Curcumol induces autophagy-dependent hepatic stellate cell death through methionine metabolism disruption.

Hepatic stellate cell (HSC) activation is a key driver of extracellular matrix (ECM) accumulation and liver fibrosis. Autophagy plays an essential role in regulating HSC activation, yet its metabolic regulation remains largely undefined. Curcumol, a bioactive compound derived from Curcuma longa, possesses potent antifibrotic activity, but the underlying metabolic mechanisms are unclear. In this study, we found that curcumol suppressed HSC activation and induced autophagy-dependent cell death, together with inhibition of methionine metabolism. Curcumol treatment reduced LX-2 cell viability and downregulated profibrogenic markers α-smooth muscle actin (α-SMA) and collagen type I (COL1A1) in a dose-dependent manner. Mechanistically, curcumol enhanced LC3-II accumulation, diminished p62 levels, and promoted autophagic vacuole formation, effects that were reversed by the autophagy inhibitor 3-methyladenine (3-MA). Silencing of ATG7 attenuated curcumol-induced autophagy-associated changes and cell death, supporting the involvement of ATG7 in this process. Furthermore, curcumol significantly reduced the expression of key methionine cycle enzymes MAT2A and AHCY. Supplementation with S-adenosylmethionine (SAM) partially reversed curcumol-associated changes in methionine metabolism and autophagy-related markers, and improved HSC viability, supporting a functional link between methionine metabolism and the observed phenotype. Collectively, these findings suggest that curcumol promotes autophagy-dependent death of HSCs in association with disrupted methionine metabolism, providing new insight into the metabolic basis of its antifibrotic action.