Mechanism and inhibitory effect of galangin and its flavonoid mixture from Alpinia officinarum on mushroom tyrosinase and B16 murine melanoma cells

Abstract

The whitening effects of the flavonoid constituents of Alpinia officinarum Hance were investigated on melanin biosynthesis in B16 mouse melanoma cells, tyrosinase inhibition and UV absorption. The melanin content was reduced to 1.276 μg/105cell for flavonoid mixture and 1.161 μg/105 cell for galangin while the melanin control was 1.632 μg/105cell. Both flavonoid mixture and galangin reduced melanin production with an inhibition of 21.81% and 28.86% at a concentration of 26.5 μg/mL and 29 μg/mL (107.4 μM), respectively. Tyrosinase inhibition by the flavonoid mixture and galangin were higher at lower concentrations and galangin showed competitive inhibition at a concentration less than 21.23 μg/ mL which was soluble. In addition, the flavonoid mixture and galangin showed a broad absorption band at 270 ∼ 290 nm related to the UV-B area. These observations suggest that galangin may be a whitening agent and a promising candidate for prevention of skin cancer. This is the first full scale report on the evaluation of the whitening effect of galangin.