Abstract Many studies have reported various growth
factors secreted from adipose-derived stem cells (ADSCs).
In particular, regenerative effects in skin have received much
attention in the clinical fields. The in vitro whitening effects
of ADSCs have been reported. A previous study demonstrated
that ADSCs secrete growth factors that inhibit both
melanin synthesis and tyrosinase activity. This study aimed
to investigate the in vivo whitening effect of ADSCs using
mouse models. In the study, ADSCs were isolated from the
adipose tissue of C57BL/6 mice and cultured. The ADSCs
(1 9 106 cells in 30 ll of Hanks’ balanced salt solution
[HBSS]) then were injected intradermally in the dorsal area
of the right ear, and 30 ll of HBSS was injected on the left
ear as a control. After 7 days, both ears were irradiated with
ultraviolet B (UVB) (150 mJ/cm2) three times at 2-day
intervals. The sections of each ear were stained with hematoxylin-
eosin, Fontana–Masson, and HMB-45 (a melanocytic
cell-specific monoclonal antibody). The histologic
parameters evaluated included inflammation (?/-), erosion
(?/-), and melanin formation (graded on a scale of 1 to 3).
No significant differences in inflammation or erosion were
observed by hematoxylin and eosin staining (inflammation:
p = 0.388; erosion: p = 0.355). However, significantly more melanin formation was observed in the control group
than in the ADSC injection group by Fontana–Masson and
HMB-45 staining (Fontana–Masson: p = 0.025; HMB-45:
p = 0.015). The study findings suggest that ADSCs inhibit
melanin formation induced by UV exposure. Potentially,
ADSCs may be used as anti-aging agents, including skin
whitening. Before human clinical studies can be conducted,
further study is required to determine the mechanisms
underlying the whitening effects of ADSCs and the safety of
ADSC use.