Identification of PFN2 as an Epimedii Folium flavonoid brain target by mass spectrometry in conjunction with DRATS

Abstract

Epimeriid Folium (EF), a traditional and commonly used Chinese medicinal herb, is known to have effects on attenuating cognitive deficits in neurogenerative diseases. As the main bioactive component of EF, flavonoids’ protein targets have not been fully understood. Moreover, no comprehensive examination of flavonoid-related protein targets in mild cognitive impairment (MCI)—a state that falls between dementia and normal aging—has been documented. In this study, a laser confocal inverted microscope was utilized to localize flavonoids in the leaf tissue of Epimedium brevicornu Maxim. species. UPLC-Triple TOF-MS and UPLC-QTRAP-MS was performed to qualitatively and quantitatively identify the flavonoids in EF. The candidate protein targets of EF flavonoids (EFF) in brain tissues were identified by liquid chromatography-mass spectrometry-based drug affinity responsive target stability (MS-DARTS). The shared targets of MS-DARTS and databases were conducted GO and KEGG analysis. Finally, molecular docking and biolayer interferometry (BLI) was used to preliminary validate the potential targets. Results showed that flavonoids were mainly distributed in the collenchyma and epidermal cells. EFF was analyzed, revealing that 22 compounds accounted for 88.54 % of the EF extract. The primary compounds identified were icariin (28.32 %) and icariside II (27.27 %). A total of 67 flavonoid-related protein targets were found by MS-DARTS, of which 45 overlapped with databases for MCI. Profilin 2(PFN2) was found exclusively in the EFF group and was observed at the maximum abundance. Molecular docking and BLI demonstrated a strong interaction between PFN2 and the primary compounds, suggesting that PFN2 is a target for the main component, icariside II. Taken together, our research uncovered the components and possible targets of EFF, highlighting PFN2 as a promising therapeutic target for EFF. This discovery enables us to address cognitive decline in clinical environments and establishes a basis for further studies on other traditional Chinese medicinal substances.