# Extraction, Purification and Identification of Bovine Lung Peptides and Its Antioxidant Effects on H2O2-Induced HepG2 Cells and Mice with Alcoholic Liver Injury

## TL;DR

This study extracts and identifies antioxidant peptides from bovine lungs, showing their potential to treat alcohol-induced liver damage in mice and human cells.

## Contribution

A novel extraction method for bovine lung peptides and their antioxidant mechanisms in treating alcoholic liver disease are presented.

## Key findings

- BLP-1 reduced oxidative stress in HepG2 cells by enhancing antioxidant enzyme activity.
- BLP-1 ameliorated liver injury in mice by lowering transaminase and inflammatory markers.
- Three peptides (GP9, FG6, WG6) showed strong binding to Keap1, suggesting antioxidant pathway modulation.

## Abstract

In this study, we constructed an extraction process for bovine lung peptide-1 (BLP-1) derived from bovine lung tissue utilizing single-factor optimization combined with response surface methodology. We systematically analyzed its antioxidant activity, biological safety, and therapeutic mechanisms against alcoholic liver disease (ALD). In vitro experiments demonstrated that BLP-1 exhibits excellent scavenging activity against various free radicals, while exhibiting no significant cytotoxicity or hemolytic activity. In a model of H2O2-induced oxidative damage in HepG2 cells, BLP-1 significantly alleviated oxidative stress injury by upregulating the activities of intracellular antioxidant enzymes. Animal experiments further confirmed that BLP-1 significantly reduced serum levels of transaminase, inhibited the release of inflammatory factors, enhanced antioxidant enzyme activity, and ameliorated lipid peroxidation and pathological injury in ALD mice. By combining liquid chromatography-tandem mass spectrometry (LC-MS/MS) with bioinformatics, we screened 12 novel antioxidant peptides. Among these, the binding energies of GP9, FG6, and WG6 to Keap1 were −10.2, −9.7, and −8.7 kcal/mol, respectively, indicating their potential to modulate the antioxidant defense system through competitive inhibition of Keap1-Nrf2 interactions. This study provides a novel approach for the high-value utilization of bovine lung and the treatment of ALD, as well as a new source for the extraction of natural antioxidant peptides.