Mechanism of Jianpi Qinghua granule in ameliorating metabolic dysfunction-associated fatty liver disease by targeting the DNMT-urea cycle axis.

ETHNOPHARMACOLOGICAL RELEVANCE: Jianpi Qinghua Granule (JPQH) is a hospital-prepared traditional Chinese medicine formula used for insulin resistance and related metabolic disorders. However, its pharmacodynamic basis and epigenetic mechanisms in metabolic dysfunction-associated fatty liver disease (MAFLD) remain unclear.

AIM OF THE STUDY: This study aimed to evaluate the therapeutic effects of JPQH on high-fat diet (HFD)-induced MAFLD and determine whether its action involves regulation of DNMT-mediated DNA methylation and hepatic urea cycle metabolism.

MATERIALS AND

METHODS

HFD-induced MAFLD mice were treated with JPQH for 4 weeks. Blood-absorbed constituents were identified by UHPLC-Q Exactive Orbitrap MS/MS. Network pharmacology, liver transcriptomics, and targeted metabolomics were integrated to explore mechanisms. Pyrosequencing, RT-qPCR, Western blotting, molecular docking, and molecular dynamics simulations were used for validation.

RESULTS

JPQH ameliorated glucose-lipid metabolic disorders and liver injury, as indicated by reduced serum TC, TG, ALT, and AST levels (P < 0.05), decreased hepatic MDA levels (P < 0.01), improved OGTT/ITT responses (P < 0.001), restored GSH/GSSG ratio (P < 0.05), and downregulation of inflammatory- and fibrosis-related gene expression (P < 0.05). A total of 44 blood-absorbed constituents and 87 JPQH-MAFLD overlapping targets were identified. Integrated analyses highlighted nitrogen metabolism and arginine and proline metabolism. JPQH restored urea cycle intermediates, upregulated CPS1, OTC, ASS1, ASL, and ARG1 expression (P < 0.01), and reduced hepatic ammonia accumulation (P < 0.01). Mechanistically, JPQH reduced DNMT1/DNMT3A expression, attenuated promoter hypermethylation of urea cycle enzyme genes, and restored their transcriptional and protein expression. Core flavonoids, including genistein, baicalein, nepetin, hispidulin, and quercetin 3,4'-dimethylether, exhibited stable binding to DNMT1 and DNMT3A in silico.

CONCLUSIONS

JPQH exerts protective effects against MAFLD by restoring hepatic nitrogen metabolism and ammonia detoxification via epigenetic regulation of the DNMT-urea cycle axis.