Identification and Molecular Mechanism of COX-2 Inhibitors From Anisodus tanguticus: Ligand Fishing, In Vitro Validation, Molecular Docking, Molecular Dynamics, and ADMET Analysis

Anisodus tanguticus (Maxim.) Pascher has demonstrated remarkable inhibitory effects on cyclooxygenase-2 (COX-2); however, the effective substances and molecular mechanism remain ambiguous. In this study, surface plasmon resonance (SPR) ligand fishing technology coupled with UPLC-Q-TOF-MS analysis were applied to identify two COX-2 binders, atropine and fabiatrin, from A. tanguticus extracts. In vitro assays verified their potent COX-2 inhibitory effects, with IC₅₀ values of 16.63 and 10.66 mM, respectively. To elucidate the molecular mechanism underlying their inhibitory effects, we conducted molecular docking and molecular dynamics simulations. Interaction analysis revealed that both atropine and fabiatrin exhibit strong binding affinity and structural stability with COX-2. Subsequent ADMET (absorption, distribution, metabolism, excretion, and toxicity) predictions indicated that atropine and fabiatrin had favorable pharmacokinetic properties and low toxicity, suggesting their potential as anti-inflammatory agents. Notably, this is the first study to demonstrate the inhibitory effect of fabiatrin on COX-2. Overall, the integrated approach developed here provides an efficient and reliable strategy for identifying bioactive components from complex traditional Chinese medicine (TCM) systems, which may offer a new perspective and scientific basis for the research and development of naturally targeted drugs.