Flavonoids from Rhododendron nivale Hook. f ameliorate alcohol-associated liver disease via activating the PPARα signaling pathway

Background: Flavonoids are increasingly recognized for their potent antioxidant properties and potential therapeutic roles in the management of alcohol-associated liver disease (ALD). Extracts derived from Rhododendron nivale Hook. f. (FRN) have been shown to influence glutathione metabolism in aging animal models, exhibiting notable antioxidant effects. However, the specific impact of FRN on ALD remains insufficiently explored.

Hypothesis/purpose: This study seeks to elucidate the efficacy of FRN in alleviating the pathology associated with ALD, delving into the underlying molecular mechanisms that facilitate its protective effects.

Study design: We employed network pharmacology to predict the functional roles and pathway enrichments associated with FRN targets. Both a murine model of ALD and in vitro cellular models were utilized to clarify the mechanistic basis by which FRN mitigates ALD.

Methods: FRN was extracted and characterized according to well-established methodologies outlined in our previous studies. Potential functions and pathways implicated by FRN were predicted through network pharmacology analyses. A combination of liver transcriptomics, targeted lipidomics, molecular biology techniques, and antagonists of relevant targets were employed to investigate the mechanisms through which FRN exerts its protective effects in ALD.

Results: Network pharmacology identified multiple target genes modulated by FRN, particularly those within critical ALD-related signaling pathways, such as PPARα signaling and fatty acids (FAs) degradation. Notably, treatment with FRN in the ALD murine model led to a significant attenuation of hepatic lipid accumulation and a restoration of serum AST and ALT to baseline ranges. Subsequent validation through liver transcriptomics and molecular biology techniques revealed an upregulation of PPARα expression concomitant with a downregulation of ACSL1 in FRN-treated ALD mice. Targeted lipidomic and bioinformatic analyses demonstrated that FRN substantially reduced the accumulation of long-chain fatty acids in hepatocytes. Importantly, the reversal of FRN's protective effects on lipid accumulation through the PPARα antagonist GW6471 provides compelling evidence for the critical role of PPARα signaling modulation in mediating the beneficial impact of FRN on ALD.

Conclusion: Our research highlights FRN's capacity to alleviate ALD through PPARα pathway activation, paving the way for innovative treatment strategies. This underscores the significance of natural compounds in pharmacotherapy, suggesting that FRN may provide an effective alternative for managing ALD.