Camellia Japonica Radix modulates gut microbiota and 9(S)-HpODE-mediated ferroptosis to alleviate oxidative stress against MASLD.

Background: Camellia japonica radix (CJR), derived from the root of Camellia japonica L., has the potential to function as an herbal tea substitute for the prevention and intervention of metabolic dysfunction-associated steatotic liver disease (MASLD). It can provide systemic therapeutic benefits, boast a favorable safety profile, facilitate convenient consumption, and support long-term applicability. Despite its potential, research on CJR remains limited.

Purpose: The aim of this study aims is to elucidate the therapeutic mechanisms of CJR in MASLD, thereby providing evidence to support its clinical application.

Methods: The therapeutic effects of CJR were evaluated using a water-supplementation model in MASLD mice. Integrated microbiome, transcriptome, proteome, and metabolome analyses were employed to comprehensively explore the mechanisms involved. A drug-target pull-down assay was performed to identify specific protein targets of small molecule metabolites in vitro. Fecal microbiota transplantation in antibiotic-treated ABX mice was conducted to confirm the critical role of gut microbiota and its metabolites. Furthermore, customized medicated feed supplemented with linoleic acid was used to explore the intervention effect of its metabolite, 9(S)-HpODE, as well as to evaluate its dietary intervention potential.

Results: This present study explicitly elucidates the efficacy of CJR extract in alleviating hepatic inflammation and steatosis in a MASLD model mice, with its pharmacological mechanism associated with gut microbiota, linoleic acid metabolism, and GPX4-mediated ferroptosis. Notably, 9(S)-HpODE was discovered to be a key metabolite of linoleic acid, which could target both KEAP1 and SLC7A11, bidirectionally regulating GPX4-mediated ferroptosis, while acting as a signaling molecule at low doses to induce redox adaptation via oxidative preconditioning, thus ameliorating oxidative stress in MASLD.

Conclusion: Our findings indicate that both CJR and linoleic acid exhibit significant potential as dietary interventions for the management of MASLD, offering promising avenues for future research and clinical application.