Naringin mitigates liver damage in a tissue-engineered liver of metabolic dysfunction-associated steatotic liver disease model by promoting autophagy via the mTOR-ULK1 pathway

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic liver disease with complex pathogenesis. Autophagy is involved in the occurrence and development of MASLD. Naringin is a flavonoid compound with anti-inflammatory and anti-oxidation effects. This study is to investigate the impact of naringin on Autophagy in an Organoid model of tissue-engineered fatty liver (TEF).

Methods and results: Human hepatocytes were cultured on a rat liver biomatrix scaffold and perfused with fat-supplemented medium to establish 3D MASLD models. Naringin was treated for 3 days. Histopathological changes were determined by oil red O and hematoxylin-eosin staining; organelle morphology was examined by scanning electron microscopy and transmission electron microscopy (TEM); the expression of autophagy-related factors was analyzed by qPCR and Western Blot. Hepatocyte injury was determined by terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) staining, cell counting and Lactate Dehydrogenase (LDH) detection. The results showed naringin significantly improved liver injury in the MASLD model, as evidenced by increased cell viability, reduced lipid accumulation and LDH release. TEM revealed the presence of autophagosomes in naringin-treated hepatocytes. Naringin upregulated the expression of autophagy-related proteins (LC3, ATG5, Atg7) and promoted the LC3-II/LC3-I ratio, indicating enhanced autophagic flux. Furthermore, naringin regulated the mTOR-ULK1 signaling pathway by downregulating p-mTOR and p-ULK1 (Ser757) and upregulating Beclin1. Autophagy inhibitors (3-Methyladenine and SBI-0206965) attenuated the protective effects of naringin, confirming the role of Autophagy in hepatocyte protection.

Conclusion: Naringin mitigates liver damage in the TEF model by enhancing Autophagy via mTOR-ULK1 pathway, highlighting its potential as a therapeutic agent for MASLD.

Autophagy; Metabolic dysfunction-associated steatotic liver disease; Naringin; Organoid; Tissue-engineered liver.