Anti-proliferative effect of auriculataoside A on B16 melanoma 4A5 cells by suppression of Cdc42-Rac1-RhoA signaling protein levels.

Auriculataoside A, an anthracenone dimer glycoside isolated from Cassia auriculata seed, shows anti-proliferative effects on cell line B16 melanoma 4A5 cells with an IC50 value of 0.82 μM. However, it shows no such effect on normal human dermal fibroblast (HDF) cells. To evaluate the mode of action underlying the anti-proliferative effect of auriculataoside A on cells, we examined changes in whole protein expression after treatment with auriculataoside A and found that the expression Cdc42, RhoA, and Rac1, which are Rho family GTPases, was reduced. Auriculataoside A also arrested the cell cycle at G1 phase. These results suggest that the suppression of the above proteins induced G1 arrest. In addition, auriculataoside A also suppressed the expression of β-catenin and c-Myc proteins. This action of auriculataoside A could be one of the mechanisms underlying its selective anti-proliferative effect on B16 melanoma cells.