Astaxanthin induces autophagy and apoptosis in murine melanoma B16F10-Nex2 cells and exhibits antitumor activity <i>in vivo</i>

Countless efforts have been made to prevent and suppress the formation and spread of melanoma. Natural astaxanthin (AST; extracted from the alga Haematococcus pluvialis) showed an antitumor effect on various cancer cell lines due to its interaction with the cell membrane. This study aimed to characterize the antitumor effect of AST against B16F10-Nex2 murine melanoma cells using cell viability assay and evaluate its mechanism of action using electron microscopy, western blotting analysis, terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, and mitochondrial membrane potential determination. Astaxanthin exhibited a significant cytotoxic effect in murine melanoma cells with features of apoptosis and autophagy. Astaxanthin also decreased cell migration and invasion in vitro assays at subtoxic concentrations. In addition, assays were conducted in metastatic cancer models in mice where AST significantly decreased the development of pulmonary nodules. In conclusion, AST has cytotoxic effect in melanoma cells and inhibits cell migration and invasion, indicating a promising use in cancer treatment.