White ginseng ethanol extract inhibits melanogenesis in B16F10 cells by regulating the microphthalmia-associated transcription factor/tyrosinase pathway

Abstract

ObjectivesHyperpigmentation is a prevalent cosmetic concern. Conventional whitening agents, including hydroquinone, arbutin, and vitamin C, exhibit safety and efficacy concerns. Although Panax ginseng has been widely studied, the whitening potential of white ginseng ethanol extract (WGEE), particularly from the Geonsam cultivar, remains unclear. This study evaluated the antioxidant, anti-melanogenic, and tyrosinase-inhibitory effects of WGEE and its active components and elucidated the underlying molecular mechanisms.MethodsWGEE was prepared by 70% ethanol extraction of white ginseng and its chemical composition analyzed using Ultra Performance Liquid Chromatography and colorimetric assays. Antioxidant capacity was assessed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid assay (ABTS) assays, while tyrosinase inhibition was measured spectrophotometrically. Intracellular reactive oxygen species (ROS) levels were determined using the DCFH-DA fluorescent probe. Cytotoxicity, melanin content, and melanogenesis-related proteins were evaluated using the MTT assays and Western blotting. Molecular docking analysis characterized the binding of ginsenosides Rg1 and Rb1, as well as arbutin, to tyrosinase.ResultsWGEE exhibited DPPH and ABTS radical scavenging of 18.18 and 48.54% at 200 mu g/mL, respectively. WGEE treatment significantly reduced alpha-MSH-induced ROS generation at all tested concentrations. In alpha-melanocyte-stimulating hormone-stimulated cells, WGEE at 40 mu g/mL reduced melanin production by 33.65% and downregulated the expression of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, comparable to arbutin. Molecular docking analysis revealed that the binding energies of ginsenoside Rg1, ginsenoside Rb1, and arbutin were -8.1 kcal/mol, -6.2 kcal/mol, and -5.6 kcal/mol, respectively, supporting their tyrosinase inhibitory effects.ConclusionsWGEE shows potential as a natural whitening agent to manage hyperpigmentation.