8-hydroxyarctigenin Isolated from Safflower Sprouts Inhibits Melanogenesis of Melan-a Cells and Light Quality during the Sprout Growth Determinesthe Compound Yield

摘要

Safflower sprouts were grown under different light frequencies and conditions, including fluorescent white light, red LED or blue LED light and darkness. The sprout extracts were tested for their inhibitory effect on melanin synthesis. Two compoundsfrom safflower sprout extract were isolated and tested for their activities. Safflower seeds were sown in growth chambers set to lights and harvested at 9 days after sowing. Methanolic extracts of safflower sprouts were subjected to melanin synthesis inhibitory effect on MTT [3-(4，5-Dimethylthiazol-2-yl)-2，5-Diphenyltetraxolium Bromide] and melanin bioassay methods with a dose dependent manner. Two compounds were identified by using open column chromatography and LC-MS (liquid chromatography-mass spectrometry) analysis. The MTT and melanin bioassays with the identified compounds were conducted. Darkness or fluorescent white light irradiation induced extracts with inhibitory effects on melanin synthesis (in a dose dependent manner). In contrast, bluelight induced extracts to slightly increase melanin synthesis. It was found that 8-hydroxyarctigenin, a compound isolated from the safflower sprouts grown under fluorescent white light for 9 days after germination, induced inhibitory effect of melanin synthesis. The compound was contained more in the darkness or fluorescent white light treatment than others. Safflower sprouts grown under dark or fluorescent white light conditions were more effective on inhibiting melanin synthesis than conditions underred or blue light. An active compound, 8-hydroxyarctigenin, may be a useful whitening agent in cosmetic resources.