Picrocrocin exhibits growth inhibitory effects against SK-MEL-2 human malignant melanoma cells by targeting JAK/STAT5 signaling pathway, cell cycle arrest and mitochondrial mediated apoptosis

Purpose: Melanoma is one of the lethal types of skin malignancies and is responsible for significant morbidity and mortality across the globe. In this study the anticancer effects of picrocrocin on the human SK-MEL-2 malignant melanoma cell line were evaluated along with its mode of action. Methods: The effect of picrocrocin was evaluated on SK-MEL-2 cells by MTT assay. Apoptosis was determined by DAPI and annexin V/PI staining. The effects on reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and cell cycle analysis were performed by flow cytometry. Expression of the proteins (JAK/STAT5) was estimated by western blotting. Results: Picrocrocin exerted growth inhibitory effects on the SK-MEL-2 melanoma cells. The IC50 of picrocrocin against the SK-MEL-2 cells was 20 mu M at 24-h incubation. The antiproliferative activity of picrocrocin was due to apoptosis and cell cycle arrest. In addition, picrocrocin enhanced the ROS levels and decreased the MMP levels of SK-MEL-2 cells. Finally, picrocrocin inhibited the JAK/STAT5 signalling pathway in the SK-MEL-2 melanoma cells. Conclusions: Taken together, these results indicate that picrocrocin can prove to be an important molecule in the search of more efficient therapies for melanoma.