Anti-melanoma potential of two benzoquinone homologues embelin and rapanone - a comparative in vitro study.

Rapanone and embelin are simple alkyl benzoquinone derivatives, mainly distributed in the Primulaceae. They have an interesting scope of biological activities including cytotoxicity. As melanoma is one of the most common types of cancer, in many cases resistant to current treatment regimens, the aim of this study was to assess and compare anti-melanoma activity of the two benzoquinones. Cytotoxicity of both compounds towards different melanoma cell lines (A375, HTB140, WM793) and selectivity with respect to normal keratinocytes (HaCaT) were investigated. Furthermore, interactions with a reference chemotherapeutic, doxorubicine, were assessed. Finally, analysis of anti-inflammatory, antioxidant and anti-tyrosinase activities of both benzoquinones was conducted as well.