Gintonin from Panax ginseng induces apoptosis in HT-29 colon cancer cells via AMPK signalling pathway

Introduction Therapeutic potential of natural extracts and phytochemicals in anticancer treatment has encouraged extensive research in recent years. In this study, gintonin, a lysophosphatidic acid receptor ligand derived from Panax ginseng , was examined for its cytotoxic and proapoptotic effects on HT-29 human colon cancer cells, with emphasis on the AMP-activated protein kinase (AMPK) signalling pathway Methods HT-29 cells were treated with various concentrations of gintonin. Cell viability was assessed using the MTT assay, and apoptosis was evaluated through DNA fragmentation analysis. Western blotting and immunocytochemistry were employed to investigate the expression of apoptotic markers, and the role of AMPK signalling was further validated using compound C, a selective AMPK inhibitor. Results MTT and DNA fragmentation assays demonstrate that gintonin effectively reduces cell viability and induces apoptosis concentration-dependently, with maximum apoptosis observed above 100 µg/mL. Expression of proapoptotic proteins (Bax, cleaved caspase-3 and cleaved caspase-9) was significantly upregulated, while the antiapoptotic protein Bcl2 was markedly downregulated. Additionally, phosphorylation of AMPK, specifically AMPKα, and its downstream substrate acetyl-CoA carboxylase (ACC) was significantly enhanced following gintonin treatment. Pretreatment with compound C suppressed the phosphorylation of AMPK markers and reversed the apoptotic effects, which confirms that the gintonin-induced apoptosis occurs through the AMPK pathway. Furthermore, immunocytochemistry staining indicated that gintonin effectively promotes apoptosis, as evidenced by the increased fluorescence intensity corresponding to gintonin concentration. Conclusions Gintonin promotes AMPK-mediated apoptosis in HT-29 cells, suggesting its anticancer potential. However, further studies using additional cell lines and physiologically relevant concentrations are required to confirm its therapeutic applicability.