactive oxygen species (ROS) levels in cells.
- These chalcones upregulated Nrf2 and antioxidant genes like Nqo1, HO-1, Gsr, Gclc, and Gclm.
- ISO's effects were abolished when Nrf2 was inhibited, confirming its role in the observed antioxidant activity.

## Abstract

Electrophilic compounds are bioactive components commonly found in foods that are capable of covalently modifying nucleophilic sites on biologically functional macromolecules. These compounds may elicit positive bioactivity or negative biotoxicity, posing significant challenges in terms of time and resource expenditure in the de novo characterization of their biological activity. In this study, we developed a database of 332 food-derived electrophilic compounds and used a semi-supervised k-nearest neighbors (KNN) machine learning model to predict their bioactivity. Molecular docking analysis identified the three chalcone compounds with the highest potential positive activity—4-hydroxyderricin (4HD), isoliquiritigenin (ISO), and butein. Furthermore, in cell experiments, treatment with 4HD, ISO, and butein significantly reduced reactive oxygen species (ROS) levels. An RT-qPCR analysis demonstrated that these chalcones significantly upregulated the mRNA expression of Nrf2 and its downstream antioxidant genes, including Nqo1, HO-1, Gsr, Gclc, and Gclm. ISO’s cytoprotective and antioxidant effects were abolished following these findings, which highlight that 4HD, ISO, and butein are effective Nrf2 activators and suggest that comprehensive virtual technology is a promising strategy for identifying functional bioactive compounds.