Komang Harry Supradnyan¹ , Gusti Ayu Agung Praharsini², Made Jawi³, Made Ratna Saraswati⁴

Abstract

Purpose: To qualitatively compare the efficacy of epigallocatechin gallate, quercetin, ellagic acid, and ferulic acid as antioxidant and photoprotective agents across preclinical and clinical photoaging studies. Methods: A systematic search was conducted in PubMed, ScienceDirect, and the Cochrane Library, following the PRISMA 2020 guidelines, using the Boolean operators “flavonoids” OR “phenolic acids” AND “photoaging”. Risk of bias was assessed using Cochrane RoB 2.0, ROBINS-I, SYRCLE, and ToxRTool. Data were extracted and qualitatively synthesized. A total of 24 studies were included, consisting of 19 preclinical and 5 clinical investigations. Thirteen were in vitro, three combined in vitro and in vivo, four were ex vivo or human ex vivo, and four were clinical trials. Study models encompassed human dermal fibroblasts, keratinocytes, reconstructed skin, zebrafish, and healthy adult participants. Investigated compounds included EGCG, quercetin, ellagic acid, and ferulic acid, derived from botanical sources. Results: Primary outcomes demonstrated antioxidant, anti-inflammatory, and extracellular matrix preserving effects, with clinical trials confirming reductions in erythema, improved dermal elasticity, and enhanced photoprotection against ultraviolet-induced skin damage. Conclusion: Flavonoids and phenolic acids show consistent antioxidant and photoprotective effects in photoaging models, but evidence remains heterogeneous and clinical translation is uncertain. Standardized clinical trials are needed to confirm efficacy, optimize dosing and formulations, and establish long-term safety.