Fig. 2.

Effects of ginsenoside Rb1 on cell viability, melanin production, and tyrosinase activity in B16 cells. a Viability of B16 cells after treatment with ginsenoside Rb1. The cells were seeded in 96-well plates for 24 h and then treated with various dosages of ginsenoside Rb1 (15.63–1000 uM) for 48 h. The cell viability was then examined by the MTT assay. b Effect of ginsenoside Rb1 on cellular melanin synthesis. c Effect of ginsenoside Rb1 on tyrosinase activity. The cells were exposed to α-MSH (10 nM) in the presence or absence of ginsenoside Rb1. B16 cells with and without α-MSH treatment (absence of ginsenoside Rb1) were used as two negative controls. The melanin content, protein content, and tyrosinase activity of each reaction were determined by a spectrometric method as described in the “Materials and Methods” section. Data were expressed as the mean ± SD of three independent experiments carried out in triplicate. Statistically significant difference *P < 0.05, **P < 0.01, ***P < 0.001 compared with 0-uM Rb1 group stimulated byα-MSH; ^# P < 0.05 compared with control group withoutα-MSH treatment; ^※ P < 0.05 compared with arbutin group or kojic acid group