Daphnoretin induces reactive oxygen species-mediated apoptosis in melanoma cells

Research suggests that daphnoretin exhibits a diverse array of antitumor mechanisms and pharmacological activities. However, there is no definitive explanation for the antitumor mechanisms of daphnoretin in malignant melanoma. In the present study, MTT and colony formation assays demonstrated that daphnoretin significantly inhibited the proliferation of melanoma A375 and B16 cells. Following treatment with daphnoretin, apoptotic bodies were observed in A375 and B16 cells via Hoechst 33258 staining. Furthermore, western blot analysis revealed that the apoptosis-related proteins cleaved caspase-3, cleaved caspase-9, Bax, cytochrome c and apoptotic protease-activating factor 1 were significantly upregulated, while the expression levels of caspase-3, caspase-9 and Bcl-2 were downregulated in A375 and B16 cells. Flow cytometry and fluorescence microscopy revealed that daphnoretin induced higher levels of reactive oxygen species (ROS). Therefore, the results of the present study indicated that daphnoretin induced ROS-mediated mitochondria apoptosis in human (A375) and murine (B16) malignant melanoma cells.