Integrated UPLC-MS/MS profiling, computational prediction, and in vitro assays suggest preliminary anti-tyrosinase and anti-melanogenic potential of Synotis solidaginea.

Synotis solidaginea (Hand.-Mazz.) C. Jeffrey & Y.L. Chen is traditionally used for skin disorders in western China. This study integrated UPLC-MS/MS, network pharmacology, molecular docking, and in vitro assays to evaluate its preliminary anti-tyrosinase and anti-melanogenic potential. Among the numerous constituents detected and tentatively annotated, 27 representative constituents were selected for reporting with diagnostic MS/MS fragment ions at MSI level 2. Network pharmacology prioritised 21 candidates and 40 putative targets, while docking indicated possible interactions with PTGS2, TYR, PIK3CA, and KIT; all computational findings were hypothesis-generating. The extract inhibited mushroom tyrosinase (IC50 = 105.0 ± 5.7 μg/mL), maintained mean B16F10 viability above 80%, reduced protein-normalised melanin and intracellular tyrosinase activity, and downregulated MITF, TYR, TRP-1, and DCT/TRP-2 mRNA. These findings support preliminary anti-tyrosinase and anti-melanogenic activity in vitro, while the predicted targets and pathways require validation.