Increased in vivo collagen synthesis and in vitro cell proliferative effect of glycolic acid

BACKGROUND. Glycolic acid treatment is believed to reverse the photoaging process by increasing collagen synthesis in the skin. However, this effect has not been clearly defined even though alpha hydroxy acid products are used extensively. OBJECTIVE. This study aimed to define the primary effect of glycolic acid on collagen synthesis that may be achieved by functional activation or proliferation of fibroblasts. METHODS. Glycolic acid treatment was compared in vivo with lactic acid (hairless mice) and in vitro to malic acid (normal human skin fibroblast culture) with controls. To find the functional activation of fibroblasts, Northern blot assay for type I collagen synthesis with histometric analysis (in vivo) was performed. Cell proliferation assay (MTT) with procollagen type I C-peptide (PICP) enzyme immunoassay and radioisotope ([H-3]proline) incorporated collagen production from cultured fibroblasts were determined. RESULTS. The in vivo collagen mRNA expression with histometric analysis revealed greater collagen synthesis by glycolic acid compared with lactic acid and control. In vitro cell proliferative effect of glycolic and greater amount of collagen production showed a steady increase in a dose-dependent manner. CONCLUSION. Both in vivo and in vitro, glycolic acid treatment increased the production of collagen and fibroblast proliferation. These effects may be the mechanism by which glycolic acid reverses the process of photoaging. (C) 1998 by the American Society for Dermatologic Surgery, Inc.