Phytochemical profiling and tyrosinase inhibitory activity of Illicium verum Hook f.: In vitro and in silico insights

Context: Overexposure to oxidants and UV radiation triggers enzymatic reactions that contribute to skin aging, in part through increased tyrosinase activity. Herbal materials such as star anise (Illicium verum Hook.f.) offer promising potential as tyrosinase inhibitory agents for skin applications. I. verum contains bioactive compounds (e.g., trans-anethole, limonene, and pinene) reported to attenuate skin aging. Aims: To assess the chemical composition and anti-tyrosinase activity of I. verum through in vitro enzymatic assays and in silico molecular docking studies. Methods: The essential oil and extract of I. verum were analyzed using GC-MS and LC-MS/MS, respectively. Tyrosinase inhibition was assessed through an in vitro enzymatic assay for each sample, with kojic acid as a positive control. Each phytochemical compound was further assessed for anti-tyrosinase activity through in silico molecular docking studies targeting the tyrosinase (5M8P) protein, as well as its physicochemical and ADME properties. Results: Twenty secondary metabolites were found in the I. verum oil, with the major compounds being trans-anethole (32.36%); meanwhile, ten compounds were detected in I. verum extract. The tyrosinase inhibition assay revealed an IC50 value of 216.27 ± 2.18 µg/mL for the essential oil, 12484 ± 147.80 µg/mL for the extract, and 46.43 ± 1.74 µg/mL for kojic acid. The molecular docking study revealed that cis-caryophyllene (∆G = -7.72 ± 0.01 kcal/mol) from oil and gingerol (∆G = -5.88 ± 0.16 kcal/mol) from the extract had the best docking score as an inhibitor of tyrosinase (5M8P) compared to other constituents and kojic acid (∆G = -4.56 ± 0.02 kcal/mol). Conclusions: These findings suggest that I. verum contains constituents worthy of further bioassay validation as tyrosinase inhibitors.