Quzhou-sourced Fructus Aurantii ameliorates MASLD by modulating glycolysis-dependent M1 polarization in hepatic macrophages.

BACKGROUND

Fructus Aurantii (Quzhou-origin, FAQ), an authentic medicinal material from Zhejiang, China, restores intestinal barrier integrity and thereby ameliorates high-fat and high-fructose diet-induced hepatic inflammation and injury. However, its direct hepatic mechanisms of efficacy remain unclear, and head-to-head efficacy comparisons with authoritative positive drugs are lacking.

AIM: Benchmarking against resmetirom to evaluate the therapeutic efficacy of FAQ against MASLD and elucidate its underlying mechanisms.

METHODS

Histopathological (H&E, Oil Red O, Sirius Red and Masson) staining, ultrastructural (TEM), and serological (glucose, lipid, ALT/AST) profiles were benchmarked against resmetirom to comprehensively evaluate the protective effects of FAQ against MASLD-associated metabolic dysregulation, hepatic inflammation, and fibrosis. Crucially, integrated transcriptomic and single-cell RNA sequencing (scRNA-seq) revealed a novel mechanism: FAQ mitigates liver inflammation and fibrosis by suppressing PKLR-mediated glycolytic flux in macrophages and consequent M1 polarization. This hypothesis was validated using macrophage-hepatic stellate cell (HSC) co-culture and PKLR overexpression-rescue experiments.

RESULT: Both FAQ and resmetirom effectively ameliorate MASLD, with distinct therapeutic effects: resmetirom had superior anti-inflammatory and antifibrotic effects, whereas high-dose FAQ effectively ameliorated hepatic steatosis and metabolic dysregulation. Mechanistically, the upregulation of PKLR in macrophages drives glycolytic flux, leading to M1 polarization and proinflammatory cytokine secretion, which in turn activates HSCs and promotes fibrosis. FAQ dose-dependently reversed PKLR-driven glycolysis and M1 polarization, mitigating cytokine secretion and HSC activation. Validation with PKLR overexpression further confirmed its critical role as a pharmacological target for the anti-MASLD effects of FAQ.

CONCLUSION

Through comparisons with resmetirom, our findings confirm the potential of FAQ in treating MASLD. In addition, we describe a novel mechanism of action: FAQ ameliorates hepatic inflammation and fibrosis by targeting macrophage PKLR-driven glycolysis and M1 polarization, providing a scientific basis for its clinical application in treating MASLD.