Ji-Ming-San enhances intestinal circadian rhythms and mitigates colitis in mice: The role of epithelial RORα

Background

Ji-Ming-San (JMS), a traditional Chinese medicine, exhibits time-dependent pharmacological effects, suggesting its potential as a circadian clock modulator. However, the precise mechanisms by which JMS regulates circadian rhythms remain unclear.

Purpose

This study aims to elucidate how JMS influences the local circadian clock machinery, and move beyond association to mechanistic discovery.

Methods

A jet lag model of circadian disruption was used to assess the regulatory effects of JMS on circadian behavior and clock gene expression. The impact of JMS on clock genes was examined in colon epithelial cells. Non-targeted metabolomics was utilized to identify key components and potential pathways. Network pharmacology, molecular docking, Gal4 co-transfection assays, and RNA sequencing were conducted to explore potential JMS targets. Chromatin immunoprecipitation assays were performed to investigate the transcriptional regulation mechanisms.

Results

JMS restored circadian rhythms in locomotor activity and intestinal clock gene expression in jet-lagged mice. Under colitis conditions, JMS reduced pathological severity and inflammation in mice with circadian disruption by upregulating BMAL1 and PER2. In mice with normal circadian rhythms, the protective effect of JMS was observed during the remission phase of colitis. At the cellular level, JMS activated RORα and enhanced the transcription and expression of BMAL1 and PER2 in colonic epithelial cells. Metabolomics and RNA sequencing revealed that JMS inhibited NF-κB signaling, contributing to its anti-inflammatory action. Mechanistically, JMS enhanced RORα/HDAC3 binding to NF-κB target genes in epithelial cells, leading to reduced H3K9Ac levels and repression of Il-1β and Tnf-α, while epithelial RORα knockdown abolished the anti-inflammatory effects.

Conclusion

This study demonstrates that JMS activates epithelial RORα to restore circadian rhythm in the colon and suppresses NF-κB signaling, ultimately promoting colitis recovery These findings underscore the role of JMS in regulating intestinal circadian rhythm and highlight its potential as a chronotherapeutic strategy for colitis.