Retinol versus epigallocatechin-3-gallate (EGCG): Effects on molecular expression in photoaging

Abstract

Photoaging is a form of skin aging caused by chronic exposure to ultraviolet radiation. It is characterized by dermal matrix degradation, reduced collagen production, and accelerated collagen breakdown. In this randomized parallel-group clinical trial, 26 women aged 30-50 years with glogau II-III photoaging were randomly assigned to receive topical 5% epigallocatechin-3-gallate (EGCG) or 0.1% retinol once daily for 12 weeks. Immunohistochemical expression of TGF-β2, matrix metalloproteinase-1 (MMP-1), and type I collagen was assessed in skin punch biopsy specimens before and after treatment. Both topical EGCG and retinol induced a significant increase in TGF-β2 and type I collagen expression, indicating enhanced dermal regenerative signaling. EGCG significantly reduced MMP-1 expression, whereas retinol showed a nonsignificant decrease, suggesting a stronger anti-catabolic effect of EGCG. No significant differences were observed between treatments in increasing TGF-β2 or type I collagen expression, indicating comparable anabolic effects. Overall, EGCG and retinol demonstrated similar efficacy in improving dermal remodeling markers, with EGCG showing superior effects in suppressing collagen degradation through MMP-1 inhibition.