Polygonum hydropiper L. ethanol extract attenuates ferroptosis and ulcerative colitis by modulating glutathione metabolism through inhibition of KEAP1-Nrf2 interaction.

BACKGROUND

While ferroptosis inhibition in intestinal epithelial cells emerges as a novel therapeutic strategy for colitis, the scientific validation of Polygonum hydropiper L. - a traditional anti-inflammatory herb - remains unexplored, particularly regarding ferroptosis modulation.

PURPOSE: This study aimed to systematically evaluate the therapeutic effects of ethanol-extracted Polygonum hydropiper L.(PHE) on colitis and elucidate its underlying molecular mechanisms, with particular focus on ferroptosis regulation.

METHODS

The ethanol extract of PHE was pharmacologically evaluated in a dextran sulfate sodium (DSS)-induced murine colitis model. RNA-Seq analysis of colon tissues and UPLC-LTQ-Orbitrap-MS phytochemical profiling were integrated with functional validation using erastin-induced ferroptosis in Caco-2 cells. Virtual docking, molecular interactions, and gene-editing were employed for mechanistic investigation.

RESULTS

PHE administration significantly attenuated DSS-induced weight loss and disease activity index elevation, while preserving intestinal mucosal integrity. Transcriptomic analysis and in vivo experiments revealed PHE's regulation of glutathione metabolic pathways and ferroptosis. The flavonoids in PHE, especially aromadendrin, were identified as the primary active component binding to Kelch-like ECH-associated protein 1(KEAP1)'s Kelch domain, thereby activating Nrf2 signaling and upregulating glutathione (GSH) synthesis genes. Nrf2 ablation or KEAP1 over-expression abolished PHE's protective effects, confirming pathway specificity.

CONCLUSION

Our findings establish that PHE exerts anti-colitis effects through KEAP1/Nrf2/GSH axis-mediated ferroptosis inhibition, with aromadendrin serving as the key bioactive compound. This mechanistic elucidation provides translational rationale for developing PHE-based therapies for ulcerative colitis.