Effect of GAE on SCF-stimulated pigmentation in human
epidermal equivalents
Hyperpigmentation causes skin darkness and medical
disorders by melanocyte activity involved in UV damage
or post-inflammation [21, 22]. Several cytokines and che-
mokines, such as SCF and endothelin-1 (ET-1), function
in hyperpigmentary mechanism related to UVB exposure
or senile lentigo [23, 24]. Therefore, we examined the
inhibition of GAE on melanogenesis induced by SCF in
normal human epidermal melanocytes. Human epidermal
equivalents were treated with GAE (100 and 200 μg/mL)
or SCF (20 nM) and skin lightening index was recorded.
The color of the human epidermal equivalents treated
with 200 μg/mL GAE was lighter than that of the
untreated control. Furthermore, the addition of SCF
gradually stimulated visible pigmentation over 14 days of
treatment. During the SCF-induced stimulation of pig-
mentation, the addition of either concentration of GAE
distinctly reduced the increase in visible pigmentation
over 14 days (Fig. 6a-b).