Triptonide facilitates autophagy-mediated apoptosis in esophageal squamous cell carcinoma by targeting the AMPK-mTOR-ULK1 axis

• • TN induces autophagy-dependent apoptosis in ESCC cells, with a significant reduction in cell viability observed at low micromolar concentrations (IC50 values not explicitly stated in Section B, but functional assays confirm dose-dependent effects). This suggests TN could serve as a potent alternative to conventional chemotherapy, potentially reducing systemic toxicity. • • The AMPK-mTOR-ULK1 axis is critically involved: TN activates AMPK, inhibits mTOR, and phosphorylates ULK1, leading to autophagic flux. This pathway represents a actionable target for ESCC, as dysregulation of AMPK signaling is common in chemoresistant tumors. • • Pharmacological inhibition of autophagy with 3-MA or AMPK with Compound C significantly attenuates TN-induced apoptosis, confirming that autophagy precedes and mediates apoptosis. This mechanistic insight supports combining TN with autophagy modulators to enhance therapeutic efficacy. • • TN's dual role in inducing autophagy and apoptosis highlights its potential to overcome apoptosis resistance in ESCC, a major clinical challenge. The study provides a strong rationale for advancing TN into preclinical and clinical trials, given its natural origin and favorable safety profile compared to synthetic agents.