Inhibitory effects of active compounds isolated from safflower (Carthamus tinctorius L.) seeds for melanogenesis

In order to develop a new skin whitening agent, safflower (Carthantus tinctorius L.) seeds were evaluated for mclanogenesis inhibitory activity and its active principles were identified following activity-guided isolation. The 80% aqueous methanol extract and ethyl acetate fraction from safflower seeds showed a significant inhibition for mushroom tyrosinase. Three active compounds, N-feruloyiserotonin, N-(p-coumaroyl)serotonin, and acacetin, were isolated from the ethyl acetate fraction as the active principles. Compared with arbutin (IC50=0.223 mm), the IC50 values of these compounds were 0.023, 0.074, and 0.779 mm for N-feruloylserotonin, N-(Pcoumaroyl)serotonin, and acacetin, respectively. It was also found that N-feruloyiserotonin and N-(pcoumaroyl)serotonin strongly inhibited the melanin production of Streptomyces bikiniensis and B16 melanoma cells in comparison with a known melanogenesis inhibitor, arbutin.