Abstract

Hepatocellular carcinoma (HCC) is the most prevalent primary liver malignancy and the third leading cause of cancer-related deaths worldwide, with high mortality and limited clinical treatment options. In this study, we identified hypericin as a potent inducer of HCC cell death by screening traditional Chinese Medicine Monomer Library screening. Hypericin, a natural photosensitizer derived from Hypericum perforatum , significantly inhibited the proliferation, migration, and colony formation of HCC cell lines, and induced apoptosis in vitro. In vivo, hypericin effectively suppressed tumor growth in Hepa1-6 subcutaneous tumor and AKT/c-Myc-driven orthotopic mouse HCC models. Flow cytometry analysis revealed that hypericin treatment increased the CD8 + T cell proportion and activity within the tumor microenvironment. Combination therapy with hypericin and anti-PD-L1 antibody resulted in significant tumor growth inhibition and prolonged survival. Mechanistically, hypericin promoted the interaction between AKT and HSPA5, leading to autophagic degradation of AKT. This process inhibited the AKT/mTOR/S6 signaling pathway, downregulated the expression of downstream anti-apoptotic proteins MCL-1 and XIAP, and triggered mitochondria-mediated apoptosis in HCC cells.