Assessment of In Vitro Anti-melanoma Potential of Ephedranthus pisocarpus R.E.Fr

Background/aim: Despite being a rare disease, melanoma is considered the most dangerous skin cancer due to its highly invasive and aggressive nature, and still requires for more effective treatments. The aim of this study was to evaluate the in vitro anti-melanoma potential of Ephedranthus pisocarpus R.E.Fr. (Annonaceae), a popular Brazilian plant with medicinal properties.

Materials and methods: Initially, the ethanolic extract (EtOH) was obtained from E. pisocarpus leaves and later partitioned using increasing polarity solvents. The anti-melanoma potential of E. pisocarpus was assessed by spectrophotometry and its cytotoxicity determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and confocal microscopy.

Results: We demonstrated that the EtOH extract and fractions from E. pisocarpus had a moderate photoprotective action (FPS 3.0-5.0) against UVA radiation. Interestingly, the dichloromethane fraction presented higher anti-melanoma activity against B16-F10 (IC₅₀=46.8 μg/ml) and SK-MEL-28 cells (IC₅₀=40.1 μg/ml) and lesser toxicity on normal cells. Additionally, our study reported that spathulenol, one of the major constituents from E. pisocarpus, acts through an apoptosis-dependent mechanism in SK-MEL-28 cells.

Conclusion: The present study demonstrated, for the first time, the in vitro anti-melanoma potential of E. pisocarpus against melanoma cells.

Keywords: E. pisocarpus; Melanoma; apoptosis; natural products; photoprotection; spathulenol.