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

Figures & data

Figure 1 Structures of galangin and 3-O-methyl galangin.

Figure 2 Separation of flavonoid mixture and galangin from Alpinia officinarum Hance.

Figure 3 HPLC chromatogram and DAD scan of flavonoid mixture.

Figure 4 The effect of samples on cell growth.

Figure 5 Four stages of melanosomes production with treatment. (Please see colour online).

Table I.  The inhibitory effect of flavonoid mixture and galangin on production of melanin.

Treatment	OD value	Average	Melanin content (μg/10^5cell)	%Inhibition*
Control	0.238	0.242	1.632	0
	0.249
	0.239
Galangin**	0.165	0.1643	1.161	28.86
	0.164
	0.164
Flavonoid**	0.185	0.1833	1.276	21.81
	0.189
	0.176

*Inhibition% = (Melanin content of Control—Treatment)/Control × 100.

**Concentration of galangin = 29 μg/mL and flavonoid = 26.5 μg/mL.

Figure 6 Effect of diphenolase activity of tyrosinase, DMSO used as control.

Figure 7 Lineweaver-Burk plots of galangin inhibition on diphenolase activity of tyrosinase, Three curves of three concentrations of galangin are: 0 (galangin-0), 9.08 μg/mL (galangin-1) and 18.16 μg/mL (galangin-2), respectively.