GA Eases Atherosclerosis by Regulating Circadian Rhythm

Atherosclerosis (AS) serves as a fundamental high-risk factor associated with the development of cardiovascular diseases. There is an urgent need to investigate efficacious therapeutic strategies and molecular targets to combat AS.

Apolipoprotein E (ApoE)^-/^- mice fed a high-fat diet were administered glycyrrhetinic acid (GA) to establish the AS intervention model. An enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of the pro-inflammatory cytokines IL-6 and tumor necrosis factor‑α (TNF-α). Concurrently, biochemical analyses measured serum lipid profiles, including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and total cholesterol (TC). Total RNA extracted from mouse aortic tissues was subjected to RNA sequencing to identify differentially expressed genes (DEGs), followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Cytoscape software, combined with weighted gene co-expression network analysis (WGCNA), was used to filter candidate target genes, and quantitative real-time PCR (qPCR) was conducted to verify the expression levels of hub clock genes.

GA markedly suppressed the overproduction of IL-6 and TNF-α in AS model mice. Meanwhile, GA reduced serum LDL-C, TG, and TC concentrations and elevated HDL-C levels. RNA-seq-derived DEGs were significantly enriched in biological processes and signaling pathways related to circadian rhythm. Three core clock genes, period circadian clock 1 (Per1), period circadian clock 2 (Per2), and period circadian clock 3 (Per3), were identified as candidate targets. qPCR results validated that GA significantly upregulated the expression of Per1, Per2, and Per3 in aortic tissues.

This study preliminarily confirms that GA exerts anti‑atherosclerotic effects in ApoE^-/^- mice. Its potential therapeutic mechanism may be associated with circadian rhythm‑related signalling involving Per1, Per2, Per3.