Vasorelaxant and antihypertensive effects of the Cibotii Rhizoma hydroethanolic extract via the PI3K/AKT/eNOS Pathway

Abstract

Background: Cibotii Rhizoma, which traditionally used to musculoskeletal disorders, contains phytochemicals exerts vasorelaxant and antihypertensive effects. However, its specific vasorelaxant effects, molecular mechanisms, and key bioactive components remain unknown.

Purpose: This study aimed to assess the key active components, action mechanisms, and therapeutic potential of the Cibotii Rhizoma extract for hypertension.

Methods: Network pharmacology analysis was used to predict major targets and action mechanisms. To validate the vasorelaxant effects and underlying mechanisms, docking studies (AutoDock Vina), molecular dynamics simulations (GROMACS), HPLC analysis, and Western blotting were conducted using isolated Sprague-Dawley rat aortas. The synergistic effects were evaluated using CompuSyn and SynergyFinderPlus. Antihypertensive effects were evaluated in spontaneously hypertensive rats after oral administration of Cibotii Rhizoma using the tail cuff method.

Results: Network pharmacology analysis revealed that the major active components of Cibotii Rhizoma induced vasorelaxation via the PI3K/AKT/eNOS signaling pathway. Molecular docking and dynamics simulations showed the stable interactions of Cibotii Rhizoma flavonoids (quercetin, kaempferol, and naringenin), which were identified in the extract by HPLC, with PI3K p110α and PI3Kγ. Ex vivo experiments confirmed the concentration-dependent, endothelium-dependent vasorelaxant effects of the Cibotii Rhizoma hydroethanolic extract mediated by the PI3K/AKT/eNOS pathway and its inhibition of angiotensin II-induced vasoconstriction. The extract synergistically enhanced the vasorelaxant effects of amlodipine, a commonly used l-type calcium channel blocker. Oral administration of Cibotii Rhizoma extract significantly reduced the systolic and diastolic blood pressure without interfering with amlodipine effects.

Conclusions: The major active components of the Cibotii Rhizoma hydroethanolic extract, including quercetin, kaempferol, and naringenin induce vasorelaxation and reduce the blood pressure via the PI3K/AKT/eNOS pathway. Therefore, Cibotii Rhizoma acts as a potential agent for standalone or adjuvant treatment of hypertension. However, further investigation of its pharmacokinetics, extract standardization, and effects on different forms of hypertension are necessary to facilitate its clinical application.

Keywords: Cibotii Rhizoma; Hypertension; PI3K/AKT/eNOS pathway; Vasorelaxation.