Berberine Alleviates Ulcerative Colitis Through Targeting Irgm1 for Anti-Inflammatory Effects

Abstract

BackgroundBerberine (BBR), found in Coptidis Rhizoma, is a potential treatment for ulcerative colitis (UC) due to its anti-inflammatory properties. However, its specific targets and mechanisms in UC are unclear.PurposeThe aim of this study was to identify BBR’s anti-inflammatory target and its mode of action in UC treatment.MethodsThe UC model with dampness-heat syndrome was induced in mice using dextran sulfate sodium (DSS), a high-fat, high-sugar diet, and a hot, humid environment. The therapeutic effects of Coptidis Rhizoma extract and BBR were assessed. Anti-inflammatory target proteins of BBR were identified using stable isotope labeling by amino acids in cell culture-activity-based protein profiling (SILAC-ABPP) in an LPS-induced RAW264.7 cell inflammation model. Molecular docking, drug affinity responsive target stability (DARTS), molecular dynamics simulation, cellular thermal shift assay (CETSA), and biological layer interference measurement (BLI) were employed to study the interaction between BBR and its targets. Lentiviral transfection was used to knock down the target protein and investigate BBR’s anti-inflammatory mechanism.ResultsCoptidis Rhizoma extract and BBR significantly improved UC in mice by reducing inflammation and enhancing intestinal barrier protein expression. SILAC-ABPP identified IRGM1 as BBR’s anti-inflammatory target, with its overexpression in UC mice and LPS-induced RAW264.7 cells reduced by BBR treatment. BBR also decreased inflammatory cytokines in LPS-induced RAW264.7 cells by inhibiting the PI3K/AKT/mTOR pathway. Knockdown of IRGM1 weakened BBR’s effects on cytokine expression and pathway regulation.ConclusionBBR effectively treats UC by targeting IRGM1 to inhibit the PI3K/AKT/mTOR pathway, suggesting its potential as a therapeutic agent for UC.

Note:
Funding declaration: This research was funded by the National Natural Science Foundation of China, grant number 82030116.

Conflict of Interests: All the authors declare that there are no conflicts of interest associated with this publication and there is no significant financial support for this work that could have influenced its outcome.

Ethical Approval: This study followed the ARRIVE guidelines and received approval from the Animal Ethics Committee of Tianjin University of Traditional Chinese Medicine (Approval number: TCM-LAEC2022233).

Keywords: Berberine, ulcerative colitis, IRGM1, PI3K/AKT/mTOR pathway