Systematic Identification and Analysis of Angiotensin II Type I Receptor Targeting Material Basis in Tibetan Medicine Formula Bawei Chenxiang Powder

The pharmacodynamic material basis and mechanism of action of Bawei Chenxiang Powder (BWCP), a commonly prescribed Tibetan medicinal formulation for cardiovascular diseases, remain largely unclear. To address this issue, we established an angiotensin II type 1 receptor (AT₁R) chromatographic method coupled with mass spectrometry for the systematic screening and identification of AT₁R-targeting bioactive compounds from BWCP for the first time. Five active components-myristicin, dehydrocostus lactone, naringenin, pinocembrin, and costunolide-were successfully identified as AT₁R ligands from BWCP. Frontal analysis was employed to determine the binding constants of these compounds to AT₁R, yielding values of (1.09 ± 0.15) × 10⁴ M^{- 1} for myristicin, (1.59 ± 0.02) × 10⁴ M^{- 1} for dehydrocostus lactone, (2.24 ± 0.50) × 10⁴ M^{- 1} for naringenin, (6.09 ± 0.05) × 10⁴ M^{- 1} for pinocembrin, and (2.59 ± 0.35) × 10⁴ M^{- 1} for costunolide. Competitive displacement assays revealed that all five compounds share the same binding site with the clinically used AT₁R antagonist valsartan, a finding further corroborated by molecular docking, which confirmed the affinity ranking and the overlapping binding pocket with valsartan. Collectively, this study demonstrates that AT₁R receptor chromatography, based on specific molecular recognition, enables efficient screening and separation of target ligands from complex natural product matrices, thereby providing a novel and powerful technological platform for bioactive constituent research in ethnomedicines.