Integration of network pharmacology and biological validation reveals the mechanisms of alkaloids from Veratrum nigrum L. in ameliorating hypertension and vascular remodeling

Introduction: Hypertension is a major risk factor for vascular diseases. The roots and rhizomes of Veratrum nigrum L. have been used to treat hypertension with alkaloids (component A) from these plants showing potential as antihypertensive agents.

Objectives: This study aims to identify the key active ingredients in component A and investigate their mechanisms in treating hypertension and vascular remodeling.

Methods: The active ingredients of component A were predicted through blood-entry compounds analysis and validated its effects on hypertension and vascular remodeling in SHRs and HUVECs. Network pharmacology and molecular docking were employed to identify related targets and pathways, with further confirmation from experiments.

Results: The blood-entry compounds of component A consisted of 12 Veratrum alkaloids, including Rubijervine, Jervine, Cevine, etc. Component A ‌dose-dependently and effectively lowered blood pressure (BP), improved vascular remodeling and endothelial dysfunction, and regulated the renin-angiotensin system (RAS) in SHRs. Network pharmacology identified 10 hub genes associated with 12 blood-entry compounds for the treatment of hypertension. Subsequent experiments validated that component A modulates the expression of key targets such as ADRB2, AGTR1, MMP9, eNOS, TNF-α, and NNMT. When NNMT was knocked down in HUVEC, the levels of P-eNOS, eNOS, and NO were decreased simultaneously. These modulations inhibit renal sympathetic nerve activity and the Smad pathway, while activating vagal nerve activity, NNMT/MNA/eNOS/NO pathway and the cAMP-mediated inhibition of the RhoA/MLC pathway. Moreover, component A, specificably rubijervine, binds directly to ADRB2, AGTR1, MMP9, and eNOS.

Conclusions: Rubijervine may be the active ingredient of component A. Component A effectively alleviate hypertension and vascular remodeling. The underlying mechanism involves modulating ADRB2, AGTR1, MMP9, eNOS, TNF-α, and NNMT to inhibit TGF-β/Smad pathway, activate NNMT/MNA/ eNOS/NO pathway and cAMP-mediated inhibition of RhoA/MLC pathway, as well as balance RAS and nervous system.