Phytochemical Characterization and Evaluation of Antioxidant and Tyrosinase Inhibitory Activities of Verbascum wiedemannianum Essential Oil and Methanolic Extract

Verbascum species have long been recognized for their medicinal properties; however, detailed studies on the endemic species Verbascum wiedemannianum Fisch. & C.A. Mey. remain limited. The purpose of this study is to evaluate the antioxidant and anti-tyrosinase activities of essential oil (EO) and methanol extract (ME) derived from V. wiedemannianum, an endemic species from Türkiye. The EO was obtained by hydrodistillation, and its chemical composition was characterized using GC-FID and GC/MS. The principal constituents of the EO were palmitic acid (27.3%), myristic acid (11.9%), 1-octadecanol (13.0%), and pentacosane (6.6%). LC-MS/MS analysis of the ME identified luteolin and chrysoeriol derivatives as the predominant compounds. The antioxidant potential of both the EO and ME was evaluated using three assay systems based on electron transfer reactions: the Folin–Ciocalteu reagent, the Trolox equivalent antioxidant capacity assay, and the cupric ion (Cu2+) reducing antioxidant capacity assay. The potential skin care effects of the EO and ME were further evaluated using a tyrosinase inhibition assay. Across all the assays, the ME consistently showed notable activities, whereas the activity of the EO was less clearly defined. These findings indicate that the ME of V. wiedemannianum contains bioactive compounds with potential applications in natural antioxidant and skin care formulations. Further studies are warranted to clarify its therapeutic uses.