Discovery of antidepressant active compounds from Polygala tenuifolia Willd. An integrated multitarget screening strategy combining network pharmacology with cell membrane chromatography coupled to high performance liquid chromatography

Ethnopharmacological relevance: Polygala tenuifolia Willd. (YZ) is a traditional Chinese herb that is commonly used in the treatment of psycho-emotional disorders and managing depression. However, the complex chemical composition of this herb poses challenges for separating and identifying the constituents, and there have been few investigations on the bioactive compounds. This lack has hindered the establishment of the antidepressant mechanism of action, impeding the development of related drugs. Aim of the study: The investigation of a comprehensive multi-method strategy for the rapid screening of multitarget synergistic antidepressant compounds from YZ and a preliminary evaluation of the antidepressant activity of the compounds. Methods: The chemical components of YZ were analyzed using ultra-high performance liquid chromatography-quadrupole orbitrap mass spectrometry (UPLC-Q-Orbitrap-MS). Building on this chemical profiling, potential antidepressant compounds from YZ were preliminarily screened via network pharmacology (NP). Subsequently, cell membrane chromatography (CMC) columns functionalized with 5-Hydroxytryptamine 1A Receptor (5-HT_1A), 5-Hydroxytryptamine 2A Receptor (5-HT_2A), Dopamine D1 Receptor (DRD1), and Dopamine D2 Receptor (DRD2) receptors were used for the targeted screening of multitarget synergistic antidepressant active compounds. Using molecular docking and surface plasmon resonance (SPR), the binding affinities were determined. Finally, the neuroprotective effects of these active compounds were explored in a corticosterone-damaged PC12 cell model. Results: Ninety-five compounds from YZ were identified using UPLC-Q-Orbitrap-MS, and nine potential antidepressant active compounds were screened through the NP-CMC-HPLC combined strategy. Molecular docking and SPR analyses revealed that the nine compounds exhibited binding affinities below −5 kcal/mol and 10⁻⁴ M for the target receptors. Compared with the positive control fluoxetine hydrochloride, these active compounds demonstrated promising neuroprotective effects. Notably, arillanin A and sibiricose A4 have not been previously reported to possess potential antidepressant activity. Conclusion: The established NP-CMC-HPLC strategy enabled rapid targeted discovery of potential antidepressant compounds from YZ, highlighting the potential of this strategy in the development of new drugs.