Pharmacodynamic substance discovery and mechanism of action of Tibetan medicine Ba-Wei-Chen-Xiang San in spontaneously hypertensive rats.

BACKGROUND: Ba-Wei-Chen-Xiang San (BWCX), a classic formula in Traditional Tibetan Medicine (TTM), has been historically employed for preventing and treating "Chalong" disorders, which correspond to cardiovascular diseases in modern medicine. Previous literature mainly describes BWCX as a cardioprotective agent that can improve myocardial hypertrophy by regulating cardiac energy metabolism pathways. But the specific pharmacological mechanism by which it regulates the systemic metabolic drivers of essential hypertension still needs to be studied.

AIM OF THE STUDY: This study aimed to systematically investigate the antihypertensive efficacy of BWCX and decipher its mechanism of action by identifying bioactive components and metabolic targets.

MATERIALS AND METHODS: The chemical composition characterization and blood-absorbed components of BWCX were characterized using Ultra Performance Liquid Chromatography-Quadrupole-Exactive Orbitrap Mass Spectrometry (UPLC-Q-Exactive Orbitrap-MS). Antihypertensive efficacy was evaluated in spontaneously hypertensive rats (SHR) by monitoring blood pressure, body weight, and liver histopathology. SHR were administered BWCX at low (0.27 g/kg), medium (0.54 g/kg), and high (1.08 g/kg) daily doses via intragastric gavage for 8 weeks. Valsartan (14.28 mg/kg) was used as a positive control. Serum and liver lipid metabolomics were performed to identify key biomarkers and pathways. Finally, the interaction between screened blood-absorbed components and the core target, choline-phosphate cytidylyltransferase α (CCTα), was predicted by molecular docking and validated by cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS), and surface plasmon resonance (SPR).

RESULTS: UPLC-Q-Exactive Orbitrap-MS identified 191 chemical components and 37 blood-absorbed components from BWCX. BWCX significantly reduced systolic and diastolic blood pressure in SHR rats. Importantly, unlike known cardiocentric mechanisms, metabolomics analysis revealed that BWCX exerts its therapeutic effect primarily by reprogramming hepatic glycerophospholipid metabolic pathways. Lipid droplets in hepatocytes were reduced after BWCX administration compared with the SHR model group. BWCX regulated the abnormal levels of serum Ang II, Ren, and Ald in SHR rats. Metabolomics analysis revealed that 19 potential biomarkers, mainly linked to primary bile acid, sphingolipid, arachidonic acid, and glycerophospholipid metabolism pathways. Liver lipid metabolomics identified 11 potential biomarkers, primarily restoring the glycerophospholipid metabolism pathway. Specifically, BWCX reversed abnormal phosphatidylcholine (PC) biosynthesis. Three bioactive chromone components (DMPEC, MPEC, and DPEC) were predicted by molecular docking and confirmed by biophysical assays that they exhibited strong binding affinity to CCTα, the rate-limiting enzyme in PC synthesis.

CONCLUSION: This study provides new insights for future research on BWCX: in addition to its known cardioprotective effects, it also acts as a systemic metabolic regulator. BWCX exerts significant antihypertensive effects and ameliorates liver lipid metabolism disorders in SHR rats. The mechanism involves the modulation of the CCTα-mediated glycerophospholipid metabolic pathway by specific bioactive chromones. These findings provide a scientific basis for the clinical application of BWCX in hypertension management.