Piperlongumine Induces Apoptosis in Human Melanoma Cells Via Reactive Oxygen Species Mediated Mitochondria Disruption

Malignant melanoma is a devastating skin cancer due to its severe drug resistance and prompt metastasis. Piperlongumine is an anti-inflammation and tumor-suppressing natural product with defined structure. While numerous studies revealed exceptional inhibitory effects of piperlongumine on several carcinomas, few investigations were performed on melanoma. Therefore, the present study investigated the anti-tumor effects of piperlongumine on human melanoma cells in vitro, and explored the mechanisms of action. Results from cytotoxicity and proliferation studies demonstrated that piperlongumine inhibited cell growth in melanoma cell lines A375, A875, and B16-F10 in a dose- and time-dependent manner. Flow cytometric analysis showed that piperlongumine obstructed cell cycle progression at G2/M phase and induced apoptosis in A375 cells. Mechanistic investigations illustrated that piperlongumine promoted reactive oxygen species production and decreased mitochondrial membrane potential. In addition, piperlongumine was reported to interfere with the expression of p21, p27, cleaved caspases-3, Bax, Bcl-2, and p-Jun N-terminal kinase (JNK), which are typical regulators associated with cell proliferation, intrinsic apoptosis, and JNKs pathway. Taken together, these results strongly suggested that piperlongumine inhibits cell growth and induces apoptosis in human melanoma cells via ROS mediated mitochondria disruption and JNKs pathway, and piperlongumine may exert promising potential for patients suffering from malignant melanoma.