Fig. 2.

The effect of GF1 on dendrite formation and melanosome transfer in MNT-1/HaCaT cocultured cells and a 3-D human skin equivalent. Cocultured MNT-1/HaCaT cells were treated with 100 μM GF1 in the presence or absence of α-MSH (500 nM) stimulation for 48 h. (A) After the fixation, we observed dendrite formation in melanocytes using optical microscopy (Scale bar; 50 μm). (B) For immunostaining, we stained melanosome with TRP-1 antibody (red color) and keratinocytes with cytokeratin-18 (green color). White arrows indicate transferred melanosome to HaCaT from MNT-1 cells (Scale bar; 20 μm). Human skin equivalent (MelanoDerm; n = 3) was treated with the 1% Kojic acid as a reference whitening compound and GF1 (10 and 50 ug/ml) for 18 d. (C) After treatment, skin equivalents were photographed. (D) ▵ L value (degree of lightness as compared to vehicle-treated control) for each test sample was calculated. (E) The Hematoxylin and Eosin (H&E) staining of tissue sections. (F) Fontana-Mason (F&M) staining of tissue sections. The slides were fixed in formaldehyde solution and embedded in paraffin wax for the staining (Scale bar; 50 μm). Black arrows indicate the transferred melanosome from melanocytes in the basal layer to keratinocytes in the upper layer. Blue arrows indicate melanocytes forming the extended dendrites. (*p < 0.05, **p < 0.01, *p < 0.001).

CON, control; GF1, ginsenoside F1; KA, Kojic acid.