Comparative caustic and biological activity of trichloroacetic and glycolic acids on keratinocytes and fibroblasts in vitro

Objectives: Beside their causticity, the biological mechanism by which tric hloroacetic acid (TCA) and glycolic acid (GA), two agents extensively used for chemical peeling, might act remains unknown. The purpose of this study was to examine in vitro the effect of TCA and GA on human keratinocytes and the influence of the released epithelial mediators on collagen and matrix metalloproteinases (MMPs) production by human dermal fibroblasts. Method: C ultured keratinocytes were treated by TCA and GA at in mg/ml brought to pH 3, 5 and 7, and the conditioned media neutralized to pH 7 were added to hum an normal skin fibroblasts. Results: TCA was cytotoxic for keratinocytes at each tested pH. The conditioned medium depressed protein and collagen synt hesis and the expression of MMPs when added to fibroblasts as did also TCA when added directly to fibroblasts. GA was not cytotoxic for keratinocytes at neutral pH and the conditioned medium obtained at each pH applied to fib roblasts did not alter protein, collagen nor MMPs production while causing an elevated secretion of IL-6. Conclusion: TCA exerts a toxic effect on ker atinocytes and fibroblasts while GA does not alter the metabolism of fibrob lasts but induces the secretion of IL-6. Copyright (C) 2000 S. Karger AG, B asel.