7‐Hydroxydehydronuciferine induces human melanoma death via triggering autophagy and apoptosis

Melanoma is the deadliest cancer. We identified 7‐hydroxydehydronuciferine (7‐HDNF) isolated from the leaves of Nelumbo nucifera Gaertn cv. Rosa‐plena to be a bio‐active agent that antagonizes melanoma tumor growth in mice xenograft model in vivo. Cell proliferation assay demonstrated strong anticancer effects of 7‐HDNF to exhibit a dose‐dependent behaviour and displayed minor cytotoxicities on normal human skin cells, including epidermal keratinocytes and melanocytes, and dermal fibroblasts. With acridine orange (AO) staining and flow analysis, we found 7‐HDNF induced the formation of intracellular vacuoles and the augmentation of acidic vesicular organelles (AVO). The apoptotic cell death ratio was measured via two‐dimensional flow cytometry by annexin V‐fluorescein isothiocyanate (FITC)/propidium iodide (PI) double stained to confirm the cellular membrane asymmetry lost. One‐dimensional flow cytometric analysis showed 7‐HDNF increased the cellular arrest in cell cycle at the G2/M phase. Through Western blot examinations, protein expressions were discovered to verify autophagy and apoptosis response mechanisms sharing the associated pathways. Finally, 7‐HDNF presented a high‐quality antimigratory activity in wound‐healing assay. Overall, 7‐HDNF presented high‐quality anticancer bio‐functions and inhibited melanoma tumor growth in vivo and in vitro.