Oroxyloside inhibits liver fibrosis and hepatocarcinogenesis dependent on hepatocyte-specific knockout of Atg5

Abstract

• We first identified the anti-liver fibrosis effect of OAG. • Atg5 deficiencies in hepatocytes aggravated liver fibrosis, while OAG prevents mice fibrosis dependent on hepatic Atg5 . • OAG induced autophagy via AMPK-ULK1 pathway in hepatocytes with the PPARγ regulation. • OAG inhibited HSC activation through decreasing IL-6 release of hepatocyte. Hepatocellular carcinoma (HCC), a leading cause of cancer-related mortality, is closely linked to liver fibrosis, yet effective preventive therapies remain elusive. Autophagy is a critical cellular process that maintains hepatic homeostasis, and its disruption is implicated in the progression of fibrosis and HCC. This study aimed to evaluate the efficacy of oroxyloside (OAG), a flavonoid derived from Scutellaria baicalensis , in preventing liver fibrosis associated with cancer. Mouse models of liver fibrosis and hepatocarcinogenesis were developed using carbon tetrachloride (CCl 4 ) alone or a combined with diethylnitrosamine (DEN), with or without OAG treatment. Hepatocyte-specific Atg5 knockout mice (Atg5 Hep-/− ) and in vitro models with silenced Atg5 or PPARγ were used to investigate autophagy's role in OAG's therapeutic effects. To analyze the correlation between autophagy and hepatic fibrosis or cancer we use the TCGA and GSE database. Patient tissue samples (79 pairs) associated HCC was investigated by immunohistochemistry. This study demonstrates that OAG restores autophagic flux through the AMPK-ULK1 pathway in a PPARγ-dependent manner, reducing oxidative stress, DNA damage, and inflammatory cytokine IL-6 production. These mechanisms culminate in the inhibiting the activation of hepatic stellate cell activation and fibrosis progression. OAG also significantly attenuated liver tumor burden and improved survival in a chronic liver injury model. Importantly, the therapeutic effects of OAG were diminished in Atg5-deficient hepatocytes, highlighting its reliance on autophagy. This mechanistic insight differentiates OAG from existing anti-fibrotic or HCC therapies by targeting the interplay between autophagy and inflammation. OAG represents an innovative therapeutic approach to liver fibrosis and HCC, acting through autophagy-dependent pathways to inhibit inflammation and oxidative stress. Its dual anti-fibrotic and anti-carcinogenic effects position OAG as a promising candidate for addressing the unmet clinical needs in chronic liver disease.