Background. Several clinical reports have suggested that alpha hydroxy acids (AHAs), including glycolic acid, may improve photoaging. However, the mechanism of action of glycolic acid is not well understood.
Objective. In order to investigate the mechanism of action of glycolic acid in improving photoaged skin, we observed the effect of glycolic acid on collagen metabolism and wrinkle effacement in chronically ultraviolet B (UVB) irradiated mice.
Methods. Skh:HR-1 mice were exposed to UVB for 10 weeks and then treated topically with 15% glycolic acid for 10 weeks. We assessed the improvement in wrinkling, the depth of the dermal repair zone, and the extent of the increase in collagen synthesis.
Results. At treatment week 10, the glycolic acid-treated mice showed a significant decrease in wrinkle score, an increased thickness of the dermal repair zone, and an increase in the amount of collagen synthesized compared to vehicle (hydrophilic ointment base) treated mice.
Conclusion. Topically applied glycolic acid may improve photoaging through modulation of collagen production.