Relation Between Tryptophan Intensity, Desquamation and Skin Smoothness in the Process of Cellular Proliferation.

Author: Viviane Cristina Albarici*; Juliana Rodrigues Pinto; Gabriela Vannucci Nogueira; Ana Lúcia Tabarini Alves Pinheiro; Janayna Rampazo de Godoi; Camila Matheus Bueno Custódio; Camila Mariano; Mayara Miranda Ferreira; Rafaela dos Anjos Neves; Luana Gavioli dos Santos; Nathalia Alves Ribeiro; Adriano da Silva Pinheiro.

Published at: October 14, 2024

Abstract Epidermal proliferation is a natural process that can be accelerated by skin injury. This study aimed to assess the epidermal proliferation induced by glycolic acid, correlating results obtained by fluorescence spectroscopy and micro-image analysis of the skin. Subjects were instructed to apply 5% glycolic acid (GA5%) to their forearms for 21 alternate days. The increase in cell proliferation induced by GA5% was assessed using the 295 nm excitation band (tryptophan). Intensity of desquamation and skin smoothness were assessed using Visioscan®. After 7, 14 and 21 days, the intensity of tryptophan fluorescence from untreated skin remained unchanged, whereas the fluorescence intensity measured from sites treated with GA5% increased. After 3, 7, 14 and 21 days, a trend towards reduced skin smoothness was observed, while desquamation showed a significant increase after 7 days of application of GA5%. Both parameters reached the highest distinction after 7 days. A correlation was observed between intensity of tryptophan fluorescence, desquamation, and skin smoothness. The combination of the three techniques - spectroscopy, desquamation, and smoothness analysis - has proven to be an effective tool for understanding the action mechanism of products designed for cutaneous exfoliation and cell turnover. Keywords: tryptophan fluorescence, cell turnover, epidermal proliferation, desquamation, skin smoothness.