Effect of juglone on C-32 and COLO 829 melanoma cells in in vitro cultures

Juglone is an allelopathin secreted by black walnut tree of the Juglandaceae family and is used as an active ingredient in many herbal preparations and as a commercial dye. It is considered as an important phytochemical with wide therapeutic potential. Black walnut extract has long been used in folk medicine to treat various types of cancers. It demonstrates antiviral, antibacterial, antifungal, and antitumor activities. The present study aimed to analyze the effect of juglone on the viability and proliferation of melanoma cells of C-32 (amelanotic melanoma) and COLO 829 (melanotic melanoma) cell lines in vitro and on the mRNA expression of genes encoding the proapoptotic BAX protein and caspase 3 and the gene encoding antiapoptotic BCL2 protein. The results showed a dose-dependent effect of juglone on the viability, proliferation, and death induction in C-32 and COLO 829 melanoma cells and in HFF-1 normal dermal fibroblasts in in vitro cultures, but melanoma cells were more sensitive to juglone. Our findings revealed different mRNA expression patterns for all the studied genes in melanoma and normal cells treated with juglone in in vitro cultures.