Treatment with Ascorbyl Glucoside-Arginine Complex Ameliorates Solar Lentigos

Little is known about the anti-pigmenting effects of skin-whitening agents on solar lentigos (SLs). To characterize the anti-pigmenting effects of a newly designed derivative ascorbyl glucoside-arginine complex (AGAC) on SLs, lotions with or without 28% AGAC were applied twice daily for 24 weeks in a double-blind half-face study of 27 Japanese females with SLs. The pigmentation scores and skin colors of previously selected SLs on the right and left sides of the faces of the subjects were evaluated using a photo-scale, a color difference meter and a Mexameter. Treatment with the test lotion elicited a significant decrease in pigmentation scores at 24 weeks compared to week 0, with a significant decrease in pigmentation scores at 24 weeks compared to the placebo lotion. In the test lotion-treated SLs, the lightness (L) and melanin index (MI) values that reflect the pigmentation level significantly increased and decreased, respectively, at 12 and 24 weeks of treatment compared to week 0. Comparisons of increased L values or decreased MI values between the test and placebo lotion-treated SLs demonstrated that the test lotion-treated SLs had significantly higher increased L or decreased MI values than the placebo lotion-treated SLs both at 12 and 24 weeks of treatment. The sum of our results strongly indicates that AGAC is distinctly effective in ameliorating the hyperpigmentation levels of SLs at a level visibly recognizable by the subjects, without any hypo-pigmenting effects or skin problems.