Comparative Study on Antioxidant Potential of Extracts Prepared by Conventional Extraction, Accelerated Solvent Extraction, and Pulsed Electric Field Method.

Oxidative stress is a major contributor to skin aging and related disorders. This study comparatively evaluated the bioefficacy of Raddi leaf extracts prepared using three extraction techniques: conventional extraction (CE), accelerated solvent extraction (ASE), and pulsed electric field (PEF) extraction, with 50% (/) ethanol and water as green solvents. Among all tested conditions, the CE-derived extract (C-4), obtained with 50% (/) ethanol for 120 min, exhibited the highest extraction yield (29.7%). It also showed the highest total phenolic (668.56 ± 11.52 mg gallic acid equivalent (GAE)/g dry material (DM)) and flavonoid content (2629.92 ± 112.61 mg quercetin equivalent (QE)/100 g DM), and potent antioxidant activity against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (12,645.50 ± 60.31 µmol Trolox equivalent (TE)/g DM) and oxygen radical absorbance capacity assay (ORAC: 7180.27 ± 101.79 µM TE/100 g DM). Liquid Chromatography coupled with Mass Spectrometry (LC-MS) analysis revealed a diverse phytochemical profile rich in polyphenols, including gallic acid, -coumaric acid, rutin, rosmarinic acid, caffeic acid, and epicatechin. Cellular assays in hydrogen peroxide (HO)-induced HaCaT keratinocytes demonstrated that C-4 extract significantly enhanced cell viability and upregulated endogenous antioxidant genes (superoxide dismutase (), catalase (), glutathione peroxidase ()), with effects comparable to established antioxidants such as epigallocatechin gallate (EGCG) and ascorbic acid. These findings highlight the influence of extraction parameters on phytochemical yield and biological activity, supporting the potential application of CE-derived extracts as effective, sustainable ingredients for cosmeceutical formulations targeting oxidative stress-mediated skin aging.