Functional constituents of Dracocephalum heterophyllum recognized by HPLC-tyrosinase: DFT calculation, molecular docking, and in vivo activity studies

The discovery of tyrosinase modulators from natural products has long been hampered by limitations in screening efficiency and accuracy. In this study, a novel online screening system for tyrosinase was constructed based on HPLC technology that enables high-throughput recognition of active constituents in complex matrices. Applying this HPLC-tyrosinase system to Dracocephalum heterophyllum ( D. heterophyllum ), three active peaks were precisely captured, which were subsequently isolated and structurally characterized as caffeic acid, verbascoside, and rosmarinic acid. Enzyme activity assays revealed that caffeic acid (IC 50 = 1.08 mM) and rosmarinic acid (IC 50 = 0.41 mM) markedly inhibited tyrosinase activity, whereas verbascoside exhibited activating properties (EC 50 = 0.24 mM). The action mechanisms and bioactivities of these compounds were further elucidated through density functional theory calculations, molecular docking analysis, and in vivo validation. Collectively, the online HPLC-tyrosinase activity screening system established in this work not only provides a theoretical basis for the high value-added development of D. heterophyllum , but also delivers a high-throughput, precision tool for discovering natural tyrosinase inhibitors, demonstrating robust application potential in the fields of cosmetic science, food preservation and pharmaceutical development.