237 IMPROVEMENT OF MELASMA WITH GLABRIDIN
group and the control group on day 28 (P 0.01). The L* value (Figure 4C) of both the
experiment group and the control group increased significantly on day 56 (P 0.01), but
there was no significant difference between them. The area proportion of melanin (Figure
4D) in the experiment group was significantly decreased on the day 14, 28 (P 0.01), and
56 (P 0.05), and there was a significant difference between the experiment group and the
control group on day 14 and day 28. The content of melanin (Figure 4E) of the experiment
group and the control group decreased significantly on days 14, 28, and 56 (P 0.01), but
there is no significant difference between the two groups. These results suggested that the
whitening essence containing glabridin is effective in the treatment of melasma.
Nonmelasma area. The clinical evaluation of the nonmelasma area is seen in Figure 5. The
changes of skin glossiness (Figure 5A) in the experiment group on day 28 and day 56
were significantly increased when compared with day 0 (P 0.01). There were significant
differences (P 0.01) between the experiment group and the control group on day 28
and day 56. The L* value (Figure 5B) of both the experiment group and the control group
increased significantly on day 56 (P 0.01), but there is no significance between the
two groups. The ITA values (Figure 5C) of the two groups were significantly different
Figure 5. Clinical study of nonmelasma areas. The changes of (A) glossiness, (B) The value of L*, (C) ITA, and
(D) the content of melanin of these subjects treated by test sample (the whitening serum group) and placebo
(control group) along with the varied periods. *P 0.05 and **P 0.01 indicate significant differences
compared with day 0. #P 0.05 and ##P 0.01 indicate significant differences between the experiment
group and the control group.

238 JOURNAL OF COSMETIC SCIENCE
(P 0.01) on day 28. The content of melanin (Figure 5D) in the experiment group was
significantly decreased on days 14, 28, and 56 (P 0.01), and there was a significant
difference (P 0.01) between the experiment group and the control group on day 56.
These results suggested that the whitening serum containing glabridin is also effective for
brightening nonmelasma areas.
VISIA-CR ANALYSIS
The visual changes of two subjects (NO.12 and NO.16) treated with the whitening serum
for different periods are observed in Figure 6. The application of whitening serum caused
a remarkable improvement of skin color for both subjects. A significantly reduced area of
skin stain and increased skin lightening were observed after day 56 treatments. At the
same time, the area of melasma in the facial skin was significantly reduced and the color
became lighter.
DISCUSSION
Melasma is a pigmentary disorder that typically appears on the face, forehead, and cheeks.
Although the effectiveness of depigmenting agents (containing hydroquinone) or chemical
peels (lactic acid, glycolic acid, ascorbic acid, etc.) was confirmed, the potential side effects
caused the rising concerns over their safety.15,16 Glabridin, as the main hydrophobic
component of the flavonoid extract, uralensis, was confirmed to prevent the formation of
melanogenesis by decreasing tyrosinase activity (IC 50: 0.43 µmol/L).17,11
In this study, the efficacy of this formula containing glabridin was evaluated in the treatment
of epidermal melasma and nonmelasma areas in Chinese women utilizing a bilateral
(split-face) model. After 56 days, the clinical experiment results show that glabridin can
effectively improve the skin glossiness and ITA value in melasma and nonmelasma areas.
Meanwhile, there are significant reductions of melasma area proportion in melasma areas
Figure 6. Images obtained by VISIA-CR.